i took my spare trottle body to work and cleaned it with solvent for like 15 minutes. then brushed everything with a fine scraper brush. soaked it in solvent for 2 hours and then cleaned it all off with hot water.

anything else i need to do before i put it on my engine? do i need a new gasket for the throttle body/plenum?

after cleaning all the carbon and gunk off it, do you think it will help my engine at all?

 

It will certainly LOOK better. As for the cleaning actually helping with performance, it really depends on how filthy it was especially in the idle air passages. With the fuel injection the throttle body is really only an air gate. So if you had rough idle or low-end "tip in" response issues then you could well see an improvement. Otherwise you will have the satisfaction of knowing that the TB is clean.

As for the gasket, I would recommend replacement just to be certain you don't end up with any leaks between the TB and upper plenum. I assume you removed the IAC and cleaned it as well. Best to replace that gasket as well. You may have to buy the gasket material and cut that one since I have never had anyone be able to find the IAC-to-throttle-body gasket by itself. New IAC's come with them and that's the only place I've ever found them.

 

every passage way was coated with black carbon build up. i did clean the IAC too but i used carb cleaner for that.

it looks squeaky clean now and no build up of any kind inside the throttle body. i even throughly cleaned the springs on top to make sure there was no rust or sand in it.

i'll make a run to the parts store and hopefully they have the plenum gasket but the other one for the IAC i can reuse the old one, its not torn yet

 

the throttle body swap was performed today. it went easy. i put new throttle body gaskets on (plenum one and the IAC one. they sell both at carquest if anyone needs to know).

after doing the conversion from the old one to the cleaned one it definitely fixed many problems i was having but new problems arose. when first starting the truck, the check engine light is on constant until i rev the engine hard to 2500 rpm from idle then let off quick.

extracted codes:
31= PFE EVP circuit bellow .24 volts (both times engine on and off)
53= TPS circuit above max 4.5 volts (engine off)
62= 4/3 or 3/2 pressure switch circuit failed open (engine off)
63= TPS bellow minimum .6 volts (shown when engine was on)
98= hard fault present (first code shown when the engine was on)


what do i do? engine runs fine. slight hesitation but much more improved then the old throttle body.

 

Ok, for starters you can rule out one thing. The 5VDC reference voltage power supply is good. Code 53 proves that one. Secondly, your PCM should not generate code 62! Code 62 is a fault code for the AXOD transmission. No such animal in a Bronco EVER! Code 98 is a freaky one. It indicates that the PCM found insufficient hydraulic pressure in the transmission during the KOER test... engine running SHOULD have hydraulic pressure in the transmission. This interpretation of code 98 ONLY applies to E4OD equipped vehicles. I am assuming your Bronco is so equipped.

Otherwise, for the two that show voltage too low, you might consider checking the connections at each of these sensors. Weak connections or damaged wires will cause this issue. The EVP code sounds like you either have a bad connection to it or the sensor has failed. You can check the voltage coming back to the PCM from the EVP sensor by taking a voltage reading at pin 27 of the PCM. Assuming the PCM isn't lying to you, you can disconnect the EVP sensor and jump the ORANGE/WHITE wire and the BROWN/LT. GREEN wire at the pins in the EVP sensor connector in the main wiring harness. With these two pins jumped together you should get the same voltage reading on pin 27 as you get on pin 26 of the PCM (approximately +5VDC). If the reading is different, you have a wiring issue that needs to be addressed before you replace the EVP sensor.

The fact that the TPS triggered two completely opposite codes (53 & 63) makes me wonder if it hasn't failed. Pin 26 of the PCM is the reference voltage (VREF). It should carry +5VDC approx. Pin 47 of the PCM is the signal return to the PCM from the TPS. With the throttle closed the TPS should not drop below 0.6VDC at pin 47 (0.72 is about normal for most TPS). At WOT (wide open throttle) the TPS should not exceed the 4.5 VDC maximum at pin 47.

Be sure to clear the codes after you have checked into these issues and before you run the KOEO and KOER tests again.

 

code 98 didn't sound too good to me. i assure you there is nothing wrong with the transmission its self unless its a circulation problem i am not aware of. otherwise it works fine.

my tranny is a AOD, not E40D. the voltage codes before never tripped the check engine light before until i did the ground pin test.

i am assuming the code 98 is what tripped the system to show check engine. but after i replaced the throttle body and TPS i don't know exactly why the thing is tripping more codes.

any idea when i rev the engine quickly and hard it makes the light go out until the engine comes to an idle again?

 

Then disregard what I said about Code 98. In your case Code 98 means that there are enough problems found in the KOEO test that the KOER test cannot be performed accurately.

So address the problems found in the KOEO test then run BOTH tests again after clearing the codes.

The CEL is being triggered by the EVP sensor issue and because the position of the EGR valve (monitored by the EVP sensor) changes with acceleration you are getting a condition that changes through out the RPM range of the engine.

 

how do i clear the codes? i know how to get the codes with the simple test but how to delete them, i don't know.

does disconnecting the battery for 15 minutes do anything?

do i need a code reader to delete codes? i got a OTC genisys and a mac mentor at my work. usually they don't do **** with my engine. does this dumb test and comes up with nothing

 

Just disconnect the battery for about 10 minutes.

 

what about taking the positive and neg off the battery and connecting them together for anything that stores voltage build up?

 

NO! Capacitive loads must discharge on their own. Attempting to "speed up" the process has the same potential to fry electrical components as a lightning strike!

 

so after disconnnecting the battery for about 2 hours and connecting it again, i started it up to let it get all the bugs out of it and reprogram its self.

i took it for a 4 mile drive and it runs worse. there is a bigger hesitation when you push the gas from a stop. check engine light didn't come on until i drove it. the light still goes out when i push hard on the gas and let off fast then comes back on when the engine is at idle.

and i am noticing a higher RPM range at idle 800-1000 rpm.

at least now i don't have the jake brake effect when i want it to coast (puts resistance against the engine after letting off the gas and coasting)

 

Yes, nothing will improve until you correct the problems that are causing the codes that were thrown. I would be willing to bet you have the same codes (if not, more) now that you have run the truck again.

 

there is no dought i have more codes now then before i started. one or 2 codes set it over the edge to trigger it.

 

this is ridiculous i can't go to work today because i can't get the idle to come down from 2000. i started it and it climbed to that and has not come down even when the engine temp is warm.

should i blow out the 2 vacuum lines on the side of the throttle body?

something tells me the o2 sensor got messed up and is messing with the engine temp.

i can't express enough what a dumb idea this was