2G Need help with diagnosis. Probably something simple but who knows.

[Nick456]

Cruising down the highway today when i noticed my car started misfiring. Pulled off the highway and car died on the on ramp. Tried to start it to get it a few feet to a better spot. Checked codes in link and had an 0300 for a random misfire. Wouldnt crank over and sounded like the starter was working extra hard trying to get the motor going. It would try to start but would only idle at like 500 rpms if that while misfiring for maybe a second and die, never fully getting started. Sat around for maybe 30-60 mins while talking with AAA and what not and tried to start car again. It starts now but idles fairly rough but throws no codes. Just a quick opinion from a local DSMer but was told it doesnt sound mechanical and more like a sensor. Ill be doing a compression test in the morning and looking over as much as I can figure out to look at but would really appreciate some places to look or things to check.

 

[motomattx]

Might have jumped a tooth on cam timing.

 

[Nick456]

Timing looks fine. Just checked that

 

[steve]

Post a log please.

 

[chrysler kid]

Boost leak

 

[Nick456]

So I did a boost leak test and no leaks. I can get it to start but its really rough. When i turn off cylinder 1 injector my car dies. When i turn off 2 or 3 nothing happens, but when i turn off 4 it dies. Im thinking coil pack?

 

[steve]

Im thinking coil pack?

Easy to test. Get out your meter and see if the coil for 2&3 is getting 12v and that the Power Transistor is pulling it's side of the coil low.

 

[Nick456]

Replaced both coil packs and no luck. Also replaced the ICM thats just to the left of the coil packs. Still nothing

 

[Nick456]

Here is a log after I replaced the coil packs and the ICM

 

[Brembo]

I would first start with checking things first before replacing parts. Now I don't have a clear visual in my head of a 2g since I had mine like more then 10 years ago but I will tell you this. First I would do a simple test on injector pulse width with noid lights. Then I would check spark like with one of those spark testers. Possible would pull the plug one by one and test to see if they are firing. You need to ground them if you will go that route. Also I would try to see if your rpm signal looks ok and cam and crank are in sync. Possible check wave form on crank sensor. Doing simple compression test would tell if you compression is good and possible confirm that your valve timing is good. Testing for 5 volt reference and testing for power and ground is also quick and easy. Test fuel pressure. Their has to be something what you are loosing. By doing some test you will find what system is not working correctly. Also if you have cats make sure their not clogged. I believe 2g has map sensor then try running it with mass disconnected. Also coolant temp sensor has to work properly.

 

[Brembo]

I just re read the previous post and you say that when you disconnect cylinder 2 and 3 the car has no affect and when you pull 1 and 4 it dies. That's some information. I would think cylinder 1 and 4 are ok or partly ok and cylinder 2 and 3 are not working good. I would do all of the above in a logical order and try to rule out what is good as you go. Also what they share like coils/injector powers/injector grounds/egr, pretty much anything that they are sharing. This should take no more than an hour to at least tell where the problem is. Fuel/spark/engine internals. Good luck and post back with info what it was.

 

[smbgsx]

Brembo is thinking like a technician.

 

[Nick456]

Thanks everyone and thank you brembo. Ill get back to you when im able to do more diagnosis is a couple days.