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View Full Version : Misfires at cruise, short video and a log attached


Jungy
09-20-2010, 06:56 PM
I'm still getting really bad misfires and hesitation under 3k rpm and need help figuring out what the problem is because I've done 3 weeks of trouble shooting so far. This is what I've done so far to no avail:

replaced plugs
replaced wires
swapped out coils
swapped out ign transistors
ran the car in both SD and w/ a 2g maf
added grounds from the neg batt terminal to the sensor grounds and block
Swapped out CAS'
ensured base timing was correct and also that the CAS wasn't 180 out
checked 6 bolt swap wiring
checked all injectors at idle

http://www.youtube.com/watch?v=Icp39MZ5RO4

CarPsyco84
09-23-2010, 05:12 PM
What injectors you run? I have 1600 bosch's and well, they do that, cause of the super non linear fuel delivery below 2ms pulse width.

Jungy
09-24-2010, 11:00 AM
I'm running Bosch 1600's and was recommended to try stockers but I don't have stock injectors to test with, I forgot to mention that I'm running e85, but I tried lowering the base fuel press to 30 psi to get my injector pulsewidths up and still the same issue. I also checked my mechanical timing and everything is in correct. Do you think it could still be injectors? Any other suggestions?

desolate
09-24-2010, 11:27 AM
That doesn't look like an injector issue. It looks like a spark/fuel issue.

CarPsyco84
09-28-2010, 03:13 PM
Does your tach jump around or smooth?

Matt D.
09-28-2010, 03:20 PM
Sounds exactly like my car when it's cold. Is this how it always is?

CarPsyco84
09-28-2010, 03:31 PM
I have some stock injectors you can test with, Its got to be something with your injectors, sounds like one wants to stay closed... These injectors were designed for LPG you know, no surprises it doesn't work perfect.

Jungy
10-10-2010, 05:11 PM
Tested the CAS wiring
Checked the wb wiring to ECU
Gapped the plugs countless different ways
Tried another ecu
Rewired the power transistor and grounded to the batt neg
Rewired the coil

What I noticed are the symptoms were a lot worse when the car has been running for a short period of time and get a lot better when the car had ran for a while. Now the car will barely start and die right away, backfire really loud when forced to stay running by giving it some throttle, and the tach is all over the place jumping around. I ran new wires from the ecu to the PT, bypassed the engine speed connector and wired the PT directly to the coil, added a new ground wire from the PT to the battery ground, and ran new 12v wires to the PT and coil. Everything was wired with new wires and soldered connections and properly taped. Could I have killed my PT?

Jungy
10-12-2010, 08:10 AM
Car wont even start now and nothing has changed. Ordered up a new PT and also found out i need a new CLT sensor cuz link is getting no temp readings from it. I'm honestly debating throwing in a CDI and going COP and eliminating the PT and firing the CDI directly from the ecu.