Random missing/rough running - datalog attached

[MrBaseball]

Edit: Unfortunately, the camshaft and rocker I replaced are damaged again and I also have 0 compression in cylinder 3. I don't know much about engines so im not sure what caused it. I need to figure out my options for getting the car running again..







My 92 3000GT VR4 has been having problems with sporadic rough running and missing since I had spark plugs, wires, coil pack changed, and smoke test done at a local shop.

Can someone take a look at the data log attached and let me know if anything looks abnormal? It looks like the O2 sensor is not cycling? is that bad?
I took this log while the car was idling rough.

Parts replaced to fix original problem of spark blowout:
Spark Plugs - NGK BKR6EIX-11 (40K miles on them) to Denso IK24
Wires - MSD to OEM
Coil pack - Arcing OEM to unknown brand wired into stock plate.
smoke test

When I got the car back, the engine was not running right and it would miss & shake when accelerating. The problems were not sporadic at this time.
I thought it was the plugs, so I changed them back to same model I had previously - NGK BKR6EIX-11 iridium.

Now the problem is sporadic. Sometimes I can drive the car without any problems and other times the idle drops low and the car misses & shakes while accelerating. Sometimes it feels like a fast pulsing when accelerating in 5th gear on the freeway. Sometimes it starts to run rough at a stoplight, idle drops and the vacuum on by boost gauge drops to around 10 from 20. It will usually start running normally by the next stop light.

I took the car to a shop who is knowledgeable about these cars and they attempted to trouble shoot. They found out that my the power steering pressure switch is bad. Before I had a chance to fix that, the rough running became a problem all the time and was no longer sporadic. The shop found damage to the rocker and camshaft in the right bank. Here is a picture of the damage: http://i29.photobucket.com/albums/c2...ne3000GT08.jpg

I replaced the lifter and the rocker for cylinder #1 and the right bank camshaft. Now im back to the sporadic issues I was having earlier. Im not sure what caused the camshaft/rocker damage or what happened to cause the initial problems.

List of new parts on car replaced after problems started:
Spark plugs - NGK BKR6EIX-11 Iridium
Coil pack - New OEM
PDU - New OEM
ECU - Swapped with Used
ECS - Unplugged, symptoms unchanged
IAC - New from schucks
Battery - New Optima Red Top


I am replacing the power steering pressure switch on monday.

[MrBaseball]

Here is another datalog. The car was idling very rough and almost stalling.

[veerfour05]

Don't have anything to read a .csv file but have you checked your ECU yet?

[MrBaseball]

Originally Posted by veerfour05

Don't have anything to read a .csv file but have you checked your ECU yet?

I swapped the ECU with a used one and the symptoms did not change. I'll edit the 1st post with everything I have tried so far.

[brutten]

First log your low fuel trims are maxed lean and the second one they are maxed rich that is not good. Have you checked for boost leaks?

Check your base timing

ISC count is way off on both logs also. stealth316.com has a page on how to clean/test them.

[MrBaseball]

Originally Posted by brutten

First log your low fuel trims are maxed lean and the second one they are maxed rich that is not good. Have you checked for boost leaks?

Check your base timing

ISC count is way off on both logs also. stealth316.com has a page on how to clean/test them.

I checked for boost leaks a couple months ago when all of this started. I replaced the IAC on Sat. I think the ISC count is high due to the faulty power steering pressure switch (ECU thinks I am turning the steering wheel all the time). I am getting that replaced and adjusting the idle tomorrow.

I need to find a known good ecu to try..im not sure if my used one is good.

[Joel_CA]

i can't read your attached file at this time.. but you look like you have some sludge issues

JJ

[MrBaseball]

Should I change the files to a different format?

[veerfour05]

Originally Posted by MrBaseball

I checked for boost leaks a couple months ago when all of this started. I replaced the IAC on Sat. I think the ISC count is high due to the faulty power steering pressure switch (ECU thinks I am turning the steering wheel all the time). I am getting that replaced and adjusting the idle tomorrow.

I need to find a known good ecu to try..im not sure if my used one is good.

Do not try someone elses ECU in your car. Take your ECU out and put it in their car. There is a posibility that your car could damage the ECU. If you think that the new ECU may be bad you may also want to pull it out and check for leaking caps.

[MrBaseball]

Unfortunately, the camshaft and rocker I replaced are damaged again and I also have 0 compression in cylinder 3. I don't know much about engines so im not sure what caused it. I need to figure out my options for getting the car running again..

I added pictures to first post.