Severe Bog Issue with 93 Chevy silverado
 

The truck is bogging something fierce.

Seems that the bog is at it's worse when the RPMs are between 1200 - 2200. Sometimes when the traffic lights turn green when sitting there, I will give it gas and seems that there was a blip of power then gone and comes back which results in me slamming my head into my steering wheel haha (Truck doesn't shut off). When I'm in overdrive, I can hardly make it up a small hill, sometimes same case scenario in 3rd gear. When in 3rd or overdrive, the truck would shake bad. Now that I have a new exhaust system in, it doesn't shake as bad. Probably ran harder because of the header pipe leak. Not sure if it's coincidence but when it's really cold out and I left it outside for the night, the bogging is at it worse. Leaving it a warm garage seems to work for a little bit then gets worse. In that case, is there some gaskets to look at?

There are times where it works perfect for a while though. So ofcourse when I bring it into a shop, they can't always figure it out because the issue doesn't reoccur for them.

I also noticed wayyyyy to much gas in the air cleaner. Pretty bad when the gas makes my air filter stick where I almost have to pry it out.

Here is the list of stuff I have already changed or replaced:

NEW PARTS
Had the truck scanned. Nothing showed up.
Put in a new Throttle Positioning Sensor.
Fuel Pump Relay
Fuel Filter
EGR Valve
A Couple of New Hoses
Spark Plugs
Spark Plug Wires
Cap
Rotor
Full Distributor
Fuel Pressure Regulator (probably wrong name for it)
New Computer PLUS new Prom for it.
Complete Exhaust System (Header pipe to Tail pipe) <-- update
New MAP Sensor <-- update

TESTED GOOD AND CLEANED
O2 Sensor Read Fine
Tested Backpresser which was fine
Tested Fuel Pressure
Test Injectors which checked out good.
Adjusted Timing so that's correct
Soaked the plug wires and no changes.
Ground to Fuel Pump <-- update
Ground under Thermostat <-- update

When the issue occurs the check engine light never pops on. If it did, I might have considered Map Sensor. Also when I drive down the road in overdrive, sometimes it runs fine. Not great but good enough. Then out of no where it feels like I lost 40HP. There are frequent times where im in 3rd gear or overdrive and the truck shakes like I lost am losing spark.

I'm pretty sure I missed a couple of things but if anybody else has some other ideas, that would be awesomeeeee. I dropped like 2 grand or more only because of this issue. Most of which was due to hours at the mechanics. Even brought this straight the GM thinkin they have this issue on record. Guess not. I seen a lot of the same types of issues on other forums with this truck in general but ofcourse if someone fixed theirs, they never came back to the forum to tell you what fixed it. Haha.

Oh yeah, My vehicle specs
93' Chevy Silverado
k1500 4.3L Throttle Body
4X4

Sorry for the long post, haha. Thank you!

Did you ever try checking or changing the temp sensor, they can sometimes give that problem. Im talking about the sensor in the intake by the thermostat. and sometimes its uncommon but could happen is that the ypipe is double lined and the inner liner could have caved in somewhere but unlikely

Yes. I'm assuming you're talking about the coolant sensor. That was one of the first thing I replaced

Huh well im sorry I must say it helped me wish I could explain more sorry.

Haha that's ok. Hopefully I haven't stumped everyone :(

Check for a bad or loose ground. I left one off one time when I changed a thermostat ( the ground was under one of the thermo housing bolts). The issues were similar to what you are describing, and yes I replaced many part$ before I found the problem. It was very random, but like the ignition was shut off, then right back on. Fixed the ground, and never had another problem. Good luck.

I have checked the ground under the thermostat thinkin that I screwed that up when installing a new thermostat when that quit working too. But I never really checked the whole wire itself. Maybe i'll check that.

Well I checked for loose grounds, didn't find any. I even looked underneath for the ground near my fuel pump.. loosened that.. sprayed some twister on it, and tightened, loosened, and tightened again. Took it out, still horrible, haha. I'll going to install a whole new exhaust kit under there this weekend. It almost needs one so figured since the catalytic converter is part of that, I could rule that out if the problem persists.

I updated my first post on new stuff I put into this truck that still hasn't fixed the issue. Hellppppp haha.

Here I will update everything I have changed.

NEW PARTS
Had the truck scanned. Nothing showed up.
Put in a new Throttle Positioning Sensor.
Fuel Pump Relay
Fuel Filter
EGR Valve
A Couple of New Hoses
Spark Plugs
Spark Plug Wires
Cap
Rotor
Coil
MAP Sensor
Full Distributor
Fuel Pressure Regulator (probably wrong name for it)
New Computer PLUS new Prom for it.
Complete Exhaust System (Header pipe to tail pipe)
Fuel Injectors
Thermostat
Coolant Sensor
Throttle Body
Idle Sensor
New gerbils on a wheel to charge my battery....

TESTED GOOD AND CLEANED
O2 Sensor Read Fine
Tested Backpresser which was fine
Tested Fuel Pressure
Test Injectors which checked out good. (new injectors now listed above..)
Adjusted Timing so that's correct
Soaked the plug wires and no changes.
Sprayed carb cleaner around the manifold. No jump in idle. (Unless I'm spraying int he wrong spots...)
Checked all possible grounds.