black88ta

Hello everyone,
Lets get down to business.... I am having a problem with my 1988 T/A. The car is a 5.0 TBI, 5-spd with a Chip and 160 T-stat. It also has Edelbrock headers, Y-pipe, no smog pump, hollowed cat (don't tell ) and a Dynomax CVX Exhaust. Thats it for the motor. The other day I went to get the car ready for inspection and decided to clean up the engine compartment a little. I noticed there were some leaves that had been building up on the DS fender well, near the firewall and under the master cyl. I gently pulled as many out as I could and then shut the hood and went in the house.
The next morning I went out and tried to start the car to go to work, and it would crank, but wouldn't fire. I didn't have time to mess with it, so I left for work. I thought about it, I never heard the fuel pump prime. So I got home and played around with it...ran the codes and came up with a Code 32 and 54. I knew about the code 32, it always comes up, that is an EGR code, and that happened after the smog pump came off and the headers went on. The 54 was a new one, so I looked it up. I have both the firebird and camaro manuals... don't ask why, and here is what they had to say:

Haynes 82-92 Firebird Manual-
"Code 54 will set if the voltage at terminal B2 is less than 2-volts for 1.5 seconds since last reference pulse was recieved. Check the FP relay, circuit, and connections. Check the OP switch. Repair/Replace faulty components."

Haynes 82-92 Camaro Manual-
Code 54: Fuel Pump Circuit Defective Fuel pump; Defective FP relay; defective OP switch; poor electrical connection; open or short in circuit; defective ECM
(Haynes Camaro 82-92)


After further investigation, it turned out that the plastic casing around the wires to the FP relay had over time shrunk, and me pulling leaves out of the engine compartment disturbed the wires and made them touch, therefore shorting out the fuel pump relay.... and a fuse by the battery which goes to the ECM... and possibly the oil pressure switch.
I resorted to my Haynes manual... traced the wiring schematic for the FP circuit. I then tested the FP, and it will run with 12V power to the diag. port on the ALDL. Then I repaired the damaged wires and replaced the FP relay, a blown fuse, and the OP switch. Now... here is the fun part. The car still wont start... but it will.
The FP does not prime when I turn the ignition on, and when I crank the motor over, it won't start. However, when I crank it over, and stomp on the gas pedal (in desperation) it will fire up but the check engine light stays on. I ran the codes again, and it still pulls up the Code 54! When I shut the car off, the FP will run for about 1-2 seconds... weird huh?
Does anyone have any idea why this is happening, or what might be causing it? I am at the end of my rope here, and the next thing to try is to replace the ECM... that is why I am here. An ounce of prevention is worth a pound of cure. If I can get some other insight I would appreciate it. Thanks in advance!

badxs

you may have another short in the wire going to the fuel pump

1MEAN92RS

Yeah, I agree. There has to be a short in there somewhere. Unless you aren't getting code 12 3 times when you bridge the ALDL terminals your ECM should be okay. I have heard of them dying and still giving a code 12, but it's very rare.

Later,
Harry

black88ta

Hey guys,
Thanks for the help. I am not sure what could have caused this. I drove the car the night before and it was perfectly fine. I will look further into this. By the way, I cleared the codes on the ECM and all I get now is 12 & 54. Oh well... I can't complain. This car has over 176,000 on it, and has never had any MAJOR problems. This also is not my daily driver, so I can afford to spend the extra time in getting this fixed right.
If anyone else has any insight on this, please let me know.
Jason

badxs

you should run the 12 v to the pump and start the car and see how it runs then, you may have killed the fuel pump, ond the ecm too but this would give you a good idea of whats going on

black88ta

Hello:
In reference to the last suggestion... I did that and here is what happens.
I can run 12v power to the test port on the ALDL connector and the fuel pump will run. Once the power is applied, the car will start and run, but the check engine light stays on. I run the codes and come up with a 54 again.
So what is the deal? If I run 12v power to a wire on the relay, that comes from the ECM, I have a FP too. Its all too confusing. I am about $300 dollars short of taking it to a GM dealer and saying "I don't wan't it back until it runs right!" I have a feeling though it is something stupid.
Any other insights?
Jason
p.s. On a lighter note... I got the headlight motor rebuild kit from Top Down Solutions..... That is one kick *** little repair kit! My headlights work like new again!!!!!

badxs

run it directly to the pump and bypass all other possibilities

1MEAN92RS

Leave it to me to eat my words again. My '89 TBI 4.3 Jimmy just up and wouldn't start the other day. It kept blowing the ECM-B fuse (fuel pump relay). Traced all the wiring, it seemed fine. Replaced the relay, still kept blowing fuses. Replaced the tank and pump... still blew fuses. Replaced the 8062 ECM and BINGO!!! That was it, and it kept giving me code 12 the whole time Try replacing the ECM. I've bought several used 8062s and 8746s here lately for ~$30 each, so they aren't expensive at all. If nothing else, it's worth a shot!

Later,
Harry

black88ta

ok... now where can I get one of these bad boys? IMO, I think that the fuel signal is not getting from the ECM to the relay, and so forth.

"Code 54 will set if the voltage at terminal B2 is less than 2-volts for 1.5 seconds since last reference pulse was recieved.

Anyway... where do I get one? Third-gen resource never emailed me back with a price.
Jason

1MEAN92RS

First of all, try the stock chip. THis shouldn't have anything to do with your car not running, but hey it's worth a shot. Second, if that doesn't do it then you can look for an ECM. An '88 305 TBI should have the 1228063 ECM. Check around the local junkyards and Ebay. One will turn up and probably pretty cheap too considering the popularity of swapping out the 8063 for other ECMs like the 8746 (but that is a different road entirely). IMO, I would not pay more than $30-$35 dollars for it used. You can find remanufactured units at places like AutoZone and Advance for about $80 (less the core charge), but in all honesty I don't think it would be worth it... it's not even a sure fix at this point.

Later,
Harry

Charlo

Well thats easy to test. Disconnect the relay and hook up a test light to the relay trigger from the computer.(you might need a computer safe test light). Next disconnect the computer and supply the relay trigger with 12v to see if the pump primes. You could even take it a step further and check the relay trigger voltage from the computer. That should help narrow it down.

Charlo

Wilburwm

I'm having the exact same problem to a "T". Started with the wire insulation shrinking back quite a bit. I took readings at the relay harness with the car off and with it running (yes it will run without the relay). Off my readings were 12, 0, 0, 0, 0. On my readings were 12, 0, 0.6, 0, 12. That tells me that the ECM is not giving the relay what it needs to energize. The 0.6VDC is the trigger from the ECM. I think that with the wires shorting together like that, it killed that circuit in the ECM. Off to the bone yard tomarrow. I'll let you guys know what I can come up with.

Wilburwm

Couldn't find one anywhere. My ECM is #1228746. I found some similar, ubt no perfect matches.

Wilburwm

I put a ECM in it today. I was the same as mine (1228746). It was out of a 92 Camaro 5.0 TBI. Well, my fuel pump relay problem went away. She starts up like a champ, BUT now the SES light flashes really fast non-stop and she idles at 1500RPM. The guy I bought it from said to call him if I had any problems. Looks to me like he sells a lot of ECM's. I bought it on eBay. I'll let you guys know what he says and what the results are.

Trickster

Well you could check your wires at the fuel pump relay again to insure that they properly installed and that the connectors are not pushed out.

Pin "A" = Tan/White- fuel pump
Pin "B" = Black/White- ground
Pin "C" = Dark Green/White- ecm
Pin "D" = Red/Black- ALDL
Pin "E" = Orange- power

Trickster

Hello Black88ta,

I have just sent you a diagram that might help you.

BMmonteSS

Sounds like you guys have the same problem I had. There is a transistor on the ecm that kicks on the fuel pump. If there is a short in the system it has a tendency to kill that transistor or the trace going to it. My ecm had the trace burned through. Sounds like the new ecm fixed that problem....but the new ecm doesn't work, thats why it's flashing the check engine really fast. My guess is the chip is either loose or there isn't one in it. The ecm will still run your car but in limp home mode. thats why it idles high and if you try to drive it be prepared for a trip. If I burn a chip that doesn't quite burn right the check engine will go nuts like this. Thats why I'm thinking the chip is either loose or not in the ecm.