Engine Performance problem
1993 Chevy Silverado 6 cyl Four Wheel Drive Manual 97,700 miles
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:
Had the truck scanned. Nothing showed up.
Put in a new Throttle Positioning Sensor.
Fuel Pump Relay
A Couple of New Hoses
Spark Plug Wires
Fuel Pressure Regulator (probably wrong name for it)
New Computer PLUS new Prom for it.
Complete Exhaust System (Header pipe to Tail pipe)
New MAP Sensor
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
Ground under Thermostat
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
Sorry for the long post, haha. Thank you!
Monday, January 11th, 2010 AT 5:28 PM