What else can cause High Idle? Slightly poor fuel economy.

[stockmover]

I have posted here several times and got some great advice. The good news is that my CEL is off and I have no codes, its been over 200 miles thus far. The vehicle is running good after replacing the following.(all in the last 30 days)

• -Spark Plugs
• -PCV Valve
• -Throttle body cleaning
• -Fuel Filter
• -MAF sensor
• -Coolant Temp Sensor
• -Thermostat
• -Water Pump
• -Timing Belt

My question now is, when I start the vehicle the idle is around 1800 rpms. The temperature here is around 30 degrees or so. In about 3-5 minutes it lowers to 1500rpms.

In drive its around 1100
In park its around 1500 rpms, firm.

I believe this idle is fairly high. What could be the cause? It seems that something is telling the engine to idle high. I replaced the coolant temp sensor and still the same thing.

Any suggestions?

Thanks

[RningOnFumes]

Beware: Do this at your own risk.

You can take it in or try it yourself. Adjust the actual throttle cable. Give it enough slack for it to bog down and then let it back a bit and tighten.

[Mike Gerber]

Have you checked thoroughly for a vacuum leak?

Mike

[jlspec]

Check your timming, your idle rpm should be somewhere like 700-800 rpm

[DFBonnett]

As Mike noted, it sure seems like a vac leak, especially considering the work you have done in and around the intake.

[stockmover]

Okay more updates....

On the way to work last night the CEL came on. I took it to Autozone, the code was P0510. Since that was the throttle position sensor I bought one while I was there. ($120 w/tax)

I came back home before installing and read the forums here and saw that the TPS could be adjusted. While the engine was on, idling, I unscrewed the old TPS and moved it, the idle went high, then lower, so I put it in the position where it would be lower.....

Looked on the dash and guess what? THE CEL WAS GONE. The idle is at 1000rpm now in park, in drive its at 1000 rpms also. I am satisfied with this, its much more quiet now. I drove it around a bit and the CEL remained off.

I will monitor regularly and check back in with everyone for updates if necessary.

Thanks Again Everyone!

Originally Posted by Mike Gerber

Have you checked thoroughly for a vacuum leak?

Mike

[DFBonnett]

I think all you did was compensate for a vac leak.

[JvR]

I have read in my maintenance manual it is normal you must adjust the TPS when you have change parts on the throtle body.

But you must be sure you have no leaks. (check it with brakecleaner.....search this forum how to)

1000 rpm is a bit to high i think....i makes parking and slow driving a bit difficult.

[Kep]

Maybe a faulty Idle-Up Valve for the A/C?

Kep

[stockmover]

After adjusting the TPS along with the adjustment screw near the TB itself. The idle rpms are at 750 and when in drive its around the same. Everything is running well.

Originally Posted by JvR

I have read in my maintenance manual it is normal you must adjust the TPS when you have change parts on the throtle body.

But you must be sure you have no leaks. (check it with brakecleaner.....search this forum how to)

1000 rpm is a bit to high i think....i makes parking and slow driving a bit difficult.