Hey guys,

Grassroots and Classic Motorsports are hosting the Walter Mitty Challenge at Road Atlanta next weekend. On Monday I need to drive my car up there because DIY AutoTune is installing Megasquirt on it. It is about a 400 mile trip and it would be very nice if the car would make it up.

Here is the problem. My GSL-SE (see mods in sig) has developed a habit of randomly cutting off. For example I can be sitting at a light and it will die. Or I can be driving at 3000 rpm and it will die. It does not sputter or cough just as though there is instantly no fuel. For example if you just turn the key and left it in gear. I suspect I have either a short or some type of relay/sensor problem.

I have a spare fuel pump but I doubt this is the problem. I also have spare ignitors, coils etc.

I searched and read bliffles post regarding the problem with his car and I still need to try some of those out. https://www.rx7club.com/1st-generation-specific-1979-1985-18/se-died-warning-lights-came-tach-needle-kicked-up-starts-few-seconds-756832/

Any help would be appreciated. I'm looking at RX-7Doctor, gsl-se addict, wackyracer, LongDuck (you still around?)

Thanks guys,

-Greg

 

If you have a spare fuel pump change it. It only takes a couple minutes. I don't think it is ignitors. Those usually go out and don't come back.

When it dies does it start back up again? If not then you can start diagnosing the problem when it happens. See if you are lacking spark or fuel.

 

or you can just build up speed, then let the car die/ coast for a while, start the car back up etc....

did you check the injectors?

 

Sometimes it starts back up in a couple minutes but never right away. Sometimes it takes up to half an hour or so.

The injectors should be good as they were cleaned about two years ago.

As an update I drove the car to an autoX last night and it ran fine. Two hundred and fifty miles and no issues. Go figure.

 

Could be the ignition rotor is grounding out and causing the issue.
Also could be losing ground from the trailing ignitor or the trailing ignitor is going bad. Make sure there is no corrosion on the screws that hold the trailing ignitor to the distributor and change out the rotor.

 

Excellent. I will take a spare on the trip with me and clean and check the connections before I leave.

Thanks guys.

Hopefully the megasquirt will at least be telling me what it screwing up. We are going with a full 2nd gen setup with the CAS and coils. I will let you know what the car dynos before and after. Or you can wait and read about it in an up coming issue.

 

I had this same sympton many years ago and it was the most challenging diagnostics I have ever done on the SE.

It did this for many many months until I resolved the issue. I would drive from the house to the store and get back in the car and it would not start. It would sit for awhile then restart. As time went on it would just die as I was driving and I would pull over and check for fuel and there was none. I had changed out the fuel pump during this whole ordeal also.

One day it quit while I was driving home and would not restart. I had it towed to the house and the next day started diagnosing. I went through everything.

I was doing a compression test and by accident had left the trailing ignition plugged in and went to crank it and it started. I then put the plugs back in and hooked up the leading ignition and cranked it and it would not fire. I then took the leading plugs back out and disconnected the leading ignitor and it started right up again. It turned out to be the distributor rotor (was only about 6 months old) was grounding it's self to the distributor and for some reason would not allow the fire of both leading and trailing at the same time. I put in a new rotor and it fired right up.

Like I stated it could be that or the other what I mentioned above or it possibly could be the main relay failing.

 

Update. Looks like the car made it to Atlanta with no issues. About 25mpg at 65. 22mpg at 75.

I looked at the cap and rotor. They have been making contact. I sanded both down, the problem did not reappear but that is not unusual. I will hopefully update you guys next week with the before and after dyno results.

Thanks,

Greg

 

That's wild; Doc: was the rotor grounding out due to carbon tracing?