TritonZ

I have a 1989 GTU and I have a problem where when I do a warm start, the engine doesn’t want to turn on. On a cold start the car turns on just fine, it’s only when the engine’s warm. When I tap on the gas pedal a couple times the car will start. I was thinking it might be the spark plug wires because I got p/s fluid on them, so I ordered new spark plug wires.

mazdaverx713b

iTrader: (91)

The first thing I would do is a compression test with a rotary compression tester. Poor hot starts are indicative of low compression. Before you go throwing money at a tired engine, this is the first thing that you should do. If the compression numbers look good then we can assist you from there with where to go.

WondrousBread

I'm guessing injectors are leaking, and in need of a rebuild.

But I agree with mazdaverx713b that a compression test is a good idea before spending money.

TritonZ

I finally did a compression test on my RX7 and I did three cranks on each trailing hole. On the rear trailing plug the results were; 1st crank 114 108 108, 2nd 112 106 106, 3rd 110 106 108. The results for the front trailing plug were; 1st 101 100 97, 2nd 98 98 98, 3rd 97 100 100. I think the rear rotor has burnt apex seals and is there anything else that could be causing poor engine start ups when it’s warm, like the fuel injectors?

WondrousBread

Those compression test results sound normal, I wouldn't worry about compression right now since it seems to check out. That is often the first step in diagnosing though, so it's always good to check before moving to other things.

The reason I mention injectors is that sometimes when they get older and dirtier, they start to leak (internally). So when the car is hot, fuel has been seeping into the housing for awhile and it floods the engine. This could be why your problem goes away if you press the throttle.

TritonZ

Are the fuel injectors the same type on the primary and secondary injectors?

Rotary Alkymist

Have you tried holding it to the floor to start it when warm?

Do you still have the orange solenoid on your car? This switch will enrich the start-up mixture and for a few seconds after start. Unplugging it might help. Most likely injectors as others have stated.

Some guys have had luck with revving to 4k and then shutting the car off with throttle position still open to drop the pressure in the lines. These are all obviously just band-aids and aren't really addressing the true culprit.

Rx7 fc

It could also be plugged cats, that's what did it for mine.

​​​​As for Rev when shut off I blip the throttle and kill it while it's coming down off of revs and that's seemed like it likes it.

All of my flooding issues and start issues literally went away with the cats.

Boner

Pull the injectors and get them cleaned, whilst you are at it pull the upper intake and lower and clean the carbon out.

RC Engineering in Torrance, CA will clean, ballance and blueprint the injectors for a fee. low turn around time .

FührerTüner

iTrader: (5)

Next time you hot start, prime the fuel pump a couple times by turning the key to run and off a few times. See if it starts. I'm thinking fuel may be seeping back through your fuel pump and you may be getting vapor lock in your fuel rails.

TritonZ

When I blip the engine and shut it off as the revs go down, the engine starts better when it’s warm. Unplugging the orange solenoid also helped. It could be the mufflers causing the issue because when I bought the car one of the mufflers had tape wrapped around it, and I think it’s because it’s leaking.

FührerTüner

iTrader: (5)

Doubt its the mufflers.

erevos

hi all, what orange solenoid do you mean? where is located?
My car does the same sometimes and I want to try that solenoid.

TritonZ

it’s near the middle of the engine bay, between the p/s pump and alternator. Where there are orange, grey, and blue solenoids.

erevos

ok thanks i ll try to find it. What exactly does this solenoid?