ECM Troubles
08-10-2015, 04:33 PM
#1
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Car: 1987 Camaro 1991 camaro rs
Engine: 305 and 350
Transmission: 700r4
ECM Troubles
So I just bought a 91 rs 305 tbi. First issue I have guy said injector don't fire so I got it home. And started testing with my test light. First I turned on key put light in terminal A it lights up on the first injector and terminal B has no light with positive or negative. And on the second injector same thing as the service book says I cranked engine light stays lit no plusing I then tested the 430 on my 4 plug no light but I hear a click like the fuel pump is coming on so I probed the B5 with a 12v no light then with a ground no light key still in the on I probe D14 and D16 key on and probe on a ground no light I sent a ground thro the B5 and tested the 430 with probe on a 12v source it lights up so wire isn't broke service book says its bad ecm , open or grounded 430 , or a open injector circuit idk where to go from her as the manual stops troubleshooting right there wat test should I do now engine runs with gas in the TB Vats is bypass by PO I'm kinda lost and I don't want to go carbed also injectors are bad tested with a 9v battery I'm going to get new ones
Last edited by Jae992; 08-10-2015 at 04:46 PM.
08-12-2015, 10:14 PM
#3
Re: ECM Troubles
So I just bought a 91 rs 305 tbi. First issue I have guy said injector don't fire so I got it home. And started testing with my test light. First I turned on key put light in terminal A it lights up on the first injector and terminal B has no light with positive or negative. And on the second injector same thing as the service book says I cranked engine light stays lit no plusing I then tested the 430 on my 4 plug no light but I hear a click like the fuel pump is coming on so I probed the B5 with a 12v no light then with a ground no light key still in the on I probe D14 and D16 key on and probe on a ground no light I sent a ground thro the B5 and tested the 430 with probe on a 12v source it lights up so wire isn't broke service book says its bad ecm , open or grounded 430 , or a open injector circuit idk where to go from her as the manual stops troubleshooting right there wat test should I do now engine runs with gas in the TB Vats is bypass by PO I'm kinda lost and I don't want to go carbed also injectors are bad tested with a 9v battery I'm going to get new ones
1. Are all your fuses good?
2. What service manual are you using? NOT the proper GM manual, I'm guessing.
3. If one of the options is "open or grounded 430", test 430 for being open or grounded. An ohmmeter connected across both ends of that circuit showing low resistance will tell you that it's not open. An ohmmeter connected across one end of the circuit and ground, showing an open circuit will prove that it's not grounded. The same goes for the "injector circuit". If they're concerned that it could be open, put an ohmmeter on it to find out.
Last edited by Schurkey; 08-12-2015 at 10:18 PM.
08-27-2015, 09:07 AM
#4
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Car: 91 Camaro RS
Engine: 305 TBI
Transmission: 700r4
Re: ECM Troubles
Start by having the ICM tested. Mine went bad on me about two months ago and it was the ICM not sending a signal to the ECM so the ECM wouldn't fire the injectors. Replaced the ICM and everything was kosher again.
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