95 K1500 350 - Miss/hesitation problems for past 2 months

[stroker52]

i have a vortec v6... OBD2 everything your saying my truck does the same.. ive had mine on a scanner GM tech2 and mine showed it miss firing and the IAC was moving slow... so i pulled the TB off cleaned it with GM top eng. cleaner or X66 then replaced the IAC, TPS.. this didnt change a thing!!! i was watching the O2's and one bank was running lean (NO check eng light) and that made me look at the intake so i shot a lil brake cleaner in the motor.... it res up!!

also just FYI if you keep driving it, it will knock your cat out... it did on mine

 

[MOBS]

ive been a GM tech for 10 year, over the years you find stuff that quick and easy... it works!! just because the head is hot dont mean it will flame up... it dont take much when there is a leak it will find its way there fast.. if you dont like this idea you can always take it to a shop and have it smoked!! but this is going to cost you way more then a $4 can of carb or brake cleaner an 10 mins of your time.. smoke testing a truck with out the line hook up takes time to set up... most shops around here charge $95+ a hour.. sooo you can count on paying 2 hours this is just my 2cents....

I was just wondering how opening the oil cap helped the situation....and I also suggested using the flammable stuff on the gasket locations because of the potential of it sucking it in and changing the rpm.

 

[MOBS]

i have a vortec v6... OBD2 everything your saying my truck does the same.. ive had mine on a scanner GM tech2 and mine showed it miss firing and the IAC was moving slow... so i pulled the TB off cleaned it with GM top eng. cleaner or X66 then replaced the IAC, TPS.. this didnt change a thing!!! i was watching the O2's and one bank was running lean (NO check eng light) and that made me look at the intake so i shot a lil brake cleaner in the motor.... it res up!!

also just FYI if you keep driving it, it will knock your cat out... it did on mine

So true, I've also got this similar problem on my work truck, but only when warm and it'll stumble on idle randomly. Annoying, at the least. The lean banks can also prematurely wear your engine on that side, when leaned out, causes excessive heat in chambers. So good luck on getting it fixed man, hate to see your engine not last you the miles it could.

 

[stroker52]

I was just wondering how opening the oil cap helped the situation....and I also suggested using the flammable stuff on the gasket locations because of the potential of it sucking it in and changing the rpm.

you just answered your on question lol... taking the oil cap off and spraying brake or carb cleaner down the oil filler if there is a vacuum leak in the blottom of the intake gasket ( lifter valley) it will find its way there and change the Rpm's

 

[MOBS]

Oh yeah, well....nevermind.

 

[rhino99]

I had the same thing and my heads were cracked. might want to get them checked.

 

[shortchevy]

I had the same thing and my heads were cracked. might want to get them checked.

you should go to a doctor

 

[MOBS]

you should go to a doctor

A head doctor? Sorry, couldn't resist

 

[shortchevy]

A head doctor? Sorry, couldn't resist

HA I know I couldnt either!

 

[95_1500]

Just a small update, I pulled the cap and found that inside the rotor all around the terminal for the carbon button there was the black lines (i consider it carbon tracking, might be called something else). Lately on a warm restart after sitting for 30 minutes to an hour it will crank and stumble stall, try to restart it immediately and it wont crank. Wait about 10 seconds and it will fire up and run like crap until I get up to speed.

The lines in the rotor and the long start time makes me think the ignition coil. I replaced it before but it was duralast and the ICM was replaced with a BWD, I believe in nothing but Delco for these trucks.

Rockauto has wholesale closeouts on all AC Delco parts so I went ahead and ordered the coil, cap, rotor, pick-up coil, ICM and reluctor. I am going to replace everything in one swoop and completely rule out everything prior to the wires and plugs.