99' V-6 24 valve double overhead cam. Not my truck thank goodness. My son's car ran great but had the engine ck light on solid. Insuff. EGR flow. EGR tested OK with Vacuum pump and ports were clear. There was a recall on DFPE sw for this. Car was past mileage (132K) so I changed it.

I removed throttle body to get at sw. Checked all vacuum ports, cleaned off throttle plate, sprayed lightly on Maf sensor wires with throttle body cleaner. Put it back together with new gasket. I was very careful.

I started it and it ran like crap. Bad idle or stall from low rpm. Going down the road at 60 mph I let off gas and it keep at same speed. Sometimes in neutral engine will race (3K) petal motion is smooth.

I cked for air leaks with a hose, no sound.

During a search someone had the same symptoms and fixed it with TPS sensor. I didn't touch this but of course turned it over couple times working on the throttle body, I didn't touch or spray the IAC. What happened?

 

Start looking closely for vacuum leaks around/under the throttle body. There's one big hose that goes under the throttle body on the intake manifold side that rots through often times. The throttle body gasket itself can be a source of leaks as well, this one will bite you easily if you let it.

 

Thanks, used hose to listen and mirror to ck. I'll do it again. I put a new gasket on base of throttle body. I saw that big hose will check.

Just wondering if TPS could cause both because all hoses look good under strong light.

I'm going to lube throttle shaft for staying at hi rpm. Cleaner may have caused a bind.

 

It's idling fast because there's a big vacuum leak somewhere. Notorious on early 24V 3.0 liters.

 

The TPS on my truck went bad. Apparently the wiring corroded causing a short. My truck would do the following symtpoms...

1) Would not engage into a gear past 2nd
2) Ran really high RPMs in 1st and 2nd
3) Ran really high RPMs idle
4) Random shut off.
5) When it finally died, the car would not start for anything!

The throttle position sensor really caught me off guard. I got one used for 20 dollars. No problems.

That is all I can say about my issue. Not sure yours is TPS related.

I would advise against is the use of TB cleaner on your MAF wire. From what I gather, that is a little harsh for it. I would check it for correct voltage if I were you just to be sure. Refer to your Chilton / Haynes manual for that.

IAC is a good thing to check. Whew, mine gets gunked up! I am always surprised of all the dirt that flows out when I spray it down with TB cleaner. IAC ever been replaced? It can go bad. I forget the mileage suggestion but it is recommended to be replaced every so miles. Again, Chilton.

Also, check for wiring shorts, spark cables, you know, give it the complete once over. Dad has a Taurus (96' New Body) so I took a look around to see if I could maybe help out but it seems like diagnosis at this level is about the same. Can you get a code? Best of luck!

Never heard of it. Hopefully never come across it!

 

Whatever is wrong is because I bumped or twisted it. Or it decided to fail from being upside down etc, ran perfect until I toke off throttle body. I'm getting some gaskets then taking it apart again and ck hoses,, thanks

It's hard to trouble shoot when you get into a blue flunk!

 

Yup, I knocked a hose off the back of manifold by throttle body. It has a boot like a 90 degree spark plug boot and was a loose fit. I used a plastic tie and its not coming off now...Runs perfect.

thanks Quintin and others for the help, I needed the boost.