Running so rich it's fouling plugs and stall,codes.

[wbrockstar]

Two ?'s ... is the fuel mpg still poor and is the MAF new or used ... What happens with the MAF disconnnected? Most times 'accelerator pump' type reactions are MAF related. The MAF may not be heating up or cooling off properly, or base volts could be off .. leading to incorrect MAF info to the computer. Air flow increases as soon as you goose the pedal, but fuel, in carb circuits/passages, takes a bit longer to get up to speed, thus the momentary enrichment by the accelerator pump helps the transition. Goofy MAF will lead to hesitation on acceleration.
I don't remember if the CTS and ACT sensors have been checked. Coolant and incoming air temps will lead the computer to fiddle with the mix. They'll put out a variable resistance based on temp. The TPS should vary in its output also, IIRC, up to about 1 volt at WOT, and less, in a smooth transition, as the throttle is closed. Ford may have changed from the system I remember.
tom

The tps should actually read close to 1.0 volt at idle then gradually increase to 5.0 volts at wot,not 1.0 volt at wot.The tps vref(supply)wire should read 5.0 volts with the key on/engine off and the signal wire should read 1.0-5.0 volts depending on what position the throttle is in.The ecm supplies 5.0 volts to each sensor,the sensor sends a voltage signal back to the ecm to verify that sensors status and then any leftover voltage that didn't get used by the sensor is sent down the signal return wire.Example::A sensor gets 5.0 volts sent to it by the ecm,it sends a voltage signal of 1.87 volts back to the ecm and the leftover voltage of 3.13 volts gets sent down the signal return.It definitely acts like a defective map/bp sensor,going by all the symptoms that were listed.The OP made a comment that detonation stopped after fueling up with 93 octane fuel and thats due to the fact that higher octane fuel doesnt preignite as easily as lower octane fuel does.Once you locate the source of your problem,there will be absolutely no reason you should need to run more than 87 octane. A defective knock sensor would also cause your issue.It retards ignition timing momentarily when detonation is detected,but when it goes bad ,poor fuel economy and poor performance occurs because instead of the timing being momentarily retarded,its constantly retarded.There are other things that will cause detonation too though,like a defective egr valve,too much compression due to accumulated carbon on the pistons,over advanced ignition timing,vacuum leak and a overheating engine.I would use a propane torch with a piece of hose attached to the gas valve and recheck for vacuum leaks.The egr valve diaphragm and gasket,evp gasket,fuel injector bosses,all vacuum solenoids,throttle body gasket,intake gasket,etc are all areas you need to check,don't just think that vacuum leaks only develop at hoses and fittings.The link below describes the propane method.A vacuum leak is well known as being the #1 cause for lean o2 sensor codes.
http://web.archive.org/web/20131229164247/http://oldfuelinjection.com/?p=93

 

[ben_2_go]

The tps should actually read close to 1.0 volt at idle then gradually increase to 5.0 volts at wot,not 1.0 volt at wot.The tps vref(supply)wire should read 5.0 volts with the key on/engine off and the signal wire should read 1.0-5.0 volts depending on what position the throttle is in.The ecm supplies 5.0 volts to each sensor,the sensor sends a voltage signal back to the ecm to verify that sensors status and then any leftover voltage that didn't get used by the sensor is sent down the signal return wire.Example::A sensor gets 5.0 volts sent to it by the ecm,it sends a voltage signal of 1.87 volts back to the ecm and the leftover voltage of 3.13 volts gets sent down the signal return.It definitely acts like a defective map/bp sensor,going by all the symptoms that were listed.The OP made a comment that detonation stopped after fueling up with 93 octane fuel and thats due to the fact that higher octane fuel doesnt preignite as easily as lower octane fuel does.Once you locate the source of your problem,there will be absolutely no reason you should need to run more than 87 octane. A defective knock sensor would also cause your issue.It retards ignition timing momentarily when detonation is detected,but when it goes bad ,poor fuel economy and poor performance occurs because instead of the timing being momentarily retarded,its constantly retarded.There are other things that will cause detonation too though,like a defective egr valve,too much compression due to accumulated carbon on the pistons,over advanced ignition timing,vacuum leak and a overheating engine.I would use a propane torch with a piece of hose attached to the gas valve and recheck for vacuum leaks.The egr valve diaphragm and gasket,evp gasket,fuel injector bosses,all vacuum solenoids,throttle body gasket,intake gasket,etc are all areas you need to check,don't just think that vacuum leaks only develop at hoses and fittings.The link below describes the propane method.A vacuum leak is well known as being the #1 cause for lean o2 sensor codes.
http://web.archive.org/web/20131229164247/http://oldfuelinjection.com/?p=93

I used ether instead of propane.I found nothing.TPS checks good.Damn thing is a pain to get to for a short person like me.I haven't had any over heating.I didn't think about the knock sensor.I'll have to find it.I haven't been having ping/knock.Fuel mileage is around mid 20's.No codes are showing when the truck is scanned.I haven't tried going down in octane because the GF has been driving it and putting 93oct in it.I'll try 87 since we are being flooded right now and I can't get outside to screw with it for a while.All of my intake gaskets and anything associated with the intake has been changed.I can't get the plugs or wires out on the drivers side without removing the intake.I replace the gaskets every time.I cleaned the EGR and IAC again this last round and replaced the gaskets.

 

[ben_2_go]

The truck engine has bent cam followers and that is why it's been acting up.There's a back story to this.I'll get to it after a quick update on the truck.Unfortunately,or maybe fortunately,the truck was rear ended on the interstate this past friday.My girlfriend and our son are both ok.She completed her trip to Kentucky to see her oldest daughters, and help with their family reunion.I haven't seen the truck yet,so I don't know how bad it is.I was told the bumper didn't make it,the bed was buckled and pushed up on one side,and the chassis is twisted and bent.

Now the back story to why the engine problems exist.This truck was rolled over back in 2003 while my girlfriend was still living in Kentucky.My girlfriend pulled over on a single lane mountain road, to let a car pass.The road side caved in,rolling her in the truck upside down in a creek.The creek undermined the road during a flood.It couldn't be seen.We repaired the truck back then.It just need a cab top,glass,doors,and hood.During this time,the engine was hydro locked with oil, from where it was upside down in the creek for a day.Sometime after the truck was recovered, some @$$hole thought it was a good idea to try and start the engine.They told my girlfriend at the hospital that the engine was locked up.After I got up there and brought the truck back to SC with me,I checked the engine out.It was still hydro locked with oil.I knew from my atv days,to never attempt to start an engine after it had been upside down for a while.So I pulled the plugs,and spun the engine over by hand.It was a pain,and sprayed oil everywhere.

So why am I telling this story.Because I feel like such a dumb@$$ for not remembering this, or even considering it a possible link to all this wasted time and money.I have been fighting this truck,ever since we finished the body work back in 2005.I feel like such and idiot.All the years I was a pro mechanic and I let this get by me. Now I remember why I gave it up.

 

[RonD]

Thanks for the update

Yes, short valve throw would account for problems

 

[ben_2_go]

Thanks for the update

Yes, short valve throw would account for problems

This has been a horrible year for car/truck/motorcycle problems.I'm running out of money and ways to transport the family and myself.I just posted a wanted ad in the proper section of the forum.


Again,thanks for the help everyone.

 

[ben_2_go]

Just came in from looking at the truck.I am surprised she made the last 500 miles after being hit.The truck is beyond repair.The frame is bowed up from the rear to under the cab.The frame would have to be back halved just under the cab,ahead of the rear cab mounts.The drive shaft has been against the tail housing from it being driven, and the suspension cycling.The transmission problems are way worse than before.The front leaf spring hangers are twisted, and that's twisting the leaf springs.The axle is cocked side ways, and already wearing the tires.The truck isn't even worth selling as a parts truck now.