Weird stall issue on my 99 2.5

[Ranger Sport Honduras]

Sup guys, well here it is, i have this weird stall/chug issue on my 2.5, its been there almost since i got it.
the truck had a full tune up when i got it(back in 08). It also got a new fuel pump and filter.
later on the road it got a new iac, cleaned injectors, cleaned maf, and replaced both coolant temp sensors.
currently runs and idles like new. No Check Engine lights, runs like a champ.

now the issue:
1.when i start it on cold, if i dont let it warm up like a minute or 2, when i attempt to take off it just stalls or bogs. ive noticed that if i rev it on neutral it wont rev. it just stalls and then it revs. thats not present if i let it warm up for a couple mins.

2. im driving down the road, then i start releasing the gas, to slow down because of traffic or tight turns if i feather it for a while and then start pressing to gain speed it wont rev up. it will just stall/bog until it suddenly takes off or i clutch it, rev a couple times and release clutch.
Thats very annoying and unconvinient on traffic. sometimes it wont wake up even if i downshift.

Ive noticed that it does it while trying to take off at a stop sometimes.

What are the chances that the accelerator cable is gettin stuck, or something related ot it?
i already did the zip tie mod, is there a chance that thats the reason for this?

keep in mind my clutch pedal is kinda low, seems like the pedal pump is going out. but that shouldnt affect when im driving on the road.

thanks in advance,
RSH

 

[adsm08]

Well, I looked over the service bullitens and there is one about a revised MAF sensor. You are only supposed to install it if codes P0102 or P0103 are in memory.

The other thing that may do that is a bad throttle position sensor. It may be taking the computer a moment to realize its getting more air. Check the TPS for dead spots with an ohm meter. If you can get someone to try and check for codes (memory codes won't turn the light on) that would help too.

 

[Ranger Sport Honduras]

Thanks ADSM.

ill check the TPS
how do i do it? LOL

and ill try to get someone to scan it for codes.

so theres no easy "clean this thing" solution?

 

[Ranger Sport Honduras]

ok i read some info about it on the tech library.
now i get how it works.

so if i decide to replace it, do i need to adjust the new one?
or its tuned from factory?

or should i try cleaning mine first?
ill try to check it with the volt meter asap.

 

[Earl43P]

Can't really clean the TPS.

To test it, turn the key to Run but engine not started.

Backprobe the center wire (DC volts) and move the throttle throughout its range.
Should get .9 (TB closed)to almost 5 volts (full throttle).

When setting the new one, same test method, just use its slotted mount holes to align it to .96 to .98v with the throttle closed. Resist the urge to adjust it using the throttle screw unless absolutely necessary. Then reset the computer (disconnect battery, turn on headlamps, then Off, reconnect battery.

Random search link for your edification:
http://www.allfordmustangs.com/foru...ng-your-throttle-position-sensor-voltage.html

 

[Ranger Sport Honduras]

Can't really clean the TPS.

To test it, turn the key to Run but engine not started.

Backprobe the center wire (DC volts) and move the throttle throughout its range.
Should get .9 (TB closed)to almost 5 volts (full throttle).

When setting the new one, same test method, just use its slotted mount holes to align it to .96 to .98v with the throttle closed. Resist the urge to adjust it using the throttle screw unless absolutely necessary. Then reset the computer (disconnect battery, turn on headlamps, then Off, reconnect battery.

Random search link for your edification:
http://www.allfordmustangs.com/foru...ng-your-throttle-position-sensor-voltage.html

thanks for the help!

so if i decide to get a new one, i have to atjust it too right?

ill try to take a look at it tomorrow.

 

[Bryan22]

I'd start by checking fuel pressure when it's cold / acting up and see what's going on there.

 

[Ranger Sport Honduras]

I'd start by checking fuel pressure when it's cold / acting up and see what's going on there.

wouldnt a fuel pressure issue give a CEL?

ive been thinking about checking the fuel filter, its been running it for a good while...

thanks for the tip.

 

[Bryan22]

usually doesn't throw a code. If the fuel filter is the issue, you'll more than likely see lower numbers on the fuel pressure test.

And no need to buy a new TPS unless you confirm it's bad. try adjusting it and take some readings and go from there.

 

[Ranger Sport Honduras]

Yeah ill try the fuel pressure test, ill replace the fuel filter and then ill try to adjust the TPS.

if it keeps the issue then ill have to get it scanned and hope its just a new TPS.

 

[Ranger Sport Honduras]

TPS is reading 0.88-0.90 volts on closed throttle. and 5.36 volts on open throttle.
is there a way to test it for blind spots?

 

[wally]

wondering if you ever found your problem, I have a very similar problem and its not turning the engine light on. I have changed the EGR valve, IAC, DPFE, TPS, and cleaned the MAF Sensor as well as my throttle body. I'm thinking now it may be my EGR tube is broken (looks Roached anyways) which is allowing air in and its messing with my O2 sensors.

 

[keithm]

zip tie modification

I just gotta ask what is it.

Keith

 

[Ranger Sport Honduras]

if the egr tube is bad u could smell exhaust fumes on the engine or feel the heat.
it would also make a strong noise like pressure leak. at least thats what i saw on a broken one i saw.

i replaced the TPS and the bog is gone. it still hesitates a bit, but thats deff wires or spark plugs, or both.

the zip tie mod?

check this
http://www.therangerstation.com/Magazine/Summer06/throttlecablemod.htm

 

[Bryan22]

RSH, sorry i never saw your last question! but to those curious, you can just slowly go through the range of motion of the throttle to check for dead spots. the voltage change should be consistent throughout movement of the butterfly. If you see a spot where voltage goes to 0 the tps is bad.