I just converted my TBI car to TPI and went to start the engine and the injectors hung open and just dumped fuel into the cyls. I have a new GM harness so i shouldnt have wiring probs. I checked the fuel pump relay and it clicks off a few secs after the key is turned on so it is not stuck open (even tho that still wouldnt explain the injectors being ground open). I tried to put a scanner and there was no data at the ALDL. So im going to replace the ECM and try that. Anyone have any other suggestions of what it might could be. Thanks in advance.

 

91,

Welcome!

Check back after replacing the ECM. The injector wiring is either grounded (which shouldn't cause any ECM damage) or the ECM is constantly grounding the injector return wiring.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

I remember someone here had a similar problem make sure there aren't any bare, grounded wires around the injectors. Becuase like vader said the ecm fires the injectors by grounding them so if you have acidently ground them they wil stay open.

 

Well the new computer fixed that problem. And it runs GREAT. But now i have a whole new set of problems. I have no data at the ALDL, the speedo doesnt work, and the tach seems to be 1000rpm off (too high). I can jump the AB terms at the ALDL and get a code 12 on the dash which the books say the prob is either the PROM or the ECM. Ive tried 2 PROMS and 3 ECMs and still no fix. That is the issue im most concerned with.

 

Welcome aboard,

I'm not sure about the speedo and tach but the code 12 you get is what is supposed to happen when you get your codes, it is always letting you know your getting codes by showing a 12 3 times then your other codes after.

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1989 Trans Am GTA, 5.7L TPI, TH700-R4, T-Tops, dual cats, 9-bolt rear, 3.27, Dynomax muffler, K&N
1992 Camaro RS, 5.0L TBI, T-5, T-Tops, 3.08, L69 Dual Snorkel, K&N - Sold

Theme song for my GTA Cake - The Distance