Weird surging/misfire problem

[Brewster]

For the first couple minutes of driving the car will start to buck when accelerating, then it will drive normally. I recently changed the spark plugs because it was doing this and the plugs were covered in soot and the first couple threads had a bit of oil on them. It drove perfectly right after I changed the plugs. The car smokes like a chimney on startup and after boosting, but the color of the smoke is different. On startup it's blue and after boosting it looks white.

Could it possibly be oil leaking from the valve stem seals and soaking the plugs causing them to not fire right for the first couple minutes, then after driving they dry off? Grasping at air here... :dunno:

 

[Shadow]

Have you done a compression test? If not, try that to see if you have good compression. You could have bad rings. You could also have bad valve stem seals as you mentioned. Compression test results would help to narrow that down some.

 

[Brewster]

If the vavle stem seals are toast would that cause low compression? I'll try to get to autozone this week and buy a compression tester.

 

[Tim]

bad valve stem seals will not cause low compression, but It will cause oil to get into the cylinders and burn causing smoke.

 

[bobiseverywhere]

i did not really read you thing cause i'm tired but from your title i had the same issues until i had all the capacitors in my ECU Changed for new ones

 

[Brewster]

I already tried another ECU and nothing changed.

 

[bobiseverywhere]

are all your plugs the same?, how do you coil packs look? definitely check your compression.

i am just having a smoke problem still trying to figure it out exactly.

Also maybe one of your injectors is sticking open at times, Maybe have them cleaned, rebuilt and flow tested??? I dont know if that will really help

what octane gas are you using?

 

[Brewster]

Plugs are new NGK 6097s gapped to .028, didn't see any cracks in the coilpacks, using Chevron 93 octane.

Like I said, it only happens for the first couple minutes of driving.

 

[bobiseverywhere]

check your connectors for the Cam position sensors. Might be the engine is having trouble due to oil in them for the first little bit, causing the misfire

I checked mine and they were full of oil and dirt. Idle improved and my back firing once i cleaned them up and put in some contact silicone.

I am just guessing at what it might be. I can't say i know.

 

[Brewster]

Where are those sensors located?

 

[bobiseverywhere]

on the intake side of the engine between the intake mani and the cam covers right next to your fuel injectors

 

[Brewster]

Just drove it after letting it sit for a day and a half and it was fine...

 

[Shadow]

If the vavle stem seals are toast would that cause low compression? I'll try to get to autozone this week and buy a compression tester.

No it won't cause low compression but it will rule out other possibilities like bad rings. When I have a problem that I'm not sure of what the source is, I eliminate every other possibility to narrow things down before actions are taken. It's easy to do, cheap and will rule out other possibilities. That's why I suggested it.

 

[bobiseverywhere]

did you check the CPS yet? also have you gone over all your connectors with contact silicone

 

[bobiseverywhere]

No it won't cause low compression but it will rule out other possibilities like bad rings. When I have a problem that I'm not sure of what the source is, I eliminate every other possibility to narrow things down before actions are taken. It's easy to do, cheap and will rule out other possibilities. That's why I suggested it.

"When you've eliminated the impossible, whatever remains, no matter how improbable, must be the truth." - Sherlock Holmes

 

[Shadow]

"When you've eliminated the impossible, whatever remains, no matter how improbable, must be the truth." - Sherlock Holmes

So true!