1982CorvetteDude

Hey all,

I have my timing set at 8 degrees BTC and all the guys on the TPI C4 tech says thiers is set at 6 degrees BTC ....I haven't had to go out and re-set mine yet. It's a 90-92 TPI swap.

I was curious if 2 degrees would make any difference?

big_G

Not really. 6*is better to keep the knock-sensor/retard activity minimal.

Mikeg72

Timing made all the difference on my car. It refused to start when it was warm and was sluggish. I advanced the initial timing 2 degrees and
it was like a new car! Starts fine now and way more power.

Try advancing the timing (back off if you get engine knock).

Mike

1982CorvetteDude

Thanks

Yeah my car has a slight miss and the engine seems to be shaking more for some reason. Headlight doors shaking and everything, sounds like a little knocking as well. At a stoplight sunday I noticed it would try to idle waaay low 300 rpm or so. Not to forget the "jerking" at cruisng speeds. Something doesn't seem right. I''l try advancing the timing and I'm changing the plug wires too.

big_G

If you are still running TBI, the E.C.M. sets the idle speed at 600 rpm. For proper operation, do not deviate from OEM timing recommendations. It sounds like you have tuning issues other than timing, IMO.

1982CorvetteDude

what tuning issues could I have? It's a TPI set-up and I thought most of everything was set by the computer

big_G

Tuning issues can be vacuum leaks, bad plugs or wires, clogged EGR ports/valve, worn throttle shafts, stuck or worn IAC motors, sensors out of spec., etc. Look at all the basics before going any further.

lars

Timing won't cause a miss - you have other issues not related to ignition timing.

1982CorvetteDude

Yeah it's driving me nuts, I didn't have it with my carb set-up..

I've done replaced the distributor, coil, plugs, cap, rotor...and now I'm down to the plug wires, the one's I used with my carb set-up were brand new "cut to fit" accel brand.

I ordered a set of ac delco wires a few days ago....going to try them next.

all of my sensors are new, fuel pump is new, injectors are freshly rebuilt.

I did put a vacuum guage on my engine at idle and it shows a "flicker" between 19 - 18 on the guage....which I think ment a ignition problem.

Kinda at a loss right now....

big_G

I would look (listen) for a vacuum leak. Vacuum leaks can cause a lean miss.

1982CorvetteDude

I have one of those push in breathers on my valve cover on the driver's side instead of a PVC valve, do you think that could be causing my problems? The spot in the manifold where the hose would go is capped off.

JackDidley

When you installed the computer, did you include the EST wire and did you unhook it when you set timimg. If not, the timing will be slow by about 20*,

1982CorvetteDude

it was included the harness, I unhooked it when I set the timing

big_G

May not help your situation, but you must hook up that pcv.

Sean82

your timing should set at 0 (zero degress)
or your chip needs to be changed to what you have the car set to.

right now your chip timing and actual car timing are not the same.

1982CorvetteDude

So you're saying that if I hook a timing light to my car right now with the EST connector plugged in, my timing should read 0?

So when I time it, I need to unhook the connector, using my light set the timing to 6 degree's BTDC and once everything is buttoned up, the computer will advance it to 0? Just wanted to make sure I understand before I contact the guy that made my chip. Thanks again!

big_G

Huh?
Set it to 6* btdc (with bypass connector apart). Shut engine down, re-connect bypass and restart engine. Timing at idle should be between 20* and 28*.

Sean82

I should have been more clear on this.

what is the timing set at in your chip?
the chip timing and your dist. have to be the same

unhook est wire. read timing with the timing light. set the dist. to match chip. connect est wire and let the computer do the rest.

computer timing for a stock 82 vette is 0

If you can tell me what computer that you are using then I may be able to get the "intial spark advance" from the prom.

1982CorvetteDude

It's a 90-92 Speed Density Computer 1227730 , the bin file on the chip should be stock 5.7 liter TPI Camaro for those years.

I've been warming the engine up, unhooking the connector, setting the timing at 6 degrees BTDC and reconnecting the connector and going from there....I may have been doing it wrong.....

Thanks again for the help!

1982CorvetteDude

Should the timing advance after the connector is re-connected?

My timing with the connector unhooked is 6 btdc and after I reconnect the connector it advances to 8* after top dead center.

Plus the smoke is burning my eyes....does that mean it's running rich??

Please help