"Smoke at start up" is back!!!!!!

[nigeljones]

Hi all

Well the saga continues I had smoke at start up this winter and changed just about everything with not much luck. (see previous post on subject)

The last thing I repaced was the timing chain and I thought that was it. With the weather warming I thought I would have to wait until fall/winter for the temps to drop to below zero to be absolutly sure.

Well this weekend at 48 deg she started up from cold smoking like a pig. Although the truck now has developed a pronounced hesitation at approx 70mph - it drives ok whilst underload, however, when cresting over a hill and backing of the gas pedal slightly as you do, thats when she really hesitates. The SES light dose not light up, but I regulary get 1216 and 1217 trouble code (fuel soliniod short and long). I have also been running with a fuel additive for lubricant to address this.

I plan on swapping out the fuel injector pump this weekend with a take off to see if that makes any difference. I'm basically out of ideas.

Shad has the same problem and he changed the pump with no luck, but it might address the hesitation.

Comments or Commiserations accepted :rolleyes:

[charliepeterson]

The hesitation can be a fuel delivery issue. You've done a lot of work to the truck, how are the fuel lines under the truck. The smoke at start up, is it gray? This could be air in the fuel, but you would have a skip too until it caught itself. have you done any exhaust work yet? Do you have a "cat"? You can try disconnecting the turbo down pipe and eliminate a restriction. This engine really likes to breath easy.

[99gmccrew]

I had a similar hesitation, it would feel like surge after I would let off of the accelerator. I did all the cheap stuff first. Finally replaced the fsd/pmd. Haven't had the surge or hesitation since.

[nigeljones]

I would like to get the exhaust and gages next. Well that is/was the plan.

But with this and other vehicle issues the funds haven't allowed just yet. Hence the swap out with a take off pump.

Reading things thru again I'm going to check that there is no moisture at the connector for the pmd/fsd extension harness as I read that has been a previous issue.

My wife who drives the truck feels that it has something to do with dampness as thats when she thinks it happens most.

Thanks

[Shad]

Mine still smokes a little approx 10-20 seconds at start. However has been running well otherwise after replacing pump and injectors. I was at a diesel Dyno last weekens and a guy mentioned a problem he has seen with a cracked head between the valves which causes smoke at start, then when the chamber warms up the crack closes up? I am at the point where I am going to just run it till conditions get worse or I run into some extra money to burn. Sorry to here your still having problems.

[jspringator]

Shad, GM makes some coolant leak stop to address that issue. Don't use any stop leak other than that from your GM dealer.

[Jim P]

I know this won't help your hesitation but my truck also smokes at startup because it has 18:1 compression(actually I think mine is even lower than that). If I try to start as soon as my glow plug light goes out, it makes enough smoke to fill up half a Walmart parking lot. But if I give it an extra 20 seconds of glow time with my manual glow plug switch, it makes no smoke at all. This is even with quick heat glow plugs.

[nigeljones]

Shad,

If we had a crack in the head is coolant getting to the cylinder?
You would think that we would see a drop in the antifreeze level and I havn't as of yet.

As I write I now remember I had also read that before, as I remember, you can test for that when the engine is cold.

Check to see if the coolant is under pressure - It shouldn't be.
Then start the truck for approx 1 - 2mins.
Then switch off and quickly check the coolant ( remove cap)to see if it is under pressure

got to go

Nigel

[john8662]

Bummer that the smoke is back!

Since you're getting injection pump codes, my bet for now is with replacing it with a newer model DS4. What model DS4 are you swapping in?

The cracks between the valves in the cylinder heads mentioned earlier are usually nothing more than cosmetic and usually don't allow coolant to enter the cylinder. The sources for coolant into the cylinder are usually a badly cracked head, one that cracks starting at one of the valves, or a leaking head gasket.

Since you're not seeing any coolant consumption I doubt this is your problem.

I'd check what you're already onto in checking the connections on the injection pump for a source for moisture to get in. I rarely deal with that, it's as dry as a popcorn fart here in west Texas. But pack all the connections with di-electric grease (sp?).

[StephenA]

This probably has nothing to do with the source of your smoking problems, given the hesitation, etc., but I had enough white smoke to bring out the fire dept before I discovered the cause... I thought my glow plugs had all given up the ghost at once, only to find that the lead spacer between the two positive battery cables on the passenger side + battery terminal was corroded inside the rubber fitting (everything else was clean). $1.00 replacement part & no smoke at all now even on cold mornings! I did the battery terminal mods, with a few changes- stainless steel bolts, nuts, washers & lock washers - all covered with diaelectric grease. Starter really spins up now. Engine starts in 1 second. Big change from smoking up the whole block before the fix. And this is despite 238,000 mi on original engine, pump, plugs, & injectors. Plan to R&R these this month even though I'm still getting 18-20 mpg with 4:10 rear & manual 5 speed. I really love my 92, especially when tanked up with B20!
;-D

[nigeljones]

The pump I'm replacing it with is a 5521 with a date of 2000. So I"ll see what happens. I have know idea whether the pump is any good but I'm going to give a go.

I think I'm resigned to adding the manual extended glow switch for the smoke at start up. bummer :(