Stuttering when accelerating

I know this is a somehwat newbie question but since im only at my house 2 days every 2 weeks I would like to try and take the guessing game out. I took my truck for a ride last night and then out of nowhere it started sputtering and running like poop when taking off. It idles great and will start right back up but the moment I go to take off its REALLY bad...i wouldnt think I could go past 20 mph now. Really wierd but anyway its got a new 650 double pump. I would say 6 months old and its been great this whole time. I blew the needle out and seems to move freely. New wires and plugs but I know this may go out. SO took another ride this morning with it cold and diud the same thing.
Coil? (no points)
Bigger squirt nozzle?
Grounding?
Pump cam?

Not sure but its weird it happened out of nowehere so I dont think its a bad carb or out of tune. I redid the float level as well...still there. Any help?

 

What kind of ignition are you running? If points then I'd check them.

 

Has it been running fine until now? If yes dont change the pump nozzle or cam, this will only confuse things.
Check the basics first. Park somewhere dark, get a spray bottle of water & wet down the wires & coil, how old is the condensor.
Check your fuel filter & fuel pump (with a fuel pressure gauge).
Does it only happen when cold, or does it continue when up to temp?
Lots of things to check, could go further depending on what you find.

 

First, check to see if the primary accelerator pump is squirting. Next thing you can do is disconnect the vacuum advance (if used) and see if it runs any better.

 

Bigger nozzle, different pump cam, etc makes absolutely no sense if it was working fine for awhile. Do you have reason to think someone broke into your shop and swapped those parts in your carb ? First 2 things I would check if it happened suddenly and went from running great to running like shit is that the distributor could be loose and the timing moved or the carb is loading up due to a stuck float. You say you messed with the float level. Before or after it started messing up ? No offense but when I read posts like this where you're thinking of changing things that were working great at one time I have to ask.. what did you fuck with and why ? Did you do something to make it run like crap or did it happen on it's own.

 

What he said!

 

bad accelerator pump ?

 

i would check the distributor advance, and vacuum.

 

I completely agree thats why i didnt screw around with it. I only checked the float level when I took the ineedle out to check for dirt/crap in the needle. I then re floated it. So we are good there. I havent touched crap but just checking. I would think either fuel pump or coil. I did have a little problem with it starting awhile back i shook the positive side of the battery post and then it started. Could a weak battery have the same effect as a weak coil? Im still learning the ignition side. I will check the distributor as well that makes more sense it maybe threw the timing off. I will check. I will also look for a stuck float but its a pretty new carb...

 

did you check the fuel filter?

 

sounds like a dirty gas tank

 

would'nt that cause popping as well

 

vac advance? how come you're only home 2 days every 2 weeks? railroad traveling track gang?

 

should have said that huh, Mechanical secondaries. Just seems it would be ignition system...i took a pic of my spark plugs and they look pretty good.

I do construction and my company has sent me to Jackson, MS and I live in Atlanta. Gotta go where the work is.

 

like someone mentioned, check your fuel filters, and the screen inside the tank too.

 

power valve....if the motor ever hiccups through the carb,then the power valve is hosed. guaranteed. to avoid that ever happening again get a power valve block out..what?! a holley thats a mystery to tune? get an afb and a rebuild kit. problem solved

 

Is the coil getting hot? Do you have a spare one to try out? I'd go there first if everything else was okay before hand.

Flatman

 

stale gas??????????????????

 

My hot rod causes some stuttering often under acceleration also.

All the chicks stutter when I get on it.

"Su Su Slow duh down Ra Rat Rod, your ur sca sca scaring me."

Lots to look at on this. Fuel filter, bad gas, something in the tank, other blockage, vac leak, timing. No avoiding the "guessing game."

Speaking of "games," when I park with the chicks they also stutter then.

"Ra Ra Rat Rod I wu wu wuve you, your ur so so dr dreamy."

Is the 650 you got a Holly? Is it an older one? Have you had any backfires?

 

My experiance was shaft wobble in my distributor ,ITwould idle fine and when I got on it would lose power ,Wouldn't pop Just didn't accelerate..I changed carb and that was not the problem.Points were in adjustment but bouncing in higher rpm ,I changed to hei and problem was fixed.What was confusing dwell checked out at 30 all day long.Do you have a double pumper on an automatic trans .

 

I have seen a bad rotor in the distributor cause what you are describing.

 

Yeah my carb isnt popping either and this is a brand enw Holley 650 so it has the power black valve so I wouldnt think it was the Power Valve...I wonde rif its either the coil or distributer...i mean everything else has less than 500 miels on them so I will go there.

 

BTW my Vette was running like after sitting a couple of weeks. Put new gas with some Stabil and problem solved. This new crappy gas looses octane after about a month.

 

[QUOTE="Whitey Ford" 62 Uni;4661928]......................................I would like to try and take the guessing game out. ............................... SO took another ride this morning with it cold and diud the same thing.
Coil? (no points)
Bigger squirt nozzle?
Grounding?
Pump cam?
............................... out of nowehere so I dont think its a bad carb or out of tune. I redid the float level as well...still there. Any help?[/QUOTE]
All problems come out of nowhere..

I think you are onto something! That is, take the gussing game out, as you say....................

You sound like you know the basics, there is no magic, just try each possible remedy one at a time, don't get distracted by that little voice in your head about the other shit until you have eliminated each possibility........

 

hahaha touche' 29Nash....yeah Im out of town now so now I have 10 days to ponder and let it aggravate the shit out of me till i can work on it. I THINK....it would be the coil...only cause it starts great, idles great but when I put a load on it its sputtering the whole way. I mean I cant go over 10 mph now. I checked for the plugs being at least hand tightened but I think its an ignition problem somewhere. I need to teach myself the ingition side of the motor now. Its pretty fun figuring this stuff out just wish I was home more....

 

usually if you have a miss under load (such as acceleration) it is an ignition problem , but i did have a race engine once that would miss on acceleration and it turned out the carb was way over jetted and was too rich

 

well I did read alot pertaining to that but this is a somwhat new carb and I never had a problem with it before until riding around and then next thing you know...just sputtering like a bitch. It was pretty responsive before this issue so I would think its ok with jetting.

 

OK so went back home for my chrsitmas vacation and changed the fuel pump, fuel fliter, coil, distributor cap, and rotor and now it wont even start. Just turned and turned. So I put the old coil back on and tried it and nothing....damn dman. It was a misty cold shitty day so not sure if that had something to do with it but figured since the cap and rotor were brand new moisture wouldnt play a role in it. I checked for spark and didnt seem to get any (i did the screw driver in the spark plug boot on fender way) and didnt see any spark. So I do understand that means no spark so now Im trying to teach myself the ignition basics. I have a Mallory Unilite with a mallory coil PN 8227.

Im wondering about grounding cause the ground wire is on the carb hold down bolt. Now its been like that for quite awhile so not sure if now it decides to stop but I will try somehting different there. Seems grounding through a gasket isnt as good as staright to metal.

If im getting 12 V at the coil and no spark could the module be the culprit? Also after investigating could the distributor be jacked up sicne it did actually start and drive and it slowly became crappy?

If im not mistaking mallory has a ballast resistor in it and does not need one added correct?

I have attached a spark plug for verification of what they look like. Seem ok to me.

My next option is to re do the timing all together and make sure all spark plug wires on correct. Maybe I messed up putting the wires in the correct spot. Then I will set timing. If need be...
Is there any special way to install a distributor on a FE 352? I read about the 350 oil pump needing to be lined up. Just want to make sure with an FE.

Multimeter??? What is a good basic one to get...i know Fluke is the best but Im not sure about 150 bucks for one. Are the 35-50 dollar ones reliable?

OK so hopefully I didnt just add too much info on here.

I dont think its carb but its a mechanical, 650 double pump, holley, mechanical choke, less than a year old. Float is on and has a steady stream (when parked and at idle)

would love a website or some basics on ignition/wiring cars. I love to learn so any info would be great.

 

So you are running a unilite?? Sometimes the modules get real tricky. You have to make sure your ground is really good, do you have the mallory back feed box in line on your dizzy?? Alot of times you can get a power surge from either an alternator, unhooking or hooing up a battery or ignition. The box protects you from getting back surges and blowing your module. Also, do you have any power coming out of the coil? Here is a link to test the ignition module-- http://www.curitibaroadsters.com.br/downloads/procedimentotesteunilite.pdf

Hope this helps.

 

Oh yeah, And crossing my fingers for you that it's NOT a bad module..around $80 that you really don't want to spend.