Carter01

iTrader: (11)

That was the next thing I was going to ask. Had the same problem when I was SI with an UD pulley. I guess I just got a bad one because the vibration of it would do the exact same thing. Would bet money that's the problem. I put my stocker back on and fixed the problem. Nobody wanted to believe that was the problem or the fix but I have yet to lead anyone in the wrong direction on this board in almost 4 years and I don't plan on it.

edit - things we checked before swapping the pullet. Fuel pressure in various rpms, plugs, wires, coil packs, pushrods, fuel filter.

rob69zombie

iTrader: (7)

^ You're the man if it works! I'm gonna try Monday and report back.

98TADRIVER

iTrader: (36)

i hope the UD pulley isnt causing the problem. what a pain in the *** it is to change on a C5. almost not even worth it. The guy on the vette forum who had the pulley before me said he had no problems when it was on his car

Ill have to find a friend who hasnt installed their electric fp gauge on their car yet and borrow it so i can check while driving

rob69zombie

iTrader: (7)

My ASP came off of my buddy's SS and it did fine on his too but after all I've changed, I hope like hell it's the stupid pulley; easy fix.

bayer-z28

iTrader: (14)

Valve float at High R's... ESPECIALLY on stock internals... Either that or the coils are getting hot. Stock coils have been known, lately, for breaking up at high RPMs. That's one of the benefits to the truck coils. Shorter dwell.

98TADRIVER

iTrader: (36)

i thought the same thing but i changed the springs and coil packs and still the same issue. it didnt happen until after i installed the ASP pulley. there isnt too much more troubleshooting i can do until it comes down to putting the stock pulley back on

rob69zombie

iTrader: (7)

^ Ditto. Not saying it's 100% NOT a spring issue, but the power wouldn't come back after 5500rpm's; it would keep falling off. I also changed all the coil packs on the dyno with no different results.

bayer-z28

iTrader: (14)

I've heard of something like this before. I thought it was a knock sensor issue, but I didn't think THAT was the issue. I think the SFI cert on the pullies was for this exact reason.

I just installed an ASP UDP also, I hope I won't have the same issue.

dtfastbear

Might be a very dumb question, but did you put a shorter belt on when you went to the UD pulley? Someone just suggested on my thread (I'm having the same problem) that there might be belt slip at the alternator... If your belt had just a tad too much slack to be effectively taken up by the idler... ??

Just throwing ideas out there.

Good luck.

Dean

98TADRIVER

iTrader: (36)

I could be wrong, but i think if it was a knock sensor issue, some Kr would show up on the datalog

I used a shorter belt with it. my voltmeter was reading 14.3 volts @ wot

98TADRIVER

iTrader: (36)

I found this in a google search. pretty interesting. http://www.ls1gto.com/forums/showthread.php?t=295981

looks like i might be pulling my pulley off in the near future

rob69zombie

iTrader: (7)

Mine is hopefully coming off tomorrow.

98TADRIVER

iTrader: (36)

let us know how you make out. ill probably order a SLP/Powerbond (same thing). ive bought both in the past and had no problems with them

rob69zombie

iTrader: (7)

Will-do. If it fixes it, I'll never put another one on here, lol.

98TADRIVER

iTrader: (36)

i hear ya there. ill probably go with a slp/powerbond, as ive never had a problem with those

s346k

iTrader: (4)

i had this problem. it came out of the blue, halfway through a 1/4 mile pass, and really pissed me off. luckily it was just the 10 year old plug wires.

on a side note, i changed the plugs at the same time and got a bad plug (new tr55) that caused me to chase a misfire for a week.

it sounds like your issue is with the balancer. good luck.

edit: i had a powerbond udp on another ls1fbod that was fine.

98TADRIVER

iTrader: (36)

i ordered my slp ud pulley from speedinc last night. 179.99 and free shipping

180ls1

iTrader: (4)

Ya it might be a pulley issue. You seem like you have gone through just quite a bit of things. One thing to note is i wouldnt always count on your knock sensors to pick up knock.

98TA Bandit

iTrader: (2)

My vette with the asp pulley is doin the EXACT same thing

Carter01

iTrader: (11)

WOW, just one more reason why i won't run one again. With the 10 hp I don't gain for the UD pulley i will make up for it with the SPRAY Just not worth it in my opinion....