No Power
Postmaster
Joined: Aug 2004
Posts: 2,908
Likes: 2
From: West Mansfield, Ohio
Haha don't worry mrl, I do too!
Clogged cats could be the problem, but what are the chances of it plugging up immediately after he did all this? The chances are slim to none.
I'm wondering if it is a timing issue. I've set the timing wrong on a vehicle or two by accident, it happens. What I want to know is why he reset the timing to begin with? If it ain't broke, don't fix it! I think that if he would put it back to where it was, we might figure a thing or two out.
The only way to figure out the converter issue is to either have someone hold their hand about a foot away from the exhaust exit while someone revs it to around 3 grand and see if it's pushing enough air. Or do the vaccuum test like I mentioned earlier. Or unbolt the downpipes and really wake the neighbors up!
Clogged cats could be the problem, but what are the chances of it plugging up immediately after he did all this? The chances are slim to none.
I'm wondering if it is a timing issue. I've set the timing wrong on a vehicle or two by accident, it happens. What I want to know is why he reset the timing to begin with? If it ain't broke, don't fix it! I think that if he would put it back to where it was, we might figure a thing or two out.
The only way to figure out the converter issue is to either have someone hold their hand about a foot away from the exhaust exit while someone revs it to around 3 grand and see if it's pushing enough air. Or do the vaccuum test like I mentioned earlier. Or unbolt the downpipes and really wake the neighbors up!
Elder User
Joined: Mar 2006
Posts: 590
Likes: 1
From: Venetia, PA
Yeah, Ive done that before on a chevy truck. Unbolt the manifolds from the y pipe and take it for a cruise. It ran like sh** but man did it sound cool. I wondered about the timing myself too, but the more I looked through the forum I saw that 10 degrees btdc was about normal for these trucks. I dunno, I say mess with whats easier to fix first and then work your way down the line until you solve your problem. About the chances of the cat clogging all of a sudden, I was just wondering if the fact that he put the new plugs and wires on it would have let the fuel burn a little hotter, just enough that the raised temp in the exhaust was enough to deliver the final blow to an old cat, and blow it apart inside therefore clogging it. I have seen that happen before, running and old cat with a freshly tuned engine, but that was only when the guy had the heads and intake machined, put bigger injectors in and ran a hotter coil and new distributor.
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New User
Joined: Mar 2007
Posts: 11
Likes: 0
Ok, the reason we set the timing was, about 2 weeks we had to replace the TFI module which we had to pull the dist. out just to get it off. We did mark it first so we would know where it went back in. But at the time we didn't have a timing light and thats when I notice how bad the cap and rotor was. So we replace then a few days ago and checking the timing which might have been off a degree or two at the most.
I haven't paid attention to the rpm's since this problem started (but I will) I do remember prior to this it seems like the rpm's were below 2500 when going 75 mph.
Timing been check and rechecked
Yes our next step is to loosen the exhaust from the maniford and then take it out for a drive.
"Ryan- what I need from you is more info. Are you having problems in the higher RPM range at low speeds? If not, then rule out the cat and fuel pressure problems. When you're at 55 MPH with the pedal to the floor, is the truck revving high, or staying pretty low? "
No problem with rpm at lower speeds. Driving 55 motor not revving and I recall the rpm are below 2000. In fouth gear easily gets up to 60 - 65mph
I haven't paid attention to the rpm's since this problem started (but I will) I do remember prior to this it seems like the rpm's were below 2500 when going 75 mph.
Timing been check and rechecked
Yes our next step is to loosen the exhaust from the maniford and then take it out for a drive.
"Ryan- what I need from you is more info. Are you having problems in the higher RPM range at low speeds? If not, then rule out the cat and fuel pressure problems. When you're at 55 MPH with the pedal to the floor, is the truck revving high, or staying pretty low? "
No problem with rpm at lower speeds. Driving 55 motor not revving and I recall the rpm are below 2000. In fouth gear easily gets up to 60 - 65mph
