coldfuzion76

So I'm working on an 86 NA. I've done every check I can think of, and I can't get her to start. No tach bounce. I've checked the reference sensors, all the way to the DME. I checked resistance, and the voltage cranking. Getting good signal, but maybe too good. Had 5 volts on the speed sensor. Could this possibly mean it's too close? That's the one thing I haven't checked, as I'm not in my own garage at the moment, and didn't bring anything to measure it with.

I've gone through the checklist, and made sure I have the correct voltages everywhere else. I'm starting to think I have a bad DME. Any advice?

PerryB

Let us know how this plays out. I have a similar problem and a rebuilt DME did not solve the no start

Perry

DarrenD

Could be bad solder joints at the big transistor in the DME. I just went through this. Try tapping on your DME as your cranking it. I have an early car so it's easier as the DME is under the steering wheel. Not sure if you can do the same as the DME is in the pass. footwell, but it may be worth a shot.. I fixed mine by resoldering some joints.

coldfuzion76

The DME has been reworked on this one before. I took the cover off, and there are several new solder joints. I couldn't see any bad spots on it. I have a couple of sensors left to check, based on the things I've read here, and on Clarks garage. Have a friend coming to help me later so I can check some more things as its cranking, too. But I'm pretty sure the fuel pump isn't kicking in on its own unless I jumper it. As I understand it, though, it probably won't unless I have tach bounce. And it still won't start even if I leave it jumpered, so it's not the relay. Rather confused at the moment.

odonnell

Borrow a good DME if you have any 944 buddies. If not, buy one outright, they're under $200 or even lower than $150 sometimes. Even if you don't need it now, it's nice to have a second one. These DMEs are pieces of crap after 30 years of vibration and humidity/water leaks.

Tom M'Guinn

Trust you've confirmed the DME is getting power and/or ruled out the DME relay?

coldfuzion76

I'm gonna ask someone somewhat close who has some parts cars for a DME, but after today, I'm not sure that's the problem anymore. I set the gap on the reference sensors, and now I have tach jump! Amazing how finicky those things are. Still won't start, but it did try to fire a couple of times on starter fluid. Just a couple of quick coughs, but I got rained out before I got any farther. I've tried jumping the DME relay, but haven't had any luck yet. Getting there, though. Next time I make it over there to work on it, I should be able to check fuel pressure and I'm gonna get a noid light to see if the injectors are even trying to fire.