wankel1988

iTrader: (1)

This is my first post in a while, and it's about my son's car. Its an 86 rx7 that has some issues. To start, he wrecked the car in October, pretty much crushed the front end in, and he got a shell to transfer all of his stuff over to. He has slowly worked on this and finally is at the point of trying to get it to run porperly again. The issue comes when we start it up and try to set the TPS. We let the car warm completely up, and then set the TPS, I got it at 1k ohms and then at WOT it goes to 4.7k ohms. We started it back up, and it seems to run good for about 20 seconds and then it acts like it cuts to one rotor after that. I can adjust the TPS back the other way and it seems to idle better, but it will not rev properly after that. We have checked all the grounds on the engine and chassis, and according to him he hooked all the wiring back up properly. The only issue I see is that there are 2 wires coming off the PCM wiring under the dash and they have eyelet connectors on them from the previous owner. He doesn't have those hooked up. We though they were grounds so we hooked them up and the car will fire up but immediately dies after it starts. If anyone has any ideas about this, I am at my wits end about it, I'd be glad to look back over things and report back. Thanks in advance.

WayneBrady

iTrader: (4)

is the throttle body stock?

Rotary Alkymist

Try adjusting the TPS using a voltage reading instead. Set it to 1v. It will be happier. Dying after a start could be a vacuum line...

wankel1988

iTrader: (1)

To WayneBrady, yes, the throttle body is a stock unit. and to Rotary Alkymist, would I set it to 1v with it running? It really isn't dying, it will start up, run ok for 20 seconds, and then act like it drops to one rotor. I've had my FC for almost 10 years now, and I haven't ever had a problem like this.

Rotary Alkymist

Yes you would want to do it while it's running and at operating temperature. I think you'll want to back probe the g/r wire with a paperclip. It's really touchy. You want it set to 1.00V. Some people may argue but the absolute best way is to use the green connector on the passenger side using this little thing:

FC3S Pro v2.0:&nbsp How-To - Zenki FC3S Error Codes

If you do check it using this method the car must not be started and ignition turned to ON. This test must be done quickly as temps begin to fall out of range because the engine is off. The FSM will explain how to do it. The connector will have three outputs. 1.No lights 2. one light 3. two lights. If you have only one light on then that means the TPS settings are correct. If lights are both off or both on then you are out of range.

If you're lazy and don't want to build that simple yet extremely valuable tool(as it can be used to fetch error codes for zenki engine/wiring) then you can test that connector via voltmeter and measure it that way. Same deal -three outputs 1. no voltage on either pin 2. voltage on one pin 3. voltage on two pins. Again, you only want to see a voltage reading on one pin.

*The reason I like the green connector method is because it is the ECU itself that is telling you the settings are OK. That is the sole function of that connector. This is the ONLY test that TRULY verifies that TPS settings are correct. All other methods are simply very good guesses or in some cases correct but "without" verification from the ECU.

Edit: I've edited this post so many times. I just wanted to add that when you're setting the TPS give the gas a couple shots so that it seats in its resting position. With everything being so old it might not find its resting position after tampering with the setting. I can go on and on about the nuances that are involved in setting that POFS. Every time you touch that screw hit the gas a couple of times. It'll save you the headache of wondering why it was set and now it's off!

Sorry that you're having TPS issues... I've found out of everything that this frustrated me more than anything else about the car. Good luck. I hope this helps.