Are TBI 350’s just this sluggish?

[SUBURBAN5]

Also plugged or old cats can make it drag....

 

[SUBURBAN5]

Believe you had 1. My 98 has 2.

 

[PlayingWithTBI]

Also plugged or old cats can make it drag....

Yes, that can be an issue but, it would be worse at higher revs and less pronounced at lower speeds.

 

[SUBURBAN5]

Yes, that can be an issue but, it would be worse at higher revs and less pronounced at lower speeds.

Yeah that's true.

 

[SUBURBAN5]

Just curious what kind of air filter are you running?

 

[PlayingWithTBI]

Another thought, these TBIs are fairly well known to have a bad coil and ICM. It appears when the coil shorts out or melts the insulation it can overheat the ICM and cause stumbling and/or surging. One trick is to spray water on the coil, not the wires, while idling and see if it stumbles. If so, you know the coil is bad but still don't know for sure the ICM is. Here's a picture of my Pertronix Flame Thrower after less than 2000 miles. Note the burn marks by the iron. My ICM went out about the same time causing surging at ~2200RPM while cruising in OD. I've found a lot of others here and on other sites experience the same issue. When replacing parts use quality ones like AC Delco, Delphi, etc.

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[stutaeng]

OP, what is the history with the truck? Sounds like you just bought it? Is the engine original? I've come to realize you can't trust much trucks of this vintage that have had multiple owners. Sure someone once upon a time didn't replace the 350 for a 305? Not sure how you could tell though.

Just throwing ideas out there...

 

[someotherguy]

Sure someone once upon a time didn't replace the 350 for a 305? Not sure how you could tell though.

Casting marks in the top rear of the block, driver side, will indicate 5.7 or 5.0 though it's a little tricky to see with the engine installed. It is possible, though.

Richard

 

[BradHSo]

Timing as mentioned, fuel pressure, CTS in good condition, all grounds good in the engine bay.. gotta cover the basics.

Also if your tires are oversized that 3.42 isn't helping, but it shouldn't be an outright dog unless you're way taller than original size.

Richard

Yea, I’ve driven old beaters my whole life, grounds is one of the first things I did haha.
I believe they are the factory size 265/75/R16

 

[BradHSo]

OP, what is the history with the truck? Sounds like you just bought it? Is the engine original? I've come to realize you can't trust much trucks of this vintage that have had multiple owners. Sure someone once upon a time didn't replace the 350 for a 305? Not sure how you could tell though.

Just throwing ideas out there...

Single owner truck, Old man died kids and grandkids wanted to sell it, came with a stack of paperwork. I’ve got most of the receipts for oil changes dating back to 93, including all the miscellaneous things that he had fixed. It has been sitting since 2013 when the PO died.
I doubt it’s 305, but your right, it wouldn’t hurt to look.