So my car has spent the last 4 months in an AOne Japanese Engine shop, where I bought a new motor from them. My first motor blew due to a combination of a clogged cat, and a crack in my coolant system, and a faulty temperature gauge. So everything has been fixed, and their new motor put in, but they can't figure out why my car is running rich. They said everything that could be replaced has been replaced, within reason. They suggest I take it to a rotary specialist shop, which I plan to do, unless either I could fix this myself, or somebody knows what my problem is. Me being pretty unexperienced, I doubt I could do anything that a professional shop couldn't figure out, but then again they aren't used to rx-7's like you people! haha, If somebody could give me a suggestion to what it could be, would be greatly appriciated. I have searched this forum for reasons running rich, and it seems to happen a lot more in FC's, and I'm wondering if they same problems come up with FD's. I have considered getting a PFC since I wanted one eventually anyways. any reason I should or should not get a PFC? Sounds like some people solved their problem this way. I have an aftermarket intake system, along with an HKS downpipe, high flow cat, and an Apexi N1 single, if that helps. Also if anybody knows some trusted rotary shops in the Seattle,WA area. Thanks anyone!

 

Exactly how are they determining that it's running rich? Do they have your car hooked up to a wideband O2 sensor with and reading the Air/Fuel ratio?

 

yeah, they said when it was hooked up, it was reading all sorts of crap,

 

If they haven't checked for ECU codes, they should. The stock ECU runs pretty rich by design. Are they having some other problem with the car aside from "thinking" its running too rich?

 

well no, they said they replaced everything they believed could be causing it, cleaned what needed to be cleaned, and they are stumped, the car starts up and it runs, but they said they get black smoke. This was over the phone, I didnt catch everything he said, but everything is good except this running rich.

 

Cool Avatar.

Anyways, it's hard to diagnose your problem having no background info, but things that come to my mind are:

Bad Oxygen sensor. No fuel trim, no adaptive strategy, open loop, running base maps.

Has the car been driven at all? Maybe the new components threw off the fuel trim and it needs a few drive cycles to adjust.

The stock ECU does run on the rich side.

Miscalibrated wideband O2.

They do need to check for codes.

 

thanks guys, il make sure the shop has done all of that. im wondering with a PFC, couldnt it just be leaned out? or is that like ignoring a problem and fixing it another way?

 

If you can't get it running with the stock ECU, there is a problem with the car. Plain and simple. There is no reason the car shouldn't run with the stock ECU if you have the stock fuel system.

 

ok well il see if i can get this figured out...

 

Have them start by pulling the ECU codes. There are many codes which can be stored but do not actually trigger the dash light to come on. Depending on what the ECU is reading, it can run the car even richer (if it's not getting the signals it expects).

 

Definitely DON'T get a PFC to fix your problem. You want your car running at it's best before you start tuning.