I was wondering if anyone could offer some advice on upgrading my distributor ignition system. I have a 1989 k5 350 tbi 5.7 l. Is there any problems that will arise from upgrading to and hei system. as there is the ecm connector that connects to the distributor have trouble finding one that has that connector. is it going to cause idle/ acceleration issues with going with one that doesnt have the connector?

 

The ECU in your truck is currently connected to the distributor and will complain if swapped out for an older HEI distributor.

 

It throws a code right? Any idea when GM started putting computers in these trucks? I think I found a Delco computer in the dash of my '82. It is not connected to anything. I think, if I'm not mistaken, that my truck may have the ability to have a check engine light... if it werent hacked all to pieces
BTW I really enjoy reading all of the threads where you post. It seems like you have more knowledge/experience than most here.

 

Thanks for the advice yet again! any idea on a good website to find a replacement?

 

Going to a older dizzy is not going to work. The computer controls it like already mentioned. Also even if it would swap it wouldn't be much of a upgrade. If you are having problems with the stock dizzy just get a stock replacement. Your not going to spin a stock tbi engine up enough to need to worry about it. If you want to upgrade the ignition system then get a MSD coil, a good cap and rotor with brass contacts, and a good set of wires. I run MSD wires with no issues. As for plugs, the stock AC Delco plugs seem to work the best. No need for any special plugs. Tbi engines in stock form run out of power around 4500 rpms. Also don't bother going to a open air cleaner. Your best bet is to leave the stock air cleaner set up on and put a K&N filter in and take the flap out for the heat riser. If your looking to upgrade for more power the best bet is headers and exhaust. Just curious as to why you want to upgrade the dizzy?

This is the last one I built for my 90. I now run a custom Howell chip because it is a offroad only rig. I deleted the VSS, egr, and knock sensor.

 

Well its not that i wanted to change the distributor, my alternator crapped out so i order a ho one and when i was waiting for shipping i got to looking around the motor and found that the cap bolts where so corroded they snapped off and the inside was corroded as well. I kinda figured the tbi wouldnt like the old hei style but i have a spare here just wanted some input. but so far ive taken the head off rebuilt them with a port and polish the tbi body has been cleaned and new gaskets, intake had a good coat of corrosion on it so that got a good helping of high heat oil res. paint. the thing about my blazer is i paid 200 for it and spent 2 weeks in the back of the guys yard troublkeshooting trying to save it from the wreackers. I am very amazed after a week of work a couple cases of beer and fuel pump, filter, plugs etc to get it up and running it ran as well as it did. But i live in canada and have no use for a/c so thats gone. No air care where i live so headers and straight pipes are ready to be strapped on , but it does suck ordering parts at xmas time still waiting for my aftermarket pulley kit, gasket kits etc. dam santa holding up my project

 

I have seen several dizzys that have looked like that. I usually replace them if they are real bad. If you go to long tube headers you will need to get a 3 wire heated O2 sensor. Most headers listed for them fit but they hit the shackle. The Headmans I run clear with no issues and are the best fitting ones that I have found. I'll have to dig around for the part number if you are interested. Brian at TBI Chips knows these engines and has some good reading on his site.

http://www.tbichips.com/

 

thanks alot ive got everything back together and while i was sand blasting i notice the a/c pump bracket looks like there is a mount for something right below it any idea on what goes there

 

I'm not sure but I think it is for a smog pump. You can see it in my pics and it is empty too. Every K5 I had was like that too.