Rough Running Chevy
when you floor the pedal it puts the engine into "clear flood mode" and will limit the fuel. i dont click links to images so i cant tell you if that one is right or not. but number one wire on the distrib should be pointing to number one cylinder and firing order is 18436572
Yep looks like I was 1 space off on all of them. I will fix that tomorrow and get back to you guys!
Also, I pulled the codes! There are none!
Great it’s running better. Nice to make progress. Definitely fix those vacuum hoses. Remove the air cleaner so you can have a really good look around.
And as Irish mentions clean the grounds. Clean the battery terminals & I think there’s a ground to the fender, one between engine block and firewall, and one on the coolant thermostat. That one is the ECM ground, I believe.
I assume you are talking about the pcv hose. It shouldn’t be leaking oil so it probably has a break or bad pcv or ? Figure that out and fix it.
Bottom line is even if it seems to run better with someone off - that’s just showing there is a problem somewhere and something needs attention. Everything should be connected and working for it to run best in all conditions.
And as Irish mentions clean the grounds. Clean the battery terminals & I think there’s a ground to the fender, one between engine block and firewall, and one on the coolant thermostat. That one is the ECM ground, I believe.
I assume you are talking about the pcv hose. It shouldn’t be leaking oil so it probably has a break or bad pcv or ? Figure that out and fix it.
Bottom line is even if it seems to run better with someone off - that’s just showing there is a problem somewhere and something needs attention. Everything should be connected and working for it to run best in all conditions.
Hey guys, sorry it has been so long without an update. Life has been busy and I've been doing more or the cosmetics of the truck. Anyway, between the last update and now I have done quiet a few things. I searched all over for vacuum leaks and haven't found any others than the ones I have mentioned. When I fixed those lines, there was no change. I brought the truck in to the tech school we have here and started doing some diagnostics with a scanner. From what I I can see, there isn't anything wrong with the truck. O2 sensors read that is is very rich (as I can smell), but as for the other sensors they all seem to be within range. The computer said that the TPS sensor was reading .48 at idle and it should be between .50-1.5 volts. This could be an issue, but I'm not sure. I replaced the Coolant Temp Sensor because I had heard that was often bad. Didn't seem to make any difference. Today, I cleaned the EGR. It was full of carbon buildup, but of course I forgot to see if the thing stuck open or closed, but I can do that tomorrow. I was running out of time.
The truck still hasn't changed it's running characteristics. Still struggles really hard to idle when cold, runs extremely rich and surges. Scan tool confirms the RPM jumps around a lot between the mid 700s and the high 800s. I guess something I noticed is that is starts to run better once warmed up. Not great, but it doesn't try to die after its been running for about 15-20 minutes. I am very stuck on what to do, this isn't making any sense to me. Do any of you have other recommendations?
The truck still hasn't changed it's running characteristics. Still struggles really hard to idle when cold, runs extremely rich and surges. Scan tool confirms the RPM jumps around a lot between the mid 700s and the high 800s. I guess something I noticed is that is starts to run better once warmed up. Not great, but it doesn't try to die after its been running for about 15-20 minutes. I am very stuck on what to do, this isn't making any sense to me. Do any of you have other recommendations?
Last edited by fiterpilot; Mar 3, 2020 at 4:43 PM.








