Pistol Pete

Ok, I've explained this in an earlier post but for those of you who don't feel like reading all that, I'll summarize. 1987 NA, starts great in the morning or when its been sitting all day. After its been driven (even for 5 or 10 minutes) and sits for a couple of hours, i get no start. I need to wait like 6 or 7 hours after shutting it off before I can drive it again. I changed the fuel pressure regulator with no luck and finally buckled and brought it to a mechanic. It did the same thing every day for a month but, of course, it wouldn't do it for him. So he suggested some things to try the next time it failed, like checking the ignition. I pulled the ignition wire from the distributor cap and stuck a spark plug in there. When the car has been sitting, i get spark. When it wont start, I have no spark. Could this be DME? Something else?

SoCal Driver

Reference sensor has problems. Most likely the plastic housing or the connector is broken and has severed one of the wires. Intermintent contact. Worse when the engine is hot.

Could also be the ignition switch. Check for voltage at the black wire on the coil with the switch on. Check at one of the injector connectors. If the coil has voltage the switch is ok. If the coil and the injector have voltage then the DME relay is ok. If the coil has voltage but not the injector then the DME relay may be bad.

951Porschiste

I would start with those connectors. See my thread on this

Pistol Pete

The thing is, the car doesn't get that hot. I can drive it for 5 minutes at 6am when its nice and cool, let it sit for 8 hours in the shade, and sometimes it still wont start. It's progressed from about 4 hours a month ago to a full 8 at this point.

951Porschiste

The main point is, take a look at the electrical connections from the sensors. And also take a look at the wiring itself. My car's no-start was related to temp and humidity, but it really was the shoddy wiring that was the culprit. Remember that there may be any number of factors that will affect bad wiring. However, in the end, it is the wiring that was defective.

gregeast

I recently had intermittent no run/start issues as well and was able to repair the DME.

Click Here for my thread on how I repaired it. HTH.

The DareDevil

Mr. Andre,

If I drive down to your place, will you help me rewire the ref-sensors? Nice work!

951Porschiste

PM me whenever!

Pistol Pete

I'm not sure if its a temperature issue. I can literally drive the car for 5 minutes in the early morning and let it sit for nine hours in the shade and it wont start. It ALWAYS starts well first thing in the morning, or any time of day when its been sitting for a long time. It also starts fine after sitting for only an hour or two. It's just during that particular interval. What can you tell me about the Locator sensor? This has been suggested as a possible issue.

dnwong

Same here with the DME. Bad solder joint at the power transistor.

lug nut

If the tach is bouncing when you crank the car and you are getting fuel. Try beating on the DME. No joke. Pull the cover back and give it a good thump. That tip got me home last night when my car wouldn't start. If the car starts when ou bang on the DME then you know there are bad joints inside. Resoldering the transitor joints it is easy. You can do it in less than an hour, and it cost almost nothing. Just follow the link that is posted earlier in this thread.