My car is misfireing very bad. I had my A-tap hooked up and it seems all the cylinders are midfireing but mostly #7, 8. It has just over 35K on it. Any ideas what it could be from???????

 

When is it misfiring. With 35k on it you might as well put new plugs and wires on it first.

 

Change the plugs/wires...this is always a start. Just my .02. Good Luck

Wes

 

It's only misfiring from 1300rpm and uder....... I want to change the plugs. It just started after I got gas kast night out of nowhere.....

 

I'm haveing the same problem. At idle #8 &#1 are misfiring. I've tried changing plugs and wires with no luck. I'm going to try and see if the wires will arch. Good luck! If I find out how and what it takes to fix mine, I'll let you know.

I'm at 35,000 miles to.......Dam GM's

 

Then I would try new gas first.

 

Let me know what you find. It's going in right after Christmas to get new plugs, wires, and check the tuning.......Scott

 

Is there anything I can try to put in the gas or should I just run through the tank???????

 

run that tank out and change the fuel filter, throw some good 100 in there too with a new refuel. u could be gettin weak spark from your coils at low rpm. like i said in another post, maybe to silverbullet, check the arc, if they all arc the same then its most likely the gas or u could use a top end cleaner...

 

top end cleaner? You mean clean out the intake manifold? If yes, how and what would be a safe way to do this?
Thanks...

 

u can go to any service station and they can do it. i work at xpress lube and we offer a fuel system cleaner ( i only use the one that sucks cleaner into the intake) and its 60 bucks i do it once a year and does a great job.

also just read in another post about oil gettin in the intake. dont know if u read that but it might be worth checking....maybe...but just go to any servise shop and u can have it done but i would rec. just getting the intake cleaner done ( we have a 3 step, oil..gas tank...and intake) i change the oil so much it doesnt matter, i put in 100 octane every once in a while which is almost waht that gas additive is, and i just do the intake cleaner like i said every year. if u need anything else let me know

 

BTW if they do it make sure they run the cleaner right after the throttle body where the pcv line goes into the intake, right before the pcv valve. i run it through at that spot and cleans from the throttle body back. helps clean off all the intake, intake ports in your heads, valves, piston tops and spark plugs, as well as and emission components u may have like the egr valve and 02 sensors. after i did mine the o2's read a lot more consistent...

 

Pardon this dumb question:
How is this intake cleaning done without getting cleaner into the cylinder combustion chambers, and eventually into the crank area?

 

It actually is designed for cleaning of the combustion chamber/valves/piston tops.

 

yeah what he said cleans everything and its brought through the engine with the incomming air, so its a air/fuel/cleaner mixture

 

If the gas doesn't clear it up I would suggest what's already being said but just use the GM top end cleaner.Dump it in slowly with the engine running,then at the end of the bottle dump it fast and shut down motor.Let sit for 20 minutes and start car.You'll need to rev it to keep running for a little bit.The car will smoke really bad for about 15 minutes.

After your done and car is running clean,change the plugs to some NGK TR55's (stock plugs are garbage).

 

First of all are you sure your car is misfiring? If your LS1 is misfiring most likely the SES light is going to come on. If your SES light is flashing that will most likely mean your misfiring. Find someone with a scan tool and try to get a code out of the computer. From there if it's misfiring you'll be able to narrow down to what cylinder it is. A bad spark plug and/or wire is possible to make a misfire so starting with a new plug and wire in that cylinder would be the cheapest way to start. From there if that doesn't solve the problem it most likely is an injector or coil pack. Let me know what it turns out to be when you figure it out. Any other question just give me a shout. Zach AIM: zmastr28

 

well i had my car on 7 cyl one time and it never threw a code...

 

It's definatly missing. I hooked A-tap up and saw it missing on almost every cylinder. I think I let it sit and idle to long when I was talking to a friend. It runs real rich at idle and it sat for about 15 min. I just bought some taylor wires and a buddy of mine works at Auto Zone and got me a really good deal on Denso Iridium spark plugs to put in. I'll do a intake cleaning tommorow at work but I think it's the plugs fouled out. I'll let you know when I know for sure......Scott

 

hey use 150 tnt shoot it will clean everything

trust me