Progress! 93 PCM tuning

[davo727]

Begginer here, Thought I needed to reduce fuel first- New engine seemed pig rich and running like crap. Gave up on messing with fuel tables and changed the main timing tables- rpm to map pressure timing table . Changed to a table for a 91 TPI L98 and Damn now this thing runs good nice and smooth. I put the initial timing setting in the bin at 6 degrees like a TPI. My distributor timing is set at 8 degrees right now. My lesson was I should have done something with the pathetic tbi timing first before worrying about fuel. I have iron L98 heads on this and a Comp 12-388-4 cam 206,212@.050, .425,.440 lift 112 LSA, 9.5 to 1 compression. My high rpm power seems a little flat, I think my fuel press of 11 psi right now may be why. Im going to add an adj fuel pr regulator and go up on pressure to get this thing some more fuel. I was getting discouraged but now feelin good about a good tuning result. Later, Dave

[Blue71]

Hi Dave,

Engines that are running pig rich will tolerate more timming
the problem is, when you start playing with the SA tables, backing off some of the fuel to get the blm's right, knocks will then start showing up.

What are you using to log with, is it leaning out in the higher rpm ranges causing it to back off some of the timing ?

[davo727]

Hi, Havent logged anything yet, I have a moates aldu1 but having a prob with drivers or port settings or something. Need to get my laptop guru buddy to sort that out so I can use it. Also have an ostrich im not using yet. So hopefully I will get this stuff up and running and have more info to tune with soon. Tried the 91 TPI timing table since it has 91 TPI heads on it and its much better, I can drive it to work without burning half a tank :) Thanks for the comments. I will post more when I get my data logging working or make some more changes. There is hope for the begginers! Later, Dave EDIT- I know just enough to be dangerous! Ha