You can type here any text you want

WOT Bucking Problem

Welcome!

By registering with us, you'll be able to discuss, share and private message with other members of our community.

SignUp Now!
Plug Gap??

Never heard of .045 gap for turbo buick plug 42/44/whatever...
Typical specs are .035, & with alky, you should tighten them up to .030-.032 'ish & try that--after you verify adequate fuel press under boost...
 
Never heard of .045 gap for turbo buick plug 42/44/whatever...
Typical specs are .035, & with alky, you should tighten them up to .030-.032 'ish & try that--after you verify adequate fuel press under boost...
Thanks, Monte, will do....
 
Yikes. As the others have said, that plug gap is too big. You are probably blowing out the spark at 20psi. :) You may find that the correct gap fixes your problem short term, but don't ignore that stock fuel pump. ;)
 

Instructions come with the FP kit & are available on FTS's site...I went (10/08) with the GSS340M from Racetronix when Walbro was having a rash of FP failures (in 07 & 08) & I was a victim...I would hardly refer to it (GSS340M)as "obsoleted" by the revised Walbro design (available 01/09 'ish)--which was born out of necessity...

While Walbro did, in fact, warranty-replace mine [tks to Mike Licht of Full-Throttle--where I originally purchased mine (F...169)], I continued to reliably-use the GSS340M @ 23-24# boost, w/ 60# injrs, TE60 & Alky,,,& it was still in car (1.5 yrs experience by then) when sold several months ago...

I had asked on this Board earlier if anyone had any recent experience to report with the revised-design Walbro (F...169), but never rec'd any responses re: "long-term" (more than 3-4 months) experience...
 
im looking at his BLMS and im thinking vacuum leak (155-158) ?
Thanks, Cobra. I see where the specs say it could be as high as 150, but I was wondering too if I have a leak somewhere. But, that has been that way for a long time, before my latest problem. I will check all vacuum line connections possible and see if I can find anything. I guess all the other numbers are decent...

Thanks again....Ken
 
Hi, just ran some number from my OTC 4000 scanner. These are at idle (750-775 RPM in Park), no time to drive it tonite:

02 Voltage 47-68
02 Cross counts 14-40
TPS 40
MAF 4
INT 118-136
BLM 155-158
LV8 31
IAC 41 cold, 24 hot
MAT 031 C
EGR 50%
Fuel Pressure, 233 stock regulator "Static" 49psi, (41psi w/Vacuum line attached)...


As others have already mentioned, tighten up up that plug gap (.035 - 0.32) and double check for vacuum leaks.

One thing that stands out to me is the fuel pressure you listed, a stock 233 regulator should be around 36-38psi line off. There is an old school trick of using a socket & tapping the top of the regulator down a bit to get an extra 2-3 psi, but if it was dimpled enough to hit 49 psi it'd have a pretty severe dent in the top! Some vendors used to offer a "stealth" adjustable fpr that was made from a modified 233 so you may have one of those. Get a light & look down inside the nipple on top of the regulator; see if there is a small allen head set-screw looking back up at ya. :)
 
As others have already mentioned, tighten up up that plug gap (.035 - 0.32) and double check for vacuum leaks.

One thing that stands out to me is the fuel pressure you listed, a stock 233 regulator should be around 36-38psi line off. There is an old school trick of using a socket & tapping the top of the regulator down a bit to get an extra 2-3 psi, but if it was dimpled enough to hit 49 psi it'd have a pretty severe dent in the top! Some vendors used to offer a "stealth" adjustable fpr that was made from a modified 233 so you may have one of those. Get a light & look down inside the nipple on top of the regulator; see if there is a small allen head set-screw looking back up at ya. :)
Captain,

This may be a stealth then. No dimples on top but it does have an adjusting screw and lock nut sticking out of the top, not down inside a nipple. Does this mean the fuel pump may have been upgraded also to support more pressure, or would the stock pump support 49lbs? This car was raced (2 owners ago) before I bought it about a year and a half ago, so I was told by the last owner who only had it briefly. He said it ran high 12's, but had no other infor for me. I am guessing they had a few tricks up their sleeve. For one thing, the boost was at about 23# when I got it. I quickly took that down to 17 to get rid of the spark rattlle, So I am guessing they had more mods on it that they took off before selling it. thx, Ken
 
The stealth unit actually hid the adjusting screw down in the nipple on top of the regulator that the vacuum line connects to, looks completely stock on the outside.

Stocker looks like this:

a207929124883f2794dc54_m.JPG


Sounds like you may have an older style "billet top" regulator that uses the lower section of the stock 233 or a 237. Fuel pump may have been upgraded at some point, but I'd hate to assume that it has for sure. Stock pump will flow enough to support that 49lbs idle reading you got, but under boost it's going to run out of steam VERY quickly. Better safe than sorry IMHO if you have even the slightest doubt about what pump it has, upgrade ASAP!

It'd be worth your time to take some good engine pics & post them for the board, we may be able to spot some stuff you didn't know you have. ;) I'm also going to suggest getting rid of that Red's chip & replacing it with something burned to match your cars mods, esp considering you recently installed an alky system.
 
fpr and car...

This would be what I have from a fpr standpoint, plus threw in a car pic for good measure...
 

Attachments

  • P9080099.jpg
    P9080099.jpg
    58.4 KB · Views: 190
  • P5170218.jpg
    P5170218.jpg
    93.8 KB · Views: 201
One thing you do not mention is your fuel pressure? :confused:

Do you know anything about the fuel pump - new, old, ever replaced?

You now have larger injectors and a LOT more boost than stock, and know nothing about fuel delivery/pressure?

Start with a fuel pressure gauge that you can view when you are driving, and be sure pressure tracks from 45 psi to 65 psi when at 20 psi boost.

After a few WOT runs with it "bucking", internal damage to the engine is very possible.

With the alchy system, if you do not have ample fuel delivery with the increased HP level, it will quickly cause damage.

It is possible you have an ignition problem, but you need to verify fuel delivery first. No spark at high RPM is not good, but no, or not enough fuel will be expensive. :mad:

That's a modified stock fpr.... Like Nick said, get an extension hose for your under hood fp gage, tape it to the windshield, and confirm fuel pressure is rising 1:1 with boost and HOLDING at WOT.... before you grenade it... absolutely, positively, most definitely the VERY next thing you do, and don't run it hard until then.... can I be any more clear??? :wink:
 
That's a modified stock fpr.... Like Nick said, get an extension hose for your under hood fp gage, tape it to the windshield, and confirm fuel pressure is rising 1:1 with boost and HOLDING at WOT.... before you grenade it... absolutely, positively, most definitely the VERY next thing you do, and don't run it hard until then.... can I be any more clear??? :wink:
Clear as a big fat bell, thank you....!
 
Gentlemen, I think problem is solved. Hooooray! Thank you all...Changed plugs from
R44TS to R43TS and gapped a "Tight" .035. 44's were at .045. Fired right up, let her warm up a litttle and went for a short ride. Took boost up to 15lbs and backed off; not a pop, buck, surge,,, nada, zippo, very smooth.
Before plug change I couldn't get past 10 pounds or so. Now, next step is to extend fp gauge to windshield and take her up slowly and see what fp pressure is doing before attempting any WOT's. I may also drop boost from 20 to 18lbs just to be more gentle on this fine machine. Oh, I did put back the original PCV valve after cleaning it up and blowing it out. When comparing the aftermarket generic one to the original I could see the bottom inlet internal diameter of the check valve area on the generic one was bigger than the original. So, it was probably sucking more vacuum and oil from the engine. But I doubt this was my bucking problem. Had to be the plugs all the way...Thanks again to everyone for the advice and lectures and I will update the thread after I check fb pressure...Then I gotta get my BLM down from 155-158 at Idle to closer to 128, small vacuum leak somewhere, should be fun to find...Thanks again.
 
If it is fixed congrats. Don't it feel good when the problems solved and you're back in the boost!?
 
Back
Top