1988 Rx7 Non Turbo...sitting at red light and all of a sudden started idling rough with some backfire. I drove it on home and it had quite a loss of power. I have had this car for 18 years. So I replaced the fuel pump, switched out the BAC Valve and the fuel pressure regulator. It is a little better but will not idle without dying and some backfire after it warms up. The biggest symptom preceding this was it became hard to start but once started it was ok. Starts good now. I got $50 for the first one to offer a remedy that works before I take it to the dealer. I want to keep this one forever. It is a NON TURBO edition.

 

first thing..compression test it.

 

I meant to mention that was done first. Compression ran around 70 to 75 PSI with about 4 to 6 PSI difference between the chambers. I did have a failure in the little switch at my clutch thats known as the starter cutoff switch. I disabled that (this was long before current problem) and am starting it with a push button directley to the starter. I have noticed that It will start really quick if i turn the ignition key all the way as normal. It almost seems to be electrical in nature, but again I have started it with the push button for the last two years. I only drive it about 200 miles per month.

 

70-75 psi is pretty low. Driveable, but low.

Since you have had this car for 18 years, are you the original owner? If so, have you done any mods at all, or is it bone stock?

 

check the fuel injectors them selves? have they ever been serviced?

I've had a primary injector crap out and cause similar symptoms,
does the car run any better when you get above 3800 rpms?

check for vacuum leaks as well, did you replace the sparkplugs or check them out at least?
I wouldn't take it to a dealer unless you want to get ripped off.

 

It Is Bone Stock. No Modifications. I bought it from the original owner, a local Doctor.

 

I did replace the spark plugs and wires before this started. It does run good at higher RPM's.

 

Ok...I spent some time went through a start up and paid real close attention to the symptoms. It runs pretty smooth until it warms up and that is when some mild but repetitive backfiring starts. Also, it DOES NOT run smooth at high rpm's and still has the backfiring. I have to hold the foot feed down to about 1200 rpm or else it will die.

 

I don't think it's fuel related.
What you can do for starters is back probe the ECU after it's warmed up and check values from FSM. Check the AFM.
Spray some carb cleaner around manifold and vacuum lines and see if idle jumps.

 

I will do that. I have a Haynes manual and perhaps the values are listed there. I made an additional post to attract some new onlookers that I invite you to read. This will perhaps explain why I feel it may be fuel related. QUESTION: if spraying the Carb Cleaner makes a difference I am assuming I have a vacuum leak, correct?

 

Yes