can you help me out here guys? got a 93 4x4 blazer 4.3 vortec. its running rough , motor shaking slightly at idle, and using more fuel. when driving and stoped at like a red light its almost like its trying to die. when you pull out it flutters . done some trouble shooting on it you can take the number 2 number 3 and number 6 spark plug wires off [ individually ] and it dont change how it idels at all. [ weve not tried taking them off all at same time though ]. we put new rotor button , dist cap, plug wires,cleaned egr valve , timing chain on it re timed it at 0tdc and we still have the same problem. got any ideas or suggestions what it could be? we are at our wits end . no code being shown by computer at all. let me knowwhat you think guys thanks . brok .

 

i would say open the plenum and see whats goin on in there. i'm thinking u have some fuel leaking inside there. i had the same problem twice lol. the first time my plastic fuel lines in there were cracked and leaking. the second time one of the spider injector lines broke off. i'm like 95% sure u'll find the answer to ur problem inside the plenum. u just have to take the top off which is like 10 bolts or so w/a few things to disconnect.

 

Thanks for the reply ! We will pull the plenum off tonight and check things out. we took it off to install a FPR about 4 yrs ago . everything looked good then but that was at 100kmiles and now its at 155k . its my work truck and i'll have to put it back together after checking for problems tonight as well so i can drive it tomorrow, do i need to put any indian head or gasket sealer on the plenum gasket before bolting it back down? thanks again for the reply, oh besides puddled gas what else should i be looking for or checking while its off? thanks again . brok .

 

ya 4 yrs is awhile lol. my 2 problems happend within 2 yrs of eachother w/ a difference of like 30K mi. and since u just took the plenum off to put it back on u should be fine but when u actually go to fix ur problem i would get a new gasket.

stuff to look for would be clean/dirty areas. if there is no gas puddled there u'll want to look for a clean area. this means that gas has been leaking there and burning off. also with the plenum off u can turn the key to the on position to send pressure to the injector and see if u can see any leaks that way.