I'm trying to get my 5.7 liter Speed Density TPI to run right...I warmed the engine up, unhooked the connector and set my base timing to 6 degrees BTDC. My question is when you plug the connector back and turn the engine on ........how far is the timing supposed to advance at idle once the computer takes over?

I checked my timing again after all this and it's showing 8 degrees after top dead center I think.....is that normal for idle? It's still running rough.


Please help!

 

There is some advance built in the ignition module so be sure to have the engine idling slow as possible when setting that base timing. With the timing set connector plugged back in you should be getting quite a bit of advance even at idle. Rev the engine up and you can see which direction the timing mark moves, that is advancing the timing. No way the timing should retard back past the base setting after hooking up the connector.

 

Thanks for the quick reply,

My timing has advanced to about 16* BTDC after I connected the connector.....it seems to be running lean right now (burns my eyes! lol). I may try and play with the timing a bit and see what I can do..

 

I believe there's somewhere in the range of 20 degrees advanced programmed into the prom at idle.

 

Mine advanced to 16* BTDC.....others have said thiers moved to approx 27* BTDC......I'm clueless

 

I found out from www.TPIparts.net that the 27* is normal for corvettes w/aluminum heads......that what I'm getting is pretty close for my settings (camaro 5.7 cast iron heads)

Still burning my eyes

 

20 is normarl warm at idle.

Also 4 degrees can be added/subtracted for rpm control as ecm sees fit.

This is assuming the proper 6 deg base timing.

later
Jeremy

 

Thanks Jeremy

I wanted to give you guys a idea on my whole set-up so you can better help me:

Engine:

Stock 1982 Corvette Crossfire Engine, cast iron heads
No modifications to engine
Tested good on compression, new stock oil pump and stock water pump

Ignition:

Stock remanufactured HEI distributor, AC Delco Wires, Bosch Platinum 2 plugs, New coil, cap, and rotor. All ignition components are new.

Double checked TDC and firing order of wires….everything correct. Base timing set at 6* BTDC and actual timing at idle is approx 17* BTDC

Transmission:

Rebuilt 700r4 w/ overdrive
Has shift kit and new TC w/ a slight stall
Also using a 4000 pulse speed sensor in transmission
http://cgi.ebay.com/ebaymotors/ws/eB...m=220095546113

Engine Control Unit:

Remanufactured ECM 1227730, custom harness and custom chip
http://cgi.ebay.com/ebaymotors/ws/eB...tem=8071872892
1990 – 1992 Speed density set-ups
Chip is written for a Stock 1990 – 1992 Camaro TPI w/cast iron heads


Sensors:

All sensors are brand new
Map, IAC, Oxygen, TPS, VSS, IAT, CTS, and Knock sensors
New relays for fuel pump and fan
http://tpiparts.net/inc/sdetail/357

Fuel Delivery:

Brand new stock TPI in-tank pump
New crossfire fuel filter
Stock 22lb injectors, flow tested and checked w/new o-rings
Fuel regulator, used, stock and looked fine




TPI unit:

Stock 1986 TPI unit removed from a camaro
Has cold start delete using the plug and cap on fuel rail
Stock 48mm throttle body, throttle plates nice and tight
Brand new gaskets
New K & N filter on throttle body

Emissions:

No emissions – EGR taken care of on the chip
Has EGR block-off plate
No fuel canister purge, removed from chip. Throttle body has vacuum cap on that hook-up.
No pvc valve, spot in manifold is capped off
Have hose ruuning from passenger valve cover to throttle body vacuum.

Charging system:

Rebuilt stock starter (brand new)
Rebuilt stock alternator (brand new)
Brand new battery
All new belts and hoses

Cooling:

Stock water pump
Dual spal electric fans
Aluminum radiator

I think that’s everything…

Now Symptoms:

1. Slight miss at idle
2. Seems to be running lean, fumes burning eyes like tear gas.
3. Chugging at cruising speed, goes away upon acceleration, comes back after letting off gas
4. Several plugs have white film on electrodes…sign of lean condition
5. Vacuum check shows vacuum at 19 inches at idle slightly fluctuates between 19 and 18….kind of like a heartbeat.
6. Vacuum at 2000 rpm holds steady at 25 or so inches…no movement.
I didn’t seem to have any of these issues until I installed the TPI system, it ran decent with a carburetor. Hopefully that’s everything……Thanks for the help!