No laughter here. I've heard of it and understand the concept. My dad has a stethoscope specific to him got mechanic, I'm afraid it will be too loud under there and blow my ear drums out though.

 

BTW I think my 300 is about ready to die. I need to hurry up and swap in the 302. I'm going through 2qts of oil every three days. I topped it off before going to Miami, OK this evening (35 miles one way) and knocked like Hell on startup to come back. I had to put 2 more in just to get it home. oil press is between the RM in normal. I'm leaving it parked till I can get a new oil pan gasket on there.
this thread has come a long way from "bucking" to 3 guys and their 300's

 

pb blaster it the only type ill buy in a pinch liquid wrench but always pb blaster.

my truck suprizingly idles fine start revs to 1200 for a min n drops to 700

 

hey bikertrash it had the problem before I cut the o2 sensor. Im getting rid of the smog pump eventually, maybe now, but I dont care about the thing, its in the way... not looking for horsepower at all, and not concerned about weight. 3 things happened all at once on my truck... the distributor lost a screw under the cap and kicked sideways and shredded all the wires. at the same time the brake booster went out, so with the new distributor, wires cap and rotor button, i couldnt get it in time untill i replaced the booster. after I caught up and Im back to setting the timing, i look under it and see the front cat is glowing red hot.. but even in time, it wouldnt run right like I described. even after i cut the cats loose. its a 93 and Im approaching 200k. the cats were clogged. the smog pump is a different issue I will deal with later. my #1 concern right now is the bucking are shudder at 900-1100 rpm......

 

jon somthing that may help without one cat the efi 5.8 woulnt have any umph ull press the pedle n it woulnt rev right if it was carb u wouldnt have this prob but efi u need atleast 1 cat.

and u can go to any junkyard and grab a smog pump cheap

and id get the o2 fixed befor u spend mony on other stuff that could help your problem

 

just to mention, I had a high (really high) idle and it turned out it was the throttle position sensor.

 

smog pump works fine, its just that now that the cats are off the tube going from the smog pump to the rear cat is disconnected and Im not going through the extra crap of reconnecting it when I get my pipes welded back. Im aiming on no cats as well, I dont see why I would need 1 for it to run, and honestly I cant afford it right now anyhow. just need to get on the road again like *****, the mini van rides great and smells better but I miss my truck...

 

If you have read the link I posted about the A.I.R. pump you would understand that the pump still sends secondary air to the exhaust ports in the heads to help burn of hydrocarbons that didn't burn in the combustion chamber. If you remove the pump, your o2 sensor is going to detect that and react accordingly. It will likely retard the timing, lean out the fuel, and then you'll be complaining about not enough power. Plus the work involved to plug off everything the system runs to. You can vent that tube into the atmosphere as it is the oxygen supply for the cats you cut off. But it would be wise to run it into the exhaust stream or you will hear it hiss when the TAD sends the air to it. Plugging it off will create a drag on the motor. If you miss your truck now, I would think that you'd want to fix it right and not have to "miss" it later. Just my .02 and again good luck.

Btw. You could probably get away without a cat as the o2 is upstream from it but I do suggest getting one back on there ASAP. I've seen magnaflow highflow converters on eBay for $70 or so.

 

efi is alot differnt then carburated engines efi needs back pressure and an aray of sensors to tell the computerwhats going on and how to adjust the air fuel ratios idle ect with out anyof that ur engione will never run right

take it from me ive dun it . i cut the cats off a 5.0 truck never ran right got poor gas mileage and no throttle responce

not trying to tell u what to do but u dont want to mess the truck up any more

u can get universal cats cheap and throw em on there

ive built header back exhaust systems for about $200 thats less then a catback would cost u but u can build emcheaper with diffrent brand parts

 

Are you saying I spent too much money on my exhaust??? I probably did. I plan on using it in the swap. I have Flowtech LT's 1.5/2.5, 2.5 pipe, xpipe, magnaflow HF cats, Spintech DIDO 18" muffler dumped after the axle, with full emissions I might add.

 

haha yeah i got a 2 into 1 ypipe welded it to the header pipes came out into a universal cat and stock o2 just welded a bung in then also welded a pipe for the air tube in the tubing then ran it back with a thrush turbo and dumped it infront of the axel all new pipe
and clamps and hangers and i passed emissions too

just time consuming but if u got the skill and a welder its the way to go

 

The backpressure myth... really man. don't go throwing that bull chit out there.
He doesn't need cats. There is a difference between no cats and no exhaust at all.
And if backpressure makes any difference on any motor, which it does to a point but it's not even back pressure it's velocity, then a carbureted motor would be effected just the same.

 

Another idea is to pull the belt off and run it for a few seconds, if there is no knock, then it's something on the pulley system. May not be the Smog pump, but it'd be something.

 

Good idear sir.
I have a family party to attend now and obligations with the girlfriend for later so tonight I'll look at it with a flashlight.
If it's not the smog I'm gunna look into doing rod bearings in a weekend (crossed fingers) or running it till dead, or December whichever comes first, and swapping in a running motor.

 

Take a road trip to Joplin and pick me up on the way lol, we'll have a motor swapping jamboree haha