I have a 93 prelude i had surging problem which i solved by adjusting the FITV. But the real problem i have is that when i have it running for 15mins and the car reaches operating temp. the RPMs drop under 1000 and the engine starts to have a rough idle and eventually stalls out unless i keep the RPMs up and the engine will not turn back over until it cools down . Ive done a lot of research into this ive checked the fuel pressure, spark plugs, changed the ignitor, cleaned the egr, iacv, TB, resoldered the main relay and checked for anymore vacuum leaks and added coolant(no air pockets). And still nothing has changed. Ive read about vapour lock or faulty temp. sensor(appears to be leaking oil from the connection, could that send a false reading to the ECU), bad o2 sensor or a bad ecu. All those things i have not checked as of yet but wondering if anyone else has this problem and solved it. Also when at operating temp. It seems to be running rich also i have not checked the fuel regulator. Any help!! Send it my way

 

First off, while the car is warmed up, pull the fuel pressure regulator hose from the intake manifold side and smell it. If it smells like fuel the fpr is bad.

If there is no smell, pull the oxygen sensor connector and drive around. If the car runs fine the issue is the oxygen sensor is bad. But I would first check for an exhaust leak with sea foam to rule out an exhaust leak causing your issues.

 

Ok thanks for the tips ill try them, but will a bad fpr cause it to not startup once it stalls out

 

It could as it could allow fuel to leak into the intake manifold which could flood it. It doesnt happen often but it does happen.

 

So no exhaust leak I pulled the o2 sensor and it still stalled out I check the fuel regulator it didn't really smell like gas but could too high of fuel pressure cause a car to stall out and run richalso when I did a startup check of the fuel pressure without it running it was about 60 psi. is that fine without it running?and could a bad fuel pressure regulator cause too much fuel to be going to the injectors

 

60 psi is way too high but im not sure if that would cause your car to stall .. you should check your return hose for blockage/collapsage .. its at the bottom of the fpr to the hard line at bottom

 

How do i check it? Ive taken it off there was a bit of fuel still in the line

 

Take off the hose and see if it collapsed internally