RecklessWOT
Full Access Member
- Joined
- Feb 20, 2015
- Posts
- 2,556
- Reaction score
- 4,764
- Location
- New Hampshire
- First Name
- Kevin
- Truck Year
- 1987
- Truck Model
- V10 Suburban Silverado
- Engine Size
- 350 TBI
Wondering if anybody knows of a way to get the ECU into limp home mode without the use of a scan tool?
The truck is an '87 suburban V10 with a 350. I've been having issues with it cutting out. Usually under load but sometimes it dies randomly while idling for a few minutes, and stalling from a start. Doesn't run rough or anything beforehand, just cuts right out. It never even throws a check engine code. I have gone through just about everything possible- full tune up, ignition module, TPS, IAC, MAP, coils, blocked EGR, got rid of all emissions parts, changed the fuel filter, checked grounds... I've got a GM service manual even the "fuel and emissions including driveability issues" supplemental book, chased it around every which way I can think of and still nothing. I had it narrowed down to only three last possibilities: Bad fuel pump, distributor, or ECU itself.
So I had a buddy hook it up to a scan tool and we took it for a drive just to see what was actually happening right before/when it died. Many of the sensors (even the brand new ones) would start randomly outputting funny readings, or lose communication alltogether. When I put it in limp mode, all of a sudden the problem was gone. It ran rich as all hell but it was actually driving around completely fine. So that means my distributor is fine as is the fuel pump and injectors. So that leaves me quite obviously with a wiring problem. I have literally given up on vehicles and used them for target practice because of wiring issues in the past. I can't fix electrical problems to save my life.
I am SO CLOSE to ripping everything off my truck, slapping on a carb and calling it a day. But until I am able to find the time to do that I still have to drive the truck the way it is every so often. I would like to know if there is a way I can put it in limp mode so I can actually drive the ******* thing somewhat normally in the meantime without stalling while taking a left across a busy street.
The truck is an '87 suburban V10 with a 350. I've been having issues with it cutting out. Usually under load but sometimes it dies randomly while idling for a few minutes, and stalling from a start. Doesn't run rough or anything beforehand, just cuts right out. It never even throws a check engine code. I have gone through just about everything possible- full tune up, ignition module, TPS, IAC, MAP, coils, blocked EGR, got rid of all emissions parts, changed the fuel filter, checked grounds... I've got a GM service manual even the "fuel and emissions including driveability issues" supplemental book, chased it around every which way I can think of and still nothing. I had it narrowed down to only three last possibilities: Bad fuel pump, distributor, or ECU itself.
So I had a buddy hook it up to a scan tool and we took it for a drive just to see what was actually happening right before/when it died. Many of the sensors (even the brand new ones) would start randomly outputting funny readings, or lose communication alltogether. When I put it in limp mode, all of a sudden the problem was gone. It ran rich as all hell but it was actually driving around completely fine. So that means my distributor is fine as is the fuel pump and injectors. So that leaves me quite obviously with a wiring problem. I have literally given up on vehicles and used them for target practice because of wiring issues in the past. I can't fix electrical problems to save my life.
I am SO CLOSE to ripping everything off my truck, slapping on a carb and calling it a day. But until I am able to find the time to do that I still have to drive the truck the way it is every so often. I would like to know if there is a way I can put it in limp mode so I can actually drive the ******* thing somewhat normally in the meantime without stalling while taking a left across a busy street.
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