Hello all!

I have had a more unique issue that started after I fixed my intake system’s issue. I replaced all the old gaskets, got new vacuum hoses, and fixed my actuator ports. In the process I also got a new mass airflow sensor unit because that broke. After awhile of driving it was doing fine, I think my cables need to be set with a little less tension since it’s idling a little higher than normal, but other than that it’s done fine. Until about 2-3 months ago, it started doing this thing after about 45-hour of driving, where it wouldnt accelerate past a certain rpm. And it was around the 5k threshold when it started. The car began to violently lurch and it sounded like my car was 2-stepping. The threshold it started doing it at began to drop lower and lower as i was getting home, so much so that it was around 3k where it would start doing that. I took it out a few days after and same thing, drove perfectly fine for an hour, then it began to do it again. I recently just replaced my spark plugs, and it was much needed. Car ran so much nicer, but after an hour again, it started to do the lurching. What could be my root causes, and what fixes should I target first? For any experts or people who have experienced this same thing. If i have to take off that intake system I will probably go insane but i will do whatever is necessary. Send help please!

 

I would pull codes first.

 

Thank you for this! My issue is, I dont really know where to start with this. It doesnt seem like there were any break downs posted on how to from what i’ve searched. If you’ve done it on your ‘87 gxl could you give me a quick rundown of how to achieve this? I have the exact same car as you.

 

https://fc3spro.com/TECH/HOWTO/ERROR...KI/zerror.html

I made my own lights. There is a seller that makes/sells them, too. Maybe Banzai... I can't remember.

 

Hi, if you are still running with old cats they could be partially clogged up.

I had that happen to me, started fine, idled fine, low speed driving fine.

But any high RPM's would just bog down.
It sounds like your cats pass enough when cold.
I would think any buildup in them would expand as the time the engine ran.
I had a welder burn the clogging out, worked for awhile, when they re-clogged I removed them.

 

That’s what i’m going to have to do, mazdatrix might have one? I need to keep looking, thank you though, I will update when i get around to it, im replacing the spark plug wires cause they were disgusting when I replaced the plugs 2 weeks ago.

 

I wish it could be this honestly, I installed a full racingbeat road race exhaust last year so no cats here.

 

http://2ndgenrx7.freeservers.com/error%20codes.html

I accidently posted the link for S5's

I forgot that the lights from banzai are for tps adjustment.

https://www.banzai-racing.com/TPS_adjustment.htm

Link above For TPS adjust
And lights

https://www.banzai-racing.com/store/TPS_tester.html

 

Fun fact - if you buy the banzai TPS adjustment light, you can depin the connector and its the exact LED setup linked here ----> https://fc3spro.com/TECH/HOWTO/ERROR...KI/zerror.html

so you can use the TPS light setup to check for Error codes on an S4 rx7

 

My apologies for no response, thank you for the suggestion. I’ve been busy with finals and other things. I will be buying that soon, I replaced the coil wires and spark plugs and it had been driving perfectly fine for awhile, it just picked up the issue again, so it’s time to just get the full diagnosis. Im thinking it’s fuel system but I’m not leaving intake system out of the equation since I did a bunch of work on it back in January.

 

Hi there!

i had it in mind to write up a post exactly like this as I recently experienced this very issue. I recently bought my very first FC, an '88 GXL, and drove it 7 hours back from Colorado. I too had your issue about an hour in where I would hit a "wall" and adding any more accelerator would make the car lurch.

The lurching felt to me like a fueling issue, like the fuel was surging. I know for a fact it wasn't the fuel pump as the friend who sold it to me had just changed that and it tested ok. On the side of the road all I could do was open the gas cap.

When I opened the gas cap, it whooshed a significant amount. I'm not entirely sure, but it sounded like the tank had been at a vacuum. All I did was open and close the cap, and kept driving. And the problem would "go away" for another twenty minutes and then reoccur.

instead of stopping to vent the tank every 20 minutes for 7 hours, I ended up driving the whole way back without the gas cap. The car then ran fine.

When I got back, I tested the vent line from the evap canister to the tank and found a small blockage; I also went under and pulled off the "cut and check valve" but it was operating as it should.

So my running theory is that these cars need a gas cap with a small vent in them. The OEM ones are yellow and seem to have this feature. My '93 Miata has a vented gas cap. But the one on my GXL is some aftermarket cap that doesn't have the vent.

TL;DR, if anyone can confirm their RX-7 has a vented cap, that may be the source of the problem here.

cheers!