Tec issues on a Woodhouse Autoform Daytona 91 Car

[Fatboy 18]

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[dave6666]

PCM failing or tune.

[Fatboy 18]

Post removed

[dave6666]

Just reread your post. May be some other things to check. Fuel pressure at idle and under load. Intake leaks - propane test method?

Regarding the PCM there are multiple fuel maps in the tune and they will change as the car warms up. If that is not working or is corrupt it could cause havoc. Knowing nothing more about the car it's a long shot but keep it in mind.

Another thing that would skew fuel are your primary O2 sensors. If they have not been changed since the car was built might be time for a fresh set. Many people throw aftermarket at these cars like Bosch but the OEM sensors are NTK.

When the car is doing this *won't start after warm-up* thing try cranking with the gas pedal mashed. Most modern fuel injected engines cut fuel at WOT. It would be another test.

If you have a simple scan tool watch the short term trims as the car warms up. Also monitor yo see if the car goes from open loop to closed loop during warm up. Some simple PCM tests.

[Fatboy 18]

Post removed.

[dave6666]

coolant temp sensors going bad can make crazy things happen as the map switch is temp related

Looks like we are on the same page with that. When Dan was tuning my Roe we went through a lot of discussions on the relationships of the different maps and how to understand in the driver's seat what was happening. It really does become interesting when you are developing a tune to know what the tuner is doing and the challenge of interpreting it in the car correctly.

Regarding the car in discussion here, and depending on the tune which we know nothing about, the warmup maps should be richer. If there is no transition to hot condition fuel maps I can see a problem with that. However if the car runs well hot but just doesn't start well hot the troubleshooting goes on.

I still say warm the car up and then if it won't restart crank it at WOT to cut fuel. That will help with the diagnosis knowing if that does anything.

[maeham]

Looks like we are on the same page with that. When Dan was tuning my Roe we went through a lot of discussions on the relationships of the different maps and how to understand in the driver's seat what was happening. It really does become interesting when you are developing a tune to know what the tuner is doing and the challenge of interpreting it in the car correctly.

Regarding the car in discussion here, and depending on the tune which we know nothing about, the warmup maps should be richer. If there is no transition to hot condition fuel maps I can see a problem with that. However if the car runs well hot but just doesn't start well hot the troubleshooting goes on.

I still say warm the car up and then if it won't restart crank it at WOT to cut fuel. That will help with the diagnosis knowing if that does anything.

just a guess but try a speed sensor if bad when its hot loses the 5 volt reference signal to pcm
if has yellow box can also cause had a few do this only when warm