Can’t seem to figure out the problem with my truck. 90 Silverado, 305 TBI w/ 175k.
The last several months it’s been running like shit then like no problem it’ll run like a bat out of hell.
Problem is after the truck warms up randomly it’ll just start sputtering and then misfire throw a CEL(comes up o2 sensor) and if I stop eventually it will stall and usually won’t start up till it cools down between 5-10 minutes. At idle it will surge up and down. If I am on the highway it will clear up after about 5-6 minutes driving.
Issue started in the summer but got worst till it wouldn’t run when cold/ start up problems. Didn’t have the time so parked it for a couple months. Replaced the fuel pump, lines,sending unit, replaced plugs, wires, o2 sensor checked timing it’s at steady 0, replaced ecu. Cold start problems cleared up, but no luck with misfire.
So I do some reading looked into the ignition pick up coil, failure symptoms matched. Bastard was original and cracking replaced that along with complete dist, cap, rotor and module. Truck ran great no signs of issue. Less then two weeks later the problem has returned.
At this moment I’m completely clueless, coming up blank.
I’m thinking about cutting off the cats, truck has a wackass exhaust with mufflers on ea side prev owner put on and it’s been falling apart.
Anyone on here maybe give me some insight?? Don’t want to get rid of truck, most of time it runs great and 2010 did a shit load of maintanence on it.
That’s what I thought too. But I did some reading and that’s the normal for TBI. Gauge was off like 2psi so it’s a bit more then 15-16. When the fuel pump was failing pressure was like 5-6psi.
Something similar happened on my beater '96 ram. Brand new wires, but one melted to the exhaust manifold lol. I popped the hood and found it arcing against the manifold.
Start it up when it’s dark out and mist it lightly under the hood with a hose. I’ve found problems with wires, caps and rotors that I thought were fine that way.
Well my friend said he’s always had luck with cutting the insulation off the wire and refitting it. I let him refit the insulation on the cracked wire. Same shit didn’t make a difference.
Would a wire that was arcing be fucked to where it can’t be saved?
It’s becoming aggravating, truck randomly dies. To add to the issue, truck also shoots fireballs out the exhaust like it’s running pig rich.
Still can’t figure out the issue. Everything ignition wise is new.
Another thing to add is truck always smells like fuel.
Today I left the truck running outside of my work and when I came back outside I found the truck dead. Went to crank it over and all It does is crank, pushed the gas pedal to the floor and the truck started seems like it’s flooded. But it’s mifiring bad. If you take your foot off the gas it eventually stalls.
So I call my dad out to start the truck while I watch the injector spray pattern and wham the injectors are pissing out fuel, way too much. And only when this happens you can hear the IAC hissing very loud.
But I am still lost as to why in closed loop, only intermittently the truck will buck, sputter and misfire like a bitch. I can drive it WOT on a stretch of the thruway.
---------- Post added at 09:07 PM ---------- Previous post was at 09:03 PM ----------
To add on, my old school obd1 OTC scanner, truck throws a CODE 44(lean o2/exhaust)
I have bad egr on my mind, but would it cause these symptoms?
gut the cat, cut the pipe behind it so you can see inside, take a railroad stake or prybar, insert, smash with mallet till it all comes out, reweld/puddy when done