3.2 Carrera no run

[r lane]

We have an 87 Carrera that came in with the complaint that it from time to time will crank but not start. It will maybe the next day correct it self. we have had it a couple of weeks and experienced this twice. Installing a test DME relay and DME unit is not the cure. We have spark, fuel, and injector pulse. What am I missing. Bob

[r lane]

I meant to add this, we have replaced the 2 speed sensors and CHT

[Flat6pac]

Years ago I had a similar problem coil had a periodic fault.
Bruce

[GH85Carrera]

Bruce has a great suggestion. If it has the new silver Bosch coil, those are at best 50-50 odds of bad out of the box.

Find 40 year old Bosch black coil and try that. The 964 coil is one possibility of a new coil for a 911 G body car.

[Nick Triesch]

You can find parts like these at European salvage yards. I have. The black coils probably were used and different model cars.

[boyt911sc]

Bob,

Have you tested the fuel pressures? The FPR could be bad. Test and verify.

Tony

[r lane]

Originally Posted by boyt911sc

Bob,

Have you tested the fuel pressures? The FPR could be bad. Test and verify.

Tony

I have not checked pressure or delivery and at the moment she is running. I just looked to see if fuel was coming out of the fuel rail under pressure. Other than leaking due to a ruptured diaphram, how would the FPR keep the car from at least emmiting some sort of combustion. I appreciate your response. Bob

[proporsche]

one little thing

check the ground connection on intake no 1

Ivan

[brianlay]

Next time spray some starting fluid into the intake. Quick way to determine if your problem is missing fuel or spark.

[FA-18C]

Similar issue with 88, think it was part check valve and failed FPR.

[mysocal911]

Originally Posted by r lane

I have not checked pressure or delivery and at the moment she is running. I just looked to see if fuel was coming out of the fuel rail under pressure. Other than leaking due to a ruptured diaphram, how would the FPR keep the car from at least emmiting some sort of combustion. I appreciate your response. Bob

On a 911 3.2, the FP is powered by the DME relay. Without any fuel (dead DME relay or FP), NO combustion occurs. It's as simple as that!

[PeteKz]

Originally Posted by brianlay

Next time spray some starting fluid into the intake. Quick way to determine if your problem is missing fuel or spark.

Agree. You should carry a can of starting fluid in the car. Spray it in the intake when the car won't start to determine whether you are missing fuel or spark.

[FA-18C]

I would check the CHT as well. Failed FPR can flood the car and preclude starting. Worth checking for fouled plugs.

[Lyle O]

FWIW, I had an intermittent starting issue in my '87 a bit ago. It turned out to be the wire harness connection for the speed sensor. When I replaced the connector (at the top-back of the engine, where the 3 connectors mate to the 3 sensors), the problem was cured.

[r lane]

I do think the problem is solved. Since it was intermittent, will have to give it some time though. So we had fuel pressure, spark at a grounded plug and injector pulse but car from time to time would not fire. Customer stated that seemed to more of an issue on damp days. Resisted installing a coil as it appeared we had a healthy spark and the only coil at the time available to me was the silver Bosch coil which had a bad rap. I finally ordered a coil out of desperation. Upon switching out the coils, found moisture at the connection, the center cable to be corroded as well as the port in the coil. The new coil immediately fired the engine, cleaned everything up and the existing coil did as well. So if a spark looks good, may not be. Thanks for all responders. Bob