Hesitation upon acceleration...

[Jims86]

Ok guys, here is an update. i kept in touch with DG during his camping trip, and the truck did ok, except for a slightly jacked fuel pump relay, and another header gasket.
Had him reset the timing...he didnt pull the connector when he set it last time, so thats squared away.
We have definately found annissue that I am 100% sure is causing most of his problems. the headers that he's using, look like they may be Thorley tri Y, and the o2 sensor is mounted in the prmary y pipe for cyl's 3 and 7, therefore, only reading those 2 cylinders.
I have suggested to him that maybe he should return his system to the stock manifold setup, because he is using his truck primarily for his camper, and other trucking duties, and because the stock setup is lower maintenance, considering the gasket issues he has been plagued with.
Nothing really Hi performance....it is a 1 ton after all.
If he decides to stay with the headers, I suggested that he upgrades to a 3 wire heated o2 sensor, and have it re located to the 3rd collector on the drivers side header, befor the Y from the passenger side header.

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[Jims86]

But, looks like Duallyguy has been busy.
The problem was completely cured in October.
He sent me a pic of his header, and the cause of the problem was apparent at that point.
He had a set of try Y headers, and the o2 bung was welded into one of the forward Y collectors, only reading from 1 and 7 instead of the main collector, to read off of all 4 cylinders on the drivers side bank.
He ordered new Dorman stock replacement manifolds, and had the exhaust system re built to fit, and the truck now runs perfect, without any of the problems that the headers were causing, like the gaskets that kept blowing.
Hopefully, He will chime in with another report on how the truck is performing.

 

[1988 one ton]

Check your map sensor. Mine was doing the same thing until i changed it out.

 

[Jims86]

Check your map sensor. Mine was doing the same thing until i changed it out.

See thread above^^^^^^

 

[89Suburban]

Good job Jim. Nice to see you were able to help out in person and report back.

I'll split the carb posts out of here into a new thread located here:

http://www.gmsquarebody.com/forum/showthread.php?t=7811


Duallyguy next time you change that oil filter snug the bolts up on that oil diverter bud

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