I have searched through the many great threads on this forum for an answer. I see a few have had this but no one has responded. I have a random no start when engine is hot. I drive it to temp, go in a store for <30 and I get a crank no start condition. I I have put in a new fuel pressure regulator and that worked for about three days. A new pcv valve and tube with new grommet and hoses, that worked for a few days. I found a damaged (not completely broken) whit wire on my TPS I replaced the connector to that and again for about 2 days no problems. I cleaned all fuel management sensors and connectors and no change there. I connected my scan tool and no issues found. Could this be a vapor lock situation? Will replacing fuel pump help this? I will check to see if spark is present the next time it wont start.. Will an cam or crank sensor go bad with out throwing a code?

 

the cam and crank sensors get weak and cause a no start issue. could be a poor connection and that may not cause a CEL

 

How many miles does your vehicle have on it? Yes, you definitely want to check for spark.

 

put a fuel pressure gauge on the system and run the engine...shut it off and check for pressure bleed down. if it leaksdown….it can only go:
-back to the tank from a bad fuel pump check valve....typically this would cause an extended crank cold
-into the manifold thru the fpr
-into the combustion chamber from leaking injectors.

 

Fuel pressure koeo was at 22psi, replaced fpr and holds at 44psi. I will double check this since its been a few weeks since my last test. The van has 245000 miles.

 

I will also add that when the engine does finally fire it has a one time backfire type sound from the exhaust. Kinda like it was flooded.

 

44 is still low, should be 52-60. prob need to replace the pump and filter. my o2 ran ok with only 22 psi but try to pass someone and wouldnt go anywhere

 

leakdown into the manifold or cylinders is flooding...hence the hard restart. after a hot soak...try restarting it in clear flood mode. if it starts better...your on the right track.

 

What is clear flood mode?

 

wide open throttle...gas pedal to the floor....crank until it starts....when it starts...release the pedal. this will shut off the injectors when cranking.