ok so i just did my lower intake on my 98 blazer lt 4x4. it ran great the past couple days. but when i went to leave work last night it ran like crap like when i went to give it gas choke. so i thought i was low on gas went to fill up 10 bucks toped it off so im not low on fuel. so i drove it home god i was scared casue it had no get up and go. floored it then it went fine. but soon as i went to give it gas to go choke choke. spit sputter. so i want to auto zone to scan it SEL came on and PO300 multiple misfire. so i did a fuel pressure test maybe my pump bout to go. 60psi when turn key on. runing 55-60 psi so fuel pump out the question. starts up fine no problem. idle ruff now. go to give it gas stutter til i get about 2000 rpm no mis no backfire runs great. if it was out of time it wouldnt even run great at all rpms right. so i called around and my family mechanic over 25 plus experiance said possible spider injector either clogged or bad. people at auto zone and orielys said the same thing. could it be the spider going bad. need help ............. sorry for the long thread enter in as much info as possible....

 

Fuel pressure leakdown rate is very important.
Did those guys explain how bad injectors affect low load rpm and acceleration more than full throttle and above 2000 rpm?

So.. it acts same when you start it, hot or cold? Any difference as it gets warmed up?
If you floor it, it works good and runs good over 2000.. sorry sounds like a timing problem or a vacuum leak to me.
Wonder if it would make a difference if you disconnected the battery for a while?

 

ive tried un hooking battery no differance it ran greta yesterday drove all day went to work drove fine. got off work bout a mile down the road choke. idles fine give it gas spit sputter get in about 2000 pm rang runs good. i did notice when i disconnected my fuel line on top of the spider a piece of the o ring broke off and fell in the hole i tried to get it out but i couldnt. im lost did a fuel pressure test and pressure stays at 60psi give it gas doesnt drop. dist is tight not loose but it back in right. marked it before i took it out. im just lost after doing the lower intake started up fine idled fine great pick up not a mis or anything just when i left to go home from work spit sputter no back fire. after i got it home went to start it up idles rough now. doesnt matter if it hot or cold. dont hear a vacum leak people told me spider injector went bad. it was really oily in the pentlum injectors had oily residue all over them i didnt clean them out though. oops.