Electrical Fun please help
Thread Starter
2nd Gear
Joined: Feb 2021
Posts: 2
Likes: 0
Electrical Fun please help
just put an 89 engine in an 85 that i bought with a seized engine
car wont start - injection bank one has ground on the power pin
injector bank 2 has power where its supposed to be but not get a pulse when cranking
I unplugged ecm to see if there's any change but nope
also no dash whatsoever but radio does work
car wont start - injection bank one has ground on the power pin
injector bank 2 has power where its supposed to be but not get a pulse when cranking
I unplugged ecm to see if there's any change but nope
also no dash whatsoever but radio does work
Racer
Joined: Feb 2020
Posts: 483
Likes: 109
From: Fairfax, Virginia
Couple of things to check,
Here's a brief diagnostic tree, the fastest test is to see if the ECM picks up RPM on the scanner.
- Verify you have 12V on both injector fuses and no continuity to ground, Continuity to ground indicates either a shorted injector or short in the harness.
- Verify all injectors are within 3 ohms of each other, and no lower than 10 ohms. An injector that reads lower than 10 ohms is effectively shorted and will take the bank out with it.
Here's a brief diagnostic tree, the fastest test is to see if the ECM picks up RPM on the scanner.
- If ECM reads RPM on scanner, ICM reference generator is functional, if it does not show RPM on scanner.
- Remove dizzy cap and rotor, do not disconnect the 3 pin connector or batt connector, measure voltage at ICM reference pin while cranking, voltage should flicker between 0V DC and some value over 1.5V DC. If there is no change either the ICM or pickup coil have failed. ICM is the more common failure, but it may prove helpful to replace both in the form of a new distributor. If scanner still shows no RPM
- Faulty reference signal cable, check for continuity from ICM 7 pin connector to ECM connector.
- No continuity, splice in new cable external to harness.
- Faulty reference signal cable, check for continuity from ICM 7 pin connector to ECM connector.
- Remove dizzy cap and rotor, do not disconnect the 3 pin connector or batt connector, measure voltage at ICM reference pin while cranking, voltage should flicker between 0V DC and some value over 1.5V DC. If there is no change either the ICM or pickup coil have failed. ICM is the more common failure, but it may prove helpful to replace both in the form of a new distributor. If scanner still shows no RPM
Last edited by ThatOneKid; Mar 24, 2021 at 11:10 AM.
