Alright I have a 91 N/A and most of the time when i start the car, it is miss firing and sometimes it runs fine. I am hoping it is just the spark plugs or wires because I have those coming in tomorrow. The car also doesn't have the TPS or any of the screws on the TB except one at the top on the front. Could it also be the fuel pump? Also the guy I bought it from said i have to use premium since it is Streetported, is that true? Thanks all for your input.

 

Is it like hesitating (bucking) when you accelerate?

My vert did the same thing when I was told by the previous owner to only use premium. I tried regular and it didn't do it anymore.

 

I've read where on an S5 the car will go in to limp mode if the TPS is disconnected. This might be your problem especially if you have the stock ECU.

 

Well it does buck. When I hit the throttle hard i pretty much completely dies.

 

Car will be totally fine on 87 octance. If the TPS is missing I would dig further and see what else was done. Get everything hooked up and functioning then take it from there. I have never tried running one without a tps but I would guess it would run in limp mode since its required to go into closed loop and most likely used at idle to define fuel.

 

OK I am running pure 87 now and still it is running like total a$$ and I do have my TPS now that i actually know what it looks like. I can drive it but if i try to punch it even close to WOT the motor stops firing at all, completely shuts down, it is really ticking me off.

 

What does this thing have for modifications? Is it a fully stock ECU? No piggy back fuel computer?

Usually what you describe would be one of the following if the ECU is stock.

TPS, bad or out of adjustment

Bad AFM (air flow meter)

Bad intake air thermosensor (in the AFM or on the upper intake manifold).

Timing off (CAS stabbed one tooth off) or badly misadjusted.

It's probably not plugs/wires. But its not bad to change them to be sure.

 

Also probably want to do a compression test, to make sure its not blowed up...

 

Yes, it is a completely stock ECU, the guy before me did the TB Mod, K&N intake filter, removed all emissions, and put a really crappy exhaust on it, well the headers and cat are crappy, the cat back is nice, no A/C so i want to get rid of the hoses going into the cabin, and got rid of the power steering, so all that is belt driven is the alternator to the water pump and e-shaft. Well I tried to adjust the TPS but with no success really, I could get it to read 11.82V on one side of the green plug and .22V on the other, the Ohms for the narrow is 1164 Ohm can't get it to go any lower no matter which way i turn the screw. I don't think it is the timing because it only started doing this since I got down to the Mankato area, didn't do it when i bought it up in the cities, but i am new to rotaries so what would I know. Just changed the plugs and wires. oh it is a rebuilt engine too, so I hope it isn't blown, i kind of ran out of money buying the car.

 

When adjusting the TPS to 1 volt it is done at the TPS plug and not the check connector located near the fender. Green/Red wire at the TPS should measure 1 volt w/key to on and engine completely warmed up.

 

sounds like it is either the mass air flow malfunctioning under load or the oil metering pump is kicking the system into limp mode under open loop.

 

so would i need a needle or something to shove into the wire to get that reading of 1 volt?
Would the OMP putting it into limp mode mean i would have to replace it or what?

 

The TPS has a short length pigtail of wires connected to it. Find where this pigtail connects to the harness and backprobe the wire terminal by shoving the meter lead into the back of the pigtail plug.

If the car were in limp mode due to the OMP then it depends on whether the OMP has fried/damaged the ECU or not. Typically when the OMP initially goes into limp mode the ECU is still safe but some people will continue to drive the car which eventually leads to a damaged ECU as well.

 

Okay, i went and pulled the ECU codes, codes are as follows, 1, 8, 10, 11, 20, 25, 30, 31, 32, 33, 34, 38, 40, 41. So all the Solenoids, Trailing Coil, AFM or (MAF), both intake air thermosensors, MOP sensor, I remind you, someone else did the engine rebuild before me, so it could be mixed up wires, but probably not.

 

Before you start buying parts left and right. You may want to check the condition of the harness. That many fault codes, to me, says a damaged harness (fire, rodents, owners with itchy wire cutter fingers etc) My guess is you have a car where the "emissions removal" went horribly wrong, and was done by someone who didn't know what they were doing. Or a bad ECU, or emissions harness grounding issue.

If you need an S5 N/A harness i have one i could sell you. I also have alot of those other parts. PM me if you want some help.

While i dont ever go down to Mankato, if you can get the car to me in Rosemount, I would be glad to help...i know S5's pretty well...

 

Hell with that many codes, you may have an entire plug down in the passenger footwell disconnected...either at the ECU or where the front and emissions harness are connected.

 

I believe I have an ECU as well. If you get the car to me we can swap it to check before you buy one.

 

Doesn't have a TPS? Sorry if I read that wrong but isn't that a vital part to an RX7's drive-ability?...it was for mine anyways.

 

that guy screwed that car up real bad. you can't remove that stuff on a 89-91 and have it run decent.

code 8 is AFM and that will put you into limp mode. (dies if you get on it) you're lucky its not throwing any OMP codes.

 

It does have an OMP code, code 20 MOP is OMP. But I am hoping i caught it early enough it didn't blow the engine. And I am hopefully getting some help this weekend to pinpoint the problem, whether it be the wiring harness or actually legit codes either way I am probably spending at least $300.

 

Ok, got the parts and fixed it, runs beautifully, but does not idle period. It thinks about idling at 200 but that is way too low. TPS green/red wire is perfectly at 1.000V

 

Any thoughts or help here would be greatly appreciated because I would like to be able to not have to use my left foot for braking.

 

If its been majorly messed with its going to take some tinkering to get it happy. you adjust one thing then adjust the tps, adjust one thing adjust the tps Repeat till happy. I Think there are at least 3 adjustment screws that will change idle. If somone had no idea what they were doing and just started turning them your going to be dorking with it for a bit.

 

gotta adjust idle after emmissions removal so try that to fix ur idle problem

 

Does the engine have a BAC on it?