truck avenger spuddering...

[shaun89]

i just put my 770 truck avenger on my 350 and it drove good for a couple days, now it spudders when i take off below 2,000rpm...i have to take off VERY easily for it to not happen,if i get on it, it will stall, then after 2,000rpm i can get on it no problem, i thought it was my secondaries not opening so i put in the lighter spring,that didnt help,it says its "factory set" but somethings wrong, o ya, i checked the bowl levels and they're fine...its a brand new 400hp engine....they dynoed it before i got it with a 850cfm carb, so i dont think its too big for it....sorry guys, i just got rid of TBI and this is my first carb i got to deal with other then my bike.

 

[Big Blzn]

Not really knowledgeable on the carb issue and I know you said it was tested with a bigger carb but the 770 just seem kinda large for a 350. I've gotta a 400sbc with approx 370hp and am using a 670 avenger and have no problems.

 

[mrk5]

You probably need to tune the accelerator pump circuit. The secondaries aren't going to be doing anything below 2000RPM, or at least they shouldn't be.

You can change accelerator pump discharge nozzles, you need to go up in size.

Also need to play with your accelerator pump cams. Best bet there is to order the set and play around with the different cams.

Not sure what accelerator pump the 770 comes with, but you may need to swap it out for a 50cc unit if it has the 30cc now.

Also you should check your initial timing. You should be able to run it at a higher setting than the factory 8°BTDC.

And if you have no idea what I'm talking about, you should get this book and start reading: Holley Carburetors by Dave Emanuel

And my thread on the truck avenger may help you some: http://coloradok5.com/forums/showthread.php?t=174116

 

[Thunder]

Cant add anything to the above post except putting in weaker /smaller secondary springs will only add to your problem.
you said you had TBI and Went to Carb? Are you still using the stock in tank TBI pump?

 

[shaun89]

Cant add anything to the above post except putting in weaker /smaller secondary springs will only add to your problem.
you said you had TBI and Went to Carb? Are you still using the stock in tank TBI pump?

thanks for all the help guys im going to start looking into that right now! but no im not using the stock pump, i put in an older style sending unit in and have a mechanical 80gph pump on my engine....and soon as it stops raining im going to crack open a cold root beer and hang out under the hood! thanks for putting up with my carb low IQ.

 

[mogulmasher]

I had a 670 ta on my 355 with I'd guess around 325 hp or so and I never could get the lower rpm operation clean enough. No matter what I did it was too fat down low (would scream over 3000 rpm though). The research I did showed it was hard to lean out the idle circuit and low rpm operation on these (even the street avenger the muscle car guys are using). Some drilled small holes in the primary throttle blades to add a little air at idle to lean it out.

I switched my truck to an edelbrock performer 600 and the truck runs mint and fuel milege went from 6 or 7 to 9 or 10.

 

[shaun89]

I had a 670 ta on my 355 with I'd guess around 325 hp or so and I never could get the lower rpm operation clean enough. No matter what I did it was too fat down low (would scream over 3000 rpm though). The research I did showed it was hard to lean out the idle circuit and low rpm operation on these (even the street avenger the muscle car guys are using). Some drilled small holes in the primary throttle blades to add a little air at idle to lean it out.

I switched my truck to an edelbrock performer 600 and the truck runs mint and fuel milege went from 6 or 7 to 9 or 10.

hmmm man, i hope i can solve this...is the performer good offroad like the truck avenger?

 

[Hogback Fabrication]

hmmm man, i hope i can solve this...is the performer good offroad like the truck avenger?

Ummm, no

 

[original balzer]

hmmm man, i hope i can solve this...is the performer good offroad like the truck avenger?

Not to be rude but, uh the truck avenger is shat off road. So is the performer. I have tried both. After lots of screwing with them they still ran like shat off road. Fine for most super mild wheeling but hills and side slopes kicked their arse.

Balzer

 

[shaun89]

hmmm...i guess ill try and tweak with it for a while...thanks for the help guys!

 

[mrk5]

Not to be rude but, uh the truck avenger is shat off road. So is the performer. I have tried both. After lots of screwing with them they still ran like shat off road. Fine for most super mild wheeling but hills and side slopes kicked their arse.

Balzer

Works fine for me.

In the situation below once we had four wheels on the bank I was able to reach in, turn the key and the truck started right up and continued to idle.

I can only think of one or two times my truck has died on me. However I'm not arguing that FI wouldn't be better. It's just in my experience the TA isn't TOTAL shat.

 

[Hogback Fabrication]

I can only think of one or two times my truck has died on me. However I'm not arguing that FI wouldn't be better. It's just in my experience the TA isn't TOTAL shat.

Fixed it for you, I think

Scott's (mrk5) truck (with a Truck Avenger) seems to do pretty well with angles.

 

[mrk5]

Man, that's like the biggest mistake I make all the time! I forget the damn "n't". I don't know how many times I've had to go back and edit that in.

Chris's (38377k5) truck (with a Quadrajet) does pretty damn well with angles. I can only think of one time he's had to re-start on a steep climb, and I've seen him on some steep stuff!