Need some help with the 350

[Dieselshine]

I got a few problems with my truck trying to figure out, the truck stumbles from a dead stop, thinking it might be an egr problem??? Should I replace it or just do an egr delete? I've swapped on an edelbrock aircleaner with a 4 inch k&n filter also has all new cap rotor plug wires plugs and accel high output coil, could it be a timing issue maybe? I picked up a timing light so ill check her tmr, also if I were to remove all the emissions crap how hard is it too do? And is there any pros or cons of doing so, I know to leave the vacuum advance on the distributor the brake booster vacuum line trans anything else it is a bit cold out yet should I swap back on the stock aircleaner or is it alright to be running an open filter right now? This is on my 79 3+3 gmc


Also with the egr the previous owner block it off by plugging the line off with a spark plug end its inside the vacuum line and hooked up to the egr

 

[bucket]

If it's a stumble right off idle, it could just be a bad accelerator pump.

 

[Dieselshine]

If it's a stumble right off idle, it could just be a bad accelerator pump.

That's another thing I was thinking Carb defs need a rebuild it died on me the other day in the middle of the road, towed her back to the house with the suburban and it was like it ran out of fuel had to put fuel in the Carb and do the old three pumps and to the floor to get her fired back up, defs looking into an intake and Eddie Carb setup, the trucks only got 173,000 km on it, runs awesome at times and compressions good, no oil or carbon build up on plugs at times it runs awesome then you can go to take it an hour.later and it runs like crap, yesterday the trans was slamming into 2nd and 3rd topped up the fluid and replaced the vac lines and now its shifting early and soft, thinking that might be the electric kickdown

 

[Dieselshine]

So I swapped back on the original aircleaner today and truck runs awesome again, guess ill put the k&n and Eddie aircleaner away till spring lol

 

[Jims86]

If it's a stumble right off idle, it could just be a bad accelerator pump.

Thats exactly what I was thinking.
If you have the bux, I would suggest an SMI q jet, you should get ahold of Manbearpig, he just installed one...they are well worth the money, and Sean stands behind them 100%
Anyone that tells you that removing emissions equipment is worth the time and work, Is full of ****...and are usually the same folks that are too lazy to properly repair such problems, and really dont understand why the stuff is there in the first place.
as far as egr, you may have a ported vacuum switch (or TVS)that regulates the vacuum to the valve, if this is sticking in the open position, it may bounce the valve open on accelleration.

 

[Dieselshine]

Smi quadrajet? Ill defs talk to manbearpig I have some sort of Carb trouble goin on, Thnx for the help, I'm not against emissions just one of the ones that doesn't understand what it does lol, I don't have any emissions tests to pass around here I'd rather just take it all off to simplify what's under the hood, half of its wrecked or been plugged off already the egr beens blocked off and after removing the blocked line seemed to cause a vacuum leak, is there an advantage over removing or keeping the emissions???

 

[Jims86]

Smi quadrajet? Ill defs talk to manbearpig I have some sort of Carb trouble goin on, Thnx for the help, I'm not against emissions just one of the ones that doesn't understand what it does lol, I don't have any emissions tests to pass around here I'd rather just take it all off to simplify what's under the hood, half of its wrecked or been plugged off already the egr beens blocked off and after removing the blocked line seemed to cause a vacuum leak, is there an advantage over removing or keeping the emissions???

At least you are smart and ask questions about it....most people dont. The dumbest questions, are those that are not asked.
EGR keeps NOx emissions down, allows you to run maximum timing, and helps keep combustion chamber temps down, especially at the combuston chamber surfaces, which helps keep detonation down...in theory, this translates into efficiency.
Benifits of emissions equipment....Its really up to you if you dont need it legally. Depends on how you feel about the air you and your family breathe. Do you want your truck to smell like a lawn mower while your window is down at the drive through? Its really your choice, I can only offer my opinions. But the stuff does make a difference when it is working properly.

Here is the link for SMI :www.SMIcarburetor.com

 

[Dieselshine]

At least you are smart and ask questions about it....most people dont. The dumbest questions, are those that are not asked.
EGR keeps NOx emissions down, allows you to run maximum timing, and helps keep combustion chamber temps down, especially at the combuston chamber surfaces, which helps keep detonation down...in theory, this translates into efficiency.
Benifits of emissions equipment....Its really up to you if you dont need it legally. Depends on how you feel about the air you and your family breathe. Do you want your truck to smell like a lawn mower while your window is down at the drive through? Its really your choice, I can only offer my opinions. But the stuff does make a difference when it is working properly.

Here is the link for SMI :www.SMIcarburetor.com

That's awesome Thnx for the link, I was gonna buy a Rochester from the autowrecker and take of to a local guy to get it rebuilt and restored to new woulda ran another $100-200 above Smi prices, oh ok I see I think I might get another egr valve then, does the emissions setup have anything to do with the egr I have the 2 canister setup with one line already snapped off as well as other lines that are disconnected and plugged its a bit of a mess right now and me not totally understandings not helping lmao but you defs cleared a bit up Thnx again man

 

[Jims86]

That's awesome Thnx for the link, I was gonna buy a Rochester from the autowrecker and take of to a local guy to get it rebuilt and restored to new woulda ran another $100-200 above Smi prices, oh ok I see I think I might get another egr valve then, does the emissions setup have anything to do with the egr I have the 2 canister setup with one line already snapped off as well as other lines that are disconnected and plugged its a bit of a mess right now and me not totally understandings not helping lmao but you defs cleared a bit up Thnx again man

cannisters? May need pics to help better. If you have access to a vacuum pump, apply vacuum to the egr valve, if it hold vcuum, its good. you may want to take it off, and at least clean it.
I have some vacuum diagrams here, do you still have your emissions stick on the radiator support?

 

[Dieselshine]

cannisters? May need pics to help better. If you have access to a vacuum pump, apply vacuum to the egr valve, if it hold vcuum, its good. you may want to take it off, and at least clean it.
I have some vacuum diagrams here, do you still have your emissions stick on the radiator support?

I don't have a vacuum pump here but there is one out at the farm so ill have to grab it next time I'm out there, its got 2 of the charcoal canisters has a line goin to the fuel tank Carb and still have to trace the others down they look the same as the ones that where in my 89 GMT 400, I don't remember having them in my 90 burb though to make the egr work again it'll need a really good cleaning or replacement looks like the factory original lol, the previous owner never degreased the motor or nothing was a total mess when I started on it, cost $15 at the car wash just to degrease the motor

 

[Jims86]

I don't have a vacuum pump here but there is one out at the farm so ill have to grab it next time I'm out there, its got 2 of the charcoal canisters has a line goin to the fuel tank Carb and still have to trace the others down they look the same as the ones that where in my 89 GMT 400, I don't remember having them in my 90 burb though to make the egr work again it'll need a really good cleaning or replacement looks like the factory original lol, the previous owner never degreased the motor or nothing was a total mess when I started on it, cost $15 at the car wash just to degrease the motor

Hmmm...never seen 2 charcoal cannisters. They have nothing to do with the egr, the egr has a vacuum line going from the ported vacuum on the front of the carb, usually low on the passenger side of the carb, to a Thermal vacuum switch in the coolant passage on the intake or thermostat housing then to the Egr valve... I have seen them go directly to the egr from the carb, but that usually indicates that someone has messed with it.

Charcoal cannister(s) store vapors from the fuel tank, and those vapors are introduced into the engine under certain conditions by vacuum to be burned in the combustion cycle, instead of being vented to the aptmosphere. Do you have dual tanks?

 

[Dieselshine]

So just running from the Carb to the egr would be better??? I do have dual fuel tanks and they're big tanks 80 liters a peice lol, if I got rid of the emissions stuff and left the egr I could just run vac lines from the Carb to the egr, vacuum advance brake booster and trans and she should run properly right?

 

[bucket]

I have to partially disagree, Jim. AIR pumps are a worthless joke and do absolutely nothing except keep the government happy. Sure, it dilutes the pollutants coming out the tailpipe, but the AMOUNT of pollution is still the same. It's just trickery to make the numbers SEEM better.

 

[Dieselshine]

Well I've decided today that the emissions is coming off, gonna get a 750 stage 2 qjet from Smi, maybe a new intake and set of headers, she's spiratic after swapping back to the original air cleaner back ran fine went out warmed it up good and she started stumbling again, might even just do the egr delete replace what's left for vac lines, I don't wanna put a huge amount of cash into this motor atm as I wanna swap in a 454 or 427 tall deck

 

[Jims86]

I have to partially disagree, Jim. AIR pumps are a worthless joke and do absolutely nothing except keep the government happy. Sure, it dilutes the pollutants coming out the tailpipe, but the AMOUNT of pollution is still the same. It's just trickery to make the numbers SEEM better.

Before cats they were useless, yes, like on 67 289 powered mustangs, and the like.
All the other things do make a difference.