86 GT V6 2.8 Open loop - very rich, Closed loop running rich (but thinks it's lean) (Page 1/1)
random69 JUL 18, 04:06 PM
This is my first post, so forgive me for asking so much. I've checked other posts and researched as much as I can to find out what's going on with this car.

This is a pretty much stock setup except:
* Cold air injector deleted and sealed - both sides.
* EGR removed - both sides plugged. PROM changed to remove this function.
* Cruise control deleted, and lines plugged/rerouted as needed.

It reeks of gas out of exhaust in open loop and closed loop. The BLM and INT numbers are up so it thinks it's lean (150 on the blm I've seen). It runs fine otherwise and can be driven, but still stinks of gas big time.

Also, in open loop when cold, I have to give it gas to keep it running. Takes a few cranks to get it started. Runs and dies until closed loop.

I've done just about everything, with the latest being injector swap.

1. FJ9 injectors put in. RP injectors taken out. No leaks from injectors. All consistent ohm measurement. All balanced with same pressure drop.
2. Replace plugs with stock copper.
3. Replaced wires, cap, rotor, coil. Nothing enhanced here.
4. Holley FPR added and also vacuum checked (had to add rubber seal to top screw to prevent vac leak).
5. MAP sensor replaced twice and tested manually and in car with no issues.
6. Oxygen sensor behaves - was replaced.
7. ALL temp sensors replaced and tested - work good.
8. Fuel pressure set to 40.5 (have tried different ranges (30-45)- didn't seem to matter.
9. Timing checked. Spot on for both #1 and #4. Yes, with jumper.
10. Gas is slightly old, did add new and additive.
11. Haven't SEEN any exhaust leaks before o2 sensor. Still have to check w/smoke to be sure.
12. TB screw set right based on iac counts.
13. Tried lowering BPC in prom (two places) about 25% (thinking fj9 injectors had higher flow rate)- still no dice and ran worse - went back to stock tune.
14. Changed out ECU's. No change. I have the slow one. (7170 I think).
15. All engine bay wiring contacts have been cleaned with deoxit. Some connectors replaced as plastic broken.
16. Sensors are seen by ecu using Winaldl. ECU contacts cleaned as well.
17. Checked for gas leaks - none.
18. Fuel pressure holds fine for several hours.
19. TPS and IAC have been replaced and tested manually - they are working correctly. Winaldl sees them.
20. Vacuum lines replaced with stainless steel. Smoke tested all ok.

So... here's my questions:
a. WTF?
b. FJ9 injectors - bought off of rockauto. I cannot find ANY specs on these. Anyone have any? Should I clean the RP's and replace those back in there? I do have a set of refurbished RP's coming soon.
c. Bad gas still?
d. I get no stumbling or misfires I'm aware of. Ignition issues?

Any other suggestions? One of my friends told me to jack down the pressure, I can only go as low as 30.

Thanks!
sleek fiero JUL 18, 04:46 PM
Did you check the brake booster for vacuum leak or the pcv valve can cause upsets in vacuum and affect fueling.. I tried a set of Accel 19 lb injectors and they definitely wanted to over fuel my engine no matter what fuel pressure. I changed to ford racing 52 lb injectors at 42 psi and it runs great now. oh and I eliminated my cold start injector and EGR.
also I presume you take out for a run to allow the ecu to adjust to its new settings

[This message has been edited by sleek fiero (edited 07-18-2023).]

random69 JUL 18, 06:46 PM
Yes, I replaced the PCV and did check the brake booster for leaks. I did not check the pcv pipe - it is stainless except the ends. Thanks.
XxdjxX89 JUL 20, 12:04 AM
I’ve experienced a similar issue , yes I’d have the rochesters flow tested , when I had the accel 15lb injectors my blm and int we’re doing the same as your rock auto
now one other possibility that’s usually overlooked is weak spark