98 blazer. 185,00 on truck, 64,000 on engine. new complete tune up, new distributor, new cat, new o2 sensors. i just bought this truck a few days ago and it made it 55 miles to my house. i did the norm and the deeper i got the deeper the problems. im a mechanic so dont ask if i didnt gap my delcos or mixed up a wire. i ran a fuel pressure test during all points. idle not running it 62ish, idle its 55ish, wot? well it never makes it past 3,000 rpm. it screams feed me. i did an injector drop test and all seemed fine with my modis. i got .53v on my tps. my maf shows steady 2500mhz at idle. map runs around 70 kpa at idle. its hard to look at the data and drive so thats outta the question. anything im missing here? my muffler does seem alittle collapsed in. also it seems to run worse when you repair a problem ie, 2 spark plug wires were broken off and dangling. one plug had no ceramic ie broken at the hex. the distributor was new b4 i bought it. only 3 weeks old. its nearly impossible to merge into on coming traffic, have to plan the 5% throttle or it bogs kinda route. i bought the truck for the ole lady so any input would be great cause shes waxing up the ole rollin pin. lol

 

bump, any luck with this? Sounds like a problem I am having with mine.

 

does compression check good ? we're having similar problem, ended up being bent valve (0 compression in 1 cylinder). don't know why valve bent, trying to figure it out before proceeding.

 

I would find someone to read the live data stream for you while you drive. Better yet....Have them drive and you study it!