JZ28Max

low fuel pressure had my headers glowing at idle. any particular ones brighter than the others? my number 5 and 7 were the hottest. if the fuel enters the pass rail and crosses over to dr side then maybe those cylinders would see less fuel and run leaner if the pressure is low. at least that is what i believe was happening with mine.

unTAmedLS1

yea fuel pressure is good too 44psi all the time

new_z

golen had an article in gmhtp. they made a new 383 and it was low. they had a brand new opti that was bad. they only lost like 60hp.... just throwin it out there.

unTAmedLS1

I have been wondering if that may be the case also. Since I have replaced every other damn sensor on the thing. Although im missing about 200 hp from somewhere...

redcamaroz28

Do you have any vacuum leaks? My friend had a heads/cam car that should have put down around 390rwhp, but only put down 305rwhp. It turned out that his intake did not seat right on his heads and it had a massive intake leak, however it leaked from the inside so it could not be heard. The glowing headers could be caused by a vaccum leak causing an extreme lean condition.

Ryan

Robs97Z28

'what do you mean 44psi all the time?

It should only read 44psi at wot. at idle it should be 3 psi to 10 psi less than 44 psi. so, it should be in a range of 34 to 41 psi max at idle.

Kryckter

I ran through this post pretty fast, But I read that the cam WAS degreed?
What did they change? Did they just check it or advance or retard it?
If the cam was changed at all, That is your problem, You can only put the cams in a LT1 straight up unless you are a tuning master....Even then, It would be hard....
The Opti is right off the cam, as we all know, So if you change the cams posistion, by degreeing it, You throw off the entire timing system of the car.
Someone else chime in on this...

Joseph

INTMD8

You are correct. If the opti is still being used, than an un-altered timing set must be used as well. As you pointed out, an offset bushing in the cam sprocket, or a multiple keyway crank pulley in the advanced or retarded position will throw off the relationship between the opti and crankshaft.

In this case, having heard the car run and dynoing it, my guess is that the problem is related to cam timing.

slverbullet

i had this problem. i certainly didnt lose 200 hp. i lost about ~40whp. i'm thinking this is something more than an intake not sealing right.

unTAmedLS1

Hey Jim it was the opti.. It wasnt on right I put a used one on but i shattered the reluctor wheel on it the same night. Time for a new one. I dont have the money for an alternative right now..I drove the car all night and day yesterday with the used one and the car pulled real hard til that opti broke..I checked cam dowel length and it was in spec so I think it was just a coincidence. I didnt go past 5000 rpms since motor is new but i raced my friends newer m3(e46) off a 60 roll in third and put a good 5 cars on him before 100..Im glad I finally got it figured out

shoebox

I guess that 1% gotcha.

Victory Racing

Glad to hear you got this resolved. Optis are fickle creatures to say the least.

unTAmedLS1

I always get owned by that 1 percent.. I should have known...That was the last thing i was checking before parting the car out..

WS Sick

I hear ya, it always seems the thing I take for granted is the first to break.

Robs97Z28

glad to hear you have things running as they should.