heard this one yet????

[stevenfromtexas]

Originally Posted by scott123

I'd go vacuum as well.

I'd spray along the intake runners and the line going to the booster.

My guess would be it is sucking air somewhere.

S

yes sir, thank you. i've sprayed and used the propane technique and can't seem to find any change in rpm's. i noticed my accelerator pump is not "squirting" like its supposed to. i will prolly try that tomorrow.

[VWNate1]

I'm subscribed as I'm keen to hear the final solution .

I've had a few inline 6's that had vacuum leaks between the intake manifold and cylinder head but only from below ~ this meant burning my hands when I was testing for vacuum leaks with the engine running .

? Have you yet attached a vacuum gauge (cheap at pawn shops etc.) to the direct manifold vacuum ? . maybe tweak the rubber hose bits at both ends of the PCV line ? .

With 10 degrees initial advance (must be zero vacuum to the dizzy @ idle !) you should be getting 21" of vacuum steady as a rock if not more at hot idle .

[Steeveedee]

I would try spraying something inert from underneath that could enter the alleged leak. Maybe nitrogen?

[stevenfromtexas]

Originally Posted by Steeveedee

I would try spraying something inert from underneath that could enter the alleged leak. Maybe nitrogen?

yes sir, that is one spot i did not try (under the intake). that's first on my list tomorrow.....

[Missourimark]

Does this still have points ? If not are still running the ballast resistor ? Have seen HEI and other systems that eliminate the point system with a ballast resistor still in the line , they don’t run well that way . It takes 12 volts to make them work .With that air cleaner you have on it’s probably a normal carb sound you are hearing. I don’t think its a vacuume leak, or you should of found it by now.

[stevenfromtexas]

Originally Posted by Missourimark

Does this still have points ? If not are still running the ballast resistor ? Have seen HEI and other systems that eliminate the point system with a ballast resistor still in the line , they don’t run well that way . It takes 12 volts to make them work .With that air cleaner you have on it’s probably a normal carb sound you are hearing. I don’t think its a vacuume leak, or you should of found it by now.

no sir, i have the petronix ignition. no more points or resistor.

ok, i couldn't remember if i would hear that "sucking" noise when i drove it 20 years ago. if thats the case, ill live with it......the one thing that is bugging me is the sputtering at a quarter throttle in all 3 gears. can't really cruise through town in any gear when it bucks and jerks with just a little pedal


thank you all for your help!!!! sorry to be a pest!!!!

[Missourimark]

17 pounds of vac is good , is there a ballast resistor on the firewall ?

[stevenfromtexas]

maybe we could all meet in a central location and discuss all of the issues we have with our pickups.......

wait...isnt that called a "car show".......

[stevenfromtexas]

Originally Posted by VWNate1

I'm subscribed as I'm keen to hear the final solution .

I've had a few inline 6's that had vacuum leaks between the intake manifold and cylinder head but only from below ~ this meant burning my hands when I was testing for vacuum leaks with the engine running .

? Have you yet attached a vacuum gauge (cheap at pawn shops etc.) to the direct manifold vacuum ? . maybe tweak the rubber hose bits at both ends of the PCV line ? .

With 10 degrees initial advance (must be zero vacuum to the dizzy @ idle !) you should be getting 21" of vacuum steady as a rock if not more at hot idle .

ok, ill try underneath tomorrow. honestly, i did not go that far down (underneath) ....my apologies....



thank you all for your suggestions!!!

[stevenfromtexas]

Originally Posted by VWNate1

I'm subscribed as I'm keen to hear the final solution With 10 degrees initial advance (must be zero vacuum to the dizzy @ idle !) you should be getting 21" of vacuum steady as a rock if not more at hot idle .

....errrrr......actually, i can't get it above 17"'s of vacuum. i hope i don't have other issue going on being as you mentioned the 21''......

[VWNate1]

Yes, that's the float bowl valve and is separate from the accelerator pump .

Sometimes the lip of the accel. pump plunger rubber gets caught during installation and flips up, reducing the ability to pump much fuel .

[firedemon]

only getting 17 inches of vacume did you try to adjust the distributor or just the carb ? sometimes the distributor will give you a few more inches of vacume and adjusting the distributor with the vacume guage will help you find your motors happy place timing wise . tons of videos on you tube that can explain way better than I can type

[VWNate1]

Yes, this is possible, they taught it @ the GM factory training I took close to 50 years ago :

Warm up the engine fully then set the idle to about 700RPM . connect the vacuum gauge to the direct manifold vacuum port and watch it closely as you s l o w l y advance the distributor ~ as you advance the timing the gauge's needle will rise, eventually it will begin to twitch, stop and ease it back until you get the highest steady vacuum, snug down the dizzy's clamp and take it for a test drive, radio off, windows closed ~ when you get it to 35 ~ 40 MPH in top gear on a flat and level road, depress the foot feed to the floor and listen for knock or ping noises ~ if none, you're good to go .

If you hear even a -slight- ping or knock, stop and using the timing light, back the timing off -ONE- degree, snug the dizzy and try it again .

The idea is to give the engine all the advance it'll take without any ping .

This is called the "Throttle Ping Test" and is how old GM i6 engines were properly tuned before the $tealerships decided that test drives were a waste of time . actually they just wanted us to work harder and faster, no matter if the Customer didn't get the high quality works they'd payed for .

Give this a try, you'll prolly like the result .

I hope you knew to open the spark plug gaps to at least .040" after in stalling the Pertronix Ignitor ? .

[stevenfromtexas]

Originally Posted by VWNate1

I hope you knew to open the spark plug gaps to at least .040" after in stalling the Pertronix Ignitor ? .

thank you for this. i've put over 100 miles driving it around a 5 mile loop after doing the little tweaks seeing what works and what doesn't......

yes sir, i actually have them a little more than that. i read some older post that mentioned even more than that of a gap. mine are at .055 right now. you reckon i should move the down to .040?

[stevenfromtexas]

Originally Posted by firedemon

only getting 17 inches of vacume did you try to adjust the distributor or just the carb ? sometimes the distributor will give you a few more inches of vacume and adjusting the distributor with the vacume guage will help you find your motors happy place timing wise . tons of videos on you tube that can explain way better than I can type

i redid the vacuum test this morning. i was taking the reading from the carburetor port. i re-read these post and i guess i missed the "manifold" port for vacuum test. I have a steady 20''of vacuum there.
i'll do all of your test again in the morning. assuming 20'' of vacuum is the correct amount, or do i go as high as possible???

[Missourimark]

Fantastic glad you stayed with it , no doubt a new educational situation. Head scratchers like these can be such a challenge for the best of mechanics and are easy to give up on.

[stevenfromtexas]

Originally Posted by Missourimark

Fantastic glad you stayed with it , no doubt a new educational situation. Head scratchers like these can be such a challenge for the best of mechanics and are easy to give up on.

yes sir!! i was at that point of sending it to a pro technician. i don't have an ego with 99% of things, BUT with this little pickup i want to say i did EVERYTHING.....(except the tint on the windows and machine work on the block).......

"educational situation" for sure!!!! the whole project has been. this has been a BLAST!!!

[VWNate1]

Don't you just love the satisfaction of taking the time to work through a problem your own self ? .

This is why I always push folks to try the DIY, you'll usually do a better job because YOU CARE and won't rush the job .

Now, figure out why it needs so much idle screw to keep it running and eventually you'll get to zero vacuum @ idle .

Peppy little thing, ain't it ? .

Unless you have problems with missing or stumbling, leave the spark plug gaps where they are ~ the ideal thing is : as much gap as they'll take without causing running issues .

We can help you get a better coil *if* you want, what the Pertronix does is : drives the stock coil to it's maximum output all the time ~ points don't really do a good job of switching the current on and off .

[stevenfromtexas]

Originally Posted by VWNate1

Don't you just love the satisfaction of taking the time to work through a problem your own self ? .

This is why I always push folks to try the DIY, you'll usually do a better job because YOU CARE and won't rush the job .

Now, figure out why it needs so much idle screw to keep it running and eventually you'll get to zero vacuum @ idle .

Peppy little thing, ain't it ? .

Unless you have problems with missing or stumbling, leave the spark plug gaps where they are ~ the ideal thing is : as much gap as they'll take without causing running issues .

We can help you get a better coil *if* you want, what the Pertronix does is : drives the stock coil to it's maximum output all the time ~ points don't really do a good job of switching the current on and off .

yes sir!!!!!.....thank YOU so much for your help.....you guys are the best!!!
this was Dads pickup and the one i learned to drive a standard in, so i will have it forever, and do small tweaks here-and-there but i do have the fever to do another one.


took my daughter ( 9 ) to the tennis court today to hit-a-round.....good friggin' feeling!!!!!

[VWNate1]

Very nice indeed .

I hope your Daughter likes the rig and decides to keep it .

I was worried there'd be some Hot Rodders who don't understand how ported vacuum works, some really big heavy duty V8's use manifold vacuum, it's very strange .

The collective knowledge here is amazing .

[VWNate1]

"question....

the "C" shaped linkage at the bottom of the carburetor, connecting the accelerator pump to the throttle body, can that be adjusted/tweaked/bent slightly to help with anything I've got going? " .

Yes, that is why it's 'C' shaped .

There's quite a lot of good info on these old Rochester 'B' series carbys in the factory shop manual, it's still available brandy new for about $30, used ones with dog eared and greasy pages for far less, you really should buy one

GM also printed a nifty 194/230/250/292 engine manual......

[stevenfromtexas]

Originally Posted by VWNate1

"question....

the "C" shaped linkage at the bottom of the carburetor, connecting the accelerator pump to the throttle body, can that be adjusted/tweaked/bent slightly to help with anything I've got going? " .

Yes, that is why it's 'C' shaped .

There's quite a lot of good info on these old Rochester 'B' series carbys in the factory shop manual, it's still available brandy new for about $30, used ones with dog eared and greasy pages for far less, you really should buy one

GM also printed a nifty 194/230/250/292 engine manual......

thank you so much, ill look this up, i like having books on hand to reference random stuff....