Beating the fuel system to death???

[RoverIIa]

Okay, I know that every other question around here seems to be with the fuel system, but I am up against a wall and need some advice.

Long story short... I just completed a 10-month ordeal of completely overhauling my 1983 6.2.

Some things installed or replaced along the way:

-DSG Gear Drive
-Rebuilt Injectors
-Rebuilt Injection Pump
-New pistons .030 overbore
-Polished Crank
-Re-surfaced flywheel and new matched clutch set
-Re-conditioned rods, upper bushing / lower bearing / new bolts / new wrist pins
-New Cam (I think used actually) and bearings.
-ALL new valves, guides, springs, lifters, pushrods
-(2) head crack repairs, re-did valve seats
-New oil pump, Bearings, Main Stud Girdle
-3 New sets of head bolts and 3 gaskets (don't ask... I'm still angry)
-Banks Turbo Kit and Exhaust System
-All Serpentine-drive accessories, including reverse rotation water pump
-New timing cover
-J code intake

Okay, I think the above info might have a bearing on my question.

After priming the oil system, I put the engine and associated stuff in the truck. It was assembled completely on a stand, including the entire fuel system.

I replaced all of the battery cables with new 2/0 cable.

With the truck hooked up to a running gasser by jumper cables, I spent about 3 hours cranking on it to bleed the fuel system. I have all new filters, and an electric lift pump that had fuel past the primary filter in about 5 seconds. All fuel lines are new, hard line, to the tank.

I would crank for about 10 seconds, wait 10 seconds, and repeat 3 times. After that, I would leave the system to sit for about 5 minutes, then repeat. I got fuel to weep at all injectors. Some of them actually leaked enough to make little puddles under the truck. After tightening lines, I still have no start.

All glow plugs are new, and seem to be working. I can smell a little bit of burned fuel at the exhaust, although the truck has only sputtered once. Ive repeated the tighten/loosen/bleed/tighten sequence on the lines several times now.

The engine cranks extremely quickly, but not so quickly that I am concerned about compression issues. You can hear the starter seem to "make a revolution" about twice per second. Before the rebuild, it seemed to crank at the same speed.

There seems to be compression, a paper towel stuffed in the tailpipe was blown out while cranking. :D

Here is the BIG QUESTION:

How long should I keep trying to crank this over before I start looking for other things that could be wrong?? I've never dealt with a completely empty and new fuel system before.

One of my concerns: The new timing cover from the dealership was for an electronic engine and HAD NO TIMING MARKS. I was able to locate the balancer timing position by a dial indicator on the #1 piston, but had to transfer the IP static timing mark with a pair of calipers from the old cover.

How far can this be off and still start/run?

The gear timing set appeared to install with no problems at all. I do not suspect timing at that point.

I know this is a lot of info, but I would appreciate any input here. I'm about ready to apply (1 ) road flare to the fuel tank and consider this an expensive lesson in why I should buy a new truck.

I'm beginning to believe the old Chevy/ Bob Seger add. "Like a rock! ... It just sits there in my yard!"

Thanks,

Nate

[Slim shady]

What do you mean by sputtered only once?

Glow plugs cycle ok?

Are they glowing/, remove one glow plug / ground it during a cycle and see if it will glow.

Try a small shot of WD 40 in the intake. If you have soaked your cylinders with diesel fuel (the glow plugs will be wet) it will be almost impossible to start.

Remove the glow plugs (the ones you can get easily) take the fuel solenoid wire (RED) on top of the Injector pump off. Crank the engine to remove all of the excess fuel. LET IT SIT with Glow Plugs out for a few HOURS IN A WARM PLACE. Then put glow plugs in and crank it without the fuel solenoid wire disconnected until it starts.

You could just disconnect the RED solenoid wire at the Injector pump and crank it. This would get a lot of the fuel out and may get you started.

If this doesn't get you a few sputters then advance the Injector pump (rotate to the driver side) a little to advance the timing.

Re post and let us know what happens. GOOD luck

[gmctd]

If it has good oil pressure, so the lifters are functional, really sounds like the IP is way outta time, maybe even 180deg.

Pull the waterpump\plate, verify the IP\camshaft timing

[RoverIIa]

I think that I will check the glow plugs out a little more. That idea seems easier than tearing back into the front of the engine. I could probably tell if the cylinders are truly getting fuel by removing the plugs too. The fuel should spray from the holes when cranked, yes?

As far as timing:

I took pictures as it went together. Each of the gears is clearly stamped. They are both keyed, so they can only go on one way. As long as those timing marks are lined up, the world should be ok, right? I could see a potential problem if the crank-timing mark was established with the #1 on exhaust instead of compression, but both valves were closed when I found this mark, so I think that should have been compression. Can the IP be installed backwards? When I was putting it all in, it seemed like it could only go one way?

Thanks for the input. Any other thoughts are welcomed.

-Nate

[gmctd]

Yes - line up the DSG crank-gear mark with the cam-gear mark using a straight-edge, install the IP drive-gear mark down on the cam, rotate the crank 180deg, line up the drive\driven-gear marks and the IP key, install the driven-gear, and it's all timed to the mark.

A lot of valves will be crunched if the crank\cam timing is out, but no-start is the only symptom if the IP driven-gear is not timed

[RoverIIa]

Okay... here are the steps I took today...

Started at glow plugs, since that seemed easier. I disconnected the fuel solenoid on the IP, after verifying that it was actually receiving battery voltage with the ignition on. It was. I cranked 5 or 6 times for about 15 seconds, while running the glow plugs (they're on a manual relay). Then I pulled 3 plugs. All had been hot (discolored) and were clean and dry. No residue came off when I wiped them with a rag.

I cracked the lines again, and cranked a bit with power to the IP to veryify bleeding. I got at least 3 more little puddles of fuel under the truck. Still no start.

I went through my photos and my GM shop manual. I saw something about making sure the IP alignment pin went into the SLOT in the IP driven gear. My photos were not really clear on this, so I tore down the front of the engine.

Everything looks to be correct. The alignment pin is in the slot, not the hole, but I don't think it could go the other way around, because of the 3-bolt pattern. When you manually bring the crank around to the 0 degree mark, the timing mark on the IP gear lines up with the mark on the IP drive gear that is attached to the Cam.

I know that I checked the cam-crank timing with a straightedge when I put that together.

If that timing is right, and the gears on the cam are keyed, and the dots line up on the pump cam gear and pump driven gear, the pump has to be aligned properly, right?

I tried to advance the IP a little bit, and after loosening the 3 nuts, it would not turn. I assume this is due to the tension on the injector lines? Could this be a warning sign, or do I need to loosen all of those lines in order to turn the pump?

GMCTD, your description of installing the pump backwards has me confused a bit. I know that the cam/crank are lined up right, but can that happen, have the IP cam and driven gears lined up at the marks, and still be 180 out?

My friend suggested trying to turn the whole thing around just to see what would happen. Has GM ever been known to stamp gears in the wrong place?

One last thought...

When the crank is brought to the 0 on the balancer, the IP drive/ driven gears are still about 1-2 teeth away from full mesh at the 6:00 position on the driven gear. I guess this would mean that they are meeting a couple of degrees after TDC. Does this seem wrong? When does the injection actually take place?

Everything I read about troubleshooting assumes that you were recently running. I can't really eliminate much at this point, because everything is new or re-build, and has not been operated since I tore it down.

Again, thank you for the input. Your further ideas are appreciated.

-Nate:confused:

[gmctd]

No, my bad - I meant to rotate the crank so the cam rotates 180deg, putting the drive-gear timing mark at 12 o'clock, then install the IP driven-gear mark at 6 o'clock to match.

The keyway in the drive gear and the slot in the driven gear correctly align the gears to be timed by the marks, and the DSG gearset is rumored to have ~4deg advance due to the design, but I've never checked.

Yes, the IP will be very difficult to rotate with the injector pipes tight, but can be done with the IP tool, even while running.

If it requires condiserable rotation, timed while running, loosen the pipe nuts after shut-down to let the pipe tension equalize, then re-tighten.

In any case, cranking the engine with no-start, even with the IP 180deg out, should result in wet glow plugs, as fuel is injected across the gps whether the valves and pistons are in correct position or not

[RoverIIa]

Okay, now I understand what you are saying. The gear timing set definately has a slight advance to it. it was not possible to line up EXACTLY on 0. I did not measure the amount of advance, I figured that they've sold enough of them for it to be accepted the way they are.

I am certain that the timing, as far as marks go, is lined up as you describe. I probably won't get to work on it again for a week, ( 1/2 day a week... this is why my overhaul takes 10 months).

It must be possible for the injector lines to bleed, and still not be causing the injectors to pop yet? Maybe I just have to go back to a lot more cranking? Right now, I'm wondering if there is a way to hook a pump to each injector one at a time and force fuel through it at 1500 PSI or so?

Thanks for the advice, I'll try to find time this week to mess with it, and maybe have good news to report next weekend.

-Nate

[gmctd]

Far as compression goes, there's 8:1, and 10:1, and 12:1 and various levels in between, but none of them will ignite Diesel fuel.

Pull all the glow plugs, and check each cylinder for ~375-425 psi, with all cylinders being within 25psi of all the rest - let each cylinder pump at least 8 times.

Best test is to leave the pressure gage connected, go thru one full intake-compression cycle with piston at TDC on the compression stroke, check the 'leak-down' time for each cylinder.

[Slim shady]

Why don't you try a little WD -40 and see if it will run before you go messing with the injector pump. The engine should start on WD-40, if it does, look at the fuel delivery system.

Basics, Cranks, fuel? If the glow plugs are not wet from all the cranking you, state you have done. Then I would suspect that I would start there first. Hence the WD-40. Also, take the fuel return line off the injector pump and see if it has fuel coming out it. If it does clamp this shut, it will advance your pump timing and help bleed the fuel system through the injectors.

I don

[RoverIIa]

I'm arriving at the same conclusions that you have. I've already tried WD-40. I tried that several times before my first post. In my experience, you need to be actually spraying the WD into the intake at the time of cranking. Unfortunately, I'm solo on this one.

I think I have a friend lined up to help this week.

(No, I don't have a temporary start switch, but will rig one up if I have to)

I'm also going to run a quick compression test on a few cylinders. It can't hurt anything.

I'm going back to believing that there is something keeping the fuel system from bleeding completely. I like the idea of pinching the return line off, will that really help, the air needs to get out somewhere.

I was wondering if there is anywhere I can hook up a vac pump to help it bleed?

Thanks for all of the help. I'll post updates if I find time to go to the shop.

-Nate

[RoverIIa]

Okay.. here's another thought.

I was showing some of my photos to a guy at work. This is embarrasing, I had one that showed the timing set up the right way, but did not find it before I tore down the front of the engine.

Anyway... the guy posed this question...

Is it possible for the cam IP gear to be turned with the wrong face out? If there is also a timing mark on the back, it could be in the wrong place, which would put the IP driven gear in the wrong position now... I might pull it, since I'm so close to having it all apart now and check it out.

If anyone has ever heard of this, please post it up.

Thanks,

-Nate

[More Power]

A loose injector line fitting won't allow fuel to be injected. Since you're seeing fuel weep at the injector line fittings, they all should be tightened.

Jim

[Slim shady]

"I'm going back to believing that there is something keeping the fuel system from bleeding completely. I like the idea of pinching the return line off, will that really help, the air needs to get out somewhere."


If you already have the injector pump full of fuel. The fuel should be coming out of the return on the top of the pump. The injectors will not build pressure until you bleed the air from them. The previous post about making sure your injector lines are tight is VERY good advice. It will not start unless all of them are tight, especially when it may have air in the lines/injector.

You can squirt Wd-40 in the glow plug holes and then try to start your truck, at least it should try to start. Don't spray to much you don't need a hydraulic lock, or a broken piston.

[RoverIIa]

I consulted with one of my mechanics at work yesterday. He seemed to agree with me that the fuel system was completely bled.

I finished tearing down the front of the engine, and now am fairly sure that I pulled the most bush-league mistake in the book, and timed my crank to TDC exhaust.

If all goes well at work today, I will have the system flipped around, and be ready to start it tonight.

I appreciate all of the advice. Thanks. Hopefully we can close this thread soon.

-Nate

[gmctd]

Don't really see how that could happen if you aligned the marks on the DSG gearset - while the teeth do not align because of the idler gear dual-pitch, the marks can be lined up with a straight-edge across the centerline of the camshaft.

360deg out is right back in, as it were - I was thinking the Inj Pump gears, since you don't have any valve\piston tete-a'-tete.

[RoverIIa]

Well.... It runs!!!!

When it finally started, there was so much smoke in the shop that I couldn't see to find the switches for the vent fans! I love it!!!

Okay here is what I did to fix it.

I brought the crank around by hand to make the balancer mark line up on TDC 0 Degrees.

I took off the water pump plate. The IP drive/driven gear timing marks were lined up. The alignment pin on the IP was in the 6:00 position and in the slot in the driven gear.

I took this apart, preserving the IP location, and pulled the timing cover. Both timing marks on the DSG gear set were at 12:00 (not lined up).

I decided that it was a safe bet that the crank was on compression, and the cam was on exhaust, based on the engine not running on WD-40, and not starting.

I pulled the Idler Gears, and rotated the Cam 180 degrees until the timing marks lined up again. I put the idler gears back in. I couldn't get the marks to line up exactly, even with a straight-edge. The idler gears won't mesh properly unless the marks are off by about 1/2 of a tooth. If the cam gear is about 1/2 of a tooth to the drivers side of the vertical line, the idlers slide in smoothly. With 48 teeth on the cam, I figure that this is between 3.7 and 7.5 degrees off.

I bolted the timing cover in place with 2 bolts for a temporary check.

After this, I installed the IP drive gear on the cam, and rotated the crank 360 to bring the timing mark on that gear to the 12:00 position. (this seems odd, like you have to set the crank up to be timed on some stroke other than compression...??).

The IP driven gear slid right on, timing marks aligned perfectly, with the slot in the 6:00 position and the alignment pin in the slot (I never moved any part of the IP).

I put some assembly lube on all of the gears, and bolted the water pump plate up to keep things out of the gears.

I lined up the IP to the theoretical mark that I transferred with my calipers, and tightened down a nut.

Praying to our lady of blessed acceleration, I hit the GP for a few seconds and cranked it over.

It sputtered and caught on the third try. The injectors quickly caught, the oil pressure hit 78 psi, and the turbo made the most wonderful howling cry you've ever heard! The shop filled with smoke, and I stumbled around trying to get the vent fans running. It was a moment worthy of the last several months of pain.

Now... I have to tear the thing down and put it together properly with loc-tite and gaskets and such.

Hopefully the last question in this saga...

Is it better to set up the crank-cam gear set to have that 1/2 tooth offset on the driver's side of vertical (6:00 on cam gear) or the passenger's side of vertical, facing the front of the engine??

[gmctd]

Passenger-side would be retarded - think I'd go with advance

The marks lined up on my gearset from several years back.

Dunno why they did that on the IP drive\driven gearset - probably the mark is indexed when the keyway is broached, so it winds up being 180deg out when timing the crank\cam

[RoverIIa]

I want to take another moment to thank everyone who put in their $0.02 on this issue. I probably would have given up on 6.2 ownership before I even bought my first one if it weren't for the great folks here at The Diesel Page!:D

[Slim shady]

GLAD TO HEAR THAT IT RUNS. Helping is what this place is all about. That is the reason this is the only place I even bother to read or post. We have the most professional people.

Get that thing buttoned up and have some fun.