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allansmith859 11-17-2012 10:52 AM

Pulled plugs while running, nothing changes
Hey guys I posted this in a different thread but thought i might get more opinions. My truck has been missing bad. I bought plugs and wires a month ago, good ones. I started it up and started to pull one plug at a time from the dis cap. ( it was easier to not get shocked) I pulled 1 cyl and nothing changed, pulled 3 cyl nothing changed, pulled 5 cyl nothing changed, then i plulled 1, 3, 5, and 7 at the same time, nothing changed, what is going on. I need help fast. Also I did change engines and I got all vaccum lines right, I got wires right, got all sensors plugged in. I did notice my IAC sensor plug has the sides broke off that hold it into place put it has always been like that and stays plugged in pretty good. There is one sensor plug that is black with a green base that has nowhere to plug into but its always been unplugged

ssimpala 11-17-2012 11:31 AM

Just guessing here, but from the description, it sounds like you have a late model GM with a bad oxygen sensor on the driver's side. Really need more info...and you should scan the engine.

painted jester 11-17-2012 11:36 AM

Need info year, model, make, Etc Etc????

No fuel to those cylinders

Had one vehicle did that!! a critter chewed through the injector wires!! LOL


Richiehd 11-17-2012 11:41 AM

TBI? one injector inoperative. Light tap with hammer might get it started!!!

ssimpala 11-17-2012 11:41 AM

I just found your other posts farther down the page. I still think you should scan it....and if one whole bank is not firing, it may very well be the oxygen sensor or injector. Hope this helps, Bill.

painted jester 11-17-2012 11:51 AM

TBI 1 injector not flowing fuel would knock out 2 cylinders on each bank of the engine not all 4 on one side on a Chevy! Post info Im not chasing down the other thread!!!!! :drunk: or put the threads together:pain:


Is intake open plenum or 180 Stock plenum?

allansmith859 11-17-2012 12:14 PM

My Bad, Its a 94 chevy c1500. Also the o2 sensor was never hooked up whenI had the other engine in it and it ran fine with pretty good gas mileage but maybe thats the issue. Both injectors are putting out fuel so I dont think Thats it

painted jester 11-17-2012 01:05 PM

Your getting shocked but are you sure the plugs are firing! when in the cylinders? If you have fuel to cylinders (you say you do:thumbup: both injectors are squirting), And spark to the plugs?, and air on the intake stroke entering the cylinders, you should have some type of ignition in the cylinders! Unless intake and exhaust valves are open and there is no compression and the fuel and air charge are going right through the cylinders and out the exhaust !!!!!!!!! Without these threads joined I have no Idea What Other People have answered already or if this is a junk yard engine or fresh rebuild!!! Is your Oil full of gas! If one entire bank isn't firing the gas must be going somewhere !!?? Be very careful if its building up in the pan or in the exhaust you could have a back fire or odd spark and get a huge explosion even blow the pan right off the engine or blow a valve cover off right into your face!!!!

Whats the compression 0n all you cylinders? Is it dual exhaust with cats on both sides of your exhaust It could be as simple as one cat or exhaust plugged solid Like putting a potato in a tail pipe!!!!! I saw a dead Rat that pluged an exhaust system one time LOL!!!!!! Ive seen dip sticks blown through hoods like a bullet!!!!!


cdminter59 11-17-2012 01:47 PM

Pulled plugs while running, nothing changes
This guy took a 350 TBI motor out of his 94 truck and installed a 93 305 TBI motor using the 350 computer. I don't know if he rebuilt the 305 or not. A moderator needs to check his post to see if they need to be combined.

allansmith859 11-17-2012 02:08 PM

OK I took the 350 out put a 305 in using the 350 heads which came on both 350 and 305 engines. I am using the same everything that was on the 350 except the block and the bottom end. I have stock exhaust (y-pipe) with no muffler no cat no o2 sensor. (it wasn hooked up before and was fine). It starts right up and actually sound alright at idle but seems like it has a little miss to it. When I take off it sputters and def has lost some power. Plugs and wires are a month old. Timing might be off but if it is its barely off. Not consernd about that. Like I said before I started the engine and started pulling plugs, nothing changes. Hell I forgot to hook the hole left side plugs up (1,3,5,7) and the truck still fired right up and sounded the same. I have fuel coming out both injectors. I have called the parts store and found this out. Throttle bodies on both 350 and 305 are the same. So are the fuel pressure regulators. The only thing that is different is the injectors. (different part numbers) But that doesnt mean they are always different. I replaced all the gaskets on this engine all valve seals, rear main so everything would be freash. I cleaned everything in a parts cleaner before reusing. I was extra careful with the throttle body. Also Im positive I have the valves (rockers) adjusted right. Im missing something. It ran fine before with the other 350 block and bottem end and this 305 block and bottm end had no issues. All vaccum lines are right. I have a diagram on my truck. I called my mechanic and left a message. If I cant figure it out Ill take it to him as he has done a 350 to 305 engine swap on TBI system and vise versa many times. Alot of people say its cause I need a 305 computer but that is not it. Also I didnt replace this with a 93 TBI motor. This block is from a 87 - 91 camaro that is bored 60 over with dished pistons. Another thing when its in park idleing i can hit the gas and it doesnt sound bad, just when it is idleing it has a small miss and when I take off it has a really bad miss

Thank you all for your help

painted jester 11-17-2012 02:18 PM

Your tbi : unless yo have a 360 plenum or slotted divider plate each injector feeds 2 cylinders on each side of the engine! But your not firing on the 4 cylinders on the left bank #1,3,5,7, each injector is feeding 2 of these cylinders!!!! #2,4,6,8, cylinder are firing each injector is feeding 2 of these cylinders fine! Ruling injectors out! So what else does 1357 have in common that 2468 dont? Not much, the head, intake gasket, head gasket, valves, rings, lifters, 4 plugs, 4wires, 8 cam lobes and the exhaust if its dual or down to the Y pipe if its single exhaust!!!! The intake is shared ruling that out too!

So its now 1/2 of a v8 a 4 cylinder engine your trouble shooting that's not running!!!! The other half of the V8 is a 4 cylinder engine that's running So that should make it much easier for you to trouble shoot!!!! a person could pull all the pistons and rods out of one bank of an engine and the other bank can run like a 4 cylinder Do you understand what Im saying!

So check what 1357 have in common that can stop them from working! If you pull 4 plug wires off with no change while running that's not a small miss! pick your idle up to 2,000 pull 1 0ff at a time and see if it makes a difference then!


Richiehd 11-17-2012 02:19 PM

You best start with the basics. Are plugs wet with fuel? did you do a compression test, on every cylinder? Is firing order right? How about timing? HEI with about 12 degrees w/no vacuum. By the way, how much vacuum?

painted jester 11-17-2012 02:44 PM


Originally Posted by Richiehd (Post 1612387)
You best start with the basics. Are plugs wet with fuel? did you do a compression test, on every cylinder? Is firing order right? How about timing? HEI with about 12 degrees w/no vacuum. By the way, how much vacuum?

:thumbup: we agree!!!!!:D


painted jester 11-17-2012 05:16 PM

You have 3 threads going 2 about this and one about how to do a compression check on an engine in you basement! Is that the engine in your truck now? If you take a compression test do a dry, a leak down,and a wet check in that order with throttle tied open and coil wire pulled or dist unplugged from ignition system!!

Did you wet check the valves while heads were off or have seats and valves lapped or a valve job done? Did you straight edge the blocks deck and head surfaces


gearheadslife 11-17-2012 05:50 PM

350 heads on a 305? wonder if the valves are hung up on the cyl wall..

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