stuttering when warm

[gsxspeedlab]

i bought the car a couple weeks ago. but it didn't exhibit the problem right away. it seemed to have gotten progressively worse. it doesn't exhibit any problems when cold though. it's usually after it's ran for a while. i've changed the plugs and tried resetting the computer. there was oil in plug wells 1 and 4. but that problem was fixed. bad plug tube seals and loose valve cover.(wasn't tightened down) and it's only getting 19 MPG. where's the best place to start? thanks in advance.
(i've searched the forum and didn't find anything similar)

 

[KBasham03]

I would check your mas, I just had the same problem with my 1g yesterday, when the car would warm up it would act like it was running on 2 cyl. We couldnt figure it out, we changed all the caps in the ecu, we changed the transistor, then we finally changed the mas and thats what fixed it.

 

[gsxspeedlab]

it has now progressed to violent bucking. but it still runs good when it's not warmed up. i can't get my hands on a new mas as of yet. how did you test it? any other options?

 

[RSTurboFWD90]

I had a similar problem and it turned out to be leaking capacitors on the ECU board. If you haven't looked at your ECU, then I suggest you do so. Especially since the car is new to you.

 

[gsxspeedlab]

another symptom i just noticed. when it's bucking, if i give ANY gas at all even as low as 1500 rmp, it will go from -7 on the stock boost guage to 7 or 14psi IMMEDIATELY. it seriously jumps right up there. did you guys notice anything like that with your issue?

 

[gsxspeedlab]

i also have a light clicking sound sometimes i can especially hear it if i rev it up at idle. then it makes the clickind sound until it gets back down to normal idle.

 

[RSTurboFWD90]

another symptom i just noticed. when it's bucking, if i give ANY gas at all even as low as 1500 rmp, it will go from -7 on the stock boost guage to 7 or 14psi IMMEDIATELY. it seriously jumps right up there. did you guys notice anything like that with your issue?

The stock boost guage is not actually reading the manifold pressure. It is an indication of the pressure based on what the ECU calculates it to be. That's one of the reasons the "serious" owners install aftermarket boost guages.

Again, if you haven't looked at the ECU capacitors, you are wasting alot of time trying to figure out your problem. Believe me.... I speak from experience. I spent a bunch of cash on unneeded items because I didn't check the ECU. It will take you 20 minutes. If it looks good, then you can proceed to check other components.

If you are planning to keep the car, you may want to invest in a datalogger.

 

[gsxspeedlab]

The stock boost guage is not actually reading the manifold pressure. It is an indication of the pressure based on what the ECU calculates it to be. That's one of the reasons the "serious" owners install aftermarket boost guages.

Again, if you haven't looked at the ECU capacitors, you are wasting alot of time trying to figure out your problem. Believe me.... I speak from experience. I spent a bunch of cash on unneeded items because I didn't check the ECU. It will take you 20 minutes. If it looks good, then you can proceed to check other components.

If you are planning to keep the car, you may want to invest in a datalogger.

haven't had time to put boost guage in, or any other parts for that matter.
also, the injectors can be spun, for some reason. and it effects the idle if they're moved just slightly.

i'll have time to look at the ecu tomorrow. working lots of hours right now.

 

[RSTurboFWD90]

also, the injectors can be spun, for some reason. and it effects the idle if they're moved just slightly.

That's causing extra air to get into the intake and messing with your idle (and who knows what else). You need to replace the o-ring seals.

 

[spinz4]

The injector O-rings are causing a boost leak. This can be your problem. Replace those and then do a boost leak test to make sure everything is tight.

 

[gsxspeedlab]

i ordered the o-rings and the insulators. i'll post if/when they fix the problem.

 

[nightracer91]

The clicking sounds like your ECU. I'd take a look at that...

 

[gsxspeedlab]

i located the ticking sound. i had the car good and warmed up. it was coming from the egr solenoid. so i disconnected it and took the car for a drive. i didn't shut it off while i disconnected it. the problem was gone. so i'm replacing my solenoid. i'm not going to replace the egr valve itself. getting a blockoff plate. thought i'd share.
thanks for the input.