VTJeep

I don't personally. But my dad might. Im actually at there place now so I'll check. Thanks again.

VTJeep

lolz.. Thanks anyways!

C H E R O K E E 98XJ

I posted a few weeks back about having cold start issues. Jeep would stumble and sputter up to a start instead of just starting but, ran and drove fine after that. Long story short, I tracked it down to me running a different fuel. I thought I'd try 91 octane (because it didn't have any ethanol in it) and well after using up all that 91 I filled the Jeep back up with 87 (10% ethanol) and what do you know, back to normal and all is good.
Just thought I'd share that because I had a hard time believing that just a few more octane would do that. I think it maybe has something to do with the 4.0L's relatively low compression ratio and maybe spark plug gap? Any other ideas?

VTJeep

sounds like it was just struggling to compress the 91..

NewKindOfClown

I feel like I'm overlooking something really simple here.

Theoretically, why can't I jumpstart a jeep by putting the positive lead on the dead vehicle's starter terminal?

VTJeep

As in both batteries are grounded, so a jump wire for positive current should be enough?

NewKindOfClown

Good batt pos > Bad batt starter
Good batt ground > Bad batt chassis ground

Doove

How hard is it to install a crankshaft senor and a camshaft senor on an automatic 97 XJ? Dealership robbed me of $240 the just check it and wanted almost $900 to replace them. I just ordered the 2 and waiting to be delivered.

VTJeep

Times like this makes me sad I don't know electronics better.. Be curious to know the answer though..

ehall

you would still need power to the solenoid to move the starter gear into position

ehall

cam sensor is not hard if you don't pull the dist, still not hard if you do pull it but requires more work to reassemble, not necessary if you are able to work on the dist while its installed (not hard)

crank sensor requires about 3' of socket extenders, and some creative thinking

NewKindOfClown

Again, hypothetically, jump those terminals. It'd be easy to do.

I'm just trying to understand the fundamental flaw here.
Would it fail to start? If so, why?
Is it a bad idea because it would overtax the alternator?
Would it damage anything?

NewKindOfClown

Or small hands with nimble fingers, a 1/4" socket wrench with various combinations of swivels and extensions, and the right wrenches.

Either way will need a lot of patience.

ehall

There are multiple powered circuits: constant power (key off) for things like headlights and alarm, accessory power for things like radio, run power for injectors and spark, and ignition power for starter. If you just provided power to the starter there would be no power on the other circuits and the computer could not make the engine run.

The main power lead to the starter motor is on a bridged circuit that is closed by the starter solenoid. If you activated the solenoid, then the power from the jumper would pass through the bridge to the battery and provide power that could be used by the other circuits. However the key is still in the OFF position so the RUN circuit would still be inactive. As such the computer could not make the engine run, and thus it would not start

NewKindOfClown

Makes perfect sense, thank you