CaptPicardsZ28

I installed a new msd distributor a little while ago. I checked the timing today and it was 40 degrees. Reset it to 15 with a max of 35. However, when at wot it feels like there is a strong crosswind pushing against the car. Not getting all the power. Was I supposed to disconnect the tan wire for electronic spark? I cant find it. I am almost sure I dont have that hooked up as I have speed density instead of MAF. If so, then where do I find this wire? Anyone got a pic?

Stekman

You need to unplug the EST wire. IIRC, its a tan wire back by the firewall. I beleive it's by the heater box. This takes the ECM out of the equation as you set the timing (the ECM cannnot adjust the timing if the tan wire is unplugged in other words, i think it throws a code as well if the EST wire is unhooked, so you may have to clear a code afterwards). Once it's unplugged, set the base timing, hook it up and go.

ede

do a search and you should find a pic. it's in the wire loom above the heater box. single wire tan w/ black stripe

vernw

iTrader: (2)

On my 91 Formula it's in front of the AC/heater box on the passenger side and the connector is in-line right behind that side's strut tower where it's crossing over the tower and heading towards the motor. Hope this helps.....


- Vern

CaptPicardsZ28

OK...thanks guys. I didnt think I still had EST hooked up. I thought it was eliminated when I switched to speed density and the new painless harness. I will look for it.

Dr.NickRiviera

omcrider posted this pic in another thread, so i'll just copy it here.

CaptPicardsZ28

thanks for the pic. I recognize it now. However, I have already set the timing to 15 degrees. What is the difference if I disconnect it now and do the timing again. Wont it still be 15 degrees? I dont understand the point. What is the purpose for disconnecting it anyway. DO I only set the base timing? What about total timing which I set to 35? I'm sorry if I sound stupid but I have never had to disconnect a wire to set timing. If someone could explain it better...I'll try a search as well. thanks guys.

vernw

iTrader: (2)

You need to disconnect it to set the base timing so the computer is not trying to correct or change it while you're mioving the distributor. Also, base timing is supposed to be 6 degrees. That number is used as the base by the ECM to determine how much advance to use for various engine load (vacuum/MAP readings) timing needs. If you're running more than 6BTDC base, then when the computer thinks it is using 35BTDC then you're actually forcing the engine to run with 44* if you set the base to 15*. Can you say detonation??? The max timing (and all timing points in between) is controlled through the computer and prom you're using. I'm using speed density on my 383 SuperRam setup and am using the $8D mask in a 7730 computer. Are you still using all the computer gear? If so, where did your prom come from? Do it yourself or buy a 3rd party or stock? E-mail me or PM me if you want and we can chat more offline on this topic. I won't claim to be an expert, but maybe I can help a little bit. With these computer setups we just can't do timing settings like the old carb days....

- Vern

CaptPicardsZ28

Ok,
Tanks for the offer to help. I will pm you. I am using the 7730 with a custom chip. All I asked them for as far as timing goes was that I wanted a total of 36-40. What they set my base timing at I dont know and I cant find out. They didnt send me a paper telling me what they did on the chip or anything.

CaptPicardsZ28

I cannot find this connection. I have a 90-92 SD setup with an msd 8366 distributor and separate coil. Can I disconnect the ecm/dist plug and set the timing that way? Will the car start with that plug disconnected? None of my ignition etc. is stock 1985 anymore. Sorry if I am a pita but I dont really know what to do. Something isnt right because I am losing power at wot.

Max_Maro92

If you absolutley can't find the wire than one thing you can try is jumping pins A and B on the ALDL to put the car in diagnostic mode. Start the car and set the timing that way. It should work the same. (at least it did on my SD car)
-Mike

CaptPicardsZ28

Oh man...your a saint! Are you sure? That makes sense. Starting the car with the pins jumped wont damage the ecm? I thought it would...Thanks.

Max_Maro92

Starting the car in diagnostic mode will in no way harm the ECM (in fact it's necissary to set minimum air) Weather or not it will work in your case I'm not sure. Since your car is a conversion I don't know exactly what to tell you, all I can say is give it a shot, cause even if it doesn't work it won't hurt anything to try.
-Mike