So i picked myself up an 88 iroc z with a 383 crate engine in it for 1k. Guy said he was having electrical problems which i have yet to come across. I did a basic tune up..plugs, wires, new oil (since it wasnt even showing on the stick), a new rotor button and fuel filter. After tinkering a little bit i got her running surprisingly well. However i was told it still had the original 305 computer in it? This 383 has the eldbrock tpi system, edlbrock heads and lots of comp cam goodies...so i find it hard to believe its runnin as good as im seeing on a stock 305 computer...

I yanked all the plugs, they all showed signs of a rich condition which obviously is not surprising however i am worried this guy used the 305 injectors on this 383...which i know are wayy too small for it.

Another problem is the tranny. It was originally a 5 speed car and is now an automatic. THe tranny was 3 qts low on fluid which i filled ( i took it for a spin and noticed the tranny was shifting extremely late and felt like it was slipping so then i checked the fluid). Does the ecm also control shift points? I am wondering if it has anything to do with it shifting so late. The tach is screwy so i cant tell you exactly what its shifting at but it feels like its winding out the motor way too far...

suggestions please..

 

anybody?..i know the tranny isnt controlled through the ecm now heh

My main concern is the injectors..any way to tell what size they are?

 

If they're oem injectors they'll have the part number, and a date code printed on them at the top.

 

yea i read like a 6 digit number off the top of them..it was like 530532..or something along those lines...ill get the number tn and post it up

 

its stamped 523 530

 

your tranny is controlled by the ecm but you should disconnect that because itll cause you to slip inbetween shifts at certian RPM. camaros arent the only GMs with that situation. after you disconnect that you should drain the tranny fluid and replace the filter (ever 50000mi tranny oil replacement) and oil with new stuff. after you do that and you notice late shifting then you can look at your throddle linkage.

up on the plenum (im assuming you still have that TPI system on that bastard) there are 2 or 3 cables comming together, one if from the gas pedal at your feet, one is for cruise control (optional 3rd cable) and the one most important is the one that comes from the tranny. it looks like the cable comes out of the housing and has a big block surrounding it, well that adjusts the cable tention. by looking at it from the drivers side, push the centre piece that points towards you (looks like "D" sortof) and hold it in and you will notice where the cable comes out that the housing will move. moving the housing out will cause it to shift later, moving the housing inward will cause it to shift erlier. before you play with it i suggest you mark it so if you lose your place or forget where you are, at least you can move it back to stock and start again. take it for a trip up the poor mans dyno (freeway onramp) and play with it accordingly.

and ya before you do the cable thing you should upgrade the injectors and the PROM chip for a 383 (im pretty sure they make chips for those engines).

 

YOUR TRANS IS NOT CONTROLLED BY THE ECM.

ONLY THE LOCKUP AND UNLOCKING OF THE TORQUE CONVERTER IS.

All gear functions and up and down shifts are controlled by your right foot which connects to the throttle linkage which connects to the TV cable(transmission valve).

Yes it should be adjusted properly, see tech article here for the proper procedure.

A mild 383 would run on the stock ecm/tune, maybe even okay. It is nowhere near optimized however and there are huge gains to be had in power and driveability thru proper tuning. See the PROM board here for more info.

later
Jeremy