I'm tired of throwing money at what I think the solution is to my dually. Truck occasionally stalls when at stop lights in gear and when I put it in drive or reverse. It's about a 50/50 every time I drive it whether it does it or not. I have replaced the distributor cap, rotor, wires and plugs. The IAC valve, map sensor and have replaced all vacuum lines. I cleaned out the EGR valve and it is moving. Change the TPS and the O2 sensor and I am still having this issue. I heard in a forum that if the power steering was low on fluid it would cause excessive stress on the motor causing it to stall so I topped off all fluids. My only other guess is that the EGR valve or solenoid is bad and also heard that the engine temperature regulator has a lot to do with it. Also change the fuel filter but it seems like the injectors are fine. I really like some insight if somebody has dealt with a similar issue I haven't messed around with these TBI systems very much.

Thanks👍

 

Injectors are plugging up, worn out an/,or just plain OLD. Try some Techron Complete or Seafoam and see if that helps. It sure won't hurt. I'd put a code-reader on it (OBD I) and see what it says, as well. TBI is just a somewhat advanced carburetor, and I know carbs.only too well.

 

USMC? My hat is off to you, Sir!

 

Thanks for the advice and kind words. I put a heavy mix of Lucas injector cleaner and will be running the truck most of the day today. I will post an update if the issue is resolved.

 

Please do so. We like to know that we have helped a Chevrolet owner repair an issue..

 

Truck is running better. I can hear it trying to stay running where as before it would just cut off. I'm going to try to see if over time they will clean out properly but it's looking like I will just need to replace them. Thank you for helping me isolate the problem👍

 

Just wanted to post an update on the issue. After using injector cleaner the truck improved but it would still occasionally have issues with stalling as described before. I replaced both injectors with the brand standard part number TJ 11 and the truck seems to be running just fine now the spray pattern seems much more uniform as well. If I have any issues with these injectors I will post to this forum but from the reviews I have seen they are quality injectors. 👍

 

I had the exact same issue with my 89 350/th400 TBI engine. After hundreds of dollars and several mechanics that never could figure it out the problem was solved when I had the transmission rebuilt with a new torque converter. No more problems.

 

Diagnosing an issue with most things that are not obvious is 80 percent of repairing it, and with vehicles that holds very true, which is why expert technicians use devices costing thousands of dollars these days. Glad you finally found out the issue with your 89' Chevy.

 

As a professional automotive technician, I can testify that not everyone who uses said devices (I assume you meant pro-level scan tools and software) is an “expert.”

The fancy tools certainly make diagnosis easier, but like any tool, they’re only as good as the person using it. If you don’t know or understand the functions of the tool, it’s not of much use; and even if you do, they have limits.

For my part, one of the reasons I’m on these boards (and several other automotive forums) is to learn. I find it very useful to be able to read and work through a diagnosis because it inevitably translates to my job.