94 Blazer

PaulQ · February 24, 2006

Ok here we go. Changed out my 94 fullsize Blazer 350 with Vortec heads and Vortec intake, in the process I put on new roller rockers, pushrods, and lifters along with a new crane cam(Duration 254/ 264, Lift .401/ .423). Also put on new headers.

Here comes the problem, I can't seem to get the timing right because at 0-6 degrees I get backfires and any hire than that I get a bad idle. I'm beginning to wonder if I'm chasing my tail and have another problem but what could cause these symptoms and not show a computer code.

I'm fairly confident I did my valves right. With the truck running I back off each one until it clatters and tighten down until it stops and went both a quarter and half turn and neither seemed to correct it.

Anyone got any ideas?

Thanks,

Paul Q.

350HO · February 25, 2006

Well im thinking its the computer did you flash your chip for the mods ?

PaulQ · February 25, 2006

No I sure didn't I bought a Hypertech for it but quite a few people said not to put it in until I get everything elsse straightened out. I'm beginning to wonder if I should just put it in and see what happens.

How do you flash the computer?

Thanks for your help,

Paul Q.

350HO · February 26, 2006

what do you have for fuel injection TBI or what cus that would not work with a vortec intake if you put it on a 350 block with the old computer.

PaulQ · February 26, 2006

TBI it is, just changed the heads and intake to vortec. Also changed cam and headers and I was reading on Hypertechs page that their chips won't support any vehicles that don't run a stock setup. I'm thinking the programmer may be the way to go due to the fact that you pointed out and that is that my computer is the original.

Unless you know some tricks of the trade. Thanks for all your help.

P.S.

Also got some codes that popped up 32, 33, 42, and 54. EGR is brand new and will put the map sensor on tomorrow. I hear the fuel pump relay is cheap and fairly easy. Not sure about the 42( Distributor maybe, my magnetic trigger looked pretty bad).

Thanks again,

Paul Q.

350HO · February 26, 2006

Well i like hypertech that's what i put in my buick GN and they had a good product back in 87 but that was a chip change as far as i know you can't power program a TBI computer.

PaulQ · February 26, 2006

So you think the programmer will do it vice the chip?

350HO · February 26, 2006

No I think that this won't work at all. and your ps. i don't get do you have a actron scanner.

PaulQ · February 26, 2006

No scanner, what's the ps?

350HO · February 26, 2006

How did you get code's ?

PaulQ · February 26, 2006

Got a key from a friend and plugged it in and counted the flashes and got the codes from the Haynes manual.

Sorry about that

350HO · February 26, 2006

Oh ok what I would do is get ahold of a chip flash compeny like tbi chips but I have never seen a TBI on a vortech intake. ?

PaulQ · February 26, 2006

Gotcha, I thought there seemed to be a slight disconnect there.LOL..Already emailed them and waiting for a reply. Everyone I talked to said it would be fine, and it seems to be I got it running and it sounds good real good just getting some intermitent backfires in the carb and now I'm thinking it's the EGR or MAP sensor error that's doing it. But once I get it all taken care of I would still like to get a chip or program for it.