Replaced spider, not running properly
 

Hello all,

I recently had a cylinder 1 misfire, confirmed after I scanned my 98 4WD 4D blazer. After a quick internet search I realized that it was most likely the spider, so I replaced the spider with the updated version. Starts right up, but when I'm driving the tack takes a moment then jumps up, and the pedal isn't responsive the way it should be. I'm also going through gas like it's cool. Before I go through that entire process again has anyone encountered this before?

Thanks!

Also the fuel gauge is not consistent, it wanters low to higher. None of this happened prior to the misfire starting.

Did you get the injectors in the proper location?

I did, I was very careful with that. The CEL is gone and it starts up really fast, but I'm going through gas like its cool and the tac and fuel gauge are acting weird and the throttle response isn't there.

fuel pressure test when engine cold and also leak down test for 10 mins? post results?

Sorry for the late response, I took two summer session classes so my blazer got the back burner.

I popped the hood and immediately found a broken vacuum line. I know that the fuel pressure regulator uses engine vacuum so I replaced that vacuum line. The fuel gauge is no longer wandering, however the tachometer is a little jumpy.

I'm wondering if any other blazer owners tac isn't very smooth or I need to proceed with some diagnostics.

Thanks.

I knew that the fuel pressure was fine, but I checked it anyways. I went by the shop I used to work at and asked if he ever had problems with 4.3 vortex spiders. He immediately asked if I cleaned the throttle body. Which of course I did, with carb cleaner, thoroughly. Apparently these engines get used to the carb build up and the TPS gets adjusted to being stuck like that. We had to relearn the computer, it idles fine now but there is still a slight wander with the tach.