QUADRAJET 102:

[Stewart G Griffin]

What things could cause a momentary "cutting out" and sort of a "sneezing" sensation (and thus a slight "bucking") from the engine?

NOTES:
stock quadrajet and quadrajet manifold

crate 350 (260hp version)

stock exhaust manifolds


Everything is basically stock.

The "cutting out" and "sneezing" (and thus a very,very slight "bucking") does not happen too often and it's only for a split second per each occurance.  It tends to usually, but not always, happen in groups of 3 or 4 at a time.

Tonight was really the first "normal" drive i've given the truck since i've sorted everything out since i got the truck.  The only thing i've changed since getting the truck is switching to a regular ignition from the "ESC" ignition system that came stock on 83's.  The distributor in it now i bought from a guy about 5 yrs ago and is of unknown origin/age/mileage.   So, i'm thinking that ignition may have something to do with it?

[VileZambonie]

Sounds like a plug wire or connection causing a miss. You can do a quick test with a squirt bottle filled with water. Mist the wires thoroughly and road test. If it becomes worse narrow it down to the source.

[Lt.Del]

how fresh is the gas? perhaps a liitle derbis causing a hiccup?

[eventhorizon66]

I let my fuel filter get so clogged one time it caused my truck to buck (or sneeze) .  But I'm sure you've already thought of that.

As far as Vile's suggestion about going over all the electrical connections, don't forget to check the battery cables.  I replaced a loose terminal on the negative cable of a friend's car.   The engine was running rough at times and the computer was throwing a code for engine misfire.  Cleared the codes after fixing the terminal and it never came back.  Engine runs noticably better.

[Stewart G Griffin]

ok, i think i've solved the problem;  It turns out that the #2 plug wire was not on all the way and i think that was the problem because it runs pretty smooth now.  It is suprising how one little thing could cause driveablility problems.  i had the same thing happen on another car--a 85 monte carlo.  After i had finished changing plugs, i apparently did not put #5 wire on snug enough. It eventually fell off and it caused a rough idle, but no missing/sneezing/cutting out.  Perhaps the reason was because on that car,  the distributor is computer controlled?

2) The fuel wasn't real fresh because the truck sat for probably 4-5 months;  i filled up last night with some fresh gas.
a) The fuel filter will have to be changed regardless because i've had the truck for about a yr and a half, the filter hasn't been changed since i got it, and i don't know the complete history of the truck.

3) As far as debris, that may have also been the problem(or became a problem as a result of the popping/sneezing) and there is a little bit more to the story and it is something i want everyone to be aware of and i will post more as soon as i can get my pictures up.

Thanks again everyone who helped.

[Stewart G Griffin]

Well, as Paul Harvey says,  now for the rest of the story............

What happened was, apparently, when the engine backfired, it blew(burned?) chunks of the foam out of the air cleaner.  i suspect the foam was burned and blown upwards because i noticed some of the foam sticking to the underside of the hood.



You might notice that the holes are not centered.  This is because i purposely oriented the air cleaner pointing towards the direction of the left, front headlight so i more easily adjust the idle speed and return spring etc. (see my other post QUADRAJET 101 for more info) This is not the best quality picture, but the mesh grille is still there it's just the foam that was burned thru.

This is another reason why i don't like this type of air cleaner.  The first reason why i didn't like it is because, while it's a nifty design, it injests hot underhood air.  i was only using it because it was easier to adjust the carb while i needed to iron out some driveability issues.  And, the only reason why i had it was because it came with another car i bought and used to own. i have since switched back to the stock air cleaner assembly and i like it.

i just wanted you all to be aware about this type of air cleaner apparently cannot take a backfire very well.

i hope the engine did not injest  some of that foam

[HAULIN IT]

WOW, I thought by now everyone who had one of those allready had trouble & threw them away. That is a perfect example of a poor design being sold over & over for MANY years creating havoc along the way. Not to pick on you, but that is what makes sorting out what a guy has going on for a problem tough without seeing the vehicle. If you would have started your first post like "I have one of those stupid cheesy little tri-angle foam air cleaners, does anybody think it could be the problem to..." We may have been able to get it sorted out sooner for you.   My brother put one of those on a car 20 years ago, the first time he nailed it, down the foam went,coughed,caught on fire,stuck the carb open a little,ect.ect.    Lorne

[Stewart G Griffin]

i like the idea of the compact design and the re-usable foam (not re-usable anymore though), but the first problem is, along with any open element design, is that we are breathing in HOT, underhood air.  The second problem is, i've read that this low profile design causes some sort of turbulence and actually restricts air intake somewhat.

[HAULIN IT]

Stewart, Did you see the picture I posted of mine in the PERFORMANCE section under "cold air intake"? A K&N filter is all you need as far as re-useable,good flow & no HOT air,ect. It is relatively easy to make & should be dirt cheap. Have Fun, Lorne

[Stewart G Griffin]

Yes i did and i like it.  i also have more questions about the truck, but i'll get to those later.

Probably my next step, after i sort out the speedometer gear problem, is to get some dual cold air intake system in place.  Although, i'm not against the high-end, top-dollar aftermarket stuff, i prefer to try to be frugal and to utilize stock type equipment first.  It's more fun.

Since i can't weld right now,  i know that 84 trans/camaros had a dual snorkel type setup.  And, also 83-88 monte carlo SS's also had a similar setup.  Repro or NOS might end up costing the same or more than aftermarket, so i'm actually leaning towards the ramairbox kit. 

Actually, come to think of it, i could find another snorkel at the salvage yard and bring it to "my" welder and have him do it;  He seems to get off on making hot rod parts as i had him make custom engine mounts another time.

[HAULIN IT]

Stewart, You could also screw the snorkel on, leaving a flange from the donor air cleaner base. If you look at the photo I posted of my brother's Mustang that is how they are. Ford did this originally,so that is what he chose to do. Yes you are correct, the fun is in spending the money wisely, it is the ONLY limiting factor. If you have lots, you can buy/have built whatever you think of, if your wrong, you start over buying/having built the new plan.  Continue on, Lorne

[Stewart G Griffin]

Well, it turns out that it isn't the rest of the story.  (My car problems are sort of like horror movies---the villan isn't dead yet!)

The truck started bucking/sneezing/missing again today, so it turns out that the #2 plug wire loose really wasn't the whole story.  And by the way, i've got the stock air cleaner assembly installed so we don't have to worry about burning the bottom of the hood.

It was intermittent;  It only did it about 5-6 times and i put about 140 miles on it today. So i feel that it is most likely a plug wire(s) going bad and needing replacement. Also, the truck was idling rough most of the time---like a cylinder was off.

Anything else it might be?

1) Your recommendations for plug wires?

[TexasRed]

Could be a plug with a cracked insulator too perhaps?

[Stewart G Griffin]

Is that the white, porcelin part of the plug?

[TexasRed]

Yeppers.