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1990 Ford Mustang- Stalling/poor Idle


Replica's Avatar
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04-15-04, 08:14 AM   #1  
Replica
1990 Ford Mustang- Stalling/poor Idle

Alrighty, heres the problem

I recently bought a 1990 ford mustang with the 2.3 L SOHC 4 cylinder , it ran fabulous when I first got it..

Now the idle sometimes changes itself at random times, will drop into the 500RPM range then go up to the 1500RPM range, which usually leads to an eventual stall

I did all the regular tune up stuff a few days ago (plugs, wires, cap, rotor) and it did seem to run better but didn't solve the problem

If anyone could throw in some suggestions it would be greatly appreciated ...

 
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04-15-04, 09:10 AM   #2  
Clean the throttle body
Pull off the air intake hose and spray some carb cleaner into the throttle body and on the blade in there
If it hasn't been done in a while it may be pretty black
On this engine that's a good place to start
You didn't mention air filter, while the tubing is off you might want to check that
Also you might want to have your codes read, the earlier EEC-IV computer doesn't always turn on the check engine light, it may have some helpful info stored

*Later Fords have a throttle body that can't/doesn't need to be cleaned
If yours has been replaced by one of these (unlikely) it will have a warning sticker posted inside there and don't clean it

 
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04-15-04, 10:40 AM   #3  
Replica
Thanks a lot for your post slickshift,

I pulled the hose and sprayed carb and choke cleaner in there, the blade was black and covered in what I assume would be carbon/soot

After doing that I went ahead and pulled the filter out of that screwy airbox down on the fender , filthy

I ran the car with unrestricted airflow for a few moments (no filter) and discovered that my problem remains unchanged ...possibly I'll head down to autozone tomorrow for a code check

Also to replace the filter just because

thanks

If anyone could contribute other ideas it would be much appreciated

 
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04-16-04, 09:12 AM   #4  
Replica
;-(

Changed the air filter and did the carb and choke cleaner thhing, now the Idle jumps sporadically and will never keep idle in the normal range ...

Idle fluctuates between 1000 and 1500 RPMS at all times

any other suggestions?

 
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04-16-04, 03:54 PM   #5  
Check the idle air control valve on the intake plenum,very common problem on Fords.

 
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04-16-04, 05:50 PM   #6  
Also check/clean the mass air sensor
And if you have a voltmeter check the throttle position sensor's voltage, pierce the wires w/pins and attach the meter to the pins if ness.
I'm not sure what yours should read ( I think .94-.99) but if it is varying, it's bad
Lot's of other sensors (failure could) do this to your idle
Those are the easy ones to check (that I can remember) without getting the codes read
The others you really don't want to start replacing w/o more info
PS If you do have a voltmeter there is a way to pull the codes with it, but if you have an autozone nearby they will do it for free

 
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04-16-04, 06:00 PM   #7  
fordman30
its a common problem with these newer fords change the idle air control valve .the part will cost you app.80.00 and take take about 5 minutes of your time to replace..you will probaly have to go to your local ford dealership to get the part.also carry you VIN number so that they will give you the right one.

 
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04-17-04, 03:17 PM   #8  
Had the same problem a while back. Ford dealer told me i would cost $212 to fix (e.g. replace the idle air control valve). Unfortunately I let them do it, valve was $94, labor was $108.
Only afterwards did I find out that it takes less than 5 minutes to replace it, so get the valve and install it yourself!

 
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04-17-04, 04:49 PM   #9  
$108!!!
Wow, it really is a 5 min. job to replace it for anyone with a socket wrench
Jeese, 108 bucks...

 
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04-17-04, 06:25 PM   #10  
Originally posted by slickshift
$108!!!
Wow, it really is a 5 min. job to replace it for anyone with a socket wrench
Jeese, 108 bucks...
He's leaving something out of this story. There's some extra time in there for diagnostic or throttle body cleaning or something like that. It's not pure installation time, I'd bet.

 
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04-17-04, 11:25 PM   #11  
mike from nj
yeah, the dealership technician probably spent some time identifying the problem, making sure nothing else was wrong with the car, and verified the repair was correct before it left the shop.

hukre....you failed to mention if it was fixed correctly the first time(no repeat visits, or 'comebacks'----which we then fix for free)



did anyone ever see a dentist walk up to you, open your mouth and pull the exact bad tooth? that's a 10 second job, but he better have diagnosed that one correctly!! and made sure nothing else was wrong, before you left the chair.

 
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04-18-04, 12:54 PM   #12  
After I read the reply from Desi501, I decided to go back to my archives and pull out the bill from the Ford dealer, because I want to get my story straight. Well, I shoudn't have relied on my memory - I paid a LOT MORE than I vaguely remembered. Following are the detailed charges as they show on the bill:
1) "Tech verified customer concern. Checked all idle controls, found IAC sticking & throttle body gummed up. Recommended replace IAC and service throttle body with injector flush.
Tech replaced IAC motor - recheck performance - good."
Labor charge for above: $ 265
2) "Technician performed fuel injector flush service. - Clean out throttle body."
Labor charge for above: $ 150
3) Parts: IAC Valve assembly $ 94.06
Gasket $ 4.56
Spray $ 9.00
Cleaner - Fuel $ 8.95 Total: $ 116.57
Total of the bill was $ 531.57. He gave me a 10 % "customer" discount, and I ended up paying $ 478.41 + tax.

 
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04-18-04, 01:23 PM   #13  
Looks like he did a number of things. The only thing that seems a little high was the diagnostic time in the beginning. It appears they got more than the customary 1 hour.

 
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04-18-04, 01:47 PM   #14  
I would like to say be careful about this discussion as it does not pertain to the posters original question.If it turns into something not for family viewing it will be lost to the delete key.I would also add in San Francisco the labor charge per hour is one of the highest in the USA.What is the labor rate per hour at that dealer?Just be civil folks I don't like doing administrative work.

 
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04-18-04, 02:06 PM   #15  
There's no problem here, the discussion just got off track a little with the bill. Your right, it's time to get back to the original subject though.

 
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04-18-04, 03:13 PM   #16  
I have had good success with removing the IAC and cleaning it.

 
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04-19-04, 02:51 PM   #17  
Originally posted by toyotaman11769
I have had good success with removing the IAC and cleaning it.
My experience has been about 50/50 for cleaning versus replacement. They do go bad a lot.

 
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