No actual ip timing signal

[High Toned SOB]

98 k2500 automatic

Bought it not running right, have replaced the pmd so far and that helped get it to stop revving way up then wayy down over and over.

Installed new 5 micron fuel filter (removed fuel module)and 115gph 9psi pump.

Had 1/2 tank offroad fuel, i topped off with new clean non-syn hydraulic oil

Started and revved good for a few weeks, didnt have time to get it out and road test, but ran it alot, burned 1/2 tank just doing this over the few weeks

Finally get to road test and throws a 251/370 set of codes, and goes into limp mode. Check fuel, it is not cloudy or wet, but is dark - ish red.

Hook up scanner again(i have a tec2 and AE) and i am not getting a “actual pump timing”

Desired is a 12.9 on a cold start, will drop to 11 once warm
Tdco is at -.53 steady

I can twist the pump anywhere and my actual stays at “0”

Went ahead and pulled optic and “cleaned” (fwiw)

Reinstalled, lined up the line on the camring with the edge of the sensor, and the factory line on the sensor to the holdown square thing.

No change. It will start and run but its a hard code, i clear it and it comes right back, like the sensor is just dead. Can someone give me a connector pinout, so i can at least check power/ground to it?

But whats a little wierd to me, is i can move it (the OS) too far and get a hard crank and lope at idle, but still show “0” on the actual.

I thought the optic is what read actual?

Thanks

[N9Phil]

If you are talking about the timing on my 95 the engine has to be up to temp (I believe 185 deg ) before the timing will set and stay.

[High Toned SOB]

If you are talking about the timing on my 95 the engine has to be up to temp (I believe 185 deg ) before the timing will set and stay.

Phil its warm, ect is 190*, IP still shows actual at “0”

No matter where i turn the pump it stays at “0”.
If i do a time set, and the desired runs down to “0”, still the same thing, i can twist the pump around and the actual stays at “0”

[N9Phil]

If you send me a private message with your e-mail I have 1999 service manual and I can send you a pdf of the info on PO 251 and 370 test procedures
These might help
Phil

[arveetek]

Had 1/2 tank offroad fuel, i topped off with new clean non-syn hydraulic oil




Before going much further, I would drain the fuel out and put fresh # 2 in. The optic sensors in the DS4 do not like anything other than standard # 2. I used to run home-brewed BIO, and I had consistent issues with timing and missing. Everytime I switched back to regular fuel, she would clear up and run normally again.

Casey

[High Toned SOB]

Before going much further, I would drain the fuel out and put fresh # 2 in. The optic sensors in the DS4 do not like anything other than standard # 2. I used to run home-brewed BIO, and I had consistent issues with timing and missing. Everytime I switched back to regular fuel, she would clear up and run normally again.

Casey

Wow so you cant even run bio?? So much for my wmo in this one������ ive ran wmo in everything ive had so far ; 7.3, 6.0, 5.9, and the old 6.2...... i guess the 6.5 is the finicky red headed stepchild.

Casey i would do that, but.........

This seems like a “all of a sudden” problem, considering it has tan/revved,started great for a month. And the fact that i am stuck at “0” no matter what. Its a hard code. Like i can clear it with the engine running and as soon as it clears it, it comes right back, instantly. Like its a circut/sensor malfunction.
But i may end up doing it anyways just to be sure.

[More Power]

And the fact that i am stuck at “0” no matter what.
Are you using a Tech II scan tool? Can you set the timing using a Tech II?

Otherwise, I agree with arveetek. The DS4 is picky about fuel color and fuel quality. The pricey DS4 is also not a good candidate for alternative fuels, fuel supplements (like oil), or off-road red-dyed diesel fuel. Jim

[High Toned SOB]

Are you using a Tech II scan tool? Can you set the timing using a Tech II?

Otherwise, I agree with arveetek. The DS4 is picky about fuel color and fuel quality. The pricey DS4 is also not a good candidate for alternative fuels, fuel supplements (like oil), or off-road red-dyed diesel fuel. Jim

I have a tech2 and auto enginuity. Both have the same result. Actual ip timing is at “0” all the time no matter where i move the pump or rev it, etc etc.

I am gonna run a clean 5 gallon jug to it tonight. If it goes past 8 counts does it just stop trying to use the optic, and go to default? If so, that would explain why its not intermittent.

I hope you guys are right, that would be nice. But im gonna regret buying this thing then, as i have a killer ststem for wmo and have used it in so many others without any issues, except the mighty cummins didnt like 100% from about 45* and colder.

This beast has 4.10’s too hahahahaha

[High Toned SOB]

4278

Hydro/offroad mix

[High Toned SOB]

I forgot how mountain dew lookin “legal” fuel is

is4279

[High Toned SOB]

Emptied out the tank completely, and added 5 gallons onroad.
Started up and ran, i still have the upper intake off, and im sure the pump and optic is way off now, i have only practically rolled the pump 360*, lol.

Still here after a while

4280


4281

[High Toned SOB]

Hahahahahahahahahahahahahahahahahahahahahahahahaha hahahahahahahahahahahahahahahahahaha


Ha

4282


So my fuel rate is low. I want to set the optic better and turn the pump to -1.94 or so.
So optic to passenger side.....do “time set” and try to get it at -1.94....then do a tdc set last?

[High Toned SOB]

Thank you guys for the help. Never thought these pumps were that finicky. I have done some wild stuff to the 2831 pumps, i guess the only similarity’s is they are both rotary, lol.
Such a stupid setup to use a optic sensor. Gotta be different i guess

[More Power]

I don't get a lot of reports, but enough through the years to know red fuel can cause DS4 optical sensor problems. Probably doesn't happen every time, but there are a nearly infinite number of combinations/components involved.

States with the highest fuel taxes and most stringent vehicle emissions regulations tend to be real hammers with fines and punishment when on-road users are caught in road-side fuel checks. It can be real tough... Generally not worth the risk to have red fuel in the tank...

Secondarily... till diesel fuel reaches nose bleed heights in pump prices, there's too much risk to the fuel injection system to warrant using alternative fuels.

Thank you for creating this forum topic and posting the scan tool images. It benefits the community... Jim

[Yukon6.2]

Thank you guys for the help. Never thought these pumps were that finicky. I have done some wild stuff to the 2831 pumps, i guess the only similarity’s is they are both rotary, lol.
Such a stupid setup to use a optic sensor. Gotta be different i guess
If you have your mind made up to use this truck...
It is still doable.You could do a switch to a mechanical pump and a stand alone controller for the trans.
If you have a large supply of alternate fuel then it might be worth it to switch and have the comfort of the Suburban.

[High Toned SOB]

If you have your mind made up to use this truck...
It is still doable.You could do a switch to a mechanical pump and a stand alone controller for the trans.
If you have a large supply of alternate fuel then it might be worth it to switch and have the comfort of the Suburban.

Yukon, if the pump craps out (before i sell it) thats what ill do. Hopefully not. Its a pretty decent truck, dont see alot of 3/4 ton extended shortbed diesels around here. Plus it has the 4.10’s to do some work. Maybe even throw a stepside bed on it. I have bought a ton of stuff for it, wheels, nerf bars, stereo stuff, etc.
But im coming out of much better trucks, we shall shee

[a5150nut]

I don't get a lot of reports, but enough through the years to know red fuel can cause DS4 optical sensor problems. Probably doesn't happen every time, but there are a nearly infinite number of combinations/components involved.

States with the highest fuel taxes and most stringent vehicle emissions regulations tend to be real hammers with fines and punishment when on-road users are caught in road-side fuel checks. It can be real tough... Generally not worth the risk to have red fuel in the tank...

Secondarily... till diesel fuel reaches nose bleed heights in pump prices, there's too much risk to the fuel injection system to warrant using alternative fuels.

Thank you for creating this forum topic and posting the scan tool images. It benefits the community... Jim


In California if you are caught with red fuel they assume entire mileage on truck was run red and it is up to you to provide receipts for green fuel or face tax evasion on all miles not backed up with receipts. They want their money!

[Robyn]

Before I retired from commercial trucking the IRS would set up at road side weigh stations to do fuel checks.

When you drove in an agent handed you a piece of paper explaining that they wanted to test your fuel for Red Dye.... They never spoke to you at all..

The paper explained what they wanted and that if you refused to allow them to check, it was an automatic violation....

Just smile at the agent and said "There is a tank on both sides...have at it"

They dip the tank with a glass/plastic tube and lift it just enough to see the color.

Had that happen a few times after they went to the ULSD

There has never been any light duty rig checks here that I am aware of. (Oregon) I know a few folks that run all manner of "burnables" in their diesels.

Wvo, filtered waste engine oil, filtered waste auto tranny oil.

As mentioned, the DS4 is very fussy and was designed to run the nearly clear ULSD and anything that is cloudy or hinders the optic sensor will foul the functions.

The old DB2 pumps would handle Bunker C :eek: :D :D :eek: (Not really, but most oils thin enough to flow will work)

[arveetek]

Wow so you cant even run bio?? So much for my wmo in this one...

Yup. My dad and I made home-brewed BIO for a few years back when fuel prices were really high. My DB2 6.2L didn't care what I put in the tank, it would run just fine. So did my Dad's 7.3L Powerstroke. But, my electronic DS4 always acted goofy, and caused me more than one injection pump swap, and one Optic sensor swap. I finally gave up on the BIO (even though I did run it for about 3 years), and was glad when fuel prices came back down.

With my engine running really nice now, I don't dare to put any BIO back in the tank of my electronic 6.5L.

Casey

[trbankii]

I don't get a lot of reports, but enough through the years to know red fuel can cause DS4 optical sensor problems. Probably doesn't happen every time, but there are a nearly infinite number of combinations/components involved.

In other threads there has been the suggestion to run a pint or two per tank of TC-W3 marine outboard engine oil to improve lubricity. Does the blue color to that cause any issues - for a couple pints per tank?

[Robyn]

That tiny bit of color should not even be seen in 40 gallons of fuel.

[trbankii]

That's what I was figuring, but with the discussion of how finicky the optical sensor is I wasn't sure.

[High Toned SOB]

Guess i cracked the whiskey bottle too soon...

Their baaaaaaaaaaaack.



Went out and started it up the next day to warm up so i could to the time set/tdco, and got distracted.
Shut it off and about 1/2 hr later went back to start it, and they were back. Fooled with it over the weekend, and same as before, HARD codes. Also back to 0.0 on the actual pump timing. I can clear it with Key On, Engine Off, and it comes right back. Check the commecter at the pump and have good power/ground.

1. Will it set those codes if the OS is too far out of adjustment? And if so, will they go away on their own once its in adjustment, or do they have to be cleared?

2. Does the engine have to be under any certain parameters to use it, or is it as soon as you crank it?

3. I cant do the timeset or tdco if there is a code, so that sucks. Any other way around it?

My current tdco shows -2.54, and wont change no matter where i move the pump. So i assume it is just “stuck” at the last reading it had when the OS quit working? And just stays at that figure until is gets corrected?

Does anyone have advice on basically “starting over”?

I have moved the pump and the optic so much, im sure they are out. So how can i “start over” like i was installing a pump without a timing mark, and replacing the OS at the same time?
Its the perfect storm, lololol

[High Toned SOB]

So something interesting i just found.

I have removed my original inlet to the IP, and installed a brass t-fitting. So i have my fuel pressure gauge plumbed into this tee.
I have had good fuel pressure, as i should with a new holley pump, water separater/filter, and no more fuel module.
All 3/8 line.

I took the top of the pump off today and it was EMPTY. So i key on and have fuel pressure at the inlet tee, but the pump body remains empty. Command the pump to stay running with the tec2, and nothing... 13psi at the inlet, and the pump remains empty.

I needed to get back to work, so i didnt get a chance to crank it or anything, im gonna do that tonight.

Any ideas?


Edit results.
Messed with it tonight, had to crank it a good bit to get the pump full. Started to come up in bubbles through a little hole in the back right hand side of the pump inside. But the whole time i had steady 13 psi at the inlet.

Also...lol... i went to roll the engine over by hand to check the OS ring. I turned it a good bit and felt a clunk, i was like “thats not good”.
Turned it back, and clunk. Sounded like a rod. It is the balancer hitting the bolts!!!! Completely shot. I have a new one already, so just gotta slam it on.
No way that could give me the IP issues though right?

[High Toned SOB]

So i got the new balancer on.
Here are some pics of my optic, is it “normal” to look like it was getting chewed on by a rat? Fuel temp still reads, so i know that part still works. The biggest wall im up against in the troubleshooting is where i need to use a meter that reads mhz. My fluke is older and i dont have that function.

Since the actual timing is read by the OS, i guess im gonna order one. Problem is i have a dude out here parting out a 93, i can get the pump, pedal, and trans controller for the same price as a new optic.
What to do, what to do

[High Toned SOB]

Also wanted to pass on a couple pics i took that might help someone out. At first, i was NOT adjusting the OS correctly. I scribed a line on the OS itself, beside the holddown thing that the bolt goes through. Not the camring

[Yukon6.2]

So i got the new balancer on.
Here are some pics of my optic, is it “normal” to look like it was getting chewed on by a rat? Fuel temp still reads, so i know that part still works. The biggest wall im up against in the troubleshooting is where i need to use a meter that reads mhz. My fluke is older and i dont have that function.

Since the actual timing is read by the OS, i guess im gonna order one. Problem is i have a dude out here parting out a 93, i can get the pump, pedal, and trans controller for the same price as a new optic.
What to do, what to do
Buy the mechanical conversion stuff.
The pictures of the flat black box on the cover,What is it?
I changed the optic sensor in one of my trucks and don't remember that.
I was having electrical issues constantly with my 98.Went through a couple of remote mounted PMD's,optic sensor,ignition switch,the list went on.This sucked more than normal because it was a tow truck and not used as a daily driver,sometimes it would sit for weeks..Having issues in remote Yukon in the winter isn't exactly fun or warm.

I had been collecting the parts needed for the conversion. Then one day i went to start the truck after i drove it into the shop,it would crank but no fire.That was the last straw,so i began the conversion.Truck started right up after it was a mechanical injection truck.Never had any more issues till the crank became a two piece crank.

[High Toned SOB]

Yukon i assumed that was the fuel temp sensor and maybe some kind of conversion box for the OS.
It looks like if you take the snap ring off the top, the connector would come out theough the bottom of the lid, and that black box is just part of it.

I really dont want to convert, because i teally dont plan on keeping this truck. I have a few others, but none are electric.
But i might just buy the stuff since its a deal.

Im am pretty mich convinced at this point the OS is dead. Parts stores dont list it, so i guess ebay?

Does anyone have any specs for like resistance of the OS?

[Yukon6.2]

Yukon i assumed that was the fuel temp sensor and maybe some kind of conversion box for the OS.
It looks like if you take the snap ring off the top, the connector would come out theough the bottom of the lid, and that black box is just part of it.

I really dont want to convert, because i teally dont plan on keeping this truck. I have a few others, but none are electric.
But i might just buy the stuff since its a deal.

Im am pretty mich convinced at this point the OS is dead. Parts stores dont list it, so i guess ebay?

Does anyone have any specs for like resistance of the OS?
When i changed mine i got one from a dead pump,i got lucky and it was a good one.
Buy the stuff for later,it's getting harder to come across.

[High Toned SOB]

So i got a used optic sensor and slammed in it my pump. Now everything is reading, i am gonna attach some pics..



But.........

Now it is starting right up at 1000rpm. Within 5 seconds it will creep up to 13-1400 and stay there. Meanwhile, it has a fishbite/miss steadily every 1/2 second, pretty fast.
It revs great, SUPER responsive. I love that. But theres no way you could put it in gear without punishing the trans...

Fyi, when i got this truck i put a new EBAY PMD on it. It would start and immediately rev to 4k, then drop to idle, back to 4k, idle, etc etc. smoking badly the whole time. The new pmd fixed that.
It has about 5 hrs of run time on it. Relocated to the grill area. How could it be bad again?

But at least the optic is reading now, im thankful for that. Now this coincidental new issue..������

[High Toned SOB]

My tdc offset is at -1.54 i think i will leave it until i get this new problem figured out.
Its reading 0mm of fuel. So the computer is pulling fuel trying to slow the engine down, but the pmd is still fueling.
So it looks like the pmd just randomly crapped out after 5 hrs of use. At the same time it decided to run good

[Yukon6.2]

Sounds like the PMD needs to be tested at the lake.
What kind did you get?
I bought a aftermarket one that didn't last very long,they replaced it and the next one started to act up shortly after as well.
I ended up using a used stanadyne till something happened and the truck would not start.At that point i had had enough and the mechanical conversion happened.
The truck started right up once the mechanical pump was inline,ended all the electrical issues the truck had.

[High Toned SOB]

Well i messed up again. The reason it was missing at idle was thefuel was at 0-1mm. It seemed to rev good and very responsive, but idle was terrible in park or nuetral ONLY. In gear it idled great.

So i moved the OS TOWARDS THE DRIVERS SIDE AND IT GOT ALOT BETTER, but had a mild surge. So i moved it a little more and ended up at 4mm idle and it was smooth.

But i lost a lot of my responsivness. So that sucks. Now its just “normal”. Timing is good, act and desired match.
Tdc is -2.54, so i am gonna work on that a little.

Cant beleive the OS is as “touchy” as it is. When you guys say “barely” move it, you mean “barely” move it, haha.

[DmaxMaverick]

....Timing is good, act and desired match.
Tdc is -2.54, so i am gonna work on that a little.

Cant beleive the OS is as “touchy” as it is. When you guys say “barely” move it, you mean “barely” move it, haha.

If your TDCO is that far off, you are in default fuel programming. -2.54 is pretty far out there. Get that correct (at least -1.94, any less and it'll code and default) at your soonest possibility, then address what's left, if anything. The PCM is pretty good and forgiving with correcting calibration variations, but if the TDCO is out of range, it can't.

Yeah, "barely" is a lot, and often too much. Fractions of barely is sometimes too much. These are originally calibrated in an engineer's environment. Adjusting in place is like swatting mosquitoes with a shotgun or kite string. Not much in between.

[arveetek]

Cant beleive the OS is as “touchy” as it is. When you guys say “barely” move it, you mean “barely” move it, haha.

Yes it is! After going through what I did on swapping the OS on my '95, I vowed to never do that again! That's why all official documentation says it is not a serviceable or field replaceable part (should only be done by a Stanadyne dealer with proper test equipment). But, that doesn't stop folks from trying and getting lucky from time to time. The whole "optic bump" you read about online causes more problems than anything, in my opinion.

Casey

[High Toned SOB]

If your TDCO is that far off, you are in default fuel programming. -2.54 is pretty far out there. Get that correct (at least -1.94, any less and it'll code and default) at your soonest possibility, then address what's left, if anything. The PCM is pretty good and forgiving with correcting calibration variations, but if the TDCO is out of range, it can't.

It seems like i have lost the “quickness revving reaponse” completely now. I really liked that, made it so much better to drive.

Can someone explain simply the correlation between the OS and the TDCO (how they are different, if going from factory setting to -1.94 is just as good as an optic bump, etc). I am having a hard time understanding a significant difference.

I slso snagged this tidbit i found from someone else for info;

Quote:
First off, lets cover the DESired timing issue first. There is NOTHING you can do about this. DESired timing is what your ECM determined to be optimal advance timing as calculated by temperature, load, throttle position, RPM etc. There's no "normal" DESired timing. 8.5 or so is a ballpark for a warm HD engine at idle, LD guys will notice lower warm idle DES readings (about 5 deg) because they have an EGR to warm the charge air entering the combustion chamber.
Second is ACTual timing, this is the advance position the injection pump is ACTually at. All thats important here is that the pump is doing what its told. If your DES is 8 and your actual is 12, you have a problem, if DES is 8.2 and actual is 8.5 or 8.0 its fine. Now lets re-discern between 'Time-Set' and TDC Offset. Time-Set is a tool designed to help technicians get the pump in an appropriate position so that TDC Offset can be successfully relearned. Its a pretty good tool, but it CANNOT be solely relied on. Here's the trick, ALL 6.5L injection pumps should be 3.5 deg advanced from TDC (0 deg) crank. So the Time set function puts the pump at full retard (0 deg internal advance) and shows you how close it is to the 3.5 degrees you want. Here's the problem, whatever genuis wrote the code for doing the Time Set functions, and from what I've seen this is true on ALL scanners (Snap-On, Tech2, OTC you name it) all calculate the existing TDC Offset value into the equation. Because they are using an old and no longer accurate value, which will be the case any time the pump is moved or replaced, it will affect your reading. Now, to TDC Offset, As stated above, this is the calculated difference in degrees between 3.5 degrees before TDC and the full retard position of the injection pump. Thats ALL it is! When the pump is replaced, this must be relearned so the ECM knows that the injection pump is in proper position relative to the crank so that it can move its internal advance (ACT) to any position the ECM determines appropriate (DES). Different year models have different ranges for 'acceptable' TDC Offset. '94-'95 are the most finicky and the only ones that require a TECH1 or TECH2 to relearn and they must fall between -0.25 and -0.75. '96-'97 are quite a bit more lenient at something like -0.1 to -1.9 (don't quote me on those values)and can be commanded to relearn with the key cycle/pedal method and any scanner to read the data. For some reason '97s are the WORST about hanging while tryin to relearn and can cause lots of headaches if you don't know what its doing. It's caused by a programming error and I don't know if there is an update to fix it but beware! ~'98-'02s are even better, they actually relearn on their own just to check periodically. Acceptable to them is +2.46 to -2.46, thats a BIG window!

[DmaxMaverick]

The OS is the sensor that reads the actual location of the rotor in relation to the rotor head porting (the moment in rotor rotation that allows for a fuel injection event at specific cylinders). If the OS is too far out of range, the PCM won't be able to fire a cylinder injection event with rotor not presented to a cylinder port. This causes the DTC's and default physical/mechanical timing and minimal fuel volume (default/limp). The "OS bump" is usually a temporary perceived improvement, as it's reset at the next complete diagnostic cycle (likely why your snappy throttle response went missing). Doing both, the OS bump and TDCO minimization can, and often does, default once all the values are realigned. If the physical ranges are exceeded, one or both, it will default. The OS bump is not advised, and can prevent proper pump timing correlation with the calibration. It's best to have it correctly calibrated, or within the middle of the acceptable range (the lucky shot), and leave it there. Mess with timing by updating the calibration (chip or programming), and/or TDCO.

A simple comparison in old school language of the timing acceptable range might be that of a distributor cap and rotor on a gasser. The cam/reluctor of a distributor presents a range for spark timing, but the rotor contact must be in acceptable range of distributor cap cylinder contact before a spark happens. It doesn't matter when a spark is commanded, if the contacts aren't close enough to complete the arc circuit. The same applies to an rotary/axial fuel injection pump. If the injection event is commanded, but the rotor port isn't presented to a head port at that time (out of phase/range), the injection event can't occur.

TDCO is the virtual compensation by the PCM, in relation to the physical index/rotation of the IP housing. The offset is the compensation value the PCM forces the timing into an acceptable range that can be varied and controlled. Too much physical advance (less than -1.94) and the PCM will determine it can not acceptably control timing variations. Setting the TDCO to a minimum creates a physical barrier that prevents the PCM from forcing more retarded timing. Fortunately, the PCM doesn't monitor the actual IP index at higher RPM's (like when under load). It "presumes" the index timing to be in relation to the previous measured, ideal condition (at idle), and compensates on a scale according to the timing map (the "calibration"). Setting the TDCO at -1.94 simply places the physical IP index timing at the edge of the range the PCM will accept. This results in the maximum timing advance before the PCM has a fit.

[trbankii]

Buy the mechanical conversion stuff.

[snip]

I had been collecting the parts needed for the conversion. Then one day i went to start the truck after i drove it into the shop,it would crank but no fire.That was the last straw,so i began the conversion.Truck started right up after it was a mechanical injection truck.

So, what all is needed for the conversion? Is there a post/article that steps you through the conversion? I have a mechanical pump I picked up for the '94, but have been hesitant to do the switch until I know everything I need. The '94 has a 4L80E, but I also have a spare NV4500 I could swap into it at the same time to get rid of those electronics as well.

[trbankii]

Seems I found my answer here: The DB2 Conversion Guide - by Bobbie Martin (http://www.kozykalpacas.com/DIESEL/DB2%20Conv%20Guide.pdf)

[arveetek]

Seems I found my answer here: The DB2 Conversion Guide - by Bobbie Martin (http://www.kozykalpacas.com/DIESEL/DB2%20Conv%20Guide.pdf)

Thanks for the link!

Casey

[phantom309]

i did an optic bump way back when it was all the rage,.. it made the throttle super twitchy and bloody nuisance trying to maneuver the truck in very tight quarters or on a real slippery surface,. was kinda cool at first,.
This was on my obd1 94 truck with the 5068 pump, i had a custom eprom done for it and it improved everything,.