what a horrible night at the track i had, got 6 runs in and not a single one i even care to mention times of..

heres the car..86 LG4, hedman hedders, Y-pipe, 3" mandrel stainless exhaust w/ no cat, edelbrock RPM intake, open element filter, all smog and a/c removed. cc qjet tuned w/ dwell, w/ G hanger and DR rods (also tried CK's)

heres whats happening at WOT throttle.. coming out of the hole its awesome, so nice infact i think i broke my trannys cross memeber last night after my last hard launch (im getting a bang on the floor-board at mid-hard throttle dip-in).

Under WOT as soon as it hits around 2k, in 1st gear, it starts pulling less and above say 3k it starts to sputter and when it makes the shift to 2nd the motor stops spinning and starts bogging and pinging until i let off the gas, and if i get right back on it it, it does it again, but if it let off it for a few seconds the motor spins (still seems to lack power, but at this point its in a lower RPM). When this sputtering and bogging/pinging is happening my O2 sensor is going a nasty low lean..

Heres what i'm thinkning; The fuel pumps not able to keep the float full, its running dry and letting off the throttle for a few seconds lets it refill enough to have some power.

Also another option; my air valve tension spring has been motifiedl. Tuning it once i over tightened it and the bent the little curved part that goes around the air valves lever, causing it to slip off. I "fixed" it by pulling the spring out a bit and bending it further down, otherwise it just kept slipping off (this happened months ago, seemed fine then). Maybe its too tight and not letting the secondaries open far enough. I actually loosened it a good 1/4 turn last night at the track and it still done it. The motor is awesome down low though, snaps you back from a stop when you punch it..

Any ideas you all?

the car was running great, my brother inlaw thought it was a damned rocket (i know, i know, its just an LG4..) last time he rode with me he was insisting that i come tune his chevelle's qjet afterwards.

 

i was wrong it wasnt the cross member it is the transmission mount.. oops.

i may juts help my self here and try a new fuel pump, they dont cost very much anyhow and the boards seem kinda slow today. i'm still open for suggestions though.

 

The LG4's cam makes it lay down and die from 3000 rpm and higher. Most won't even rev above 4500 rpm.

You have everything you need for a decent 305 except a cam. I'd suggest a Comp XE256 or 262. Also look over the fuel pump. Carb may need rebuilding or replacing ... who knows, eh?

 

thanks for the input sittingbull

turns out changing the fuel pump fixed the problem, i also replaced the transmission mount because it had been split in 2.

my carbs in great shape, sittingbull, ive spent a good amount of time learning them in and out and tuning, these CC qjets are great i cant understand why they have such a poor rep.

after replacing the transmission mount yesterday my uncle finds my TV cable is out of adjustment and throttle cable was only actually opening the carb less then say 3/4th open throttle. After fixing that i filed down the secondaries tab that stops them from opening more then 60 degrees and they open what looks like 80 degrees now.

The difference these changes made, including the new fuel pump was unreal, it was a night and day difference it was pulling so nicely you wouldnt have known it was the same car. The sad part though, my very first "test" from a dig was a disaster. It was running awesome and when it hit the top of 2nd gear there was an awful sound and a rod started knocking loudly.. damn damn..

im almost certain its a rod, but im going to pull the valve covers and check out the valves and rockers.