2000 Astrovan Won't Slow Below 70 km/hr

My goodness. This is a safety issue (not an annoyance) and it needs to be bumped up the line to GM corporate.

Do you have any friends that are attorneys?

Have you tried another GM dealer?

I would be pushing on the dealer to resolve the problem or move the problem up the corporate chain for you.

Are there any recall notices on the vehicle? Have they been completed and the work performed correctly?

I would assume that by this point the obvious things like stuck mechanical accelerator pedal, linkage, and assembly have been gone over in great detail.

Can you make the vehicle malfunction (idle racing) at a stand still?

The engine races as soon as it is started....and has also been taken of the road till the problem is found!!

Good.

I take it pulling the pedal and the linkage does nothing?

Flywheel sensor is good?

My goodness...!?! It's 12 years old!!! How much has happened to this vehicle in that time?

I think the manufacturers responsibility ended a looooong time ago.

Attorneys...sheesh!!! How about trying to fix the friggin' problem before you go bothering the entire auto industy and hiring an attorney.

Since this guy's vehicle had the battery replaced in order to fix an engine that won't idle down, I don't think we are dealing with a super-genius' to begin with.

Sorry to be misleading... the battery was replaced because it was 6 or 7 years old and had finaly died.

You wrote, " I think the manufacturers responsibility ended a looooong time ago."

Not if this is a safety issue that can be traced to a manufacture's fault.

I agree with Anonymous Hero. This vehicle sounds like it has the "Toyota syndrome", and is an accident waiting to happen. You could be liable, and your insurance company might just tell you to pound sand if someone files a claim against you.

You might try some Chevy forums with better luck. Can you physically pull the throttle pedal up and slow the engine down?

If the factory trained mechanics at the GM dealer can't figure it out, I doubt the answer will come from here.

Don't drive it!!!!

They never should have started putting computers in cars.

Definitely ECU or it's wiring/connectors problem because ECU gets RPM and speed FB signal from more than one source. An since you don't get an error code it's one of the very few occasions lawyers have reasons to live. S.M.

Why do I think the throttle body isn't closed to an idle position? You might want to take a look. I've seen a groove develop over time where the throttle plate normally rests in the throttle body bore. And of course you'd want to check the shaft for excessive wear.

I'd be remove the linkage and be looking down the bore with a flashlight and would exercise the plate back and forth.

Pulling on the accelerator dosn't make a difference. Wear within the throttle body is a very possible answer to the problem. We'll pass that on to the mechanic in the morning. Thanks!

I, myself would blank off the EGR valve,(possible carbon deposits holding it open). If that doesn't solve it, try disconnecting the vacuum hose to the power break booster and plugging the manifold port and see if this doesn't lower the RPM

It would be helpful if you let us know what RPMs the engine running at in park and no load on it.

The van belongs to my brother, he is going to be talking to the mechanic this morning and will ask for the RPM reading, he thought that it was between 2 and 3,000. Will find out for sure. Thanks!

Tps issue. Is it installed upside-down? Very easy to do. The idle air control works on overdrive and you have a racing motor. All this with the idle adjustment bottomed.

I don't know if this will help, but here goes. A coworker had the air filter changed on a 2000 Olds Minivan (3.4L FWD ?). Immediately after he had a problem similar to yours and took it the dealer. The dealer fixed the problem. There is an electrical wire going to the transaxle running under the air filter housing that got disturbed. Somehow this causes these vehicles to want to exhibit symptoms like your vehicle.

GOOD LUCK!

Never spray WD-40 onto electrical connections that you want to remain intact.

I once sprayed WD-40 into the mechanism under my steering wheel thinking it would lube the signal light cams. Result: No lights at all!

It is common for people to spray WD-40 on their distributor cap and plug wires to arrest sparking.

WD-40 is death to electrical connections.

All good advice, My 2 cents after all the pro's looking at it I'm sure no codes have been set that is the problem only the result of the real problem. The fuel pressure regulator works off vacuum only and won't set a code. If it's bad it will give the injectors high fuel fuel pressure / higher RPM no mater where the throttle is, or what any sensor is telling the computer to do. Also the IAC is very suspect in these conditions, but usually easy to check. A clogged fuel return line as well. Could be kinked some where under the car, and keeping fuel pressure high instead of dumping back to the tank. Good luck.

The fuel pump will only go just so high. Even when at max fuel pressure, the system will still idle down. I have never had the IAC backwards, so I can not address that. I would be looking for where the engine is getting air to run that fast from. The power brake booster line is large enough to allow that much speed, as is the PVC line, I would look to remove both of these lines and block them. If the high speed is still there, my next stunt would be to duck tape a piece of hard wood, or plastic across the engine air inlet. If the OP is able to stop all air from entering the engine in the designated air inlet, and the engine continues to race, it will have to be a leak at the throttle body mating surface, or the intake manifold itself.

One thing I would like to know, is what has changed since the last time the engine ran correctly. The last one that touched it screwed it up. JMHO. Good luck.

Wonder what happen to the OP and if they found the problem yet?

We're still waiting for answers from the mechanic, they had already covered all the tests mentioned in the first 19 comments, with out any success, but have yet to get feed back on checks that jaysauto1 and bob c offered. Thanks for all the help, I'll be sure to post any progress!

Thanks.