https://www.rx7club.com/general-rota...-help-1041684/

 

You didn't provide a lot of information thats needed to help you. But if its crank-start-die then first check the MAF connector. If it comes lose the car will almost immediately stall. After that make sure there are no vacuum leaks. A big vacuum leak will also caus stalling.

What year car is this?
Modded or stock?
N/A or Turbo?
Have you recently done any work on the car or had work done?
Has it been sitting for a long time?

 

Sorry, I didn't click on your link before the last post. Your problem could also be fuel supply related. Verify fuel pump pressure. There's a filter in the fuel tank that gets clogged over time and could cause fuel starvation. Make sure your TPS is good and correctly adjusted.

 

How do I check fuel pressure? And the tps should be fine its never been Touched. The car was fine this issue came outta nowhere. Thx for the response.

 

I am having the very same problem with my 90 n/a I just replace my mid intake gasket, top intake gasket, new fuel injectors with new seals, new plug wires, plugs, new in line fuel filter, new AFM and replace some hard vacuum lines and it runs better but its still not idling. But every so often it will hold a rough idle right below 1k. I feel your pain brotha ive been dealing with this for about three weeks now. If you find anything PLEASE let me know cause im about to lose my mind with this problem. don't waste your money on a AFM cause I highly doubt that is it.

 

Word. Thanks for the info on the afm. I was thinkin that was it. I'm gonna change fuel filters and see what happens. I'm wonderin if it could be the fuel pump:/ hell if I know.

 

Get yourself a multi meter and start checking voltages on everything and see what's in spec and what's not at the ecu and at the sensor.

My car would start up and stall when I hit the gas, I found out my water thermal sensor wasn't getting voltage because of a bad connection and that my iat sensor was bad.

Fixed both problem gone.

Rotary > Pistons

 

Details about how to pressure test the fuel pump and the fuel lines are found in the FSM. However, you will need a specialized tool for the jobs.

Throttle Position sensors are probably the most tempermental in the entire RX7. They can cause a wide range of ills. Check it to make sure its not faulty and that its adjusted correctly. Using a volt meter read the output voltage from no throttle through WOT. The readings should smoothly sweep from 0 to 5 volts without any spikes or dropouts. Max reading will occur well before actual WOT. Thats normal. Correct setting with the engine warmed is 1 volt.

 

I know mine is running lean right now from the looks of the plugs they have some starting in the middle. After work today I'm going to test fuel pressure and see where that takes me I'm running out of ideas.

 

I know mine is running lean right now from the looks of the plugs they have some white starting in the middle. After work today I'm going to test fuel pressure and see where that takes me I'm running out of ideas and if I'm not mistaken we don't have a fuel filter in the tank it's more like a screen then a filter.

 

So I unplug my efan so I can actually hear somethin while sitting in the rxockpit. And my fuel pump is not coming on w the ign. What would cause this? Is there a fuse for just the fuel pump?

Thx so far guys. All the help is appreciated. Peace.
Nick

 

Fuel pump only comes on with the car trying to start or running unless its jumpered

Rotary > Pistons

 

I have an idea but not sure if it makes since...maybe it's ignition, like coil packs or alternator? But that wouldn't explain why it runs good at high RPMs though.

 

The alternator will self excite itself at higher rpm's. If the voltage output at lower rpm's are too low it will run poorly. What is the voltage output of the alternator while idling as measured on the alternator's Black output wire?

 

Ill check this when I get home. This would just require replacing alt w a FD one like I wanted to anyway.

Thanks for all the ideas and such. Ill get this figured out soon.

 

14.3 sound right? I dont think its the fuel pump or the alternator. I gotta figure this out.

Just a few min I started it and it idled fine. Was gonna check the voltage on the tps'. I revved it up a few times to like 3k seemed ok then it started sputtering. I tried to start it again and the rpms will slowly drop and the car will shut off.

 

14.3 is just right.

 

Ok so I noticed that when the car was cold it started and idled fine...even revved fine. Now after it got kinda warm and was running for a min it doesn't stay running. And won't start. But if i hold down on the gas it'll stay running but it does what I showed in that video. It pulsates. If i let off gas it instantly dies. I notice that when its pulsating the lights in the car pulsate too.

Fuel pump is good, alt is good, tps' are good. WTF IS IT? The injectors were just rebuilt like 3k miles ago, fuel filter replaced around the same time. I'm gonna replace plugs and wires tomorrow.

I was thinking of checking the wires running to the afm. Is there a way to check them w the multimeter? Like what voltage is goin to each one? Bare w me this is a learning process for me lol.

 

The light pulsating is caused by the rpm dropping relatively low which creates an undercharging effect of the alternator and when the rpm climbs it is then making enough voltage to cause the lights to fully brighten.

You might want to check the Water Thermosensor at the ECU. When cold w/key to on the reading should be 2 to 3 volts which then drops down to about .3 volts w/the engine fully warmed.

You might also want to look at the two intake temp sensors w/one being in the AFM (pin 2K)and the other in the throttlebody (pin 2L).

And if the catalytic converters warm up they can cause a restriction if they are rather clogged to begin with. They can tend to become more problematic w/higher temps.

ECU pinout values (the ones you need).

https://www.rx7club.com/2nd-generati...wires-1013741/

 

Thanks a lot man. Ill check all these sensors tomorrow.

So I go back out 20 min after the car wouldn't start back up and it starts and idles fine. I got it to idle for about 5 min till it got to op temp. If I revved it it would just die...wouldn't go back to idle it just shut off. I gave up and came in for the night lol.

 

You said lights dim when pulsating idle.. Im assuming you mean lights inside too. like dash lights? First thing I would check is main grounds..specially that ground at the engine block itself. a quick check. Set volt meter to direct voltage. Ground lead to battery ground. Positive lead to motor iron plate or rotor housing. If you have anything over .5 volts... ive had 5 volts on the intake manifold with a loose ground at the block.You have a bad ground... Also sounds dumb and I recently had a friend do this, he rebuilt his fc. Car has long cranks and rough pulsating idle. the Guy left a rag in the intake boot and got stuck in the throttle body choking it out. But you said you went back through it for injector o rings so you should have seen that but still look. Visually check afm too if you haven't. Easy quick checks and overlooked.. Your issue sounds like a power supply issue tho. Good luck!

 

[QUOTE="Socalhatchy;11531403"]You said lights dim when pulsating idle.. Im assuming you mean lights inside too. like dash lights?/QUOTE]
Lights don't pulsate if car just idles. It's idling fine. If i push down on gas 1/4 throttle when it's acting funny the revs pulsate from 500-1000 rpms. When I let of gas car dies.

If the car sits for a while I notice it starts fine and everything even will rev normally. After running for a min or 2 everything starts to act all funny. It won't even be funny warmed up...ust a min or two after I start when things start. It's so random. Does anyone think it could be a fuel filter or this screen in the gas tank? It just weird how its fine at first then once things start flowing they get all stirred up and something's getting clogged? I just wanna fix this!!!!

 

It's certainly worth looking at, if only to eliminate the doubt.

 

Ok guys. Started the car this am after checking the afm and stuff. Started and idled but acted weird when I revved it. After it was warm I got a little more aggressive w trying to rev it and it stuttered a few time an blew out some white smoke. Now she revs fine...I took car down the street for a coup redline passes and it seemed ok. Got back home and opened the hood an there's oil every where from my oil catch/breather. Why would this happen? This is what the rest of the oil that came outta the catch looked like...

 

The car starts, idles fine. Once in a while it will stall for no apparent reason but it'll start right back up. When i go to drive it seems fine in 1st then when i shift into 2nd it seems to hesitate, lacks power and or stutters. The car was jerking real bad today and i had to pull over. I'll push the clutch in and hit the gas sometimes it will rev and sometimes it will die. Or it will do what It does in the vid...Oh and the CEL came on today but while the car seemed fine. It went away after a turned the car off and back on. Is there a way to check the CEL codes? Need to figure this out ASAP.