Bad ICM?Starts when cold, runs great, dies
10-07-2013, 06:27 PM
#16
Registered User
Thread Starter
Join Date: Mar 2012
Location: Phoenix, AZ
Posts: 42
Re: Bad ICM?Starts when cold, runs great, dies
I'd like to check it, but I can't even afford the deposit right now to borrow the gauges from the parts store.
New fuel pump, authentic walbro. Pressure was checked out great. Harness was soldered by a pro, with the best heat shrink tubing on the market. Can hear pump priming. New FPR. I do notice that sometimes the pump primes a little longer than usual. A buddy said that the relay could be getting too hot? Is there a relay that I can swap out to check it?
New fuel pump, authentic walbro. Pressure was checked out great. Harness was soldered by a pro, with the best heat shrink tubing on the market. Can hear pump priming. New FPR. I do notice that sometimes the pump primes a little longer than usual. A buddy said that the relay could be getting too hot? Is there a relay that I can swap out to check it?
10-08-2013, 06:15 PM
#18
Registered User
Thread Starter
Join Date: Mar 2012
Location: Phoenix, AZ
Posts: 42
Re: Bad ICM?Starts when cold, runs great, dies
I got it to start and run again. About to test the fuel pressure and swap the fuel pump relay.
Here are the data logs.
( much thanks for the help so far, very appreciative)
https://www.dropbox.com/s/5yqk3glpw75m77w/camaro.csv
https://www.dropbox.com/s/swqp5wg7m7h2yq2/camaro.uni
https://www.dropbox.com/s/xnbyaust20fowli/camaro3.uni
Here are the data logs.
( much thanks for the help so far, very appreciative)
https://www.dropbox.com/s/5yqk3glpw75m77w/camaro.csv
https://www.dropbox.com/s/swqp5wg7m7h2yq2/camaro.uni
https://www.dropbox.com/s/xnbyaust20fowli/camaro3.uni
10-08-2013, 06:43 PM
#19
Registered User
Thread Starter
Join Date: Mar 2012
Location: Phoenix, AZ
Posts: 42
Re: Bad ICM?Starts when cold, runs great, dies
Just tested fuel pressure. Weirdness. Primes all the way to 55psi, then slowly drops off. At idle, pressure stay at a steady 49psi. When revving, the pressure doesn't hardly go anywhere.
10-08-2013, 07:01 PM
#20
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,650
Re: Bad ICM?Starts when cold, runs great, dies
Stock fuel pressure regulator??
Pressures are too high and out of spec. When you open the throttle the pressure should initially rise as vacuum drops.
Pressures are too high and out of spec. When you open the throttle the pressure should initially rise as vacuum drops.
10-08-2013, 07:06 PM
#21
Registered User
Thread Starter
Join Date: Mar 2012
Location: Phoenix, AZ
Posts: 42
Re: Bad ICM?Starts when cold, runs great, dies
Not a stock, BWD - Cheapo. Just change it out last winter. No fuel coming from the vacuum line. Was going to pull the vacuum line while running the engine and check that out, but it wouldn't start ( waiting a little bit).
Thanks again for the prompt reply!
Thanks again for the prompt reply!
10-09-2013, 08:45 PM
#25
Registered User
Thread Starter
Join Date: Mar 2012
Location: Phoenix, AZ
Posts: 42
Re: Bad ICM?Starts when cold, runs great, dies
I was wondering, if the optical sensor in the opti is bad, will it always throw a code?
* A note* Started it yesterday, ran it, let it idle. It revved up a little bit on its own.
Picking up a multimeter tonight to check the harnesses.
* A note* Started it yesterday, ran it, let it idle. It revved up a little bit on its own.
Picking up a multimeter tonight to check the harnesses.
10-09-2013, 10:58 PM
#26
Registered User
Thread Starter
Join Date: Mar 2012
Location: Phoenix, AZ
Posts: 42
Re: Bad ICM?Starts when cold, runs great, dies
Checked ICM terminals A ( Pink / black) and D ( White / Black) A= .13 DCV D= .10 DCV
Also checked Terminal B ( white) while cranking B= 2.9+= ACV ( fine)
Sounds like an ICM harness??, it does look a little crusty. Anybody run into this issue before?
Also checked Terminal B ( white) while cranking B= 2.9+= ACV ( fine)
Sounds like an ICM harness??, it does look a little crusty. Anybody run into this issue before?
10-10-2013, 06:20 PM
#27
Registered User
Thread Starter
Join Date: Mar 2012
Location: Phoenix, AZ
Posts: 42
Re: Bad ICM?Starts when cold, runs great, dies
The ignition fuse blew. Wire are now reading at a correct voltage. I guess that leaves the wonderful optispark. I just wish it threw a code for certainty. Failing optical cam sensor not throwing a code? Anybody?
10-10-2013, 11:18 PM
#29
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,650
Re: Bad ICM?Starts when cold, runs great, dies
If the optical sensor signals are not getting to the PCM you will get codes for the low resolution pulse signal and/or the high resolution pulse signal. If you are getting the correct voltage on the white wire to the ICM the PCM is receiving at least the low resolution signal which is all it needs to run the engine.
10-11-2013, 04:27 PM
#30
Registered User
Thread Starter
Join Date: Mar 2012
Location: Phoenix, AZ
Posts: 42
Re: Bad ICM?Starts when cold, runs great, dies
Thank you Injuneer for the info!
Now the hunt is on for the best priced / quality opti. I found a Delphi on eBay for $395. Also was thinking about that Summit opti, just didn't know what to expect as far as quality.
Now the hunt is on for the best priced / quality opti. I found a Delphi on eBay for $395. Also was thinking about that Summit opti, just didn't know what to expect as far as quality.