Chrysler Repair/1994 LHS crank no start no spark
QUESTION: Hey Roland,
jumped both fuel pump relay and asd relay 30 to 87. car cranked did not start.
took out jumper wire on fuel relay left the asd jumped. i sprayed starting fluid into the air intake and car started for a few seconds.
i flipped the pdc box over and found that the wire from pcm number 51 goes to fuel pump relay in socket 85. then coming out of that same socket there is another blue and yellow wire that goes into the 85 socket in asd relay.
im totally stumped man, still no code on key flash, just the start and end 12/55
ANSWER: Hi Russell,
I would wonder if the fuel pump is working. Do you hear it run for a second when you turn the key to the 'run' position? And then have a helper try to start it while you listen at the tank to verify that the pump is running while you have the starter going.
[an error occurred while processing this directive]---------- FOLLOW-UP ----------
QUESTION: ill check the fuel pump, im pretty sure the last time i tried to jump it i didnt hear squat when i was listening at the gas cap.
how can i make sure the coil side of relay is working? i know i have switched power on 86 but what about 85. all i know is with test light clamp to positive then probe into socket 85 it lights then goes off when i turn key on. i think the shows that pcm is grounding it.
also discovering that the pcm goes into fuel relay not asd, if the pump is broken could that be the reason why relay isnt being energized.
can a bad ignition switch be at fault i noticed that my key sometimes has trouble turning in ignition.
ANSWER: Hi Russell,
I have a problem when you describe pins 85, 86 etc. because the wiring diagram doesn't show those on either the asd or the fuel pump relays. Rather the pins are A B C and D. I suspect the power box diagram shows those as well, no? I know they are shown on the relays but they are not shown that way on the wiring diagrams.
The ASD relay and the fuel pump relay are in parallel to one another, both being controlled by pin 51 of the pcm. So if the relays are OK and the pcm is happy with the signals it is getting from the crank and cam sensors that the engine is rotating and it closes both relays, then you should have power to the fuel pump, the spark coils, and the fuel injectors. But if you don't hear the fuel pump run for about 1 second when you turn the key to "run" the either the relay is bad (so listen to whether the relay clicks when you turn the key to run), of if it clicks then the fuel pump is bad. And the pump should run when you are cranking the engine. You have to have a helper to operate the key to do this.
I believe you said that with a squirt of starter fluid you got some combustion but never got that otherwise, which is why I suspect the fuel pump. Listen for it.
But way back you said that you didn't have spark (that is the 'subject of the question') but if that is the case why did you get some 'action' when you used the starter fluid?
---------- FOLLOW-UP ----------
QUESTION: I got it to start because I had relay jumped from 30 the constant power to 87 the one that goes to coil. Sorry I don't have abcd lol
Relay is good just checked it again so it's either the pump or wiring. Would a bad pump stop relays from energizing
No a bad pump won't stop the pump relay from closing. If you got the engine to run by jumping across the pump relay then the relay is either bad internally (makes click sound but doesn't actually closed points) or the circuit that actuates it isn't doing so (and that would be that wire from pin 51 of the PCM to the relay, which seems very unlikely).
If you got it to run with the asd connected that means that the PCM must be activating the asd and so too should that same wire activate the fuel pump. Now when you say 'run' do you mean just for a few seconds with the aid of starter fluid or do you mean it ran continuously?
If just for a moment and then died, it could either be the fuel pump or the pump relay, or lastly it may be that you do have asd and fuel pump relays working and that fuel pump is also working, but the mixture may be too lean because of the stuck ajar exhaust gas recirculation valve. So check out the stem of the egr valve by moving it with the tip of screw driver inserted in the slot of the stem to verify whether the internal spring-action is closing it to a dead stop or not. If not, then spray WD-40 on the stem where it enters the valve body and move the stem to loosen up the action.
At this point I am out of ideas, so I hope that your next follow-up will say that the problems you are having are resolved.