Hei guy's.
I'm having a problem with my car. I bought it without a motor, and I bought a used motor and installed it. I can start the car and keep it running by pumping the gas, and it sounds really good, but the car won't run/idle. And I can't hold like a steady rpm f.x. 2000 rpm, then it just dies. And when I start the car it runs for about 1 - 2 sec and then dies. Anyone got any good ideas?
Btw it's a '93 with a 16 bit motor and harness that I've reconnected with 8 bit connectors. And yes I've pinged the wires that are in the engine harness.

Best regards, Aron

 

What engine did you install? Have you verified your fuel delivery system is functioning? Sounds to me like fuel starvation may be the culprit .

 

O sorry, forgot that. It's a 16 bit 13b-rew that i put in. Just a oem motor

 

I'd like a better idea of exactly what the symptoms are. Can you keep the car running by holding the gas pedal and it only dies with no throttle? If it starts, you're getting fuel and spark (although don't rule that out just yet) but if you can't idle I might start at the ISC/IAC solenoid. Wiring is what I'd check there. Its only got a two-wire connector so make sure it's got a healthy battery voltage when keyed ON the power pin and that you've got proper connection of its control pin to the correct slot in the ECU harness. (on the 8 bit, its ECU pin 4Q, unsure of if that changes for the 16 bit)

 

I recently had what sounds like a similar problem. You can read what I did here, I never came up with a definitive solution but it seems rewriting the power fc did the trick, just unconfirmed. If you dont have a power fc my thread should atleast give you some troubleshooting ideas.

https://www.rx7club.com/3rd-generati...ideas-1141348/

 

The car only runs if i feather/pump the gas pedal, if i just hold it it dies. ISC is on the right place in the ecu and I shall measure the voltage tomorrow. The fuel pressure is good and the vacuum is good while the motor runs.
Thanks for the tip.

 

Sparks??? You check it's not flooded? The spark plugs could tell you if there is fuel going in there by just reading the ends. Should be blackish/brownish if you definitely got fuel going in. I would think you could at least ease it down to like 1200 or keep it running by holding it. Try spinning it without ignition/fuel to try and push any excess fuel out and try again.

 

It's not flooded and I've got spark and fuel. I can't hold it on a specific rpm, then it dies. Must feather/pump the gas pedal to keep it running

 

Thanks for tip, I will get my buddy to rewrite it for me since I don't have datalogit. I've tried most of the same things as you, besides jumping the pump ( do you remember which pins and where ).

 

I did a few things. There is a sound system in my car so I already had a large power wire conveniently located near the fuel pump. The other way was through the diagnostic port under the hood. I'm not sure if this would exist with your 16 bit car but it is on the USDM 93-95 cars and was on my JDM 92 model.

2nd picture here for the diag port to jump fuel pump:

https://www.rx7club.com/3rd-generati...system-871361/

 

Oki thx. My car is '93 JDM. Just installed a +'99 motor because there was no motor in the car when I bought it and I got a hold of this one but I've connected it to my '93 car

 

Problem solved. Defected MAP sensor.

 

glad you got it fixed and thanks for updating the thread