TennesseeT

Bought a 2000 Classic, 150k, California Car, very clean. It ran rough. Chrysler tech said it had a bad injector on number 2 and three bad injector plugs. I replaced all the injectors and the all injector plugs. Now it won't start, nothing. Cranks but it won't hit a lick. I was very carful in changing the plugs to insure the correct wire alignment. Cleaned the fuel rail and the head. Greased the O rings with Dielectric grease. The replacement process went as normal. Before I start over, any ideas? Thanks in advance.

agreen

Check for injector pulse. Use an LED test light or (as I like using, a logic probe)

Fuse 18 in the under hood fuse box is a 15a fuse that powers the injectors. That one might be blown.

Also, how did you make the connections? Twist and tape? Solder and heat shrink?

TennesseeT

Thanks for the reply. The plug wire were soldered and heat shrink and the full wire re-taped. I forgot to mention I checked the fuel rail and it had pressure. I'll check the fuse and the injector pulse and report back.

TennesseeT

Reporting Back: The issue with not firing on any cylinder was the new injector plugs. They came separate, wires and plugs. I had to press the wires into the plugs. In all of them the receivers on the end of the wires did not reach far enough into the plugs to make contact with the injector prongs. If I pushed the wires further in, the top of the plugs fell off. I got a new set of plugs and replaced the other new plugs and she started right up.

NOW, I'm back to the reason for changing the injectors and the injector plugs. Number 2 is not firing. I had her into my local Chrysler/Jeep dealer to ID the reason Number 2 was firing. They said, "Bad injector on Number 2, also bad Plug on Number 2, and possible bad plugs on Numbers 3, 5, and 6. To do the work and the parts they wanted a mere $1600.
After changing all the injectors and all the plugs...............Number 2 is still dead. I used an LED test light on Number 1 and Number 2. I got a constant light on the ground side of both, no difference.
At this point any advise d be greatly appreciated.

lawsoncl

At this point, I'd verify the wire is good all the way to the ECM connection. Then I'd suspect a blown driver in the ECM if you're not seeing it pulse the ground side of the injectors.

TennesseeT

.I tested Injector plugs 1 and 2 and got a constant light on the ground side of both, but not a pulse that I expected. I plan to trace the number 2 injector wires back to origin. let's see what that shows.

Thank you for your response

agreen

I have dealt with a Jeep wrangler with a bad ECU for this exact reason. I think his was #5, but same idea. The only thing you can do is check the wire for continuity or a short to ground with the ECU unplugged (you're on the right path). If the wire looks fine, looks like you're dealing with a bad ECU.

thelonejourney

$1600 to do this work???? What a rip off! For that amount of money you can replace the entire fuel system and still be under that amount! That's why I always work on my Jeep myself!

TennesseeT

Thank y'all very much for the responses.

Part of the reasoning for the $1600 repair bill was the cost of the one injector, $276.

Can someone explain why I get a constant positive, (led light on), on the negative side of the injector plugs and no light on the positive side. I expected a pulsing light on the positive side.

agreen

The injectors get 12v when in run, and the ECU pulses ground to them when the CPS senses engine rotation.

lawsoncl

I'm sure half of that was for Mopar parts with injectors at $150-$200 each. Versus a whole set of refurbished 4-hole Bosch for about $100.

For any Pre-91 Renix folks who stumble across this thread, lest you get confused, yours are the opposite with the injectors sharing a common ground and the engine computer driving the +12 side.

doublechaz

Local shop just quoted me $3500 to change three oil seals in a rear diff. Since I can do the work in about an hour with about $50 in parts I politely declined their offfer.

TennesseeT

[QUOTE=lawsoncl;3676053]I'm sure half of that was for Mopar parts with injectors at $150-$200 each. Versus a whole set of refurbished 4-hole Bosch for about $100.
The 4-hole Bosh is what I used.

TennesseeT

Update> The XJ is running just fine. The Bosh Injectors and the new, replaced the new, pigtails did the trick. I need to start a new post after I do due diligence and research on the XJ's next issue.

Thanks to all those how answered my call.

Jimbo Slice

Good work! This is an awesome community that has helped me a TON!