Pop, Stutter, Stall January 21, 2023, 07:40:30 pm 1989 Chevy G30, 5.7l, 8 Cyl.It idles just fineWhen I try to drive, after about 1/3 miles, it begins to pop, stutter and then stalls.When I immediately try to retart, it won't.If I leave it for about an hour, it' starts and drives a short distance and then the popping etc. cycle begins again.The fuel filter has about 1 1/2 miles on it and is known installed correctly.I have checked and cleaned electrical connectrs and checked vacuum hoses for leaks.I have spent the last week researching thoroughly (including this site) what the causes might be and therefore understand there are myriad possible reasons. e.g., Fuel Filter/pump. EGR Valsve, O2 Sensor, MAF, Injectors and more.I am adopting the process of elimination regarding the fuel system. First of which was the fuel filter. Fuel pump next?Any tips on how to move forward would be most welcome.OBD1 shows no error codes. (Unless I am using it incorrectly).
Re: Pop, Stutter, Stall Reply #1 – January 21, 2023, 08:02:14 pm Not absolutely sure about this but a bad Catalytic Converter can cause similar issues. Here is an article I located. Bad Catalytic Converter Symptoms- Lopers Performance CenterI don’t think OBD1’s give all the data you need. OBDII’s are much richer in data.Kent
Re: Pop, Stutter, Stall Reply #2 – January 21, 2023, 08:39:11 pm It does sound like a fuel problem. A failing fuel pump or a plugged filter sock on the fuel pump are possible causes.I would start by testing the fuel pressure and fuel volume flow. It does require the proper tools.https://www.harborfreight.com/basic-fuel-injection-service-kit-64939.htmlLarry
Re: Pop, Stutter, Stall Reply #3 – January 21, 2023, 11:11:04 pm Quote from: Larry W - January 21, 2023, 08:39:11 pmIt does sound like a fuel problem. A failing fuel pump or a plugged filter sock on the fuel pump are possible causes.I would start by testing the fuel pressure and fuel volume flow. It does require the proper tools.https://www.harborfreight.com/basic-fuel-injection-service-kit-64939.htmlLarryAs usual, thanks Larry! Given the vehicles' age, and that I can do the work, I may just get a new fuel pump assembly. What is confusing me, is that it idles great and does not cut out when I raise the revs. (While doing that, I checked the fuel being injected, and it has a circular outside spray with more of a drippig in the center). However, the moment I try to drive, it stutters and cuts out. Could that mean something electrical?
Re: Pop, Stutter, Stall Reply #4 – January 21, 2023, 11:54:54 pm Are you throttle body fuel injection? The in tank pump usually just quits. How about the distributer Have you looked at the cap, rotor and coil? The coil is built into the cap. I think I'd bet on a fuel pump or coil. Coils usually work cold and quit as they get hot. I just reread your post and saw that you are throttle body injection. I had a pickup that had one injector quit it would run but wouldn't pull itself. I also lost the pump one time and it just quit. yours could be failing.Jon
Re: Pop, Stutter, Stall Reply #5 – January 22, 2023, 01:57:37 am Quote from: Mindispower - January 21, 2023, 11:11:04 pm I may just get a new fuel pump assembly. What is confusing me, is that it idles great and does not cut out when I raise the revs. (While doing that, I checked the fuel being injected, and it has a circular outside spray with more of a drippig in the center). However, the moment I try to drive, it stutters and cuts out.A weak pump may provide just enough fuel to idle or rev in neutral. When asked to do real work, the fuel supply may be inadequate and would cause stumbling. The throttle body may be dirty or partially plugged, I never owned a vehicle with TBI so little experience with it.There may be an obstruction in one of the fuel lines that limits fuel flow.Testing for fuel pressure and volume continues to be where I would start looking before changing any parts. It appears your LD's fuel pump is in the tank, it could be difficult to change.Larry
Re: Pop, Stutter, Stall Reply #6 – January 22, 2023, 01:00:24 pm Quote from: Larry W - January 22, 2023, 01:57:37 amA weak pump may provide just enough fuel to idle or rev in neutral. When asked to do real work, the fuel supply may be inadequate and would cause stumbling. The throttle body may be dirty or partially plugged, I never owned a vehicle with TBI so little experience with it.There may be an obstruction in one of the fuel lines that limits fuel flow.Testing for fuel pressure and volume continues to be where I would start looking before changing any parts. It appears your LD's fuel pump is in the tank, it could be difficult to change.LarryIt is a difficult change, but I have done this before. I have to watch my pennies.
Re: Pop, Stutter, Stall Reply #7 – January 27, 2023, 06:40:51 pm Thanks all! It was the fuel pump. I put in a complete module and she purrs like a cat. (Actually, better than a cat). 5 Likes
Re: Pop, Stutter, Stall Reply #8 – January 28, 2023, 12:43:51 am Quote from: Mindispower - January 27, 2023, 06:40:51 pmThanks all! It was the fuel pump. I put in a complete module and she purrs like a cat. (Actually, better than a cat).Thank you for the update. Updates always help future readers when conducting a "search" on this website. Due to the wealth of knowledge from many of the "Hero Members," this group is the best resource for all motorhomes, not just LDs. 1 Likes