White Smoke at 1500rpm

[Plowboy81]

Had a felled Dtech pmd box friday 2nd one six mounths, cause my truck to take off like a toyato. Push clutch in to stop it turned key off to keep engine from running past 4500rpm. Just so happens had a spair pmd behind seat. Replaced it and truck started and run just fine. Let it set over night and started it again next morning ran fine, started sputering and just died. So thinking injector pump, I replaced it with one off my wrecked truck that was a year old and ordered a new styandan pmd grey one. Relocated it to the front bumper instead of intake. Now when you start truck it idels fine but when you get truck up to 1500rpm it starts a steady stream of white smoke. Smells like unburt fuel, dont do it idealing at 750rpm. Hooked my Snap On MT2500 scan tool to it and says its timed at 6.7 if i am reading it right, where says desired timing. Dont know what to do now? Injectors or only a year old so dont think its that. Hope I ant lost a cyclinder.

[Robyn]

How does it do when you put it under a load????

How long sice the fuel filter was changed ???

Any codes (SES Light) ???


Missy

[Plowboy81]

Havnt put it under a load yet went to drive it down the road and seems like it loses power after shifting to 3rd and 1000rpm, bogs down hesitates and sounds rought. No engine light on and not seeing any codes. Fuel filter was replaced two mouths ago.

[john8662]

What pump model did you swap on?

[Robyn]

If there was an issue in the IP or sensors the ECM would be howling and setting codes.

Be sure the fuel supply is good.

Missy

[Plowboy81]

Havent got the pump number off yet, but I did advance the timing today and that didnt help, got a miss in one of the cylinders, took a thermal gun and test each cylinder at the exhust manifold and on glow plugs. All are reading 173 accept number one its reading 143. Far as fuel goes supply pump working good.

[Plowboy81]

Pump model is a PD4, and the pmd box i used is the new synading gray box I mounted on front bumper with the new extenton harness that has the old style plug for pump and new style plug for pmd box

[JohnC]

Swap the injector from #1 with a different one and see if the problem follows the injector. Also, you may want to pull the valve cover off and see if the rockers are OK.

[Robyn]

I agree, yank that injector and swap it.

May be that your whole issue is a bad Squirt.


Missy

[Plowboy81]

Thanks took out 1 and 8 today. having them tested tomorrow. Well let you know what find out.

[DmaxMaverick]

Thanks took out 1 and 8 today. having them tested tomorrow. Well let you know what find out.

You don't need to test them, yet. All you need to do is switch them. If the problem continues and the "cold" cylinder follows the injector, the injector has failed. If the problem remains with the cylinder, the problem is related to that cylinder, and the injector is probably OK.

[Plowboy81]

well I did the swap and nothing changed still missing on 1. Had a buddy come over and we pulled the vavle cover and looked at number 1. all the lifter caps are in good shape and the lifter rods don't look bent, springs on values look good to. Bared engine over and movement looks good. couldnt do comprison check dont have the adapter. So for hick of it took injectors down to school and they tested fine. Can an injector pump cause a problem on just one cylinder and if find a comprison adapter can you test with valve cover off.

[DmaxMaverick]

An injector pump failing on one cylinder is extremely unlikely. I can't think of any condition that would cause it to "overfuel" one cylinder. The head can fail at one cylinder, causing an "underfuel" condition, but not overfuel. The fuel volume is determined by the piston (plunger) stroke, and can't be exceeded on only one cylinder (multiple cylinders share pump pistons, which is what the "4" means in DS4, 4 pistons/plungers). An internal pump leak on one head outlet port could cause insufficient pressure to pop an injector, but I don't see any way it could overfuel. However, a worn/broken injector can do that (fails to hold up to pop pressure).

It sounds like you have low compression on that cylinder, if in fact the white smoke is fuel related. This can be caused by any number of reasons.

[Plowboy81]

Yea its white diesel smoke. I wish there was somewhere around here that could do the comprission test besides chevy place. I cant do the whole arm and a legg price they want just to check it. I got a comprission gage just dont have adapter for this engine.

[DmaxMaverick]

You can buy a compression testing kit from Harbor Freight (the "Full" kit, not the cheapo) that will have the adapter, or you can make one. Years ago, I made one from a glow plug. All you need is the body part of it, and a fitting can be braised or welded to the nut end after the core is removed. I used a shop air fitting, which was compatible with my compression gage of the time. The gage you use should range up to 500 PSI. Some kits have a rubber-nipple-thingy that can be used to push against the hole, but I don't know if you could hold it against the Diesel compression. Never tried that (although they work fine for smaller engines, like motorcycles and lawn mowers).

If the compression is low enough it's huffing white, smelly fuel smoke above hot idle, the reason for the low compression, especially since it happened suddenly, must be significant. A compression check should be your next diagnostic step. Check all the cylinders on that bank to develop a trend. That should be enough to determine the compression condition of the suspect cylinder. Normal compression should be between 320 and 400 PSI, with about a 15% maximum spread (10% on a new engine). Test with the engine at/near operating temperature, 6 puffs per reading (full batteries and glow plugs removed). Be sure to unplug the pump power supply connector. Any other test method will be unreliable.

Here's another option (or an addition). Ignition OFF. Rotate the engine by hand until the suspect cylinder is on the power stroke. Remove the radiator pressure cap, oil filler cap, and air cleaner. Have a helper apply continuous 20-50 PSI of shop air to the glow plug hole (rubber tipped nozzles work), then listen and watch (caution---the crank will rotate to BDC, unless the leak is huge). The location of the leak should be fairly obvious. Listen to the intake, exhaust pipe, oil filler, and watch the coolant for bubbles. If no indication of air passage yet, apply soapy water around the head and deck.

[Plowboy81]

Switch out injector pump with one that was on it before and the smoke at 1500rpm went away. Done comprission check and at 6 peffs each cyclinder has 400psi. But now when you go to pullout and speeding up at 1500rpm acts like ant got no power and engine is flutering. Seems like after that it runs good after you get up to 2000rpm. Have noticed alittle viberation at idal that wasnt there and hardly no turbo pressure on gage. Could lift pump be bad?

[Robyn]

Do you still have the factory chip for the computer ??? If you do, swap it back in and see if the issues go away.

Your 40 HP chip may be dieing or ???
Make sure you have good vacuum at the wastegate actuator.

Give it a go and keep us posted




Missy

[Plowboy81]

Will try that today, I still have it.

[mobilevet]

stupid question but what does "peffs" mean? I'm also doing some compression testing and was wondering.

[DmaxMaverick]

stupid question but what does "peffs" mean? I'm also doing some compression testing and was wondering.

Probably "Puffs". That's one compression cycle during the test (2 crank revolutions). The gage needle will jump with each puff, until you reach max compression. Do this on a hot engine (up to or near operating temp), or your results won't be reliable.

[Plowboy81]

Yea had alittle type o on that one suposed been puffs lol. Switched out chips yesterday, put factory one back in. The viberation has degressed. Still feels week, when pulling out. Not missing anymore that can be heard or felt. Still hearing a noise on passenger side of the truck, sounds like when the vaccum pump goes bad. Going take belt off tomorrow for bit and start it see if noise goes away. Is there a better way to see if that is where the noise is with out having to take belt off waterpump and alternator. Wish there was a way to post sound file so you can hear what I am hearing. Didnt have this problem till that dtech box went bad and ran motor up like it did.

[Plowboy81]

Well spoke to soon, the miss is back at idel, this time it starts up and idels fine for a min then it starts acting like its going die, spuddering, like a push mower fixing run out of gas. Any one know how much pressure is supposted be coming up from the lift pump or do think injector pump is fixing to go?

[DmaxMaverick]

Too many factors that aren't adding up. This is screaming fuel quality, or something is interrupting the fuel supply (bad OPS, failing LP, damaged/restricted line, poor electrical connection, etc). Verify your lift pump is pumping fuel, all the time. Install a gage on the water drain line and try to repeat the conditions (don't forget to leave the valve open with a gage installed). Also, check your fuel for something other than #2 in it (gasoline, etc.). If you have less than 1/4 tank of fuel, add 5 gallons or more of fresh #2 and try again. If more than 1/4 tank, either add enough #2 to double the volume, or drain the tank and start over.

Any fuel pressure above zero is enough. At idle, it should be 4-8 PSI, and should not drop below zero at any time under any condition.

[phantom309]

almost sounds like water in the fuel,.?

[Plowboy81]

Hooked up fuel injection gage onto the water drain valve and opened the drain while it was running. Gage never moved off zero mark. took hose lose from drain valve and fuel started coming out. But gage never moved. Cut truck off and removed gage from end of drain vavle and the hose was dry. So its getting fuel to drain vavle but not enought push air out of line. Took hose off gage and put in bucket its got a stream running out it but not alot of pressure. Have attched some pics, as you can see for got to put a clamp on line at the drain vavle with gage hooked up but there wasnt enought preasure to blow it off or leak.

[JohnC]

Gage never moved off zero mark.
Don't waste your time on anything else until that is corrected. At idle you're expecting 4-6 psi.

[Plowboy81]

Ordered a new lift pump today going give that a try. Changing filter didnt help.

[JohnC]

Did you check the oil pressure switch first? this is a much more common (and cheaper) cause...

[Plowboy81]

Yes I just put the oil presure switch in in febuary when we put this engine in the truck. Put lift pump on today, rebleed the system by opening fuel filter and taking out relay and crossing over the hot to pump. Tried test pressure on it and gage I got ant right one cause it didnt show anything either, but truck ran fine got to town and cut it off. Was in store maybe 30 mins came back out started it went pull out. It started acting like it was going die again. Spiting and spudering running like a push mower not getting enought fuel. Cut it off drifted it back into parking place sit a minute restarted it and she missed just little guned it, it spit and spudered till got to 15 mph then smoothed out and I drove it home. Left if running when got home it was fine. Just cant figuire it out. The pmd box is new its under front bumper. Only thing I can think of is injector pump or ignition switch. Anyone from here from virginia I am out of ideas. Still not getting any codes on the scan tool.

[rameye]

Sucking air??

[Plowboy81]

How do you go about checking for that? I have looked at all the return lines and feed lines going to the fuel bowel but have not seen any leaks. Has anyone had a problem with the new napa fuel filters with the cap made onto it?