Engine Troubleshooting





Manifold clearance

Computer Mounting on firewall

Jeep Mileage

Jeep distributor.

Jeep Mileage

I've put on 100's of miles

Double Clap Fuel lines

Double Clamps on Fuel pump outlet

Turned out, Yesterday, that my jeep quit on me. It had been giving me a few symptoms that seemed a little odd for a little while. The jeep began once in a while skipping cylendars a few weeks ago. I didn't think much of it since id had some not to good gas in there from the winter. So I was thinking, maybe with the heat out here (100F+) I was getting some vapor locking. Especially since the Jeep would run well, idle fine, in the morning when I'd first drive it, then later it would start skipping.

These past few weeks the skipping was getting worse, and I'd started thinking mmaybe fuel pump. but since it still ran I wasn't that worried.

So yesterday I drove it to work (I was planning on getting an Emissions Check later in the day) and it was fine when I drove it to lunch. but on the was back to work it was skipping. when I was leaving work it was really hard to start. it would turn over, but not catch. Finally it started up and ran rough, so I skipped the Emissins test and drove home. Once I was in the driveway it was a fight to keep it idleing, but it died and now won't start....

So I started thinking about what it's doing. Engines need 3 things to run, Fuel, Air and Spark. So remembering how the EFI system works, I turn the key and hear the Computer turn on the fuel pump, so I'm thinking it's not the Computer. Next I've checked the Schrader Valve on the EFI manifold, and there's Fuel there. That means likely fuel in the cylinders, Thus Fuel pump is likely okay.

The 4.0 Engines are notorious for having the Computer stop the Start Process if the engine isn't recieving a signal from the CPS. so I next checked the CPS, it appears to be close enough to the flywheel. But to double check, I went and bought another CPS to try it out, Unfortunately, this isn't the problem, still won't start.

So next I'll need to check the Spark, I pulled out a plug and grounded the outside where the wrench goes, and see if it sparks when I crank the engine. (Careful of spilled flamables, gas etc when doing this.)

-To Be continued ;-) Pictures coming soon.

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New Jeep Intake

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Remounted Fuel Sender

CPS mounting

Notated CPS