I have an 87' na. hard to start when cold, will not hold fuel pressure, and runs like ****. After it warms up it runs fine. Have replaced ecu, air flow meter,

injectors, fuel pump, all lines & hoses, engine harness, temp sensor, temp switch, coils, wires, plugs, and all vac. hoses. Also has a dead spot at 3800 only if you punch it. PLEASE sombody help if you have any ideas.

 

If it won’t hold fuel pressure, it will be hard to start, idle poorly, and run lean on a load. Since you replaced the fuel pump and the injectors, that leaves the fuel pressure regulator. Have you tested it?

 

Just about to say that.



And your 3800 dead stop. It has to do with some type of hesitation. I don't know nothing about it, because I never had to deal with it before. I think there is a thread in 2nd Gen F.A.Q. on this forum about that. And also on www.rx7club.com.



Good luck.

 

I haven't checked the pressure regulator yet but when I pinch off the high pressure and the return line back at the fuel pump it only holds pressure while the key is open once I close it it drops the pressure to zero really quick. I've already swapped out the pump twice and same thing. I took the car to rotary performance and they told me it had a bad harness because the engine had been swapped out and possibly rubbed a wire somewhere. So I changed that and still same thing. Any one have any new ideas. PLEASE help.