abroom

Just bought this rx7 last week... So far i’ve driven it 40 miles since then and now the car will not rev when you floor it. It will climb to about 5k when you slowly press the gas but the second you mat it the car stutters and backfired like crazy. Weird thing that I haven’t seen on the forums is that when i disconnect the ground on the battery and let the ecu reset the car runs perfect for about 45 seconds to a minute and then starts to do it again. And even weirder is the fact that it is hit or miss. i started the car 10 times right after each other and every few starts the car would be fine without touching a single thing and would rev smoothly for about 45 seconds to a minute and then would start stuttering again.

So far i have checked all the grounds and voltage at the battery and alternator. I haven’t had much time to look at it. Any pointers for the first things to check? I know there’s an absolute laundry list of things that could cause thing but just looking for some guidance.

rxshun7

It sounds to me like your car is going in and out of limp mode. Resetting the ecu might solve it until the error code pops up again. Make sure when you reset your ecu you are also holding the brake down for a short period before reconnecting the battery.

If this is the case, what you then really need to solve is what is causing the car to go into limp. Have you checked your error codes?

Once you narrow down the code you can focus your troubleshooting better. Among other causes you may also have a problem with your ecu.

Red94fd

iTrader: (5)

Is it stock car?. Limp mode maybe.
fuel filter, bad injectors, clogged catalic converter, bad coils, old sparkplugs and sparkplug wires,.
More details the better someone can help.

DaleClark

iTrader: (55)

Typically if it will rev up in low RPM but bogs when you try to get to higher RPM it's something with the secondary injectors.

We need to know mods and what ECU is on the car.

Dale

abroom

Only mods on the car is a little bigger inter cooler. Stock ecu. I just got a snap on code reader so i will plug the car in after work and update you guys with the codes i get.

DaleClark

iTrader: (55)

That code reader is probably for OBD-2 which won't work on an RX-7. Here's the procedure to check codes -

https://www.rx7club.com/3rd-generati...-codes-851414/

Just need a paper clip, that's it.

Dale

abroom

Update:

I did the diagnostics method by using a small led light with a 680ohm resister yesterday and had the light flash for code 27 which is bad or stuck OMP. Ordered a remanufactured pump that should be in sometime next week. Does this make sense that if the pump is stuck or bad it will throw the car into limp mode? i’m gonna check all the connections to the pump later today to see if i can find anything.

rxshun7

The OMP error among many others will cause limp mode. Dale actually covers this here: https://www.rx7club.com/3rd-generati...p-mode-784617/. Let us know how it works out.