1991 Ford Bronco Running rich

NICKOLYN1

MEMBER
1991 FORD BRONCO
V8
4WD
AUTOMATIC
112,000 MILES

My Bronco just had a major tune up consisting of:
spark plugs, wires, dist. Cap, rotor, fuel pump, fuel filter, fuel injectors, fuel pressure reg, map sensor, ignition control module, coil, IAC. It just about had all emmision stuff changed out. Even changed out the dist. Doubled checked the timing. Now my bronco is running rich with black smoke coming out of the exhaust. Its acting like the fuel filter is clogged. Can't give it throttle when under a load its bogging down. In neutral it revs up fine. I'm not sure what is going on. I don't have a CAT converter, due to long tube headers and don't have a O2 sensor either. It ran fine befroe but now I'm clueless on what is wrong.

4 Replies

BUDDYCRAIGG

MECHANIC
2,262 POSTS

Wow.
That was a lot of things to replace all at once.
If you paid a shop to do it. Take it back to them and tell them to fix it.

If you did it yourself.
Hummm.
Well why did you replace so much stuff?
A tune up at the most would be
spark plugs, wires, dist. Cap, rotor, fuel filter
you missed the air filter, oil change, tranny fluid change, coolant change.

Unless there is a problem you should not have needed to touch these items that you changed.
Fuel pump, fuel injectors, fuel pressure reg, map sensor, ignition control module, coil, IAC, distributor.

If you had a clogged fuel filter, it would be running lean, not rich.

If you brought this truck to me as it is. These are the things I would check in this order.

Spark plug wire order.
Timing
load balance test

good luck

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Thursday, December 25th, 2008 AT 9:55 PM

BUDDYCRAIGG

MECHANIC
2,262 POSTS

Sent via PM

What does a fuel pressure test show?
You replaced the regulator, hopefully it's just letting too much fuel pressure to the injectors.

Are the replacement injectors the correct type?
Nothing that would let more fuel get into the combustion chamber right?

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Friday, December 26th, 2008 AT 4:43 PM

NICKOLYN1

MEMBER
2 POSTS

Stiil have the same issue. No power under load and to much fuel. Can you set timing if the timing chain has to much slack? I'm thinking now it might be timing problem. I can set the timing according to spec. 10deg. BTDC. What about any sensors I may have missed or not set after changing them out?

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Wednesday, February 25th, 2009 AT 1:34 AM

BUDDYCRAIGG