I have a 2000 ZR2 with 180,000 miles on the body but 80,000 on the motor (put in by the previous owner earlier this year before I bought it).

I'm not sure but I believe the motor is a gen II any way to determine the difference? The problem began when I was on the road to memphis and after about 45-50 minutes the car started surging but the RPMs wouldn't change and it countinued to surge when I changed gears. I slowed down and exited, I had a quarter tank of gas at the time so I pulled into a gas station put more in and drove the last 10-15 minutes to memphis without complication. On the return trip about 50 minutes into the trip the car started litley surging again but stopped fairly quickly before I got home.

It has been doing this on every long trip that I've taken with the car. Right around the same time interval and hour to hour and a half into the trip, the car will start surging like it's running out of gas but it stops. The car doesn't idle rough and I don't see signs of smoke leaving the tailpipe.

I've been reading the forums enough to suspect that my injector, spider, and nut kit were going bad. I pulled the throttle body yesterday to look for signs of washing but could see NONE! Both sides were equally dirty. So now I'm a little worried because if this thing only acts up at highway speeds after an hour of driving it makes it midly difficult to trouble shoot.

Anyone have experience with a similar problem?

 

I know if you find the vin on your engine and you look at normally the 8th character and call up a auto parts store they can tell you what size engine it is.

for the rest check out this site
http://www.ehow.com/how_4814893_read-engine-vin.html

 

Thanks 84blazers10.

Anyone have any advice about the mechanical issues? Is there another thread I should be looking at I've read most of them but I could have missed it. Thanks for the help.

 

I have a similar experience with my blazer. With the engine warm, I could be driving at 55 and the whole truck would lose power and then regain it from the RPM's. It would create a shudder that felt like I was driving through water and then back out of it.
It wasn't throwing any codes, and the only indication that I had it was about to happen, was the temp guage would drop. If I saw this happen, a second later it would shudder. Weird, I know.
Anyway I took it to a shop since I suspected the transmission, as everything else was checking out good. They pulled it and showed me the problem. My number 1 and 2 clutch rings were burned up, and my torque converter had its fins floating around in the housing. They replaced all this and everything seemed to be fixed.
This may or may not help you out... but I thought I'd share anyway.