Dougs951S

Trying to diagnose an issue with my NA. It sometimes has a hard time starting, when it does this, I note that no tach bounce is present. Usually, wiggling the DME relay will eventually get it to fire up. This is the case with 3 different brand new, confirmed working relays. The car will also sometimes completely cut power while I'm driving. It seems to be independent of engine speed, load, or throttle position. when this happens, I note that the tach is still reading properly, which indicates to me that the DME relay is still powering the DME. My question is, is that assumption correct? I have reason to suspect the fuse block (late car) is dodgy, but if the fact that my tach is still alive when the power cuts (it feels like the car completely cuts fuel) proves that the DME relay is still powering the fuel pump and the DME, then I am looking at maybe a failed TPS or some other sensor. It feels like the fuel pump is getting shut off.

Toran

I had similar issue mane years ago. I replaced the speed and reference sensor and the issue went away.

Noahs944

Congrats on your NA purchase Doug.

Have you tried reaching under and wiggling the wires under the fuse block and to dme while idling to check if that cuts it out?

Tiger03447

Good to see ya back on here, Doug...congrats on your purchase..Hope that this one does a bit better for you...good luck with the wiring issue...Tiger

Dougs951S

I thought the S&R sensors at first too, but like I said, the tach stays alive whenever the power cuts..usually after a few seconds of me coasting with my hazards on and pumping the throttle, the power will come back and it will drive normally. Its definitely an electrical issue. So again, my question is, if the wiring for the DME relay was bad, would the tach still be alive if the DME were to lose power? I say no, because the tach is driven off DME pin 15. sooo, that being said, I believe I am looking at a fuel delivery issue of some sort independent of the DME. Is it possible the wiring for the DME relay is flakey only for the fuel pump, but solid for the actual DME?

znd just for the record, the speed and reference sensors are new and properly gapped. that isnt the issue on this car.

Noahs944

Am thinking YES & the problem might be the female connectors for the fuel at the relay. Have you "drag tested" the fuel female terminal at the relay box ?