n4ynu1010

Just a FYI for everyone with jerking and or bucking problems on light acceleration with the 3VZE V-6 motor :
I found something that is one of those stupid things we all take for granted sometimes , I have not been using the NGK or Denso Plugs and found that the pre-gap for the aftermarket plugs for 3VZE motor (pickup) is .042 - .044 (at least the ones I bought for this truck) , when the actual gap should be .032 !!!
I removed and re-gapped all the plugs and oooohhhhhhh what a difference it made , no bucking on light acceleration anymore and the idle smoothed out drastically as well as a great improvement in low end power and beautiful throttle response !!!!
Intermittent bucking / jerking on light throttle was completely solved by just the plug gap , go figure , another good reason to always check the gaps ( which I didn't do this time and do not trust the pre-set specs I guess when it comes to aftermarket plugs for 3VZE !!! )
Not saying it can't be other things causing this problem but I already changed plugs,wires,cap,rotor,o-ring on idle adj screw (vacumn leak) and the fuel filter and the problem still plaged me until I re-gapped the plugs , I guess .012 difference on these motors is a big deal considering the difference it made in idle,throttle response and eliminating bucking prblem .

4JOGGER

Thanhks for the info. I am gonna do that to mine.

Gator

Thank you very much for posting this!

I have been wondering what has been going on with my truck since I got it back from the shop (had the HG replaced). I have already bought wires in beginning my TS process. you probably just saved me a wad of cash.

Again,

Thanks.

MudHippy

Close, but no cigar.

It's supposed to be .031"(.8mm).

n4ynu1010

Well I checked about 4 diff. sources and they all said .032 and the dealer told me they had no way to look it up , LOL .
Did you get your info from a Service Manual , aka a reputable source ? Just curious but am sure that .001 won't make a discernable difference , I make my gaps snug so maybe I am at .0315 ROFL !!!
at least not as bad as +.012 did .

MudHippy

'93 FSM, for one. CHILTON for another. Both state clearly 0.031" .

See for yourself: http://personal.utulsa.edu/~nathan-b...14services.pdf

What were your sources?

And your decimal point is still misplaced.

n4ynu1010

LOL , decimal points , your right hehe , I am too old , need to go back to school eh .
I looked it up on sparkplugs.com and 4 other generic sites , got the links for the sites here and on pirate so I figured they should be reliable (go figure) , thats why I love this forum stuff , lots of heads and no end to knowledge or finally getting the right answer , can't beat the SM for correct answers .
I am a old school GM Motor Head ( I think thats what they call me , will that get me banned for being a old GM Motorhead hehe) , grew up in the land of carbuerators and early throttle bodies before electronics replaced the simple but reliable things , though I will say that the Toy I have although not a 4 Wheeler so to speak is very reliable and even more so since I have the gap right on the plugs (though I am off .001 ) hehe , see there is hope for me .
Thx for the correction and the infalible source ref , I have that link and am going to open every link and catalog the pdf's so I don't have to pull my hair out later (being old I have to watch the hair thing hehe).
This is a really good forum and I really like the moderation ( I actually read the rules and requirements) , very respectable site and full of nice people .
And like the guy with the Gecko for his Avatar , like his sig says it is really saving me allot of money , I guess it would have been nice to have worked for a Yota Dealer turning wrenches instead of GM for all those years back when Mallory Dual Point Dist.'s ruled and Holley Synchronus Dbl. Pumpers were the ticket but it is always good to learn something new though I still like the smell and sound of a non-emissioned muscle pig lopeing on some 120 Octane Aviation fuel .....ahhhhhhhhh just can't beat it.
Anyway to make a long story short Thx for the actual SM specified gap for the plugs and for getting me straight on my math problem .

Guy

coupstar

Hey thanks for this thread- I've been pulling sparkplugs all morning since I read it last night. They dont look great- gapped around .040 and covered in ash. I just got this '95 and after looking at it today I'm getting new plugs and wires. Hoping to fix my hesitation and weak acceleration- also hoping to fix the bucking/serious stumble at 50 mph. Its been killing me.
Thinking this will also help with fuel economy and power

MudHippy

You betcha!

Good luck on the bucking/stumbling at 50 mph. That can be tricky to diagnose sometimes.

BTW, I wonder what happened to n4ynu1010 anyway? I miss that avatar, it's a classic.

coupstar

I was going to direct a comment at n4ynu1010 but its a little much to type and sound casual.
that bucking at 50- do you have any idea what that might be? I just replaced the fuel filter.. and it only seems to be a problem 'under load' anyway. RPM's will go pretty high just sitting and revving. and in gear (automatic) its hesitant but okay until I hit 50 and then it gets so that I dont want to push it- you can, and then it evens out, but I like to be nice to my baby- so I don't push her. but up an incline its a real bummer..

coupstar

just wrapped up the spark plug replacement/ spark plug wire replacement and it corrected the hesitation, and bucking at 50mph . A couple of times I thought I was going to shoot myself though. Learned a lot. I'm a junior mechanic at most and was under the hood all day. when I pulled the plugs yesterday I noticed that the 5 cylinder spark plug looked like it was original. The others were denso's- that one was an NGK- it looked older. Only took part of the air intake off for access to the 2-4-6 side (driver) for the 1-3-5 I unhooked the diagnostics plug, but that was it. 5th cylinder (closest to firewall on passenger side) was the hardest. I'd suggest using your right hand to access 246 and your left hand to access 135. Got it done, and now I'm running great. Stoked.