This is topic car running rough at idle and part throttle in forum Tech Talk at Northern California Ford Owners  .


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Posted by getjobdone (Member # 4666) on :
 
i have a '92 hatch with an s trim and it has been running very poorly. the rpms will drop and shut off upon initial startup unless i keep on the throttle. but once it warms up, the car will idle without a need for me to keep on the throttle. the idle however is very rough and the car noticeably shakes. when under part throttle less than 2k rpm it will buck. when i blip the throttle it will rev with slight hesitation as if it were missing, but once i rev it past about 3k there appears to be no miss. i do know there are exhaust leaks, or at least one because i can hear it from the passenger side headers. i also hear a hissing sound in bursts from the vicinity of the intake near the throttle body and EGR when the throttle is tapped. there was a leak from the EGR gasket that i could feel air coming from, so i replaced that gasket. the car runs the exact same and i still hear the hiss when i rev. the only difference is that upon initial startup the rpms do not drop anymore. any and all help is greatly appreciated. [patriot]

[ 06-30-2005, 17:02: Message edited by: getjobdone ]
 
Posted by getjobdone (Member # 4666) on :
 
i was just thinking that the exhaust leak from the passenger side header gasket could be causing the roughness and make it seem underpowered at part throttle. could it be sucking in air through the leak causing it to run poorly? but then there is still the hissing from the intake which i suppose is a vacuum leak. i tried following most of the vacuum lines to make sure none were detached and they all seem fine.
 
Posted by SmokinLX (Member # 1684) on :
 
Did the car ever run good with the supercharger? Do you have a custom chip in it? If the answer is yes to both of these questions then replace the gaskets and due a full tune up with new fuel filter,that is probably the best place to start since you will need to do them reguardless, if there are other problems or not. [patriot]
 
Posted by JohnB (Member # 969) on :
 
From the posted description, you over-tightened the throttle body, warping it and creating the vaccum leak. Pull the TB off and check it with a straight edge. [Wink]
 
Posted by getjobdone (Member # 4666) on :
 
t-body edge seems straight. i only changed the EGR gasket, is it possible to overtighten that? i'll be changing the t-body and EGR spacer gasket tomorrow along with the header gaskets. does anyone have any pointers on changing the header gaskets? do i need to unbolt them at the collector in order to change them? thanks [patriot]
 
Posted by Quick 88LX (Member # 1950) on :
 
If your h-pipe is on hangers, then you may not have to unbolt the collectors. It will be a little more time consuming, but personally, I would unbolt the collectors and unbolt the headers to do the job right; you don't want to do it again.
 
Posted by getjobdone (Member # 4666) on :
 
thanks, ill be changing them tomorrow morn. will this fix the rough idle and slight hesitation in lower RPMs?
 
Posted by SmokinLX (Member # 1684) on :
 
So did ya get the job done yet and fix that thing?Let us know. [Big Grin]
 
Posted by getjobdone (Member # 4666) on :
 
nope, haven't gotten to it yet. i have been really lazy lately lol. this weekend those gaskets are getting in there for sure. i hope it will fix this rough idle and bucking at part throttle because the exhaust leak sounds pretty major. [burnout]
 




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