Where is the ICM located on a 93 Firebird
12-09-2011, 01:30 PM
#1
On The Tree
Thread Starter
Join Date: Nov 2010
Posts: 101
Likes: 0
Received 0 Likes
on
0 Posts
Where is the ICM located on a 93 Firebird I have a 93 Formula with a LT1 and have been getting this spitting and misfiring. I was thinking a optispark, but was just told a possible ICM. Where is it located and can it be tested.
12-09-2011, 01:35 PM
#2
TECH Fanatic
iTrader: (11)
Join Date: Sep 2005
Location: fort walton beach,fl
Posts: 1,954
Likes: 0
Received 0 Likes
on
0 Posts
Directly above the IGN coil, on the same bracket bolted to the driverside head, yes a competent auto parts house can test it, make sure they do it 3x back to back..
Worn wires or old missgapped plugs will cause a miss . Here's a icm cooling mod
http://shbox.com/1/4th_gen_tech2.html#ICM_cooling
Worn wires or old missgapped plugs will cause a miss . Here's a icm cooling mod
http://shbox.com/1/4th_gen_tech2.html#ICM_cooling
12-10-2011, 08:27 AM
#5
TECH Veteran
Could be, but it could also be a number of things. There just isn't enough diagnostic information presented to know. If you have not done any basic tune-up maintenance in a while, I would start with plugs and plug wires.
Trending Topics
12-12-2011, 01:01 PM
#8
On The Tree
Thread Starter
Join Date: Nov 2010
Posts: 101
Likes: 0
Received 0 Likes
on
0 Posts
Well I just replaced the ICM, and it is doing the same thing. Is the ICM supposed to get real hot. The new one I put one was too hot to touch after 20 mts of driving and it was not bolted to the head. I guess I am going to check the fuel pressure now also. Any other ideas.
12-12-2011, 01:03 PM
#9
On The Tree
Thread Starter
Join Date: Nov 2010
Posts: 101
Likes: 0
Received 0 Likes
on
0 Posts
And I was wrong about where it was breaking up, normal driving is ok, as soon as I give it more gas it is like knocking(kinda like a lean knock) and as soon as I get off the gas a little it is fine. Now when I am driving normal and just floor it, it stumbles gives it that knock and then takes off.
12-12-2011, 05:50 PM
#10
On The Tree
Thread Starter
Join Date: Nov 2010
Posts: 101
Likes: 0
Received 0 Likes
on
0 Posts
UPDATE- I had it by a friend who is a mechanic and we tested the fuel pressure and it was ok, then we started looking into other things. He looked into his mechanics database and it came back possibly a EGR, we tested it and it had no vacum. We put a new one on and the same thing. While it was cold, it ran fine then 5 mts of driving and the spark knock came back at the same exact part of throttle. I took the car then he told me he wants to hook it up to the scanner and check O2 sensors, but otherwise it might be leaning to a Optispark. Any ideas here guys.
12-12-2011, 06:13 PM
#11
TECH Fanatic
iTrader: (11)
Join Date: Sep 2005
Location: fort walton beach,fl
Posts: 1,954
Likes: 0
Received 0 Likes
on
0 Posts
Make sure you put new heatsink compound under/ on the back of that icm, you may gave to go to a computer repair shop or radio shack to get some locally, search your wiring for shorts! Check where the wires go to the connectors for shorts, remove and check your opti harness for corrosion , replace the coil,I suggest the MSD unit available from any auto parts house if ordered.. I had a simular issue when the coil was bad, then again when the opti rotor screws came loose. Do also check to see that the o2's are quickly jumping around in measurements.
02-14-2012, 07:26 PM
#13
On The Tree
Thread Starter
Join Date: Nov 2010
Posts: 101
Likes: 0
Received 0 Likes
on
0 Posts
Ok sorry to bring up a old thread. The car was running fine after I changed the cat, but I went to move the car the other day and the problem is back. It ran fine for a couple of weeks and then I stopped driving it. What should I start with now.
03-06-2013, 10:46 AM
#14
Teching In
Join Date: Jan 2013
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
You changed the catalytic converter? 
