IAC nipple exposed...

[goalkeeper21986]

The X seems to be getting harder to start. Also, today after start, it idled very high (around 2000 RPM) for a good 30 seconds. Got me pretty worried.

I ordered a new Throttle Position Sensor (TPS) today. I'm hoping that, coupled with a cleaning of the throttle body, will do the trick.

Oh also, the shuddering is back and as bad as ever. First thing in the morning I will replace the fuel filter and clean the battery terminals as well.

 

[masospaghetti]

If you have P0171 and P0174 codes, you probably have vacuum leaks in your intake. Very common problem that results in poor drivability, especially at low throttle openings (like idling).

The rubber o-rings that seal the upper intake to the lower intake shrink and allow air in.

 

[goalkeeper21986]

Changed the fuel filter...it needed it! Check out how disgusting the fuel that came from the tank side of the filter was.

The downstream side fuel seemed clear, so at least it was doing its job.

The horrible shuddering that came back was because the lower bolt of the IAC had worked itself loose and had fallen out. The IAC was just hanging there. I cleaned the battery terminals while I was in there.

The shuddering is less bad, but I'm STILL getting noticeable vibration at idle. I think I should check the fuel pressure now that the filter has been changed, I wonder if I ruined the fuel pump with the old filter? I'm thinking of putting some fuel system cleaner in the gas as well. Would someone recommend one brand vs the other? Also, fuel injector cleaner/valve/fuel system cleaner? Which one or are they all the same.

I'm also thinking of seafoaming the throttle body. I ordered a new TPS so I might make that one job.

 

[goalkeeper21986]

I back probed the TPS this morning. .8V at idle and 2.5V with the throttle pedal fully depressed. 2.5V is out of spec, so looks like I was right in ordering a new TPS. Hope it helps.

I also checked coil voltage, primary and secondary resistance.

I was getting secondary resistance and got right around 13.5Kohms for each pair, however, Haynes says it should be 6.5-11.5 Kohms. Is this a problem?

 

[GRNMACHINE]

Curious, which IAC did you order? FORD OEM is pricey, and from my understanding, should have the cap on, there is a filter located within the cap.

 

[Runnin'OnEmpty]

........I also checked coil voltage, primary and secondary resistance.

I was getting secondary resistance and got right around 13.5Kohms for each pair, however, Haynes says it should be 6.5-11.5 Kohms. Is this a problem?

That's fine, as long as the values are close on all
three packs. Resistance varies with temperature, so
that might account for the difference.

 

[koda2000]

while disgustingly, the gunk that you got out of your fuel filter, on the tank side, is pretty common/normal. that's why i plan on cleaning my fuel tank while i have it out changing my fuel pump.

 

[goalkeeper21986]

Curious, which IAC did you order? FORD OEM is pricey, and from my understanding, should have the cap on, there is a filter located within the cap.

To be honest I ordered the cheapest one on RockAuto.com

 

[goalkeeper21986]

RunningOnE, thanks, looking around on here ~13K is pretty normal for a lot of people.

Koda, thanks, good to know it wasn't just me.



Anyone have trouble getting the TPS screws out? They're soaking in WD right now, but still won't budge. I'm thinking of using a manual impact driver to get it out if it won't go.

 

[backroads]

Did the new tps help? I'm having similar problems,shuddering, missing,rough idle. Could be the same thing.

 

[goalkeeper21986]

Did the new tps help? I'm having similar problems,shuddering, missing,rough idle. Could be the same thing.

It should get here on monday, Ill keep you posted

 

[goalkeeper21986]

Going to buy a manual impact driver to get these stupid TPS screws out...
http://www.northerntool.com/shop/tools/product_36882_36882

 

[backroads]

Goalkeeper

The problem with the screws is that those are supposed th be torx with the security pin in the center, so you would need a torx with the hole in the center that fits over the pin. They did that to keep customers from cleaning or replacing it on their own. On one of my origional screws there was a drop of some glue to make it more difficuld. I removed it with pliers and then heated it to burn out the glue stuff.

Someone probably destroyed them to get them out and then used some phillips head screws with the wrong threads on them and forced them in, and now they're locked would be my guess.

BR

 

[goalkeeper21986]

@backroads, the screws on mine are regular phillips - M5-0.8x30 if I remember correctly (replaced them at Lowes). They were totally stuck. Manual impact driver worked, being VERY careful not to strip the head and using lots of penetrating oil once a little gap opened up.

As far as my idle issues...

SUCCESS!!!!!!!!!!!!!!!!!

The story: I ordered a TPS from RockAuto for my 99X Sport, OHV. Guess what...the one I got was not the same as the one on my vehicle. Same mold-line, but mine turned left while the one I got turned right. A trip to autozone, they were going to give me the same one, so I got the correct part, mine just doesn't use the correct part. We ended up having to use a TPS out of a 2001 (we didn't check 2000 but my guess is that probably would work), weird, but maybe mine was built late in the production of the 99s?

Drove around for a while. WAY more power and throttle response. I'll see if the lean code comes back, but given that at full throttle the TPS was only reading 2.5 volts, I could imagine the engine getting WOT air but only half the fuel, triggering a lean code. Will update if anything changes!

 

[goalkeeper21986]

No CEL yet, so I think I got it fixed.

Thanks everyone for all of your help! I'll post a summary when I get a chance!

 

[goalkeeper21986]

NOOOOOOOOOOOOOOOO

IT'S BAAAACKKK...I'm so mad.

Clearly I keep getting duped by the computer. Every time I change out something and I've unplugged the battery in the process, i think it's fixed...that is until a few days later when the computer has had time to process everything and adjust itself into rough idle and CEL.

Not too sure where to go from here. My next steps are to check the fuel pressure and buy an OBDII reader. I plan on backprobing the new TPS to see what the voltage reads.

Any other suggestions?

 

[backroads]

Bummer! Have you changed your plugs and wires, that could be part of the problem. Sometimes it's a combination of things.You could also have a bad injector,thats what I think I have going on (vibration at 1/2+ throttle). The problem with injectors and code scanners is that a cheaper one can't tell you if it's a bad injector if it's partially clogged.You need a ford dealer one or an expensive pro one to read fuel curves and more in depth injector info.I'm too cheap right now to go to the dealer and pay $$$ I'm thinking about a scanner too but I need to figure out which one to get. I'm just living with the vibration for now.

BR

 

[1992fordgreen]

Did you ever replace the ECU? could be leaky capacitors.

 

[goalkeeper21986]

Plugs/Wires are less than a year old.

I ordered an OBDII scanner to see if I can see O2 voltages (even tho they're new), intake air temp sensor voltage, and anything about the fuel line.

I basically plan on getting everything whittled down to fuel injectors and replacing intake gaskets and then spend a weekend on that if necessary. I've had shops look for intake leaks twice...but if it wasn't cold enough maybe that would cause a false negative.

92fordgreen, never thought about the ECU. I'll have to read about it.

 

[goalkeeper21986]

Did you ever replace the ECU? could be leaky capacitors.

You might be on to something...Reading up on other threads, it seems it's definitely worth pulling the PCM and checking the capacitors. Will update.