95 Escort 1.9LX Idle Surge

[dlbdata]

My 1.9L just started doing this a couple days ago. When the car is idling in neutral or in park, the idle speed constantly surges up and down. It seems to be especially worse when I put my foot on the brake, sometimes when I take my foot off the brake it stops surging. If I put it in gear (drive or reverse) the surging stops. I checked for vacuum leaks and replaced one hose, but no different. It seems fine when driving it.
I've recently (10k-15k miles ago) given it a tune up, new plugs, air filter, timing belt.
Any ideas?
Thanks in advance.

[chevyn0va1]

Originally Posted by dlbdata

My 1.9L just started doing this a couple days ago. When the car is idling in neutral or in park, the idle speed constantly surges up and down. It seems to be especially worse when I put my foot on the brake, sometimes when I take my foot off the brake it stops surging. If I put it in gear (drive or reverse) the surging stops. I checked for vacuum leaks and replaced one hose, but no different. It seems fine when driving it.
I've recently (10k-15k miles ago) given it a tune up, new plugs, air filter, timing belt.
Any ideas?
Thanks in advance.

I think there is a vaccum leak but look up how to clean the IAC in this forum

[dlbdata]

Originally Posted by chevyn0va1

I think there is a vaccum leak but look up how to clean the IAC in this forum

Thanks. I'm going to take a close look at some of the other hoses, etc, and also try cleaning the IAC & MAF sensors.

[chevyn0va1]

Originally Posted by dlbdata

Thanks. I'm going to take a close look at some of the other hoses, etc, and also try cleaning the IAC & MAF sensors.

let us know how you make out

[dlbdata]

Originally Posted by chevyn0va1

let us know how you make out

Had plans of checking it out this weekend. I filled up with gas Friday night, and it seems like the problem went away. Maybe a bad batch of gas? Will have to wait and see if the problem returns.

Reminds me of when I was a kid and filled up my old AMC Green Hornet. Got up the rode about a mile before the car died. After draining the tank I realized I ended up getting 8 gallons of nasty looking swamp water.

[dlbdata]

Originally Posted by dlbdata

My 1.9L just started doing this a couple days ago. When the car is idling in neutral or in park, the idle speed constantly surges up and down. It seems to be especially worse when I put my foot on the brake, sometimes when I take my foot off the brake it stops surging. If I put it in gear (drive or reverse) the surging stops. I checked for vacuum leaks and replaced one hose, but no different. It seems fine when driving it.
I've recently (10k-15k miles ago) given it a tune up, new plugs, air filter, timing belt.
Any ideas?
Thanks in advance.

I'm just following up with the fix for this problem.
I was having the up & down idle problem when I came to a stop. I tried taking the IAC off and cleaning it. I probably made a mistake in using WD40 (too strong a cleaner or maybe the lubricant in it caused problems?), and it actually seemed to make the problem worse. So I went out and bought some CRC Throttle Body&Air Intake cleaner (says it is safe for teflon coated parts). I sprayed this into the throttle body (took air intake hose off) while revving the engine up & down. Also sprayed some of it up into the holes in the throttle body that lead up to the IAC. This seems to have fixed the up&down idle problem.

[AzTumbleweed]

Hope it's fixed. Sure sounds like a vacuum leak to me....

[dlbdata]

Originally Posted by AzTumbleweed

Hope it's fixed. Sure sounds like a vacuum leak to me....

Yeah I hunted everywhere for a vacuum leak but couldn't find any. Cleaning the Throttle body/IAC with the CRC Throttle body & Air intake cleaner did the trick. Thanks.