acting weird

[swynx]

So I've previously had a high idle problem. Ron was helping me with that but then I tore the front end down and installed a aussie so I haven't fiddled with the high idle. . Started it up, it has a squeel. When I let the clutch out without pushing the gas to see if it would move it idled down really low and stopped squeeling. Then rpms jumped to 3000 and it ran funny. Then ran high idle but not rough. When I shut it off it has a real distinct hissing sound.

I have replaced Tps iac both 02 pcv valve maf fuel pump fuel filter fuel pressure regulator ect sensor

Idk if it makes a difference. My buddy said it wouldn't matter but I thought it would. They didn't give me any gasket for the maf so I used red gasket maker.

It also seems to get worse with every new sensor I change. Fuel pump/fpr is what caused this. It never idled high before that. It was drive able before I changed maf and pcv

 

[black_demon69]

have you checked TPS sensor?

 

[truckerdawg]

I am not a big fan of just replacing things-it gets very expensive really quick without fixing the problem. But here goes another suggestion- the cam position sensor. Erratic readings will cause poor idling and may be jumping timing to increase rpm's. Squeal could be gear in the bottom binding if there is a lot of wear. But if you don't have the sensor type all bets are off-I think after 92 they do.

 

[swynx]

Tps is new although not checked. Pretty sure its on warranty. Maybe ill get a new one. How do you check? I have multi meter. 'm going to be unplugging sensors today to try and make headway.

I did just replace sensors. It was 100$ a payday on sensors. Its a 300k mile engine so I figured it couldn't hurt. Plus everything I've done has made an improvement some how. All the new sensors made it run better but with a high idle.

The cam position sensor. I haven't replaced that. I've thought about it.

The truck does have cel. But its had a cel since before I first road in it.... 3 years ago. I've owned it a little under a year . I was going to go to the auto parts stores when it running good enough and have them run codes.

 

[ab_slack]

The truck does have cel. But its had a cel since before I first road in it.... 3 years ago. I've owned it a little under a year . I was going to go to the auto parts stores when it running good enough and have them run codes.

Should be possible to pull without a reading. There was something in the tech library I thought.

 

[swynx]

I found the vac leak. My buddy left a hose unhooked when he put on the PVC valve. Its driveable but stillbidles high. I found a hose that only stays on because of the suction. Its pretty lose fitting. There is a egg valve controller thingy I unplugged it and nothing happened. There is positively no air leaks

 

[RonD]

Pull off the air intake plenum on the intake manifold, the BIG air tube.
Look inside and make sure throttle plate is closed all the way, if in doubt remove throttle cables, gas pedal and cruise if so equiped.
And see if it is closed now.
Throttle plate should seal the intake, IAC valve passage should be the only place for air to enter.
On some model there is a screw adjustment on the throttle linkage, people often adjust this like an idle control, it's not, but it is sort of an idle control in that it is a stall preventer idle control and a TPS sensor adjustment.
Anywany make sure that hasn't been set to high causing high idle

Start engine, place hand over intake to air starve the engine, engine should start dieing pretty quickly, if not, any air leak should start to get louder.

 

[swynx]

today I removed all of the throttle linkage stuff. Even replaced the throttle body. No difference. Unplugging the iac doesn't do much difference. I thought about messing with that screw to close the intake more but I didn't. I'm thinking about replacing the iac. Pretty sure it had a 2 year warranty

 

[RonD]

Why wouldn't you close the throttle more if you have a high idle?

If that screw is holding the throttle plate open too much then IAC valve can't do it's job.

IAC valve is controlled by the computer, and the computer reads the pulses from the Crank position sensor to determine RPMs.

The computer has preset RPM settings base on coolant temperature, it gets this from the ECT sensor
Cold engine should idle at about 1,000 RPMs
Warm engine at about 750 RPMs

The computer opens and closes the IAC valve to raise and lower idle.
If idle is higher than 750 because of other reasons then IAC can not lower it, and unplugging it won't change that, it is already closed all the way by the computer trying to lower the idle to 750

 

[swynx]

Today I'm going to mess with it more. I didn'tess with that screw because I had to put my car in the garage and was working on the truck in the drive way. Then it decided to rain. I did find. Spring that was not hooked up on the throttle body. Made no difference once hooked up

 

[swynx]

Alright so I messed with that screw a little. It made no difference.

Ran all around town just to find out that nobody has an obd 1 scanner for ford. So I bought one off amazon. Innovation 3145.

Unfortunately I couldn't get the engine running codes from it. The triangle showed up for test mode but it just sstayed 000. And yes I warmed it up 5 minutes then took the trash down.

With engine off I got codes

116-engine coolant temperature higher or lower than expected. It never ggoes past half ussually sits at a 1/4 of the gauge. I did change ect sensor awhile back.

114- air charge temperature sensor higher or lower than expected.

327- evp/ept circuit below minimum voltage.

522-vehicle not in park or neutral during Koeo


Also, when I unplug this plug nothing happens. My understanding is its a egr controller thingy?

 

[swynx]

I unplugged the 2 hoses on that while running and it made no difference. I felt air coming out in quick short puffs but thats it.

 

[adsm08]

This may seem an odd question, but have you checked the charging voltage when this happens?

And that's not an "EGR controller thingy", it's the Differential Pressure Feedback Exhaust Recirculation Gas sensor" or DPFE for short. It's the sensor that tells the computer when and how much EGR is flowing. Has less than nothing to do with idle.

 

[swynx]

reads fine on the gauge. Never had any charging issues.

 

[adsm08]

I don't give two shifts about the gauge. I want a number with a voltmeter.

Overcharging can make the computer do all sorts of stupid things, and the alternator loading up real high can cause a squealing.