yet another "no start" thread..

i know i know.. lets beat this dead horse one more time.. heres the deal..
i picked up a 87 laredo a month ago knowing it had a few issues.. no big deal.
what i know about it..
previous owner did some clutch work, just putting that in here for an overview, it was a project truck so it wasnt driven for a while... he said one day he was running it in the driveway and came back outside and it was dead.....
dead = cranks strong no start
has good spark as near as i can tell by putting a spare plug in a plug wire and laying it on the head..
has fuel to the rail... pressure not checked with a guage
1 thing to note.. fuel pump comes on when key is turned.. it doesnt stop after a few seconds of running... it keeps going.. regulator issue? or is this normal? maybe not building enough pressure?
new CPS installed today
new MAP sensor installed today
tested TPS with a volt meter. results are right in line with the chiltons book and previous threads..
tommorow i will test the coil, inspect the C101 connection, and check the fusible links....
anything else? i think im headed in the right dirrection but we all need a lil encouragement.... if you see me advertising a D44 for sale you know ive lost my cool and given up...
thanks guys.....
mike

a couple more questions... what is a good way to clean the C101 connector... is corrosion the culprit when this connector acts up? and what "goop" is in it that i should seal it with?
how do i check the fusible links besides tugging on each end to se if its separated inside?

mike

i checked the coil today per my chiltons book.. that looks ok..

well.. i may have figured it out.. i swapped the ignition controller under the coil between my 2 87's and the "running" truck would not statrt.... so i get all happy thinkin i have the upper hand.. i put the "good " ICM in the "non starter" and ............... NOTHING!!!!!! F'in battery is dead!! magic jumper cables give it juice but turn the key and absolutley nothing happens.. it even shorts out the lights and clock...
starter fried?
or bad ignition switch?
thats about where i stopped cause we had a school thing going after dinner...
gonna hit D/C parts counter tommorow for a new starter maybe...
mike

On the fuel pump thing - you may wanna look at the fuel-pump relay -- the start-up timer is just that - a timer it's 100% an ECU controlled signal regardless of other input (Timer continually resets based on data from the injection buss - all inside the ECU...

... so if the pump isn't shutting off (and there's been no modifications to the circuit intentional or otherwise), then the ECU is either providing continuous drive to the relay or the relay has issues.

(fuel pump relay is the 2nd one working front to back in the cluster: O2 sensor heater relay, Fuel Pump Relay, Power Latch Relay, A/C Clutch relay)

i guess ill play it safe and get a new relay when i go see the parts guy today.. thanks for the feedback, every lil bit helps..
mike

well i thought i had it..... new starter went in and still wont start with the good ICM from the good truck.... and the good truck will only run with its own ICM in it.. the bad truck will sputter and try to start with starting fluid.. i dont understand why the ICM will not work in both trucks... does it make a difference that one is a 5 spd and the other is an automatic?
same question goes for the CPS i installed.. it was for an 89 with an automatic.. i replaced the fuel pump relay and the pump still runs....
am i looking at an ECM problem here?
i have not done anything with the C101 yet but that is next... i think i have covered everything i can think of and have gotten by searching the archives... what are the real chances that cutting out the C101 will make this go away? i dont want to do this but i will do it as a last resort before i scrap it for parts....
where do i go from here??
mike

It doesn't add up- the business about the fuel pump staying on. I would suspect the pressure regulator on the front of the fuel rail....but quit guessing on this one and put a pressure guage on the port on the fuel rail! It will either confirm or rule out fuel pressure as a possible (likely) source of the trouble. Another way-maybe swap the regulator from your other XJ and see what happens. 4xBob

looks like i get to buy a new tool .... i think thats one of the few redeeming factors this headache has going for it..... aside from having half the miles as my trail rig... and a D44...
mike

Hey, now I was looking a CPS on the Autozone sight, and they list two different parts numbers for my 87 MJ, and my 88 XJ. Both are 4.0l motors. A Wells SU3015 for the 87(it also asks if it was a high alltitude unit) and a Wells SU3228 for the 88. IT never asks about the tranny though.

You said you were getting a spark from the distributor right? I'm with 4xBob...think I'd take another look at the fuel pressure. (If you are getting a spark still)

i have spark... just not sure how strong... i picked up a fuel pressure tester last nite so thats getting checked this afternoon... it will run on starting fluid, i need to figure out which signal is not getting to the computer to fire the injectors...
thanx
mike

fuel pressure is fine.... with key on and pump running it holds 39 PSI and spikes to about 58 when the return is pinched... did i shoot myself in the foot by putting in an old but brand new CPS from my previous 89 XJ with an automatic?with this being a 5 spd is there a different unit for each tranny? i will talk to the parts counter tommorow..
as near as i can tell i have narrowed it down to the following....

the wrong CPS

bad C101 connector

bad ICM

bad ECM

they will be replaced or adjusted with a fine-point BFH in the order listed...

damn do i have patience or what???
mike