QuestionQUESTION: Hello Roland, and thanks for your time in advace.
fI have a 1991 5th ave 3.3L(R) 190k miles that just all of a sudden died. I checked spark at plugs, seems fine. Problem is, no fuel pressue. Checked fuel pump connection with volmeter, no voltage, and no pressure at fuel rail. Replaced fuel pump relay, and checked fuse. Cam/Crank/charge/map sensor were replaced OEM mopar about 14 months ago. Replaced fuel pump, even though it didnt have voltage...and obviously it didnt fix it. If this was a faulty crank/cam sensor, wouldnt it not have spark either?
Any suggestion greatly appreciated. Im agonizing over this one.
Thanks Again,
Chris
ANSWER: Hi Chris,
If you have spark you should have fuel pump voltage supply. I had a similar question this weekend on the same vehicle. There is a 10-pin disconnect (black in color) that is located on the steering column pencil brace. One of the wires there is dark green/black and that wire goes to the fuel pump and comes from the same voltage supply as the injectors and the spark coil which is the auto shutdown relay. So maybe that disconnect is separated, or the wire is damaged along its path under the dash. Check it to see if it is carrying 12V when you crank the engine.
Roland
PS If this is a rear wheel drive model then the above may not be correct as it would have a different wiring diagram set that I don't have.
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QUESTION: Thanks for your reply, just one more thing I forgot to mention. I never noticed this and not sure if it is related, but the cooling fan comes on and stays on with the key in the on position. Never remember it doing that. Think there could be a connection? Will try the other test in the morning.
Thanks again,
Chris
ANSWER: That probably means that there is a false coolant temp sensor on the engine, at the thermostat housing, or something else having to do with its wiring. It could, if that were true, make for a poor mixture and a no start for that reason, but I don't see a tie to the fuel pump not powering up.
PS: Please 'rate' this or the earlier answer. Where you find the question about 'volunteer of the month' consider giving a 'yes' answer if my responses have been useful. Thanks
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QUESTION: Roland, think I found it. Its up on the steering column by the high beam handle/switch, 14ga wire. It does not have 10v. It also seems to be fine going back through the dash.
AnswerI assume you mean no 12v, when you are cranking it over. If you are getting spark action when cranking over, which comes off the same splice, then there must be a disconnect of the wire that goes to the fuel pump at that splice. Other than the general location of the splice I can't tell you where to find it. The solution will be to run a wire from the ASD to the connecter you now have found, or find the splice and figure out what is wrong inside of it that the fuel pump branch is not also getting its 12v supply.
Just to be sure you might want to check that you have continuity from the disconnect to the fuel pump plug.
