[Tank92]

press gas pedal RPMs Drop!?(More information!)

Hey everybody, I'm having a few problems with my truck. They're kinda messing me up on what it could be.

92 bronco 302 e40d no major work.
Park Idle 900-950
Drive Idle 650-700
Headers no smog pump no cat flow 40


Okay the problem, My truck about a few weeks ago just randomly started to idle eradicly when i went to start it one day it was jumping all over the place! and wasn't doing much better while driving. Finally threw a code which was for the TPS after checking it it was bad and I replaced, Idle smoothed out alot better ( when i did this I also cleaned TB intake IAC etc. now the problem I'm having is that when I go and give it gas to keep it steady it drops down in RPMs when I'm costing it'll be at like 980-1000 RPMs and once i give it gas lightly and hold it drops to like 700 and kinda feels like it wants to go faster but something is holding it back, Once i give it alot of gas the rpms rise up but it's shifting at about 2500:doh0715: I'm not sure if I have any codes again need to check saturday when i go back to work got my MT2500 there. and I don't know if this was a command problem doesn't seem like it.


Now old buddy at work told me to just replace my IAC and it'll fix the problem but I know with fords it just doesn't work so easy.

Hopefully someone could understand this mess i typed and help me out

TIA
Frank

 

[waltman]

Sounds like you installed a faulty TPS. By the way, your RPMs should drop to 650-700 when in park...at least mine does.

 

[Tank92]

Yeah seems like it's advanced some. but I can't even get the timing on this truck right with any light I use. The timing mark always ends up on the buttom of the truck no matter what i set the base on the light too it barely moves I don't know might be a bad dampener in the pully ( I think it has one )

I'll try another TPS
(And yes I did buy motorcraft)
I don't buy cheap no names for fords.

 

[waltman]

Do you remove the spout connector when you time it?

 

[Tank92]

Yeah I have the SPOUT With the jumper type plug in it I remove it and doesn't retard my timing at all either, (Like it suspose to) I don't know I've been having problems with this truck since I first got it, well sortly after owning it. Fix one thing something else comes around

 

[waltman]

Yeah I have the SPOUT With the jumper type plug in it I remove it and doesn't retard my timing at all either, (Like it suspose to) I don't know I've been having problems with this truck since I first got it, well sortly after owning it. Fix one thing something else comes around

If the timing doesn't change when you remove the spout connector than I would say you either have a faulty spout connector or a break in the wire somewhere. Either way you will have to track that down.

 

[RLKBOB]

First don't assume the new TPS is bad without testing it first, backprobe it. Should be 0.5 to 1.0 Volts at idle(key on engine off) and 4.0 to 5.0 volts at WOT. I agree that something is screwed up if nothing happens when you remove the spout connector. I think the SPOUT is just a shorting connector, if so you should be able to just short it with a wire and see if that does anything(find out if this is possible before trying it though). You definitely need to pull codes before spending any money. Maybe the TFI module is going/gone? Might want to have it tested too(that's free).

 

[Mels]

Did you calibrate the TPS when you installed it? My dad replaced my TPS and didn't find out til after the fact it has to be calibrated...so we did that one day and it fixed my hesitation issue.

 

[waltman]

Did you calibrate the TPS when you installed it? My dad replaced my TPS and didn't find out til after the fact it has to be calibrated...so we did that one day and it fixed my hesitation issue.

Yes, that's right, check the TPS first.
How do you calibrate the TPS anyways?

 

[Mels]

You have to get a voltage reading on it and move/turn it until it's reading in range.

 

[Mogley]

I decided to clean my IAC after the tech write was posted about. I didnt have any idle prob's before the cleaning, but afterward mine would idle over 1000 rpm in park nonstop, I unplugged my IAC and the idle went down to normal. Ive just been leaving mine unplugged till I can afford a new IAC. So try unplugging yours and see if thats fixes it. If so you need a new IAC like me.

 

[Tank92]

I don't think my TPS is calibrated type it doesn't have adjustments, (some year models did) I wonder if I mess up my IAC this was the 3rd time I've cleaned in in the past year might of got in the solenoid.

P.S
Where do I test my TFI?

 

[RLKBOB]

Where do I test my TFI?

Pull it off and take it to a parts store like Advance or Autozone, they will test it for free.

Mogley: if you're idle went up after cleaning your IAC you may have got some carbon lodged between the seat and disc. Try cleaning it again more thorough and move the stem with a scribe while blowing it out to try and make sure you get everthing out.

Even the non-adjustable TPS will adjust a little bit, just loosen the screws, you'll see that you can get a little movement. You can also drill out next to the screw holes to turn it into an adjustable one. Just gives you more room to adjust if needed.

 

[colinlesser]

check your TPS heh

 

[Tank92]

I just wrote a noval and it didn't post it! so I'm going to rewrite it short becuase i don't feel liking typing so much again.

Today i did some more things on the bronco.

Changed IAC no change
TB and Intake clean as can be!
New Air filter it was clogged no change
Used TB cleaner and Breakcleaner on everything no vacumm leaks i could find!


Using the Snapon MT2500

I got
1.07 on the TPS at idle(1200-1400!!!Park)
And 4.58 At WOT
Smooth flow as i opened the plate.

I went into Idle base adj mode and tryed to adj it down to normal

I got to .99 Volts and 800ish RPMS when it said correct Idle but it was boggin bad and shortly shut off wouldn't stay on so i put the idle back up.

If i remember correct my base timing is at 13Degrees.

I just don't know where to go from here.
I checked for codes didn't get anything but the RPMS are high in KOER and the 311 which is for the smog pump i removed, but a few weeks ago i got the 328 EVP circuit below minimum voltage of 0.24 volts. And both O2 lean and O2 rich codes. Deleted them and haven't came back.

EDIT:

Truck has always ran very very rich