OK, on my 90 Sedan DeVille I keep getting a code 22. Checked TPS and replaced with a seemingly good one. Set voltage to .5 at idle and tried to set the ISC at 1.2V and it is a way high idle and while driving caused the engine to idle high, too high to drive. My question is, how wide open should the throttle be to get the 1.2V position? On mine it seems to be about a quarter throttle, does that sound correct?
Should I be jumping the ADLD A & B while setting this?
I had a TPS put on my 92 Deville and I don't think the mechanic set it at all.
I had to adjust it and drive it and adjust it several times before it would idle down and shift gears. It still seems to have the shift points high.
Before I got home from the mechanic it was ideling at 60 mph so I stopped on the side if the interstate and re adjusted it.
I am getting old and senile and don't quiet understand how to do it like a technecion would.
see if I can be any help with this. I just performed this earlier today. From memory the steps are. Andget to the section for Ics retracted all the way to 00. ground the generator at the green clip. all of this while the car is running slide the plug in off the ics motor to lock it into the retracted position. car should stay running. get back into the ecc and go to the tsp and find your reading. adjust the tsp until you get within .5--.5. lock the tsp down and rehook up your ics. shut car off turn key back on watch ics relearn.I have step by step I could scan for ya just email me Wagener7@sbcglobal.net
That's what I've been doing, but it doesn't seem to be working correctly. I have the factory manual and have been reading it. I think I'kk get a second set of eyes to help and set the TPS to 0 using the onboard computer, I have a value of -8 right now. The problem I'm having is when the TPS is set at .5V with the ISC retracted after you hook up the ISC it get wild high idle, like the other guy said, 60MPH! To get the vaue to 1.2V like they call for with the ISC fully extended it is at quarter throttle. Hard on the old brakes in traffic! Right now I have the ISC disconnected and have run it out a bit to get a decent idle with the AC on.
Yep, done all that. As a matter of fact I had to go to the u-pull-it the other day for some other stuff so I grabbed 3 TPS and 3 ISC, and they all behave the same (and I got them all for less than $10!). Anyway, tomorrow I think I'll get my girlfriend to watch the display and set the TPS to 0 (from -8) and work from there. I may pull the ECM and clean all the contacts just to be sure, even though I have the exact 5V signal coming from it.
Thanks for the input and if anything else comes to mind let me know!
yes, it stays running, what I did was nudge the ISC out a bit to up the idle to support the A/C. It runs well otherwise.
BYW, I love u-pull-it yards. There are always tons of interesting cars and one I go to is huge. I bet there were better than 20 4.5/4.9L Caddys there. Saturday is Cinco de Mayo so they are doing a $5 admission and all parts are half price. Next month there is a special $30 to get in and everything is a dollar! Now where do I put that extra 4.5 for $1.00????
i was having a problems keeping mine running with the Isc withdrawn until I put a mightyvac pump and squirted the hell out of the vacumm port of the fuel reg port and work it with pressure, everthing smoothed out. while the car is running pull the vacumm line off the Frp and see if its leaking gas. if not squirtin the vacumm inlet with wd40 , while running pull the vacumm hose off and see if the car changes rpm and keep installng and pulling the hose off to slide the inside diaphram free.
Stop and try this...way easier than what you guys are doing and it has worked for me:
Don't worry about the 0.5V thing for now--just hear me out.
First, set your min. air idle screw to about 450 rpms with the ISC fully retracted. Then, observe parameter P.0.1 on the fuel data center after entering diagnostics at min. air. It's supposed to read 0 at 0.5V or thereabouts according to the factory manual, but I've found that this setting doesn't work well, and I used to get a lot of high speed coast down cruising, so try this:
From what I can discern, the computer always tells the car to set the throttle position to around 2.1-2.5 degrees on a coast down with the throttle switch closed (this, again, is parameter P.0.1) until the speed drops to about 2 mph, at which point the computer bases the throttle setting on RPMs. This is true regardless of where you've set the TPS. So, to eliminate your problem, set the TPS to around 1.1 degree of throttle at min. air instead of 0 (i.e. higher than 0.5V--but put that multimeter away for now).
If you do this, when you are coasting to a stop, the computer will set the coast down throttle to about 2.1 degrees, and when you slow to 2 mph, the car will require about 1.5-1.7 degrees of throttle to idle at the correct rpms...considerably more than before.
I've done this on both my 91 Deville and my 85 Deville and it worked like a charm. Took me several tries to actually stop and think about what the computer was trying to do before I figured this out.
OK, set it that way and it seems better, but I'm still getting a high idle at times (too high). I think the next check is the various connectors in the system because I think I have an intermittent fault, it keeps setting an E22 code still. I guess I'll disconnect each connector, clean them and put some dielectric grease on them.
It seems to run fine, but I'm concerned if it will pass the tailpipe test in PA with this fault. The ISC is disconnected and I've bumped it out a touch to raise the idle over the minimum to compensate for the A/C. Anybody have any other input? Thanks!
You have a strange problem...are you sure that you're setting the min. air screw to 450 rpms, or are you not able to achieve that low of an RPM setting? Seems like you have a vacuum leak somewhere. Also, check your fuel pressure regulator.
Checked min RPM and it's OK. Have looked high and low for a vacuum leak but find none. Tried to old cover the intake with a rag method and it kills it instantly and sprayed carb cleaner on all the hoses and fittings. After reading the manual over and over, plus the fact that your method of setting the TPS helped, I'm thinking that I have a bad connection between the TPS and the ECM, so the ECM isn't getting a full or constant signal from the TPS. In other words, it doesn't realize exactly where the throttle is... The fact that it keeps etting E22 also makes me think it is an intermittent connection somewhere.
I'll check the fuel pressure tomorrow. I honestly haven't considered it. The re-occuring E22 code keeps me on the TPS and it's wiring.
I'm going to the u-pull-it tomorrow to grab some other stuff, it's half price day. For the $15 they'll get for a throttle body I may grab one as well as an injector set, piping etc. At those prices it's easy to have the parts laying around just in case.
Thanks again for your input. The ay that you said top set the TPS seems to have helped and it makes more sense that the factory way!
A couple of other things to consider about your adjustments with a high idle: is the closed throttle switch working (does the "Off" indicator always appear on the display when you take your foot off of the gas pedal)? Are you sure that the ISC plunger can retract properly or is it set out too far? It should retract to the point where there is a 3mm gap between the plunger and the throttle plunger at min. air.
Another strange fix which you might not believe, but should consider (this happened on my 85 Deville)...your distributor gear may be worn, and could be causing the car's timing to fluctuate significantly at idle. If you have a timing light, check to see how much your timing mark fluctuates at idle. Easy check, and it'd be good to rule it out. If everything above is in order, I'd really check this item out.
This was the cause on my 85 Deville and the idle was a MESS--it idled high like yours. And, my car only had 30,000 miles! Sure enough, pulled the distributor and the gear was well worn. The slack in the teeth caused erratic timing only at idle which sent the computer into a frenzy. I went through the service manual, and noticed this strange item listed in the "Rough, Unstable, or Incorrect Idle" trouble tree.
Seems like you probably don't have a vacuum leak given your test. What RPMs is the car currently idling at in park/drive?