egr prob
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egr prob
well started the other day when the idle on my 92 e 150 302 started to surge real bad and started dying shot in the dark changed the tps no help and idle air control still no help then when watching the engine run noticed that the egr tube started to get hot so I unhooked the vacuum to it and it started to run great so I guess my question is what controls the vacuum to open the egr at an idle I thought it was just supposed to open at or around highway speeds and will it hurt anything have the vacuum blocked off until I can get this problem resolved .
Thanks in advance
John
Thanks in advance
John
Tuned
Joined: Jul 2003
Posts: 455
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From: Berkeley
egr should not be open at idle. thats' actually how you test if egr is working: pull vacuum to engage egr at idle and engine will stumble and/or die.
so your egr valve appears to work, but is being opened when it shoudn't be.
you'll need to check a vacuum diagram for your year/vehicle/motor to sort that out.
maybe just go thru all vaccum hoses and replace any that appears to be clogged?
anyways, if you run without egr, you risk pinging, as the distributor is set up to advance timing in higher rpm range to compensate for EGR. this is particularly a problem on the 351m/400 engines. dunno how crititcal it is on your 302. if you don't have any ping under load or at high rpm, you'll be safe running without EGR, but spewing more emissions until it gets sorted out...
so your egr valve appears to work, but is being opened when it shoudn't be.
you'll need to check a vacuum diagram for your year/vehicle/motor to sort that out.
maybe just go thru all vaccum hoses and replace any that appears to be clogged?
anyways, if you run without egr, you risk pinging, as the distributor is set up to advance timing in higher rpm range to compensate for EGR. this is particularly a problem on the 351m/400 engines. dunno how crititcal it is on your 302. if you don't have any ping under load or at high rpm, you'll be safe running without EGR, but spewing more emissions until it gets sorted out...
Tuned
Joined: Jul 2003
Posts: 455
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From: Berkeley
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thanks
illl keep checking into it drove it today on the highway and didnt notice any pinging or problems at all actually ran really good better than before it started messing up going to look farther into it this weekend thanks again
Posting Guru
Joined: Sep 2006
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From: Jasper, MO
There is a TSB/Recall on the vac lines for the egr. Basically they get hot and fuse closed. The solution in the TSB is simply tie the ntubes away from the manifold. That isn't the case here, though. THe vaccuum is obviously pulling, or it wouldn't make a difference. The SENSOR may have gone out... The default position is OPEN. Are you able to pull any codes? Maybe the O2 sensor, too. Good luck!
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dawhits1
1987 - 1996 F150 & Larger F-Series Trucks
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Jan 9, 2011 07:05 PM
