Scan tool needed

[Ryan]

I don't know how you got this many replies into an OBDI scantool thread without anyone mentioning a paper clip or rocket science. That will give you the same thing a scan tool would.

If you read the manuals you'll probably find your answer. you can paperclip more than just TEN and GND, there are other pins that can tell you stuff in there.

you need to adjust your idle at the same time you adjust your ignition timing, or you're wasting your time. A new coolant sensor is like $20. Fan trick for the TPS is fine, its probably not your issue. Quadruple checked for vac leaks? tried other VAF, or tested current one?

[tbondo]

Thank you Ryan for your feedback. I have noticed through your other posts that you know a great amount about these cars. I will try and locate that information in the online manuals.

As for adjusting the timing/idle I am assuming you are referencing the TPS. Correct? I only have had a chilton manual to reference for adjustment and they only stated having the key "on" not running to adjust the TPS. Is there a "how to" somewhere out there that could step me through the correct way of adjusting the TPS?

I believe my VAF is in good working order. I tested it (again according to Chilton) last summer and it checked out good. I also tried unplugging it today and running the car and instantly it through a code and the car ran terrible. Sputtering and stumbling at idle. Plugged it back in and all smooth again just high.

I can't guarantee there are no vacuum leaks, but I tore it all apart last year. I may have to go through it all again.

[mikeinaus]

the first thing you want to do is throw out your chilton manual. they are so basic in terms of individual cars they are almost useless. read the online manuals. they have all the information you would need on how to test/remove and install almost any component in the car. by timing and idle he meant checking the cars timing and setting the appropriate idle speed.

just because i havent seen it posted yet have you adjusted the idle set screw on the top of the throttle body? 90% of the time of a high idle is a vacuum leak. check the pcv intake tube on the rear valve cover, mine was leaking there and it wasnt until i took off the intake that i found the leak.

[tbondo]

After Ryan's post I was questioning the usefulness of my Chilton. I actually backed the idle screw all the way out so it is not affecting the throttle at all. Wanted to take that out of the equation. I will have to double check my vacuum system. I did not check the rear pcv last time I went through it. Thank you for the idea.

[Ryan]

Eep, put the throttle screw all the way in and back it out 3 turns. Thats approximately factory.

If you're not playing with a hot engine, the BAC valve will be messing with you too. Its a wax valve like the thermostat that forces a higher cold idle.

The most useful section in the manuals is the F2 section. In there it will tell you basically all about the stuff that controls the engine.

[Beccabob593]

I find that the Haynes Ford Probe manual is better than the Chilton. It has helped a ton this weekend.

[davmac]

I'm going to 2nd recommendation of using the manuals at this site. The F2 section applies to the K8 and most other K engines too.

Ryan is also right that you need set the idle screw to 3 turns out to start and to check idle on a hot engine since during warm up the idle should be around 1500 rpm.

I'm not sure how you've tried to adjust the TPS, but no key is required. The procedure does require feeler gauge and multimeter. The procedure is found in the service manual starting at this page.

If idle problems continue vacuum leak (including air leak in air tube between air cleaner and tb) or temperature sensor are 2 usual suspects.

[tbondo]

Okay so I finally found some time to get back out to the garage and try and track down my problem. I let my car warm up to temp and put it in diagnostic mode. I set the TPS (checked with the fan trick), set the timing to 10 degrees, and tried the temp sensor and IAC trick. When I unplugged the temp sensor the motor idled up. When I unplugged the IAC the engine idled down. Both threw a code when unplugged. Is the IAC sounding like the culprit since the motor idled down when unplugged? Also what is the best to spray around to look for vaccum leaks? When everything is plugged in and in diagnostic mode, the motor idles around 1000-1200. When not in diagnostic mode, the motor idles around 1500-2000. I feel like I'm chasing a ghost and am getting to the point of bringing it to the shop to see if they can find the problem. Hate to spend the money on something stupid or simple. Any and all ideas are welcome.

Thanks