Hi Guys,
To start, I have read several threads on here related to poor/intermittent starting, as well as RPMs dropping to zero while driving. It all seems to lead to EFI circuit being compromised.
Symptoms: No CEL when key turned to on and no spark, starter would crank perfectly when turning key to start.
First thought: just replace the EFI relay/fuse, since jiggling the relay seemed to temporarily improve the chances of starting. This seems to have been just coincidence, as neither replacement restored continuity along EFI circuit (presence of CEL).
After messing with it a bit more, it appeared that jiggling the fuel pump relay/harness restored the circuit. Started and drove for a couple of days without further issue after jamming the harness up into the relay real good. Just today, however, she gave out on the way to work (dropped to zero RPM, all systems failed; steering and breaks stiffened, engine died, just rolling along at that point). Pulled over, got a tow home, no problem. Whilst messing with the relay (pulled it, took cover off, cleaned contacts and switch parts with sensor cleaner/sandpaper, replaced it) I also attempted to clean out the harness by spraying sensor cleaner in there and jamming a zip tie end down into the pin holes and working it around a bit just to try and clear up any corrosion or what-have-you that may have built up. The situation is now thus:
With the fuel pump relay installed on the harness, I get no CEL at all, not even the brief flash when first turning key to on. The interesting part, however: with the FP relay out (just bare harness, not jumped at all) the CEL flashes once or twice upon first turning the key, and then five seconds or so later comes on solid and I hear a constant clicking at a constant interval somewhere between 1 and 2 seconds (sounds like whichever spark plug the distributor rotor happens to be connecting, as opposed to some relay somewhere, but I could be wrong). I assume by now the sensor cleaner inside the harness has dried out and it's not completing the circuit thanks to residual fluid in the harness.
I've tested this several times: turn the key to on with FP relay installed; no CEL. Turn key to on with no FP relay; CEL flashes, then seconds later turns solid accompanied by the constant clicking. Each time, same results.
So... what gives? What should I test next? I have to assume the issue is either the FP relay or its harness. I ordered a relay ($25 for a used, tested and working one, maybe should have just coughed up the dough for a new one) which should get here shortly, but are there any other obvious harnesses/relays/fuses/ground points/problem wiring spots that I should absolutely check? I looked at oxygen sensors/harnesses, most other harnesses I could reach easily, MAF sensor and harness; saw no changes after messing with any of those.
To start, I have read several threads on here related to poor/intermittent starting, as well as RPMs dropping to zero while driving. It all seems to lead to EFI circuit being compromised.
Symptoms: No CEL when key turned to on and no spark, starter would crank perfectly when turning key to start.
First thought: just replace the EFI relay/fuse, since jiggling the relay seemed to temporarily improve the chances of starting. This seems to have been just coincidence, as neither replacement restored continuity along EFI circuit (presence of CEL).
After messing with it a bit more, it appeared that jiggling the fuel pump relay/harness restored the circuit. Started and drove for a couple of days without further issue after jamming the harness up into the relay real good. Just today, however, she gave out on the way to work (dropped to zero RPM, all systems failed; steering and breaks stiffened, engine died, just rolling along at that point). Pulled over, got a tow home, no problem. Whilst messing with the relay (pulled it, took cover off, cleaned contacts and switch parts with sensor cleaner/sandpaper, replaced it) I also attempted to clean out the harness by spraying sensor cleaner in there and jamming a zip tie end down into the pin holes and working it around a bit just to try and clear up any corrosion or what-have-you that may have built up. The situation is now thus:
With the fuel pump relay installed on the harness, I get no CEL at all, not even the brief flash when first turning key to on. The interesting part, however: with the FP relay out (just bare harness, not jumped at all) the CEL flashes once or twice upon first turning the key, and then five seconds or so later comes on solid and I hear a constant clicking at a constant interval somewhere between 1 and 2 seconds (sounds like whichever spark plug the distributor rotor happens to be connecting, as opposed to some relay somewhere, but I could be wrong). I assume by now the sensor cleaner inside the harness has dried out and it's not completing the circuit thanks to residual fluid in the harness.
I've tested this several times: turn the key to on with FP relay installed; no CEL. Turn key to on with no FP relay; CEL flashes, then seconds later turns solid accompanied by the constant clicking. Each time, same results.
So... what gives? What should I test next? I have to assume the issue is either the FP relay or its harness. I ordered a relay ($25 for a used, tested and working one, maybe should have just coughed up the dough for a new one) which should get here shortly, but are there any other obvious harnesses/relays/fuses/ground points/problem wiring spots that I should absolutely check? I looked at oxygen sensors/harnesses, most other harnesses I could reach easily, MAF sensor and harness; saw no changes after messing with any of those.
