Flooding Fuel ... Fuel Pump Replacement .. Starting Issue
 

75 280Z with 114K miles.



Took my z in to have the rear tranny seal changed and my mechanic asked if I had been smelling gas in my car .... Yes, I have been for several days. Turns out the fuel pump was leaking.



That may answer the other problem I have been having ... in the am the car would start up right away but run rough until warmed up. If It died before being warmed up, I would have to crank the car for long period of time (40+ secs, 2 or 3 times) before it would eventually start, acting like it was flooded, but got through it and ran well. Would have no problems for the rest of the entire day, stop and go, starting fine.



Forgot to tell my mechanic about the morning ritual when I left it at his shop the night before to get the tranny seal fixed and sure enough, in the morning he started it, didn't make sure it keep running and it died ... after cranking it for a little bit, he concluded it ran out of gas and called me for the gas cap key. After me explaining the morning ritual, he said that he had gone ahead and just pushed the car on the rack and got to work on the tranny.



After fixing the tranny, he changed the leaking fuel pump, but now can't get the car to start. He says the fuel pressure is good, has spark and is getting so much fuel it's "washing out the cylinders and the oil smells like gas".



Suggestions?

The main cause of a flooded L28E is usually the coolant temp sensor (280z) aka CHTS - cylinder head temp sensor (280zx). It's either disconnected, corroded, or otherwise not functioning correctly.

But also check the AFM and injectors.

Any thoughts about the Thermotime Switch as a possible issue?

Update.... my mechanic has discovered there is an "overflow line" from the fuel pressure regulator that goes to the gas tank...and that line apparently is not allowing the gas that exceeds the amount regulated by the regulator to return to the tank, rather it is being forced into the chambers via injectors .. HENCE, Flooding.

We suspect there is a problem associated with the evap system.

My mechanic noted that if they pinched the fuel line coming from the FPR the engine would run well....let it go and ran terrible = too much fuel. He decided to pull the fuel line running from the FPR that goes back to the tank, let it hang to the ground and see what it does...and, sure enough, it ran well = line back to the tank has some blockage?? Blew "shop air" into line returning to tank, hooked all lines back up and is running great!

please help! iv got a 1980 280 zx .when u start it up cold it starts an runs perfect. but after u drive it an stop an try to start it it dont want to start like its flooding ! but doesnt do it all the time . just swwms to do it only when it warm!

Zx intermittent start/no start issues
 

In my experience as a tech in most cases it's the Ign control module on the distributor. The if that checks out good it could be one of a number of things or more. I would try at the module first. Good luck pal.