Roc87

Just finished an engine swap, Grounds are good, VATS is wired correctly, BUT, injectors 1,3,5,7 are not firing/pulsing. Starts right up, runs really rough since it's running on 4 cylinders. Is it a bad ECM? The donor car ran good before engine was pulled, don't think I dropped the ecm or had any static issues with it. Anything else to look at?

Zepher

iTrader: (1)

check your wiring and fuses. there is only one injector driver in the ECM so if half are firing, then it is a wiring issue, since I doub't all 4 injectors on one side would fail at teh same time.

Roc87

I'm really lost, I've checked all the wiring for the injectors, made sure I have power at the ecm where needed, made sure I have a good ground for all grounds. I replaced the ecm with a reman, didn't make a difference, then I tried a new ignition module and that didn't fix it either. I ohmed those 4 injectors, they all came out to 16.7, check continuity between injectors and ecm, that was fine.

EDIT: Would a bad pickup coil cause this? The distributor is VERY rusty around that area.

91GTABird

Thats about right.

Like Zephyr said, check the fuses.

On the fuse panel there is a bank1 injector and a bank2 injector fuse. It is fused as 2 banks but they are NOT fired as 2 banks. The are batch fire (fired all 8 at the same time) But if one bank fuse is blown or bad connection then it will cause the left/right bank to not fire. IIRC

If i remember, i will pull one bank fuse out tomarrow to see if i can duplicate this problem. I might be way off, but this all is to my knowledge. Its 10pm right now so itll have to wait till tomarrow. Just reply to this to remind me if you havent already checked this out.

Brian

thirdgen88

Yeah, a blown fuse on one of the banks will cause that... Like was said above, it has got to be a wiring problem since there is only one injector driver...

D's89IROCZ

Actually when I had one bad injecotor I had the same issue . One goes that whoel bank does.

Roc87

I'll double check the fuses, it's an add on fuse block (4 ign. & 3 constant)from Painless wiring since the harness/engine/ecm/tpi/trans is now in the '81 El Camino. I believe that I checked power to those two fuses that I wired them into, but I'll check again. I did check power to the injectors with the key on, but not running and there was around 13.2 volts to one side of the plug for the injector. I'm thinking it may be that even though I have continuity between the ecm and the injectors for the black/pink wire, it may be pinched or against something causing a constant ground. Thanks for the help.

jr. gearhead

put your meter across the injector itself. should jump around as you crank it. if constant at or near batt volts you have a wire grounded somewhere. if you have zero then it's a wire not connected somewhere. the injector should be plugged in for this test (puts a load on the circuit).

RednGold86Z

iTrader: (1)

Actually, if you have a hard time finding the fuse, just put a voltmeter on either side of the injector and ground the other probe (rather than both probes across the injector), and check for battery voltage with the key on, but engine off. If nothing, then keep searching for a blown fuse or broken wire on the power supply side. You've already checked the injector to ECU wire, so I'm sure you'll find the problem on the power supply side.