Okay so my truck has had this issue since i bought it...has a webber 32/36, and it runs cherry...the problem is if i try to accelerate fast it hesitates. I could tell it was intake realated by the sound..first thing i noticed was the accelerator pump was wrong (the lever underneath had the tab facing out not in) and one of the studs in the adapter plate was stripped....so i fixed both things and still has same problem....kinda confused on all the vac lines around the manifold so idk where to go from here....vac advance maybe?

 

Take a pic of your manifold side so i can see your vacume lines. I'm thinking it might need a rebuild kit and s good cleaning. does it have the filter on it? Rebuild kit is like $60 over here. comes with o ring and gaskets everything you need.are you running manual or electric fuel pump?

 

bradda adjust distributer cap..ders one srew lossen that and just trun it up and down...while it on..youll feel it change idle...that will work...we did to my bradda 86...

 

I had a similar problem it fall on its face when I'd floor it from say 10 15 mph and just stumble all the way up I purchased a holly low pressure fuel regulator and problem stopped some pepole say u don't need them some say you do I run 2.7 pounds of fuel pressure . And I can floor from a dead stop on a weber 34 snyncronized .... And if u don't have emissions just run the one vacuum line to the distributer and set your timing around six advanced se if that helps

 

Okay soo i shouldve mentioned i rebuilt the carb when i got it...still same problem...played with the timing(distributer) and ive also had a different carb on there and its the same..

So i dont think its the carb, my truck was advanced about 6* and i just recently retarded it a little cuz was backfiring choke..

@scrub88~~~your pretty much on the money, when i try floor it (not literally) it just falls on its face for like 1 sec, then its good...The truck runs cherry!!!!! IF u gradually accelerate...It can hold RPMs no problem with no sputtering


BASSICALLY IT SOUNDS LIKE ITS JUST SUCKING WAY TO MUCH AIR BEFORE ITS GETTING ANY FUEL...so i guess it definitely could be fuel related...oh i have a mechanical FP.

 

If i was to literally floor it...it would just die....

 

Picking brain . I would believe that it is carb related sense I've experienced similar problem I've down right wanted to beat my carb with a hammer . Fuel supply keeps coming to mind messed around with the regulator much . Do you have both your vacuum hoses hooked to the distributer and then again the acel pump issues

 

Did some yanking and capping and its helped a little...messed with the carb a bit as well as the distributer, and got pretty good improvement

 

Bow,
I had the exact same issue as you are descirbing... Here is what I learned the hard way and yes, I am hessitent to say a word because its embarrasing!!! However, I am certain that I am not the first to experience this rookie move... First make sure you CAP every port that does not need a vacumm line. Second, make sure that you have the PSI coming into that carb. You have to eliminate the variables to get to the root of the problem.... So once you have those down, it becomes a matter of timing, which I believe is your problem... I dorked around with my stock pice of **** and after I got my weber installed and THOUGHT my timing was on, I FAILED to realize I set the timing with the vacumm line connected (ROOKIE mistake!!!!!!). I messed with that for a day and when I realized that was the case, I got the timing set at 8 deg (NO VACUMM) and then set the RPM and of to the races....

Long story short, make sure you are setting that timing mechanically. Also, you HAVE to elliminate possibilities. It could be MANY things, so make sure that you narrow it down.....

those are my two cents that aren't worth but a penny!!!

Cheers and good luck

 

Thank you for your 2 cents which is more than i got right now...making some improvements...

 

Navymc is right gotta be disconnected . Looks like in the pic u have both vac lines hooked to distributer I only use the one port facing nearest to the radiator then u can buy a plug at autozone to screw into were that multi port vacum housing is with a little Teflon tape or suitable liquid sealant

 

So what Navym is saying is i have to disconnect the vac lines coming of the distributer and THEN mess with the timing??

 

Exactly correct Bow... This is what I learned... If you set the timing with the vacumm connected, you will never get the advance required for acceleration because the vacumm is present on the distributer when you adjusted it (when the line is connected). It will run fine but it will NOT accelerate. Sooooooo, ideally, the distributer has fly wieghts that as the rpm increases it will advance to a small limit then be tapped out (wont advance any more, thats mechanical advance). After it hits its mechanical limit the vacumm takes over........... I felt like an idiot when I found that line connected because I know better and it just goes to show that I am human. I spent an entire day messing with that thing, pulling the number one spark plug figuring out EXACTLY where TDC is and trying to get that thing to accelerate. When I found that line I was pissed like you read about! Essentially I was timing my engine using the carb instead of the other way around. Set MECHANICAL timing and adjust the carb second. I followed this method after discovering the vacumm line connected...

-make sure the weber is set to lean run. With your hand, tighten the fuel/air mixture screw IN until it seats (don't tighten it as it will damage the needle tip), then back that screw out 1.5 turns, no more for now.

-make sure the vacumm is disconnected and get the truck to run at idle, which might require you to turn the idle set screw in until it will run. Then get your mechanical timing set.

-Go bakc and fine tune the fuel/air mixture screw the way weber advises and then set your final RPM with the idel adjustment screw.

-NOW connect your vacumm lines, close the hood and, voila! It should solve the problem!

Cheers!!!

 

Thanks ALOT!! I bassically worked on it most of today got the timing light out and was wayyy off...busted out the Haynes and like u said..."felt like a dumbAzz"pretty much learned what u just told me but not as detailed...THANKS.. Going back at it tomorrow, gonna do it the right way and hopefully problem solved!

 

Trucks running perfs!!
@ about 7-8 degrees Advanced..
Fxxking thing Yotalz haha i like go race some hondas!

Mahaloz for da tips guyz!

 

Good deal man glad it worked out

 

Sweet! I am also glad it worked out as chasing a timing issue can be tricky if you are uncertain of the variables you are dealing with...

Scrub, where are you at in TN? Anywhere near Tullahoma?

 

I'm fifteen minutes outside of memphis on the east side in collierville ...had to get away from Memphis gets wild the further west you go love the ville no emissions . My yota can't pass any test looks like your straight down 64

 

64 is one way to get there thats for sure. Its a nice ride for my little 78 as I dont like winding that little 20R up at freeway speeds! ESPECIALLY where you are at, thats some crazy traffic between Memphis and Nashville! If you ever need anything, give me a shout... I will probably be looking for a 88 as my goal is to have another yota in that year specifically. It will have to be a daizy though, I waited forever to find the 78 that I have. It was well worth it!!!

Alright, later...

 

Bow u can get wanna theses plugs at auto zone and not have to worry about your vacuum caps getting old and cracking bout three bucks .