I've got a high idle with no SES!

[risteff]

Hello everyone. Relativley new to this site. I recently picked up a 2000 Safari SEL AWD. When I got it, the previous owner said she had the IAC replaced to get rid of a check engine light. The code remained. When I got it, same issue. It'd go down the road at about 45 mph with my foot off the pedal. Got it home, took doghouse off. removed the IAC (which looked new) and measured the pintle to make sure it was in spec. I also cleaned the pintle & inside the intake with carb cleaner & lint free rag. Checked vaccuum lines, disconnected the battey & no more SES. It is still idling fast but now it will only run about 35mph on its own! Anybody have any direction I can take to get this van back to normal idle? I'm about stumped! Thanks.

[v8famvan]

Well, I suspect you have either a vacuum leak or a control/decision problem. I would utilize a scan tool to monitor the Mass Air Flow reading while the fault is occurring and also see how the computer is trying to drive/command the Idle Air Control motor. This would get you to the quickest identification of the cause of the problem.

[risteff]

I appreciate the reply. I have no way to scan it (no tool) while driving. After further research, I found that it idles a little high (arond 1000 rpm) in park and in D. It will idle up quite a bit (guessing 2000+ rpm) at around 30 mph & not idle back down until a complete stop has been acheived for 1 or 2 seconds. Could this have anything to do with a speed sensor? With no Engine Light on, I'm not sure what to look for. Any sensor could influence the PCM to make it run that way I would guess.

[astroturf]

risteff, When was the last time you cleaned out the throttle body? A carbon buildup can cause a high idle. Check it out, clean it out, and keep us posted. Jim

[risteff]

Update for you. I took some advise & cleaned the TB. I just bought this van so I'm not sure of the maintainance history. I decided to cover all the bases I've read about on this forum. After cleaning the TB, I cleaned & lubed the throttle linkage. Cleaned the MAF, & replaced ALL of the vaccuum lines just to be safe. I inspected the inside of the intake where the TPS & IAC attach too. Both looked pretty clean, but both got a shot of MAF cleaner too. (wanted to be sensor safe!). At this point, it is running 97% better! It has 110,400 miles on it & I'm thinking it could use a tune up too. All of the advise & past postings have helped me very, very much. Thanks.

[risteff]

Next update. RPMs where they are supposed to be now. I took it on a local test drive to get it good an warmed up & see how everything was. Noticed it pulls to the left upon breaking (only at first). I also noticed my amp gauge (dash) fluctuates from 12 to 14. Stays around 14 at idle, even with the front & rear A/C on high. Drops to around 12 as soon as I start to accelerate. Also, once in the 150 miles I've had it, it shifted hard into second gear. It's only done it once. With my Bonneville, I had the same thing happend & it turned out to be a sensor proble.
Anyone else have / had these problems with your Astro / Safaris? I've got some pretty good ideas on what to check for first with these problems. Just wanted to see if any of these problems are commen to 2000 era Safaris.

[astroturf]

Risteff, Glad to hear it worked out. You prolly want to start another topic about the other things. Just a thought. Jim

[kings-x59]

check all your grounds at the alternator and starter to make sure they are clean and tight. put a voltage meter on the battery terminals while it's running to see if the fluctuation shows up there - could be the gage. If it does after cleaning the grounds, my first suspicion is the voltage regulator on the alternator is in the process of giving up the ghost.

[risteff]

You're right. It did die. However, it turned out to be a faulty plug. Replaced it & replaced the alt. Just took it on a 2250 mile ride. Works fine. The auto parts store did not charge me for a core so I plan on rebuilding the original as a spare. I still have a high idle due to sticky throttle linkage. It only sticks if I floor it. Found that out in Georgia while on vacation. Still haven't got it fixed yet. Just got home today.

[risteff]

Here's another update for you all. Now at 123,000 miles, and I have a few minor problems (actually many). It seems this thing is falling apart around me. I really miss my 1990 AWD Safari! My high idle is back. I have checks all the same items as before with no luck. Any chance it could be my EGR or my intake gasket? It had a new TPS, and a new IAC valve. These two were installed on the last "go 'round" with this ride. I did so many things to it last time all at once that I don't know what curred it for the last 10,000 miles. I'd hate to go through it all again. Any advise would be greatly appreciated and put to good use. Thanks!

[97CargoCrawler]

Sticky throttle cable? You lubed the linkage and cleaned the TB but perhaps the cable itself is sticking a bit inside the sleeve. Confirmed by a quick visual test. You've spent a lot of time curled up between the seats so it's unlikely...but you never know. You could detach it altogether and see if the idle drops.

Idle should be around 550rpm. The PCM does tell the engine to run around 1200rpm during it's warm-up but then backs it off to 550-ish after. I have no idea how it knows when to do that, but if it's a sensor it could be faulty. You can also program the idle rpm in the PCM...but someone with the dealer scan tool would have had to do it manually. That seems unlikely. You won't be able to check that with a normal scan tool.

I'm not sure how well it will work on your engine, but I use a can of carb cleaner on my Land Cruiser to check for intake vacuum leaks. Squirt it here and there and see if the idle increases.

Also, if you start experiencing hard shifts on a regular basis then your trans is dying. You're feeling the TAP mode kicking in and it's sending additional amperage to the shift solenoids making them increase the line pressure. It's compensating for worn parts and trying to maintain shift timing. You need a dealer scan tool to check for that too.

Good luck!

[risteff]

Thanks for the reply. The linkage and cable are okay. You're right, lots of time on my side between the seats! The idle problem is definately not related to linkage or anything mechanical I believe. When started, idles around 1200 to warm up & drops to around 600. Depress brake, no changes. Move shift lever into R or D and idles up to about 2000 for a few seconds and then settles back down to around 700. Generally there are no further issues until it is brought out of D or R again. Lately however, after and driving of 40 mph or higher for a minimum of 2 minutes will also result in a high idle making it difficult to stop at traffic lights. After complete stop is acheived, it will idle back down (on its own) to around 700. I just when through the intake gasket ordeal with my Wife's Isuzu Rodeo. What a POS! I never could detect a faulty gasket with spray or any other methods. I just went on a hunch. During disassembly it was visual that it had failed. Do you think my EGR could be a cause of this idle BS? It and the intake gasket are pretty much the only two things I have not checked or changes yet. Thanks!

[MountainManJoe]

If you only get fast idle in certain gears, then I'm inclined to think the problem is somehow connected to transmission. Just going out on limb.