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Discussion Starter #1
'96 Econoline with a 302- has no power. No check engine lights. Garage I got it inspected at says it seems fine, but especially when you get on a hill it loses power - our 92 cavalier 4cyl with the ac on could pass it. I used to tow a 3500 lb trailer with it - now I won't even consider it. Our 92 chevy van with a 305 doesn't have lots of highway guts and this Ford would eat its lunch at one time - not now! When you get it to 65 mph on the highway I hate to slow down for traffic, it takes forever to get back to 65. No miss - hits on all 8 fine. EGR tests fine. Brakes don't appear to be hanging up. New fuel regulator, new fuel filter, new cap and rotor. Doesn't run hot. No apparent vacuum leaks. Again, it sounds fine and there are no check engine lights, and no codes. Anybody ever have this with a 302? Only things left i can think of is a timing chain issue or a partially blocked cat.
 

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If you hadn't had prior experiance with it I'd have said "Too much vehicle and too little engine" but if all was good and everything checks out I'm at a loss too. Maybe clogged up air filter or like you said, the cat. :confused:

Good luck!

John
 

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Is it down on power at all times, or just at certain times? Exactly when and what conditions if so (cold, hot, light throttle, high speed, etc.)? Did this happen totally at random, or did something possibly cause it? Did the problem creep-in or happen suddenly?

Diagnostic - Check for throttle cable slack with engine off. Have a buddy or brick fully floor the pedal, then check if you can open the throttle blade more to fully open by hand. Experiment - Disconnect your knock sensor and go for a drive.

David
 

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Discussion Starter #5
About 3 years ago it had an issue with the temp sensor and MAF. Once I figured that out, it cleared the codes but never ran the same. It has a K&n cone filter,that isn't dirty. Shortly after the sensor issues it developed an exhaust leak at the right exhaust manifold, at the head. Could that be throwing it off? I just pulled a plug and it looks ok, but I'm putting new wires and plugs in anyway (118k miles, might be original stuff). We don't use this van much anymore except for family trips that my stepson ( who is in a wheelchair) goes along ( it has a wheelchair lift) and tomorrow we want to take him to the Jersey Shore so i'm trying to get this thing running ok.
 

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Discussion Starter #6
It acts the same in all weather conditions, terrain ect. No 'guts' when you need them. Only thing strange is initial pull-out, from a dead stop feels fine, until maybe 10mph, then its weak. Like I said, it used to tow 3000 - 3500 lbs ok ( for a 302, not like my 460 though) but now I wouldn't even try that. Back in 08 we used it to go to an amusement park in central PA. It was 85 degrees, air on, and if you have been near Knoebels Grove Amusement Park, you know how mountainous it is there, the van did it fine. Now, no way would I try that.
 

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Discussion Starter #7
It's got 2 cats - inline to each other. If I remove those, can i replace them with just 1 high flow cat? I got the tools and a mig, I'm just afraid of throwing codes.
 

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Is it an automatic aod? Could be tranny problems.
 

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You might be on to somthing with the cats. I had this happen on my Mustang once(cost me a race that I dearly wanted to win :mad:). It ran fine, sounded fine, no codes, started out fine, but once the rpms came up it would fall flat on its face. It was pluged cats. You should be fine going back with one cat. Also take the MAF out and clean the wire off with some non clorinated brake cleaner. Good luck
 

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If you tried the other stuff, the exhaust leak is a potential, as teh system will read lean and can over-richen just the injectors on one side enough to kill power without blowing smoke. Check all the plugs when you change them to see if there are any differences between them.

You can test the cat theory by replacing the cats with a straight pipe or cheap muffler. If your van uses an after-cat O2 sensor, also install a spark plug anti-fouler under your after-cat O2 sensor. This will slow the swing frequency of the sensor, indicating to the ECM that the cats are good, preventing codes from popping. This is a temporary test, and all will have to be made right for legality and emissions testing.

David

Typical long 18mm spark plug anti-fouler at any auto parts store, that's screwed onto the after-cat O2 sensor, and then into the exhaust pipe:
 
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