Are there any codes?
What should I check?
Thread Starter
Racer
Joined: Oct 2004
Posts: 288
Likes: 18
From: Somerset PA
What should I check?
Hello all!
This year I replaced the rockers (1.6 roller tip), valve seals, push rods, and springs as well as a new set of valve covers on my 89 coupe. I haven't had much time this year to drive the car, but I finally got my chance...
It idles fine, but when i get it out on the road and get into the throttle it seems to actually have less power than before. I plan on readjusting the valves to make sure i have the lash set correctly, and I suppose that although I added Stabil to the gas that it could use some new fuel.
Is there anything else that I'm missing here? Would this small of a change require getting a custom tuned chip? If so, any suggestions on where to get one?
Is there anything else that I may have missed?
I'm not expecting to see a hige gain in performance from this move, but getting less performance is certainly not right!
Thanks in advance for all your suggestions! I have always been amazed at how quickly even my stupid questions are answered!
This year I replaced the rockers (1.6 roller tip), valve seals, push rods, and springs as well as a new set of valve covers on my 89 coupe. I haven't had much time this year to drive the car, but I finally got my chance...
It idles fine, but when i get it out on the road and get into the throttle it seems to actually have less power than before. I plan on readjusting the valves to make sure i have the lash set correctly, and I suppose that although I added Stabil to the gas that it could use some new fuel.
Is there anything else that I'm missing here? Would this small of a change require getting a custom tuned chip? If so, any suggestions on where to get one?
Is there anything else that I may have missed?
I'm not expecting to see a hige gain in performance from this move, but getting less performance is certainly not right!
Thanks in advance for all your suggestions! I have always been amazed at how quickly even my stupid questions are answered!
Instructor
Joined: Jul 2007
Posts: 174
Likes: 0
From: Toronto Ontario
Adjustable fuel pressure regulator (AFPR)
Get an after market adjustable fuel pressure regulator. The engine is ingesting more air than it did before your mods, therefore you need to give it more fuel. Once you've installed the AFPR, increase pressure ( using a fuel rail pressure gauge ) in increments of 1psi until your comfortable with the performance of your vette.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
You don't need a custom chip nor an increase in fuel pressure for a rocker arm ratio change. Go back over your work. Chances are you left something disconnected or misconnected. Could you have swapped a pair of plug wires? Set the timing wrong? I know you don't have to mess with either of those to change the rockers, but I don't know exactly what you did or how you did it. I have never used Stabil and don't know how it affects things afterward. Since it idles smoothly, and doesn't pop back through the intake or exhaust, I'd assume you don't have the preload too tight. And since it isn't clacking, I assume it isn't too loose either. I'm sticking with saying to go back over your work and look for a problem.
RACE ON!!!
RACE ON!!!
Thread Starter
Racer
Joined: Oct 2004
Posts: 288
Likes: 18
From: Somerset PA
Yeah, I'll check that I haven't missed anything. I'm pretty sure the plug wires are all correct. I replaced them and the plugs as well when I was finished. But, I'll check just in case.
When I first start the car the idle is erratic, it races and then almost shuts off. This only lasts for a minute or two. Runs smooth after that. I'm assuming that maybe I just haven't tightened down the intake well enough. I guess that may play into this too...
Great! I have things to check!
When I first start the car the idle is erratic, it races and then almost shuts off. This only lasts for a minute or two. Runs smooth after that. I'm assuming that maybe I just haven't tightened down the intake well enough. I guess that may play into this too...
Great! I have things to check!
Drifting
Joined: Aug 2004
Posts: 1,430
Likes: 2
Get an after market adjustable fuel pressure regulator. The engine is ingesting more air than it did before your mods, therefore you need to give it more fuel. Once you've installed the AFPR, increase pressure ( using a fuel rail pressure gauge ) in increments of 1psi until your comfortable with the performance of your vette.
Instructor
Joined: Jul 2007
Posts: 174
Likes: 0
From: Toronto Ontario
Could be something as simple as a clogged air filter or cat. Also check your springs (make sure there not binding) and re-torque studs to recomended procedures as per manufacturers recomendations.
Last edited by trackman44; Aug 22, 2007 at 11:03 AM.
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Pro
Joined: Nov 2005
Posts: 536
Likes: 0
From: Bardstown Kentucky
Yeah, I'll check that I haven't missed anything. I'm pretty sure the plug wires are all correct. I replaced them and the plugs as well when I was finished. But, I'll check just in case.
When I first start the car the idle is erratic, it races and then almost shuts off. This only lasts for a minute or two. Runs smooth after that. I'm assuming that maybe I just haven't tightened down the intake well enough. I guess that may play into this too...
Great! I have things to check!
When I first start the car the idle is erratic, it races and then almost shuts off. This only lasts for a minute or two. Runs smooth after that. I'm assuming that maybe I just haven't tightened down the intake well enough. I guess that may play into this too...
Great! I have things to check!
Also, how did you adjust the valves?
Thread Starter
Racer
Joined: Oct 2004
Posts: 288
Likes: 18
From: Somerset PA
I don't remember the procedure I used to adjust the valves. Basically the procedure from the FSM.
I hope to check these things out soon, and will report back with an update...
Thanks everyone!
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
There is a HUGE acceptable range that the valves will be happy in. Like I said earler, if the valves are closing and they aren't sounding off, the adjustment isn't the problem.
"re-torque studs"??? WHAT??? This is starting to get old.
RACE ON!!!
"re-torque studs"??? WHAT??? This is starting to get old.
RACE ON!!!
Instructor
Joined: Jul 2007
Posts: 174
Likes: 0
From: Toronto Ontario
Follow the procedures of the manufacturer's recomendations, not FSM. You're installing rocker arms that are not OEM. Also check valve springs are not binding with this new setup.
Thread Starter
Racer
Joined: Oct 2004
Posts: 288
Likes: 18
From: Somerset PA
No, no cam change. Not yet anyway...
The kit from Comp cams that I bought came with the springs and pushrods, so those were changed as well.
I've got alot of good suggestions (and a few silly ones). Now I just need the time to do them!
I'm betting on a vacuum leak, but i'll recheck everything...
Thanks everyone!
The kit from Comp cams that I bought came with the springs and pushrods, so those were changed as well.
I've got alot of good suggestions (and a few silly ones). Now I just need the time to do them!
I'm betting on a vacuum leak, but i'll recheck everything...
Thanks everyone!
