So here is the rig
1990 Bronco XLT
302 (5.0)
automatic transmission AOD

Cold start Idles rough while the exhaust is black until it smooths out then it seems to idle fine and will even rev up fine.
When warm to running temp it seems to sputter hard until either Floored or backed off the throttle a little.

New plug wires new cap and rotor
All new fuel and temp sensors and TPS and a new o2 sensor.
New fuel pump

was plugged in to pull codes
No codes where found

Anybody have this happen to them?

 

Check the fuel pressure and stop using a code reader.

Use this procedure and see what codes you get.
http://fordfuelinjection.com/?p=13

 

I have done the light way but the computer pulled the same thing
How do I get a reading on the fuel pressure?

 

If you got no codes then somthing is seriously wrong. You should of atleast gotten 11

Youll need a fuel pressure gauge to read the fuel pressure.
You can get inexpensive ones at any chain parts store.

 

Nothing out of the ordinary. Now the cold studder has seemed to disappered. but it still seems to be missing pretty bad.
I will check the pressure next to see what I get. Thank you for the info

 

"Black exhaust" is a symptom of bad fuel/air ratio. If the computer can't find it, then its somewhere that the system is not monitored OR the system is getting readings that are "within parameters". If exhaust is black at idle, its unlikely that the problem is fuel pressure unless there is almost NO air getting into the system simply because excessive fuel pressure at idle is far less likely than low pressure. Not that its impossible, just less likley.

The FIRST thing to check since there are no FAULT codes being generated, is the resistance of the ECT sensor. If the sensor no longer changes resistance, it is possible that the PCM is getting a reading from the ECT that the engine is extremely cold and therefore the fuel/air mixture is being run very rich by the computer. This isn't necessarily something that computer see as a problem since the engine CAN be VERY COLD at times and so this is considered to be "within paramters" even though the engine is warming up. I will try to find the exact resistance numbers for the ECT sensor and post them. I've got 'em here somewhere. If the engine warms up and the ECT sensor still "tells" the computer that its cold, there is the root of your problem because the computer is still running things as though the engine needs the extra fuel for cold running.

(The truth of the matter is, that if you want to get a little more performance out of the truck, you can replace the ECT sensor with a resistor that makes the computer "think" the engine is still a little cool. This ups the fuel in the mix just a bit. I don't recommend this for daily driving at all. Its a "track and trail" trick for boosting the power temporarily AFTER the engine has warmed up.)

 

Thank you for all that info. It only starts rough then smooths out. Runs best when it is cold as far as throttle responce goes. When it is warmed up it really sounds like it is missing when i try to accelerate until I get the rpms (flooring it) up or I let off the gas a little

 

hey if your ecu needs repair i can do it for 50.00 (plus shipping). 12 month guarantee. if it is burnt and cannot be repaired i can offer a replacement for 100.00 shipping included.

lemme know thanks.

 

Run 2 bottles of heet and 2 bottles of iso heet water in the gas can cause all kinds of havoc that seems like bad sensors. If it is not throwing codes run gas line dryer on whatever is in the tank 1/2 1/4 tank run until almost 1/8 tank refill with fresh fuel and 2 more bottles. $7.00 can fix phantom problems or at least rule out water in the fuel!! Then get back and we can go frome there with the multi meter.