Hello rx7club members, I have a single turbo fd with bigger injectors,fuel pump, exhaust, wideband, boost gauge, pfc, and all emissions removed. So i got the car tuned in summer and when it turned really cold outside in winter i would have to hold the cars throttle to idle until it got up to temp or she would die but then she drove fine with good afr, but now after a month or two of winter its still cold out and now when i go to start my car i still have to hold the throttle but now the afr are way rich and is steady reading 10.00 at idle and when i give it more gas to see if it changes it doesn't and its still didn't and stayed really rich. If you guys have any ideas on why all of a sudden my car is running super rich just let me know and i can start checking things out.

 

Can you varify fuel pressure? Once driving, do your afr's lean out respectively? There are air and water temp correction maps that my need adjusting for the cold ambient temps. I would check fuel pressure, inj settings, and then log what temps you are seeing as constant for current driving conditions. Referencing those temps with your correction maps may reveal something.

 

Thanks for the quick response and fuel pressure is at 38 or 35 and i can see it on my fpr. while I'm driving it barely leans out maybe to 10.8 then back to 10.00 if i go up in the rpms and i didn't want to drive it/ go any faster with it running like that. This was after i sat in the driveway getting it to operating temps and it wasn't holding an idle like it normally did, just super rich.

 

Has or was anything changed perhaps by anyone via the pfc commander? What size injectors are you using?

 

Make sure it is actually getting up to the proper temperature. A stuck open, or missing thermostat would prevent it from reaching operating temp.
Also, a disconnected or improper reading coolant temperature sensor would incorrectly report the engine is cold.
Keep in mind, this problem MAY be unrelated to outside temperature, it may simply have gotten worse over time, and it just so happens it's cold now.

 

Yeah I can see on my pfc that it's warming up and I warmed it up to operating temps and tried driving it and it was super rich still. The car has been running great since I got it tuned just when it warms up in winter I have to hold the gas but its never ran really rich before a couple days ago

 

I don't think so I looked through some settings but I don't think I changed anything and 850cc primary and 1680cc secondary's

 

Ok if it's warming up and says so,

Probably the next thing would be to look at the spark plugs and see if it is running rich overall, or if it's just one rotor.

 

take a picture of the commander, showing a 4 channel monitor with water temp, air temp, boost, and inj duty, with the car fully warmed up. We can start ruling out potential issues.

 

I pulled the spark plugs and it looked like the front spark plug was covered in gas

 

Ok I'll do that when I get home

 

update. When I started it to try and warm it up it was starting up l, still running rich and I can see the temp rising and can read the intake air temp sensor so I turned it off and seen gas dripping out of my down pipe.. So I took my injectors out to get cleaned and serviced. Any ideas ? It doesn't look like the injectors are dirty

 

Internally, the injectors, can be plugged or dirty without you being able to see them. Are you 100% sure it was gas coming out or could it just have been water condensation?

 

Some injectors don't like running E85 and may rust internally, sticking open or closed. They need to be tested.

Also.you may also want to check the integrity of the injector circuits a shorted wire could cause an injector to stay open.

 

Yeah I'm pretty sure it was gas. It smelled like it

 

I can check the integrity of them in a day or two but they look fairly new

 

By injector circuits, I'm not talking about the injectors themselves, but the wiring to the injectors.

 

Update! Today i unwrapped my wiring harness and checked the wiring to the injectors. It checked out good to me no shorts or loose connections... The only thing is that who ever did my single turbo conversion left the wiring for all of the solenoids... could that be a problem for the all of a sudden running stupid rich ?

 

Could be intermittent connection... My harness ohmed out perfect when unplugged but when connected the plugs were disconnected from the slight bend.

 

bump.. any ideas to check anything out. i just had the injectors cleaned and i went through the whole engine harness and no intermittent connections and It still won't run right.

 

Update! Its fixed and back on the road. So the problem was my pim volts i didn't realize i changed it when i looked through my settings but it was on option 4 and not on normal, thanks for all the responses and help.

 

Ahh Haa!

Were there Bells and fireworks going off when you made the discovery?

Anyhow, I'm glad you found it. I was getting worried. Because the next thing on my mind was bad. Something that would effect the volumetric/pumping efficiency could also cause that.