FEOA Forums banner

1 - 15 of 15 Posts

·
Registered
Joined
·
267 Posts
Discussion Starter #1
My old Escort (96 LX) which I have since sold to my dad has had this progressively worsening rough idle issue. It started last winter and I was told on here to replace the IAC (idle air control) valve. I got a new one from RockAuto but it did nothing - it's still exactly the same. Also tried changing plugs and wires, but still the same.

It will run fine for the first few minutes after starting it, but after that the idle will drop and it will 'chug' - the RPM bounces up and down between about 500-1000. If you tap the gas the RPM comes back up to normal and it 'corrects' itself for maybe 15 seconds or so, then it starts again. If you don't tap the gas, it 'chugs' harder and harder until the RPM bounces so low that it stalls.

My dad wants to take it to a mechanic to diagnose it, but I was hoping to save him a few bucks and figure it out myself. Any ideas?

Thanks.
 

·
Registered
Joined
·
15,318 Posts
Exacty what brand and type were the new spark plugs?

Did you check for vacuum leaks? Pay special attention to the PCV elbow.

Did you clen the MAF?
 

·
Registered
Joined
·
267 Posts
Discussion Starter #4
It has a rebuilt head with the improved seats. It also runs fine, with the exception of the idle.

How do I go about cleaning the MAF?
 

·
Registered
Joined
·
267 Posts
Discussion Starter #6
Oh, its on the airbox..

Well, I don't know if this could be part of the problem, but the airbox is cracked. I have it held together with duct tape and rope right now. None of the junkyards around here with Escorts have one.

fwiw, I've seafoamed the engine before from the IAC opening and the PCV hose.
 

·
Registered
Joined
·
15,318 Posts
Yes, a cracked airbox can cause idleing problems! Depends where it's cracked though. Where is it cracked? Check for air leaks on the flex tube as well.
 

·
Registered
Joined
·
267 Posts
Discussion Starter #8
It's cracked where it clamps down. The plastic was brittle and the last time I changed the air filter and went to clamp it back down, the clamp just cracked the plastic. I've checked ebay in the past and the local junk yards but no luck finding a replacement.
 

·
Registered
Joined
·
15,318 Posts
Well, if it's cracked past the filter, than that could be causing or otherwise contributing to the problem. If it's on input side of the filter than it's probably something else causing the problem.

I can't imagine why you are having such a hard time finding one at a junkyard, I could go to a crappy one here and get all I want.
 

·
Registered
Joined
·
267 Posts
Discussion Starter #10
All the wrecked Escorts have had everything torn from them already. On some of them the whole engine is gone. Oh well.

I'll try cleaning the MAF and see what that does.
 

·
Registered
Joined
·
15,318 Posts
wa1dh said:
All the wrecked Escorts have had everything torn from them already. On some of them the whole engine is gone. Oh well.
You need to find a U-pull-it type of junkyard.
 

·
Registered
Joined
·
267 Posts
Discussion Starter #12
I removed and cleaned the MAF today with the contact cleaner but no luck. the CEL is on with trouble codes P301 and P171 (cyl 1 misfire and lean fuel mixture).

Does the ECU read fuel pressure by any chance? I have a scangauge I could hookup if it does. I know there is a schrader valve on the injector rail but the gauge is like $30.
 

·
Registered
Joined
·
119 Posts
All the escorts in the local junkyards here also have completely stripped escorts - nothing left. Couldnt even get a rim, they're on their axles on the ground!
 

·
Registered
Joined
·
551 Posts
My first thought is temp sender has gone bad.
This may trick the computer into staying in cold run mode even though the car has warmed up.

I did the whole MAF, throttle body, air valve cleaning with the killer vacuum leak search before I found the sender trick.

Bruce
 
1 - 15 of 15 Posts
Top