HELP with WEIRD problem!!

[Forcedfed]

My '87 Turbo-T has been experiencing a weird problem lately. It feels like the engine is missing or a plug is fouled up, the engine is not smooth and it lacks low end power. And also every now and then it blows alot of white smoke out the exhaust as if it were extremely rich. So we started by changing all the spark plugs; same problem. We checked the rockers, all were fine. We switched the coil pack; same problem. We checked the compression, it was fine. Checked for vaccumn leaks, found one and repaired it but the problem is still present. The car doesn't have a MAF sensor anymore since we installed a new DFI computer last year. The tuner checked the DFI and said it's fine. Through all this checking and test driving we noticed that the problem is not always present. The problem is present 90% of the time but every now and then the problem will almost disappear; it smoothens out, has good power and no smoking.

Has anyone out there experienced any problem like this? Anyone have any idea what's wrong? Any help would be appreciated. Obviously the car is not stock, it has a DFI and complete engine rebuild with a T60 series turbo. But all the work was completed over a year ago and it's been running fine until the above symptoms just started up.

 

[Forcedfed]

ANYONE?

 

[Topjimmy]

White Smoke: Coolant leak into exhaust (usually from a faulty headgasket).
Black Smoke: Rich condition/incomplete combustion.

Good Luck - Jim

 

[Tow Man]

Well here's my .02!

If it were a rich condition, it would be blowing black smoke. Did you check up pipe and TB for oil accumulation? Are you loosing any coolant?

If you are loosing coolant and smell anti freeze at the tail pipe= head gasket or possibly intake gasket. Do a pressure test on the cooling system.

If you have alot of oil in the TB, bluish smoke = turbo seal

Just my thoughts considering the "white smoke".

 

[Forcedfed]

Originally posted by Tow Man

If it were a rich condition, it would be blowing black smoke.

Correction, it's blowing white smoke as if it were burning antifreeze not like it's running rich (my mistake). But it only does this periodically and it doesn't smell like antifreeze (it smells like gas), I checked the antifreeze level and it's fine. What about the other symptoms; the hesitation or missing and power loss? Anyone wanna take a stab at it?

 

[87gnand00ws6]

,

Do a compression test first. see if any of the banks are low. that will let ya in on if ya have a blown head gasket, bad rings or whatever. ull know u have a problem if they all dont read pretty close. within 10-20 from normal

 

[87gnand00ws6]

also,

NO SES CODE?? if so maybe a maf? then again if it was the maf it probably wouldnt start up and stay running. try the compression test like i said earlier. if that turns out ok check intake for leaks. have you checked your fuel rail for presure, throw a fuel presure gauge on the rail and make sure its reading proper ammounts. if its not maybe the fuel presure regulator. oh well. do all the tests//

 

[Forcedfed]

Originally posted by 87gnand00ws6
Do a compression test first. see if any of the banks are low. that will let ya in on if ya have a blown head gasket, bad rings or whatever.

Did the compression check the other day, all the cylinders are pretty close; one is about 20psi less than the others but that's normal. Besides, that wouldn't be causing all the symptoms I described in the original post. I'll continue checking other areas ypu suggested, in the meantime, if you or anyone else have any suggestions feel free to jump right in.

 

[Forcedfed]

t

 

[Tow Man]

This is just wild guess but....Did your problem start after a fuel up? I'm thinking bad tank of gas or water in the tank.

Next time it starts missing and blowing white smoke, let some fuel out of the fuel rail into a clear glass. Let it sit overnight and see if there is water in your fuel! Water will settle to the bottom.

I know it's a long shot but may be worth a try if all else fails.

Good Luck

 

[NASSTY]

Plug Wires

 

[TurboJim]

Maybe you got a flaky module. Remember dont fire one coil, 2 cyls die. Does it feel liek it runs on 4 cyls?

 

[Forcedfed]

Originally posted by Tow Man
This is just wild guess but....Did your problem start after a fuel up? I'm thinking bad tank of gas or water in the tank.

Anything is possible, I'll give it a shot.

Turbo Jim: I'm not sure if the tech switched the module yet, I'll check that too. Thanks

 

[Jim P.]

hope you figured it out by now but about a year ago my car would just barely idle ran like garbage was puffing white smoke ever now and then and smelled like garbage. turned out it was a messed up o2 sensor from the goofy race gas i was using. i thought i blew a head gasket but it was just running super lean.

 

[steve hughes]

What do the plugs look like? Any of them wet ,oily, or fouled? If you have a coolant pressure tester or can get one warm up the car a little. Then put the tester on it ,put abput 10 -12 psi in the system. Let it sit for a half hour then fire it up see if it blows lots of white smoke and smells like antifreeze and the miss comes back. I've seen a lot of 4.3's blow head gaskets but not to the point where it would act up in the shop. Give it a try.

 

[TRENT THOMPSON]

If the car is powered by DFI then there is no way it could be the MAF as it shouldn't use one

 

[Sleeper-6]

I'm with NASSTY, Simple (cheap) stuff first. You said that the plugs and coil were changed. What about the plug wires? that's where I would start. A while back i had a really nasty stutter that would clear up when the car was hot or at WOT. Turned out the cam sensor was out of adjustment.