350TBI extreme hesitation under initial acceleration

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Ksanete

Newbie
Joined
Oct 7, 2016
Messages
2
Reaction score
1
Location
Mesa, AZ
1989 C1500 5.7L Single cab short bed Silverado pkg.

About this time last year, i had a spark plug wire melt on the header, shorting the connection and causing a really bad misfire on cylinder 1 or 3, don't remember. Ran it for a couple months before i found the issue, and replaced all wires. The truck ran perfectly before the wire melted. Even after that, the truck would have extremely bad hesitation, sometimes stalling randomly. It idles perfectly fine, NO SURGING. I've cleaned and checked all spark plugs, fuel mixture is about right, replaced cap and rotor, fuel and air filter. Run a couple cans of seafoam through to no avail. I'm about to check timing and clean the throttle body this weekend. Ive searched google for anybody else having the same problems, with no luck.

Ive checked EGR valve and it moves freely, air filter is new,
cleaned and checked all vacuum lines for leaks, all are good.
Truck idles and responds as it should when in park/neutral or at driving speed, It hesitates very badly when under acceleration from a stop.
I've been told it has a "shift kit" on it, and it really slams into 2nd, but i've not had a problem with it before the plug wire melted.
oil pressure is 30 to 45psi when idling, 60+ under any amount of throttle
Truck runs cold at about 175F and tends to get a little better at response when up to operating temperature.

No clue how many miles, odometer broke well before i got the truck, I'd guess around 250-275k.

I'm sure it's something very stupid, thanks in advance.
 
Joined
Dec 10, 2016
Messages
518
Reaction score
160
Location
Hampton, VA
Start with fuel pressure, check your CTS on the intake (the 2 wire one), and vehicle grounds.Did you replace the egr? I'm leaning towards the CTS.
 

HOFer30

Newbie
Joined
Apr 27, 2017
Messages
21
Reaction score
4
Location
Vernon bc canada
I changed my all my engine grounds particularly the chassis to body ground and added a chassis to battery junction ground, plus fixed my knock sensor wire which was shorting out and something helped it x100. Best part is I spent a max $10 on it
 

redfishsc

Tired of fixing lousy engineering.
Joined
Nov 7, 2016
Messages
515
Reaction score
243
Location
South Carolina
If the distributor cap and rotor are even slightly old, replace them. At the very least, pull them and clean off any carbon or corrosion that's on them.
 
Top