jh7823

did a cam swap and had the computer tuned..motor seems to be detonating no matter where i put the timing timing is set at 8 degrees..it only does this while its under load or in gear..motor seems sluggish as well under low rpms. any ideas?!

sofakingdom

iTrader: (1)

How long has this been going on? Has it ever run right since the cam swap, or did it run OK and then go bad later?

Sounds like an exh valve isn't opening.

Observe the valves while it's running; make sure all are moving about the same amount.

jh7823

its been ever since i did the swap..u think one of the valves are too tight maybe?

sofakingdom

iTrader: (1)

Could be; or too loose.

Are you saying, you haven't done ANY basic troubleshooting on it yet?

jh7823

i have done all kinds of trouble shooting and cant figure it out..

ex-x-fire

I'd start w/ a compression test. See how even the numbers are.
Is it using oil? Any oil sucked into the chambers causes a great reduction in octane.
Pull the valve covers & recheck the rockers.

jh7823

it uses a little on start up (valve stem seals) but thats it..i checked one side so far and they seem good

jh7823

well i check all the valves and they r all good..any ideas?

jh7823

vacuum problem maybe?

ex-x-fire

Whats the cam specs?
Who gave you the cam recomendation? Just make sure its a match for your tpi.
Did you do a compression test yet? Check the fuel pressure too.

jh7823

cam specs are duration 268 ext and int, duration at .050 218,valve lift is 0.454, lobe lift is 0.302,lobe seperation is 110 degrees, fuel pressure looked good but havent done a compression test yet(trying to avoid that haha)

The Wolff

Check the valve lash to see if it is correct.....go through the entire cycle 1-8-4-3-6-5-7-2. Put the engine at TDC and see if the rotor is in the correct location---you may have dropped the distributor in a tooth off.