Missing when Warm ?
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Joined: Jul 2009
Posts: 55
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From: beverly hills Michigan
Missing when Warm ?
Ok 1990 VERT, 80K maunal.
Runs great when cold. It warms up and runs terrible. I make it home but not with a lot of power. I have replaced 6 of the plugs the ones on the passenger rear area going to be replaced tomarrow.
I have also done the Fuel Filter. ?
I will be doing Wires (Taylor) and AC DELCO cap and rotor this week also.
when I have had vehicles with bad wires or plugs it was constant not when it gets warm .. any ideas ?
It reminds me of a VACCUM leak in my old 289 ?
Thanks,
Steve
Runs great when cold. It warms up and runs terrible. I make it home but not with a lot of power. I have replaced 6 of the plugs the ones on the passenger rear area going to be replaced tomarrow.
I have also done the Fuel Filter. ?
I will be doing Wires (Taylor) and AC DELCO cap and rotor this week also.
when I have had vehicles with bad wires or plugs it was constant not when it gets warm .. any ideas ?
It reminds me of a VACCUM leak in my old 289 ?
Thanks,
Steve
Instructor
Joined: Nov 2008
Posts: 199
Likes: 1
From: Asheboro NC
since you say it happens after it gets warm and not throwing codes (i assume)
cat converter comes to mind, then O2 sensor (but that should throw a code), then injectors not flowing properly when warm. check those areas during your plug change then look for naked wiring around the coolant temp sensors.
cat converter comes to mind, then O2 sensor (but that should throw a code), then injectors not flowing properly when warm. check those areas during your plug change then look for naked wiring around the coolant temp sensors.
Navigator
Joined: Apr 2006
Posts: 9
Likes: 0
yep the cats usually keep you from a certain higher RPM.
COuld be MAp or 02 Sensor. time it-- if it happens at 5 minutes from cold, about 3 from warm and about 2 from hot start it is moving into computer mode and trying to adjust fuel based off the 02 sensors. They may not throw a code if they are really dirty and dying.
on the Map spray a fine mist of lightly soapy water on it and see if you see it streak into the sensor-- could be broken.
Check EGR, PCV.
If it happens when it is ambient hot-- not eng hot-- check output from fuel pump.. sounds crazy but in texas heat I had one that was failing and would lower output on a 90+ day...
if it is running rich check your temp sensor
COuld be MAp or 02 Sensor. time it-- if it happens at 5 minutes from cold, about 3 from warm and about 2 from hot start it is moving into computer mode and trying to adjust fuel based off the 02 sensors. They may not throw a code if they are really dirty and dying.
on the Map spray a fine mist of lightly soapy water on it and see if you see it streak into the sensor-- could be broken.
Check EGR, PCV.
If it happens when it is ambient hot-- not eng hot-- check output from fuel pump.. sounds crazy but in texas heat I had one that was failing and would lower output on a 90+ day...
if it is running rich check your temp sensor
Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
I just went thru this on my '95 S10. I had two plug wires that were burnt. When cold they would work but when they got hot they would not. My S10 runs like a top now that I have replaced the plugs, wires, dist cap and rotor button. Of course, there are other things that could cause your problem too. But the idea is to start from a clean sheet with parts that you know are working properly before you try to diagnose it further. Good luck with your repair!
Bernie
Bernie
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Check them both cold and hot.