having issue with ruff idle (missfire)

[qcdsmtsi]

Ive had this very strange idle issue since Ive owned the car. I purchased her broken, skipped teeth on the Tbelt, so ive never had her running before I got her.

This is the problem: The car seems to missfire/ runs like it has a lopey cam at idle. Also it doesnt feel like it pulls like it should through the rpm range.

Since the rebuild I have just put on 1,000mi. I just replaced my oil and sparkplugs again before I went to the chicago meet this sat.


What ive done:

I just did a compression test today. 170 165 170 170 (with 150,000mi on stock bottom end!!!)

New plugs/wires I just replaced the plugs again, after 2 days they are blackened, like its running rich

I have test/ and swapped ISC motors with a known working one - no change.

I have tested the coil pack, and coil pack transistor - all ok.

I did the emissions removal from Taboo so I have no vac lines, so very slim chance its a vac leak

Did a boost leak test, and shes solid

base timing is -5

idle has been set and reset.

Now today we were messing with her, and there seems to be a clicking noise coming from pcv valve area - changed pcv valve (for the hell of it) and nothing, could it be injector?

I have done injector cleaner when I got the car first running, and I bought the full cleaner.

The car was sitting for about 2 years...


I might have left out something ive tried, as its late and im tired.

Is there something simple im overlooking?
Any suggestions/advice would be much appreciated.

Oh BTW the car is totaly stock, only thing done is the emissions removed, which we also did on my buddys 92 awd and we followed the same instructions and his runs great.

Thanks in advance!!

 

[snoddy]

I'm having the same problems...(including the weird ticking sound near the PCV valve).
Idles rough, pulls fine through the RPMs

I had my car in for a timing belt, balance shaft, front main seal and water pump replacement. Idle was surging pretty bad after that. Things I have done to fix it:

replaced plugs, wires, fuel filter and vacuum lines.
blocked EGR and capped the 4 intake vacuum nozzles
filled FIAV with JB weld
cleaned TB
did a boost leaktest (none) and compression test (155,155,141,145...descent)
checked ISC 33 ohms across the board
set BISSS according to vfaq (replaced oring)

idle no longer surges, just idles like it has a huge cam. Tonight I am going to tripple check the timing, try a friends working ISC (in case mine is faulty), check the resistance on the TPS, replace PCV valve and then reset base idle and see what happens...let me know if you figure this one out.

.eric

 

[bullettdsm]

Ive had this very strange idle issue since Ive owned the car. I purchased her broken, skipped teeth on the Tbelt, so ive never had her running before I got her.

This is the problem: The car seems to missfire/ runs like it has a lopey cam at idle. Also it doesnt feel like it pulls like it should through the rpm range.

Since the rebuild I have just put on 1,000mi. I just replaced my oil and sparkplugs again before I went to the chicago meet this sat.


What ive done:

I just did a compression test today. 170 165 170 170 (with 150,000mi on stock bottom end!!!)

New plugs/wires I just replaced the plugs again, after 2 days they are blackened, like its running rich

I have test/ and swapped ISC motors with a known working one - no change.

I have tested the coil pack, and coil pack transistor - all ok.

I did the emissions removal from Taboo so I have no vac lines, so very slim chance its a vac leak

Did a boost leak test, and shes solid

base timing is -5

idle has been set and reset.

Now today we were messing with her, and there seems to be a clicking noise coming from pcv valve area - changed pcv valve (for the hell of it) and nothing, could it be injector?

I have done injector cleaner when I got the car first running, and I bought the full cleaner.

The car was sitting for about 2 years...


I might have left out something ive tried, as its late and im tired.

Is there something simple im overlooking?
Any suggestions/advice would be much appreciated.

Oh BTW the car is totaly stock, only thing done is the emissions removed, which we also did on my buddys 92 awd and we followed the same instructions and his runs great.

Thanks in advance!!

Yep, I think you left something out. What did you do for a rebuild? Does car smoke at all? Since you bought it with this problem, there could be a lot of things "funky." Did they put a 255 walbro in? Did they upgrade to bigger injectors? (I am aware that you said car is stock but these are things that you may not notice). Both things could cause the quick spark plug fouling that you are talking about. There are other things but I'll start with these.
MB

 

[Wickdblast]

Check your coolant temp sensor. If its reading faulty then the pcm could think its -50 and will dump tons of fuel into the cylinders.

 

[snoddy]

Check your coolant temp sensor. If its reading faulty then the pcm could think its -50 and will dump tons of fuel into the cylinders.

My temperature gauge in the dash never reads above the first tick mark. I figured it was a problem with the sensor that goes to the dash (its one of 4 if I remember right). My fans still kick on and I have a brand new thermostat. I will replace the coolant temp sensor soon and see if that cures it. Thanks for the tip.

 

[bullettdsm]

My temperature gauge in the dash never reads above the first tick mark. I figured it was a problem with the sensor that goes to the dash (its one of 4 if I remember right). My fans still kick on and I have a brand new thermostat. I will replace the coolant temp sensor soon and see if that cures it. Thanks for the tip.

Careful. Different sender than temp gauge. What wickdblast is calling out is the the sender that sends to ecu (which, incidentally, he is correct. It can be a cause of this problem). There are two below the top housing (I'm trying to remember here...) the one you want to change has a funny looking oval type connector to it. They are both located under the T-stat housing and they are right next to each other. Replace the larger of the two. The other one goes to the gauge (If mammories serve me right).
MB

 

[snoddy]

tried to find a coolant sensor today...no luck!!! I have a strange connector that Autozone or Advance Auto dont have. They have a very similar one but the connection clip is not the same. Need to do some research to find the correct one.

Anyway, I checked base timing today and I am about 20 degrees before TDC and I cant adjust the cam angle sensor enough to correct for it. I believe that when the shop put the new timing belt back on they must have not lined it up correctly (or it has skipped a tooth). I know that they didnt use a timing light to set it...all they did was put the new one on and just "lined it up with the old one". I am taking it in monday and asking them to fix it.

I haven't done a compression test yet, but do you guys think I may have done some damage driving it about 120 miles with the timing that far off?

.eric

 

[snoddy]

skipped 2 teeth..fixed, car runs great

 

[bullettdsm]

skipped 2 teeth..fixed, car runs great

Hooray!

 

[Project ES]

might be time for a new timing belt tensioner