I just bought a 1994 z28 and it kind of hesitates out of idle. It's not like it's not engaging, but rather not getting full power. Once it gets to around 2k RPMs it seems fine. I took it to 2 mechanics and one said it could be the distributor or the ignition module (Code 43 comes from the SES light, which is the knock sensor, but that code could be the ignition module he said since the knock sensor is working), and the other mechanic said I needed a new transmission. I don't think it's the transmission because it seems to shift fine and all, and the transmission doesn't control the amount of power does it?

Also, it has an new distributor from JEGS in it, not the stock GM. He said he started having this problem a little while after the new distributor, as well. Could the distributor be messed it up? Or the ignition module? Do I need a special ignition module for an aftermarket distributor?

I'm a little confused about what to do. A new transmission is pretty expensive and if that's not the problem, I definitely don't want to shell out $1,800.

Anyway, I tried browsing the forums and there was a really long thread regarding this with pretty much people just saying they had the problem too, but no solution. Has anyone else had this problem and fixed it? Thanks for reading my long post if you've gotten this far Thanks for any advice, as well.

 

How many miles are on the car?

Plugs/Wires
02 Sensors
Ignition Coil
Fuel Filter
Clean/Replace Air filter
Could be the distrubitor or Ignition module as well, but try the above first.
Could also be a fuel pump...
Lt1's are known for having weird "mysterious" Hesitations as high milegae increases. Some ppl tried about everything to fix hesitaions, and had just given up and sold the car.

i dont know why he said its the trans, ask him to give you reasons why he thinks that.

 

There are 155k miles on the speedometer, and it was a state trooper car that was gotten with a blown engine so the LT1 is a different rebuilt one with 50kish miles on it...

I'll have to contact him Monday regarding why he thinks its the tranny, I don't understand why he would think it is, especially considering he only had it for about 5 hours max before he made that guess, not to mention he was really busy so probably even less than that.

 

I highly doubt it's your transmission. Yes, I'm also a victim of this strange hesitation that goes away past 2K...and only happens in first gear starting from a stand still. No issues on the highway after shifting below 2K. Mostly in hot weather, but oddly sometimes right in the cool morning as well.

My next step is to replace my spark plug wires...and maybe...if I really had to...switch the opti. There's a slight chance it's my knock module....I recently installed a new Y-pipe and I hear some rattling once and a while. I think the heatshield over the cats is somehow hitting the Y-pipe and making an obnoxious sheetmetal vibration noise...don't know if the knock module is picking this up and retarding my timing. This is a long shot, but going to address this rattling this weekend to eliminate that.

The way I look at it, there's 3 elements to the engine firing: air, fuel, spark. For my car, I'm betting it's has to do with the ignition..we'll see.

Don't fee bad...you're not alone.

Whatever you do, don't dump a lot of cash into the tranny.

 

check your EGR valve i had the same problems as you
(hessitation below 2000rpm)
i replaced fuel filter, plugs, leads ,coil and i even had a lt4 k/s shipped over from the usa!

still the same (hessitation) but no ses light??

i took the EGR off and it was solid, full of carbon+crap
if they are stuck they can make your car run bad
so i took all of the egr off,made some plates up,there is a guy on ebay who sell them
now my ZED is running great no hessitation at all!!

andy