I need your Diagnosis!

[keifer1122]

ok bronco2 ran fine all day and when i got close to the house everytime id hit the gas the truck would bog down and if i pushed the throttle to the floor boards my car would backfire but its not backfiring out the tailpipe, its backfiring out the air intake hose. so n e ways had to get her home but i couldnt get enough rpms to move so i shut it off and restarted it and it worked fine like nothing happened so i drove it home then i neede a cold six'r so i wen to the store everything was fine to the first street light. then i hot rodded it to the next light and when i got to about the 3grand on rpm gauge while my foot was to the floor it just stayed at 3 grand wouldt go any higher.backed off the throttle and hit the gas again to the floor and bogg dwn till it backfired out the intake hose right at the k&n air filter.

any tips lets hear em.

 

[Downey]

clean your maf

 

[Tyler M]

clean your maf

Unless his 2.9 is a California Emissions spec engine or a computer conversion has been done, the 2.9L is speed-density fuel-injection not mass-air fuel injection. However the problem does sound computer related, try changing the MAP sensor.

 

[Downey]

whoops not thinking old enough

 

[keifer1122]

yyea its got a map sensor im goin to go get 1 right meow

 

[holyford86]

pull codes, throwing parts at it won't fix the problem, unless you get really lucky

 

[jasongind]

stop hot rodding a 2.9 might help also.

 

[keifer1122]

wheres the map sensor located at . lol funny thing is u cant hot rod in a 2.9 fyi

 

[keifer1122]

well changed the map sensor still no go so im going to take that back tomorow. i dont think its o2 sensor cause when i drove it back from the muffler shop they didnt hook it up ran ok lilttle ruff but not like this.

 

[nightshift]

First...

First, pull the codes, and follow the flow chart for the codes you get. You're shooting in the dark if you don't.

Also, look at the cap and rotor. Tracking could possibly cause the backfire through the intake.

Also, check the fuel system, particularly the fuel filter. Fuel starvation could result in what is known as a "lean backfire", which may be the backfire through the intake you're seeing.

Fix this before you screw up your MAP sensor. It must be lovin' those backfires through the intake.

 

[keifer1122]

pulling codes 41 system lean-fuel control and 77 Goose whats the goose when do i have to move throttle halfway dwn i dont get the goose code pls explain. also since its starvin for fuel where do i start i was thinking the fuel pressure first thing

 

[Tyler M]

Interesting, my truck threw code 41 at me about a 2 weeks ago but I did not have any of your symptoms. I changed the oxygen sensor when I did a tune up and that made the code go away. When was the last time your O2 sensor was changed? As for code 77, my book on the EEC-IV computer says that it is an operator error during dynamic response test and that wide open throttle was not sensed. The purpose of the dynamic response test is to check proper function of TPS, MAP, and knock sensors.

 

[keifer1122]

yea its something electrical i think cause when i first start the car it runs fine then as soon as something heats up looses power like when i restart the computer resets itself

 

[IMenriched]

yea its something electrical i think cause when i first start the car it runs fine then as soon as something heats up looses power like when i restart the computer resets itself

How much time has the O2 sensor have on it??
When was the last time it was tuned up....plugs, wires cap rotor, fuel filter??

I'd be suspicious of o2 sensor at this point, one point of this is that the muffler shop didn't hook it , the O2 sensor, back up and it ran better. Hmmm

so when you hooked back up it returned to running worse. faulty sensor feeding bad info

another thing is to check.... that carbon hasn't clogged or restricted one of the ports in the upper manifold

 

[keifer1122]

i did a full tuneup i unplugged the 02 sensor and ran it still the same way idles fine little rougher but when it gets warm and i give it gas its the same way boggs dwn and backfires threw intake so far i changed map sensor throttle position sensor 2 heat sensors on upper/lower intake, the big long round one on top of upper intake i think its iac. the cats are not pluggeg i just got new one a month ago. when i restart runs fine till it senses somethings hot then boggin