Need help - '88 died
Thread Starter
Burning Brakes
Joined: Aug 2002
Posts: 926
Likes: 2
From: chandler az
Need help - '88 died
Does any one in the metro Phoenix area have an ECM (engine computer) that I can test with. Went to start my car after cleaning out the radiator and the thing wont start and I smell gas.
I went ahead and changed the ignition control module since it was the original (and cheap) No go . I hooked up the timing light today and I am getting spark.
so I pull the cap off of the fuel rail and there is no pressure. I have my kid turn the key and i listen at the fuel tank. I hear the pump run.
So I pull off all of the fuel injector wires and it fires for about 30 sec.
I went and grabbed my multimeter and each bank has 6 volts at the injector. So my guess is that the ECM took a dump.
Autozone doesn't carry the computer in stock any more.
I went ahead and changed the ignition control module since it was the original (and cheap) No go . I hooked up the timing light today and I am getting spark.
so I pull the cap off of the fuel rail and there is no pressure. I have my kid turn the key and i listen at the fuel tank. I hear the pump run.
So I pull off all of the fuel injector wires and it fires for about 30 sec.
I went and grabbed my multimeter and each bank has 6 volts at the injector. So my guess is that the ECM took a dump.
Autozone doesn't carry the computer in stock any more.
Instructor
Joined: Sep 2005
Posts: 173
Likes: 0
From: St. Louis MO
I bought a replacement ECM for my 84 vette from advance auto parts just last week. They go by a differnt name in other areas, but they have a webpage at www.partsamerica.com.
It was only like 100.
If you are wanting to verify the ECM death, couldnt you just pull out the prom, if it doesnt give you a code 51, it would point at certain death of the ecm. However if it still gives you a code 51, it could still be bad I guess.
It was only like 100.
If you are wanting to verify the ECM death, couldnt you just pull out the prom, if it doesnt give you a code 51, it would point at certain death of the ecm. However if it still gives you a code 51, it could still be bad I guess.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
There are two injector drivers in the ECM; it's hard to believe that both failed at the same time.
Have you tested to see if you can still pull codes by jumpering A&B on the ALDL?
After you pulled the injector connectors did you recheck fuel pressure at the fuel rail?
If so, connect a test light in series with and injector does it glow when you try to start the engine?
Have you tested to see if you can still pull codes by jumpering A&B on the ALDL?
After you pulled the injector connectors did you recheck fuel pressure at the fuel rail?
If so, connect a test light in series with and injector does it glow when you try to start the engine?
Thread Starter
Burning Brakes
Joined: Aug 2002
Posts: 926
Likes: 2
From: chandler az
Doublecheck my sanity/troubleshooting here.
As I mentioned in the beginning = I removed and cleaned the radiator and replaced the cooling fan. There is nothing up front that is remotely involved with the injectors - except the cold start thermo switch connection.
I don't have a fuel pressure gauge - I should probably get one.
The injectors are activated by a switching ground against a fixed 12V right? I figured something let go in the ECM - I can't explain why I am seeing 6V instead of 12V or nothing.
As I mentioned in the beginning = I removed and cleaned the radiator and replaced the cooling fan. There is nothing up front that is remotely involved with the injectors - except the cold start thermo switch connection.
I don't have a fuel pressure gauge - I should probably get one.
The injectors are activated by a switching ground against a fixed 12V right? I figured something let go in the ECM - I can't explain why I am seeing 6V instead of 12V or nothing.
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Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
If you are familiar with changing memory in a computer it is the same thing. There are two levers on each side of the PROM. Press them down (open) and it ejects the PROM. It is keyed and will only install one way so you can't get it installed incorrectly.
Once you have the existing ECM out, and remove the cover for the PROM access, smell the insides and see if it smells like burnt silicone. You may have a component that is failing or has failed due to heat. It is a unmistakable scent.
Once you have the existing ECM out, and remove the cover for the PROM access, smell the insides and see if it smells like burnt silicone. You may have a component that is failing or has failed due to heat. It is a unmistakable scent.
Thread Starter
Burning Brakes
Joined: Aug 2002
Posts: 926
Likes: 2
From: chandler az
Napa carries the reman for $88 with a $106 core.
The change out will be easy - I have had the computer out a couple of times in the past - once for the heater door motor - and once for the heater core.
Thanks!
The change out will be easy - I have had the computer out a couple of times in the past - once for the heater door motor - and once for the heater core.
Thanks!
Thread Starter
Burning Brakes
Joined: Aug 2002
Posts: 926
Likes: 2
From: chandler az
Fixed - Sort of
So - I get the new(reman) computer from NAPA and put it in. The car fires right up. I dont know if it even made one revolution before it started. So I take it out for a drive and about 5 min into the drive - I go to stop at a light and it starts running rough and dies.
So I start it again and Hi tail it back to my house. I get out of the car and there is water pi$$ing out all over the driveway. The stupid waterpump decided to take a dump. Water is running out of the weep hole not just dripping but running.
Anybody done a water pump on an L98 lately? It looks like all of the accessories on the passenger side of the engine have to be removed.
So I start it again and Hi tail it back to my house. I get out of the car and there is water pi$$ing out all over the driveway. The stupid waterpump decided to take a dump. Water is running out of the weep hole not just dripping but running.
Anybody done a water pump on an L98 lately? It looks like all of the accessories on the passenger side of the engine have to be removed.
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
Sorry I feel for you, I went through one of those cascading series of problems a few weeks ago. It lasted like two weeks. Well look at the good side, it's not an LT1 so you didn't trash an opti-spark.
