86 IROCZ28

Okay here is my story. Have an 86IROC with a 305 TPI 700R4 all stock. Car was converted to MAP but was not done properly. I had to get a new computer 730 ECM, knock sensor, rewired the car to MAP. Before I started this conversion the car started perfectly, it was always running in open loop so I decided to fix the problem. After I installed everything and changed some eprom settings like VATS disable and MAG VSS. I finally try to start the car.

The car cranks starts for about a sec then immediatley shuts off. Then I try again and it will just crank and that is all. Leave it for 1hr try again will start for 1 sec an dshut off then just cranks and no effort to start. What happens is my SES light keeps on flashing when I have my key turned to on. It flashes once every 4 seconds and there is a clicking noise coming from the engine. I traced the clicking noise to a black part just behind the alternator (looking at car from front it is on the left hand side) the clicking noise then can also be felt going into what looks like a relay mounted very close to the radiator. It has 4 wires going to it one is quite a big black chunky one, but that one is cut and does not lead anywhere. The clicking noise will not go away no matter how long I leave it. Sometimes it will click irregular but 95% of the time will click once every 4 seconds. Th eblack part behind the alternator has about 3 hoses coming into it and one steel pipe. There are also 2 connectors attached to it and they both have 3 or 4 wires each connected to it.

Seems like the fuel is being shut off but I do not know why! The car has been standing for 1.5 months. Fuel pump works fine I can hear it perfectly.

Anyone have any ideas??

Vader

86,

The "black chunky part" might be the AIR diverter/dump valve assembly. There are vacuum solenoids on the assembly that are probably getting signalled by the ECM to operate. This should not be occurring.



Unfortunately, it sounds as if something is wired incorrectly or the ECM is not functioning. The MIL lamp should not be flashing with the ignition turned on. What SHOULD occur is that as soon as you turn on the ignition, the MIL lamp will turn on briefly, turn off, then turn on and remain on until the engine is started. The flashing MIL means the ECM did not pass the power-up self diagnostic and will probably not run the engine.

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Later,
Vader
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"Let the bodies hit the floor!"
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[This message has been edited by Vader (edited May 28, 2001).]

86 IROCZ28

Vader, thanks for the reply. I double checked every single wire going into the ECM if they are in correct order. They turned out to be all okay. I turned the key on and it started clicking again coming from the relay I mentioned. I also found the relay connected to the purge canister or what ever the name of it is (on the left hand side of the car at the front. The connector on that was hot too and it was also clicking. Then for no reason it stopped clicking. I jumped in the car and tried to start. It took a while to start but it did. Let it idle for 5 mins and then it all of a sudden just died and the clicking was back again! Could not start the car either after that once the clicking began. I cant get any codes out of the car either once it is clicking. When it stopped clicking I jumped A and B on the ALDL and all I got was code 12. I also noticed when the car was started that the SES light was on all the time, that should not be happening.

But the looks of it, it looks like there might be a bad connection at the ECM and this causing the relays to play up. That is all it can be really, because for no reason it starts and stops clicking at any given time. When it stopped clicking I tried playing with the ECM and it came back again. Maybe it was coincidence or maybe the fault lies there. It is a PITA removing those wires from the connectors but I'll have to check them out.

All least I got it started today but the SES light was on all the time which is not good either and I did not get any codes after that either.

Might be getting closer to solving the problem

86 IROCZ28

Well turns out to be a faulty ECM. And this one is a remanufactured unit that I bought of ebay. Not an old on either. Well at least the guy will send me a replacement, so I am lucky in one way.

Cheers,
Mike