Start from the begining
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Start from the begining
Being 61 years old, I made the mistake of not starting from the begining, Purchased a 88 Aerostar, started having problems, allowed engine to get hot, Replaced with crate long block (3.0), then again had idle problems, search for sensors and controls that do not exist on my model/year..But if I had read this forum from the begining I would have save time and money..
So to all thank you, and a sugestion, Start from the begining. She is now running great, but failed the NOX emissions test here in Texas, replacing both cats..
Harry
So to all thank you, and a sugestion, Start from the begining. She is now running great, but failed the NOX emissions test here in Texas, replacing both cats..
Harry
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Joined: Apr 2005
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From: Washington state
failed NOX, engine may be running too lean
caused by:
failed MAP or air leak in gasket intake manifold, plenum, TB seals...also can be failed IAT or ECT sensors telling computer intake air or coolant is hotter than actual causing fuel cutback
may also be caused by deposits in combustion chamber raising compression
all of these will cause idle problems also
high NOX is caused by high combustion chamber temperatures....
failed cats were probably caused by extreme engine overheating...damaged the active cores
does the '88 3L have an air pump for pollution control?
caused by:
failed MAP or air leak in gasket intake manifold, plenum, TB seals...also can be failed IAT or ECT sensors telling computer intake air or coolant is hotter than actual causing fuel cutback
may also be caused by deposits in combustion chamber raising compression
all of these will cause idle problems also
high NOX is caused by high combustion chamber temperatures....
failed cats were probably caused by extreme engine overheating...damaged the active cores
does the '88 3L have an air pump for pollution control?
Postmaster
Joined: Sep 2003
Posts: 4,452
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From: Southern California
Cliff:
The cat has two sections. The first one is for NOx reduction and the second one is for HC reduction. If the engine is running properly, and NOX is still high, it can only be the cat since most Aerostars I have seen do not have an EGR valve.
The cat has two sections. The first one is for NOx reduction and the second one is for HC reduction. If the engine is running properly, and NOX is still high, it can only be the cat since most Aerostars I have seen do not have an EGR valve.
Post Fiend
Joined: Apr 2005
Posts: 5,720
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From: Washington state
Tung,
dafalcon stated his new engine was not running correctly with idle problems....an extra lean condition overly hot combustion gases will cause high NOX and low HC...also will cause engine overheating
i agree that in EGR equip'd engines, a stuck open EGR that is passing too much recycled exhaust back into the engine will cause NOX
my suggestion was to search for the cause of the rough idle and see if the high NOX quits....cheaper than new cats if not needed or proven damaged and the idle rough running still has to be repaired...i admit it, i'm cheap....i do the cheap stuff first
Cliff
dafalcon stated his new engine was not running correctly with idle problems....an extra lean condition overly hot combustion gases will cause high NOX and low HC...also will cause engine overheating
i agree that in EGR equip'd engines, a stuck open EGR that is passing too much recycled exhaust back into the engine will cause NOX
my suggestion was to search for the cause of the rough idle and see if the high NOX quits....cheaper than new cats if not needed or proven damaged and the idle rough running still has to be repaired...i admit it, i'm cheap....i do the cheap stuff first
Cliff
Last edited by 96_4wdr; Dec 14, 2006 at 08:45 PM.
Postmaster
Joined: Sep 2003
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From: Southern California
Hi Cliff:
You are right. If the engine is not running correctly, you must fix that first before attempting any expensive repairs. I must have misread his post. I thought he said the engine was runing OK.
You are right. If the engine is not running correctly, you must fix that first before attempting any expensive repairs. I must have misread his post. I thought he said the engine was runing OK.
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Thanks to all..
The van does not have a air pump, nor a EGR, which I went hunting for because I did not read from the begining.. I suspect that I burnt out the cats when I ran the van to and from work while the engine acted like it was starving for gas, then I changed out the MAP, which made the engine run like a Swiss watch, until it was time to have it inspected a week ago, failing the emissions test..oooppss...But I will check the other sensors IAT/CT..I'am awaitting some penesi(money) to purchase new cats.. About the differences between the front rear cats, can they be interchanged..?? Again Thanks..
Harry
The van does not have a air pump, nor a EGR, which I went hunting for because I did not read from the begining.. I suspect that I burnt out the cats when I ran the van to and from work while the engine acted like it was starving for gas, then I changed out the MAP, which made the engine run like a Swiss watch, until it was time to have it inspected a week ago, failing the emissions test..oooppss...But I will check the other sensors IAT/CT..I'am awaitting some penesi(money) to purchase new cats.. About the differences between the front rear cats, can they be interchanged..?? Again Thanks..
Harry
