TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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My car is a 89 formula 350, the trouble that im having is if i set the timing to the factory setting I get valve rattle, several different tanks of gas, octane boost, nothing helps except for setting the timing lower, i actually ran a better time with the timing set to 4 deg atdc. Would the valve adjustment cause this at all, that is the only thing that i have not checked. i have checked tdc and every thing is lined up correct on the timing mark.
I did get a chip from tpi chips, the chip was set up for lt1 injectors and when i got it the paper said it was recommended to set timing to 8 deg, i cant get near that, it rattles at 6deg.
Octane boost (in the cans) is useless. What's the highest octane fuel you've put in the car? Did it do this before you swapped chips? My hunch is that it was fine before. Lastly, are you sure you are seeing true static (non-advanced) timing when you are checking it? The only thing that doesn't really add up for me is the valve rattle - Never heard that before as a function of slight timing changes.
I never really got to run it before the injectors because when i bought it i had to put injectors in it and got a good deal on the lt1 injectors so i ordered the chip to put in when i got the injectors. As far as the gas octane, i always put 93 in for every tank. I did have the advance wire unhooked while checking the timing. Im thinking of trying the original chip and see how it runs.
timing should be set before tdc, not after. stock setting is 6 degrees.
ignition timing should have no effect on the valve train, you may need to adjust your rockers.
__________________ 89 Formula, Maui Blue,355 TPI(used to be TBI) Auto, B&M shift kit, afpr, 3.42 Richmond gears, auburn posi. 3" Flowmaster cat back system.
86 Camaro Z28 LB9 T-tops pretty much stock
current ride 2004 Cadillac Deville.
timing should be set before tdc, not after. stock setting is 6 degrees.
ignition timing should have no effect on the valve train, you may need to adjust your rockers.
I understand where it should be set, thats why i was saying that it ran a better time when it was set to 4 deg atdc, i didn't actually set it to that, i just got irritated one night at the track because i was getting detonation and turned it back without a timing light.
I actually adjusted the rockers about an hour ago so will see if that makes any difference.
well i got to mess with it some last night, the track was hooking good so got some good runs in, with the timing set 6deg btdc i turned a 74 mph run at like 9.3, with the timing set to 4deg atdc i ran 9.15 @ 76mph, im thinking that the chip that i got is putting to much timing in, my question now is would there any trouble with setting the timing up and leaving the advance wire unhooked just to try it?
