JeepingDan

What if you cycle the key on and off before you start it to build fuel pressure. Because mine does that once in a while. last week I actually had vapor lock on a hot day and it did the same thing you described. A couple years ago I was getting a interment bad signal to the fuel pump and it turned out a wire on the ballast resistor wasnt making a good contact. Hope this helps out.

sgt_why

Pulling my hair out now ... picked up a volt ohm meter for $20 at napa.

Unplugged my CPS (CKP) and measured for resistance (ohms) between the leads on the sensor.

It measures (1.) from A->B, A->C or B->C ... which implies 100% resistance (right?)

So I test the new one that just showed up ... it measures exactly the same.

I tried the suggestions on this site;
http://www.lunghd.com/Tech_Articles/...iagnostics.htm

... but it actually says for my HO motor (Jeep is 1992 HO 4.0L),it should be near 0hms from A->C ... which neither of these seem to be showing.

Am I testing this wrong?

I'm still getting spark, but can't hear the fuel pump coming on ...

And hesitating dropping the transmission and such, just to swap out the CPS/CKP sensor ... especially if that's not the issue.

Mechanic was trying to tell me maybe they used the wrong flywheel 4-5 years ago when the engine was rebuilt - but that makes no sense, as it was awesome up until maybe 6-9 months ago.

Of course, that was after wheeling all last summer....

sgt_why

Thanks for the picture, I wasn't sure where the ballast resistor even was located. The the resistor tests out fine, barely any resistance.

I've exhausted my chilton manual troubleshooting steps.

* checked the cables going into the Camshaft Position Sensor & Crankshaft Position sensor ... all check out.

However, was hopeful for a moment ... when I found that the CKP/CPS was missing a bolt and barely held on.

After replacing that, now I can hear the fuel pump engage when I turn on the ignition. However, still not starting.

Checked again and still getting spark; solid blue spark from coil wire, small orange spark from plug wires. So that suggests camshaft sensor working ok too.

All the electrical seems to be good, got spark and turns over ... and fuel pump is engaging now, but still not catching -- just turns over and over, etc...

I know the basic rule is gas / spark / air ... but honestly not sure what(or how) to test much more.

Went and ordered a Factory Service Manual for 1992 -- will see if its any help when it arrives.

Computer still spits out the same error codes, even after unplugging the battery for 10s or so. (listed earlier)

sgt_why

I tried testing the fuel pressure today and keep coming up with (0) ... the gauge doesn't even move.

But I can see some gas is making its way there and I hear the pump come on when I turn the key.

Maybe this gauge is worthless ... but it looks like the fuel pump isnt producing any fuel pressure.

I swapped out the fuel filter, but no change ... should I pull the tank and dismantle the pump?

or is there another sensor which might prevent pump from engaging ?

Metmknice

You should be able to remove the pump without dropping the tank.

sgt_why

This is frustrating and confusing ... I checked the engine codes again.

12 battery disconnect w/in last 50 starts
35 radiator fan relay
33 a/c clutch relay (doesnt have A/C)
11 ign. reference signal
55 * end code *

Could the (11) indicate the camshaft sensor ? I just replaced CPS (crankshaft sensor)

If it were faulty, would it cause fuel pump to not engage? (thought I read that somewhere)

Called around and nothing local ... will have to get it from a dealership.

Might try pulling a used one off a junker, to test it ...

Not sure there is any point in pulling fuel pump now.

Firestorm500

But putting it back in is a chore to nearly impossible without dropping the tank.

Metmknice

Did you test both the old and new CKP? Checked Pump relay?

Its not horrible, just takes some finess.

sgt_why

Tested old and new CKP ... old one was only held in with (1) bolt - and Pump wasn't coming on with the key.

After replacing it, now I can hear the pump coming on.

But no fuel pressure getting to the engine (or so it appears since no pressure on gauge) -- so I replaced the fuel filter. It had some gas in it.

I tested the plugs for the CKP and camshaft sensor as well ... both appear proper voltage (wiring plugs not sensors).

With code #11 -- I'm wondering if now the camshaft sensor (inside the distributor) is bad and stopping pump from producing pressure?!

Or somehow the line is plugged / kinked.

sgt_why

Before I dropped the tank and took out the pump -

I connected my fuel pressure gauge between the pump (out) and the fuel filter (in)...

and then I "hot wired" the pump, by jumping the fuel pump relay (top and bottom, center ones) ... pump ran for 30s and still -- no fuel pressure.

That tells me the problem is in the pump, right?!

BudgetXJ

Most likely yes

sobobajoe

mine 89 just started this problem today after alot of checking realized its the icm(igniyion control module)

redhandstudios

I second that, your symptoms sound like what happened to mine in 1999...and it was the CPS got shorted out.

red91

According to my chiltons that code 11; is camshaft signal or ignition signal - no reference signal detected during engine cranking. It also says else where that if the signal is lost the engine will run but won't start after it is shut off if it happens to get a good signal to the ECU it will start and run there is a pretty lengthy dianostic for it if you want I can scan it and post

sgt_why

My brother came over and we re-checked everything ... second set of eyes really helps.

He found the same thing -- good fuel pressure (now that I replaced the pump) but no spark.

We broke open the service manual and tested all the sensors / wire connectors for each ... and all checked out.

However, the computer still wasn't telling the coil to shoot a spark -- so we even swapped out the computer, but not difference. Still code #11

We got to reading about th CKP (CPS) Crankshaft Sensor. My original one was missing one of the (2) bolts that holds it in place. And it has special bolts which somehow hold it just right and make things "work".

And I had gotten a replaced bolt from NAPA, but it was too long so I had added a couple washers to even it out. On a hunch -- we pulled off the new sensor. Then pulled a bolt of the CPS on my brothers jeep -- and put back on the OLD CPS -- after cleaning it and smacking it around a bit.

With the old one back in place, with (2) proper bolts -- guess what, it fired right up!! I pulled out my brother bolt and used my "aftermarket" replacement -- without loosening the "good" bolt.

And still running great, yippee!

LESSON : Aftermarket (CKP)CPS is worthless, get an OEM replacement from dealer. And those bolts ARE special, don't substitute anything else.

Oh and its near impossible to "test" a CPS short of putting it in ... the directions say to test for resistance betwen left and top pins -- but my meter didn't budge off "1" ... both the new and old read the same way.

I came across some text which mentions this fact, something about a HALL generator or such ... so voltage jumps around (while its working), which means you need a analog VOM just to notice it.

P.S.
These engine codes went away, after I plugged in some extra relays to the fuse panel ...
35 radiator fan relay
33 a/c clutch relay (doesnt have A/C)

Which only left these;
12 ## battery disconnect
11 IGNITION
55 ## end

I'd recommend any who gets this error #11 -- check you crankshaft position sensor first!