I need some EFI help

[Dyehard]

A little history first: 76' Bronco with original 302 block, 93' Thunderbird EFI (H2M1 EEC), I added the resistors connected in delta to eliminate the EGR.

I checked my codes and get the following:
181-Fuel system at rich adaptive limit at partial throttle / system lean
189-Fuel system at rich adaptive limit at partial throttle / system lean
332-Insufficient EGR flow detected

552-Thermactor air bypass solenoid circuit fault
558-EGR valve regulator solenoid circuit fault
565-Canister purge solenoid circuit fault

Are any of these causing the others? Can any of them be ignored without consequences? How do I clean this up?
Thanks,
Steve

 

[DirtDonk]

Interested to hear what the experts say as well.
Seems like the first two are the most important. The last three are either to be ignored or programmed out, but I don't know if they are causing the others or not. Don't think so, but someone else will know for sure.

Good luck. Seems like the first two could be a fuel pressure issue or throttle position sensor or something like that.
This is a Speed Density setup by your description. yes?
No aftermarket cam was installed at some point, was it?

Paul

 

[Jebus]

I have an 89 3.8 SC TBird ECU. SMPFI, w/only the EGR load sense module hooked up and no mil light. Those EGR codes are visible on mine with the ford scanner. My mil lamp comes on at key on and is off when running. I think I have read the EGR strategy is ignored if faulty. It runs fine.

The first two fuel system codes are worth checking into more though.

 

[Dyehard]

Thanks guys. Paul, mine is MAF not Speed Density. Also, I am using BC Broncos fuel lines, 23 gallon tank, and their fuel pump mounted in the tank.

 

[SevenT]

EFI help

Dyehard,

What kind/brand of harness do you have? That information will help us diagnose your problems.

v/r,

SevenT

 

[Dyehard]

I used the Tbird harness and reworked it to use in the Bronco.

 

[SevenT]

EFI help

Dyehard,

Did you electrically eliminate the EGR and purge functions in the harness? If not, that is why they are showing.

This is what I found on the Mustang forums:

DTC 181
Fuel system at rich adaptive limit at part throttle, system lean (bank #1, Passenger Side).

Possible Causes:

•Fuel pressure
•Fuel injector
•Air intake
•Manifold Absolute Pressure (MAP) sensor
•Fuel injector electrical circuit
•Fuel filter
•Vacuum
•Air filter

DTC 189 is bank #2 (the other side of the engine, Driver Side).

Hope this helps

SevenT

 

[CA Monkey]

not sure if your harness was originally MAF or not... if not.

if you swap from speed density to MAF, you have to change the MAP sensor to and open atmosphere sensor. Did you do that?

 

[DirtDonk]

Good point. Luckily the two are exactly one and the same inside, so all he has to do if it's being used as a MAP would be to disconnect the vacuum line (and plug it of course) and leave the sensor's port open.
Automatically turns it into a BAP sensor as long as that's what the computer is expecting.

Paul

 

[Dyehard]

This was never Speed Density. I took all of the EFI stuff straight off the Tbird (5.0 HO engine) and modified the harness to mate up to the Bronco and it runs great. I just want to stop the check engine light from coming on.

 

[ransil]

If its both banks are lean I would do the free easy stuff first.

vacuum leak , get a smoke machine google making one .
fuel pressure
fuel volume
clean MAF
change fuel and air filter if using a K&n throw it away and use something dry or an AEM filter K&N oil fouls out MAF sensors
exhaust leak ahead of O2 sensors

the delta EGR is questionable IMO , but it works pretty sure a simple divider wil work. I always keep the EGR Functional. this should not be an issue here.
I'm assuming the EGR has been blocked off if not make sure the EGR is closed

 

[Dyehard]

Thanks Ransil, yes the EGR is blocked off. I'm leaning towards a vacuum leak. I will check it out. Thanks again to all of you.

 

[needabronco]

I'd look for an exhaust leak and make sure your O2 sensors are plugged into the correct side.