TBI... one injector works all the time and the other intermediate

[shotough]

i have an 89 k5 with a 350. I pulled a camper over the past weekend ran fine the trip out... but the trip back was a different story.. The truck will run perfectly normal for a minute and the next feel like it is starving itself of fuel. I put a new fuel filter in and still the same problem. Then i figured i would spay the injectors and that is when i noticed one of the two injectors was not working. one second it will and the next it wont. There are 4 wires, red, green, white, blue. The white and the red have 12 volts. green and blue noting.. I switched the two wires for injector to injector and that made the other side work.. So i think there is a wiring problem because i can force both injectors to work. Also when the one does work it dribbles and dosent seem to spray like it should.. Anyone else seem to have this problem.. Computer possibly? thanks

 

[NITRO]

First off, welcome to CK5 and please fill out your profile, maybe someone can help that lives close. second, you have already established it is an electrical error since switching the wires allows the other injector to fire. Try to trace those wires and make sure that one has not been split or burned or whatnot. I am not really good with fuel injection so maybe someone else can give you some more ideas. But there is somewhere for you to at least get a start.

NITRO

 

[HarryH3]

As you discovered, 2 of the 4 wires should have 12 volts on them any time the engine is running. The computer turns on the injectors by supplying the ground side of the circuit through the other 2 wires. Since you have already switched the wires and noted that the problem followed the wiring, then you have proven that the injectors are both good. This leaves either A) one of the wires is chafed or broken, as suggested above, or B) one of the circuits in the computer that fires the injectors is dying. /forums/images/graemlins/frown.gif

Check the wiring very carefully, check that the connectors at both ends are in good condition, check that the INJ fuses are plugged into the fuse box well, and use an ohm meter to check for continuity while moving the wiring harness around to check for an intermittent condition. If everything checks good there, then it's time to swap in another computer and see if the problem goes away. /forums/images/graemlins/frown.gif

 

[Thunder]

Yup. If all the wireing is Ok the ECM probabally has a bad injector driver.

 

[4xcrazy]

[ QUOTE ]
Yup. If all the wireing is Ok the ECM probabally has a bad injector driver.

[/ QUOTE ]

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