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Fuel injector harness poblems?

Superhonky74

NAXJA Forum User
Location
Arizona
I have an 87' XJ that wants to stall out on me and sometimes not even start at all. I have replaced the O2 censor and that had no effect. When I try to start the Jeep, and it does not fire up, I have to wiggle and twist the injectors. Once I have twisted each injector back and forth, the jeep fires right up. I think it has something to do with the harness but I called the dealership and they don't even offer it anymore. What can I do? Oh yeah, it has the 4.0L.
 
Did you disconnect the injector and check the condition of the connections? If there is some corrosion on the connectors, you moving them around some may be clearing it up enough to get good contact. Also look at the wiring harness side of the injectors and make sure there are no broken wires. While it is discinnected, check the condition of the little connectors inside the harness. These may be spreading out and loosing the connection there too.

Just something to look at and maybe rule out as the culprit.;

chris
 
Check the connection for the crankshaft position sensor, if I remember correctly, the plug is at the end of the FI harness, rear of the engine. That's where the problem on my '87 was when it was having a no-start problem. If that is the problem the dealer sells a kit with a new CPS and a new harness that wires the sensor directly into the connector of the computer. Anyway, that's what fixed mine. Btw..twisting and wiggling the injecters sounds like a way to start a fuel leak! : )
 
Thanks for the responses! No, I haven't had a chance to really dig into the harness yet. I am hoping that I can accomplish that this weekend.
I'll see what I can find and reply with an update. Thanks again.
 
The wifes 87 had a broken wire under the insulation by the bend at the rear of the fuel rail. I´d wiggle the harness and it would start. The fatigued wire was hard to find, I finally felt it, while squeezing the wires. There is a TSB for this somehwere, though I haven´t seen it in years.
I´m pretty sure the grounds for the injectors, end up at the same spot as the ECU and TCU, the ground strap at the dipstick holder.
 
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