J-Body Automobiles Forum banner
1 - 16 of 16 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #1 · (Edited)
Changed ICM, coil packs, spark plugs, IAC valve, map sensor, crank positioning sensor, coolant temp sensor, fuel pump, and fuel filter. Still getting crank no start, or will start but die out immediately. Problem originally would only not start 15-20 mins after shutting it off while it’s hot but would start back up not a problem if waited for engine to be cold or if I started it again right after. Looking for what could be the most likely problem?
 

·
Registered
Joined
·
59 Posts
I had a similar problem, but it was the fuel pump. Maybe you just got a faulty new one?
I also had a weird starting running problem that turned out to be the knock sensor wire was almost broken in 2.
Check compression, fuel pressure at the rail, clean air filter, and for spark at the wires.
Or look at the MAF sensor.
Just spit balling here.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #3 ·
I had a similar problem, but it was the fuel pump. Maybe you just got a faulty new one?
I also had a weird starting running problem that turned out to be the knock sensor wire was almost broken in 2.
Check compression, fuel pressure at the rail, clean air filter, and for spark at the wires.
Or look at the MAF sensor.
Just spit balling here.
Thx for the response but the only thing I haven’t checked outta those is the compression but when it does start and run it runs decently nice so I didn’t think it was a problem with compression. Ended up checking the injectors with a multimeter and it does should 4 are bad so I’m gonna swap those out and hopefully she’s good after that.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #4 ·
Thx for the response but the only thing I haven’t checked outta those is the compression but when it does start and run it runs decently nice so I didn’t think it was a problem with compression. Ended up checking the injectors with a multimeter and it does should 4 are bad so I’m gonna swap those out and hopefully she’s good after that.
Also I tested new fuel pump before install
 

·
Premium Member
1988 Z24 Coupe 5spd, 1988 Wagon w/94 Auto Drivetrain, 1992 Z24 Convertible Auto, 1994 Z24 Coupe 5spd
Joined
·
2,712 Posts
Don't skimp on injector. I strongly suggest using Standard Motor Products FJ105 injectors.
You can normally buy a 6 pack set for a little less than buying them individually.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #6 ·
Don't skimp on injector. I strongly suggest using Standard Motor Products FJ105 injectors.
You can normally buy a 6 pack set for a little less than buying them individually.
Got injectors changed. Ran beautiful for a day. Now she doesn’t want to start again. Have good pressure at fuel rail, have spark, and changed out almost all sensors already. Anyone have a clue of what this could be?
 

·
Registered
Joined
·
59 Posts
Bad ECU?
I had to replace my 87 ECU before. Had a really weird running issue that I could not diagnose. Then I was checking connections under the dash and bumped the ECU and the problem went away. I bumped it again and it came back. Replaced the ECU and it went away for good.
 

·
Premium Member
1988 Z24 Coupe 5spd, 1988 Wagon w/94 Auto Drivetrain, 1992 Z24 Convertible Auto, 1994 Z24 Coupe 5spd
Joined
·
2,712 Posts
Call around some local garages, ones that have been around for a while. Asked them if they can scan OBD1. Quite possibly someone still has the capability to check it.

Here is the self check the MIL does in relation to the Run position of the key.
When you turn the key to Run, does the MIL flash on - off 1 time, then quickly comes on and stay on?

Key Run
MIL ON
MIL OFF
MIL ON, stays on until key turned off?
 

·
Registered
Joined
·
6 Posts
Having same issue, new fuel pump, filter. Plugs wires, alternator, coil packs and Ignition module, crank sensor. Car starts and idles but after a minute of driving, it quits like someone cut the power. Not sure where else to look. New ECU?
 

·
Premium Member
1988 Z24 Coupe 5spd, 1988 Wagon w/94 Auto Drivetrain, 1992 Z24 Convertible Auto, 1994 Z24 Coupe 5spd
Joined
·
2,712 Posts
That is known to happen if the ICM is going out. What brand ICM did you get? Do you have any old ones laying around you could try out?
 

·
Registered
Joined
·
6 Posts
That is known to happen if the ICM is going out. What brand ICM did you get? Do you have any old ones laying around you could try out?
Bought on Amazon. MAS is the brand. My mechanic said it started and was running on all cylinders. He took it up his driveway and just as he was about to drive off, it stalled. It has good fuel pressure but could it be the injectors?
 

·
Premium Member
1988 Z24 Coupe 5spd, 1988 Wagon w/94 Auto Drivetrain, 1992 Z24 Convertible Auto, 1994 Z24 Coupe 5spd
Joined
·
2,712 Posts
Yes, it could be injectors. They can cause the same type symptoms as a failing ICM.
You can check their resistance with a multimeter. They should be around 12.5 ohms.
You have to pull the plenum off to check them all. Just unplug them and test for resistance on the injectors contacts. If any of them are low, you should replace all of them, imo. You don't really have to, if you don't want to spend that much.

Write down the reading for each one and post your results.
 

·
Registered
Joined
·
6 Posts
Yes, it could be injectors. They can cause the same type symptoms as a failing ICM.
You can check their resistance with a multimeter. They should be around 12.5 ohms.
You have to pull the plenum off to check them all. Just unplug them and test for resistance on the injectors contacts. If any of them are low, you should replace all of them, imo. You don't really have to, if you don't want to spend that much.

Write down the reading for each one and post your results.
I will. Getting it back tomorrow.
 

·
Registered
Joined
·
6 Posts
Yes, it could be injectors. They can cause the same type symptoms as a failing ICM.
You can check their resistance with a multimeter. They should be around 12.5 ohms.
You have to pull the plenum off to check them all. Just unplug them and test for resistance on the injectors contacts. If any of them are low, you should replace all of them, imo. You don't really have to, if you don't want to spend that much.

Write down the reading for each one and post your results.
Ok, so I got to the injectors and here are the readings.
Front left to right 11.3, 8.7, 12.1
Rear left to right 12.2 8.1, 10.5

I think I found the problem. Now I just need to figure out how to install the new ones. I assume I unbolt the fuel rail to get access.
 

·
Registered
Joined
·
6 Posts
Also, should I replace anything else while I’m in there? TIA
so I dodged a bullet, noticed that part of the tip on one of the injectors broke off inside. I cut the magnet tip of one of those telescopic magnetic tools and jammed it up in a clear plastic tubing. Was fishing around and was about to give up when I heard a click, low and behold I got it. Waiting on the injectors to get in. Ordered from Amazon.

Automotive tire Motor vehicle Finger Automotive lighting Engineering
 
1 - 16 of 16 Posts
Top