98 SOHC...Low Rough Idle, Stalls, Bucks....

[crawfr1312]

Anyone had problems with the SOHC motors such as Low Idle, Stalling at stops, bucking like the fuel filter is clogged between 35 - 50 mph? Had it in the shop for two days. They said it sounds like it had a vacuum leak but couldn't find it. They also said it may be the MAS, but they didn't want to guess at $190.00 part. Plugs, fuel filter were changed a few thousand miles ago. Also, does this engine have a PCV Valve on it? I saw it on the vacuum diagram, but can't find it anywhere. There are no pictures or info in either Haynes or Chiltons on where it would be on the SOHC, only the 5.0 & 4.0 Pushrod. Help..................Thing runs horrible.........Wifes been complaing for months.

 

[Alec]

Have you had all the necessary recalls performed? Have you checked the intake manifold for damage or loose bolts?

 

[Apten]

do you have a K&N air filter?

I agree it does sound like the MAF. What I would suggest is cleaning the sensor. You remove the MAF sensor from the housing, and carefully clean the two wires with alcohol and q-tips. Deposits accumulate on those hot wires, and they no longer accuratly read air flow.


This should help you understand...

http://www.tccoa.com/articles/intake/mafclean.html

Brian

 

[crawfr1312]

To answer both questions, I just printed out all of the TSB's and Recalls for the 98 SOHC. I going to call the dealer to find out what has been done and what hasn't. I pretty sure it hasn't had the 00M12 work done. I'm almost positive that's the vacuum leak.

No K&N filter. I have the stock replacements in it.

 

[jobunn]

My SOHC will sometimes stall at idle but only if it is cold and if I tap the accelerator quickly then let off it. The revs also jump on their own if I do this and it is cold.

I had all the recalls completed also. Recall 00S04 Multifunction switch and harness - Recall 00S46 Reprogrammed PCM - Recall 00M12 Replaced Manifold Gaskets and Timing chain tensioners.

After these were done the problem was solved. However, that was a year ago and while the problems are much less common, it still happens now and then.

Get these recalls done (if you haven't already) and do the MAF sensor clean like bjherron says. I'm doing that next.