engine running rough

[tannerezell077]

My last post...promise. If you have a cold air or high flow air filter added to exhaust system, you might be confusing your 02 sensors . Create some backpressure with a couple of beer cans.
Firing order for 5.7 is...18436573... later LS engines are different...but coil packs keep them straight.

i will try the cans where should i put them. i don't have an after market filter

 

[L29Sub]

The cans can be loosely wired to the pipe tips...as long as the tips are not chrome or such. Don't want to mar up a nice finish. Anything that cuts down the exhaust flow will work. If improved performance, it's too lean. If no improvement...your exhaust isn't the problem.
If you have a stock induction system, this "fix" probably won't make any improvement.

 

[tannerezell077]

The cans can be loosely wired to the pipe tips...as long as the tips are not chrome or such. Don't want to mar up a nice finish. Anything that cuts down the exhaust flow will work. If improved performance, it's too lean. If no improvement...your exhaust isn't the problem.
If you have a stock induction system, this "fix" probably won't make any improvement.

when the truck is running it smokes pretty heavy out the exhaust and leaves like a wet spot under it it doesn't smell like gas or anything i'm confused on what it could be?

 

[tannerezell077]

update: another theory in thinking is that when i installed the headers on i got two plug wires mixed up and didn't realize it till minutes later when it was constantly backfiring i drove it a little ways before i realized i mixed the plug wires up so i switched them and it fixed the backfiring. could it have fouled the plugs or messed something up when i switched them?

 

[L29Sub]

Maybe oil burning out of your new exhaust...or water? Where is the coolant going?
Many an engine has been trashed due to Dexcool aging out. Dexcool is good if maintained...ruins heater cores and radiators if not.
Get your hands on a cheap IR temp gun and check èach header tube and verify that all 8 are within a few degrees. If any cold or hotter than the others, getting close. And the 190* operating temp has to be attained.
You also need a scan tool with "freeze frame" and check the L and R bank 02 ýsensors. That will tell you if too rich or too lean and ID the bank (s).
Might want to pop the spark plugso out and keep them in order. See if any look super clean (water) or black (fuel).
A loose intake would cause a lot of your complaints. A loose or leaking plenum will also. ,
You need da good local GM side man that likes beer and a challenge.
Did you have the distributor out when installing the headers? Do you know how to get #1 piston on TDC compression stroke? If so, the rotor electrode should point to the front of the engine (or thereabouts). Wherever the rotor points when #1 is at TDC is now #1 tower for the time being. Pay attention to the rotation and arrange the plug wires from #1. Using the #1 tower, place each wire into the cap and on its respective plug. Follow the routine using 18436572.
#1 cylinder is drivers side front. The driver side head is 1,3,5,7.
The passenger side has #2 at the front. 2,4,6,8 respectively for pax head.
Some confusion could be LS carb and distributor conversions have the odd firing order that you may be seeking. You wanr only the 350 5.7 cast iron..

 

[L29Sub]

update: another theory in thinking is that when i installed the headers on i got two plug wires mixed up and didn't realize it till minutes later when it was constantly backfiring i drove it a little ways before i realized i mixed the plug wires up so i switched them and it fixed the backfiring. could it have fouled the plugs or messed something up when i switched them?

Backfire may have blown out an O ring or do gasket on .or damaged the IAC? It got hammered. Also plenum,regulator, MAF, TBI, and the plastic spider.

 

[tannerezell077]

update: i solved the problem! i replaced the old plugs with new bosh platinums and it runs like a new truck! has so much more power with the new plugs and wires cost me about $30 but it was worth it so glad the problem is fixed thank you all for the help you guys provided!

 

[L29Sub]

Excellent!
Now what's up with the heater?

 

[tannerezell077]

Excellent!
Now what's up with the heater?

i have no idea what to do about the heater i flushed the heater core burped the system and everything and no luck i have no idea what to do now the engine runs right under ideal operating temp so it's running like 190-200 instead of 210