Code 43,, ugh

[4xcrazy]

I haven't done a ton of research on this just yet, just sort of tinkering with it today to get an idea as to what's TRYING to go on with this thing.

Here's what's going on,,, it acts like a carb'd engine with dead spot in the throttle, it'll idle just fine and once you get past that weird spot just off of idle, it runs fine as well, but if you try to keep it in that "hair past idle" area, it idles like it's got a stupid crazy hot cam in it and sometimes just stalls out. Coming to a stop light it will also stall out due to this action. Idles fine, starts fine, just that one area it seems.

IF I unplug the coolant temp sensor, you have to hit the throttle once to even get it to start first thing in the morning, after it's started you have to hold the throttle down just a hair to maintain idle until the water starts to get a bit warm, but after that, it'll run, start and idle just fine all day long, no issues even at part throttle application.

I have replaced the coolant temp sensor just the other day, the MAP sensor and ESC have been replaced before the harness wiring issue (3 years ago,non running)

According to the list I pulled off the internet, a code 43 for this K-vin'd engine is
"The ECM did not detect a knock signal during near wide open throttle operation with coolant temperature above 194° F or the knock signal was present for 5 seconds or more during normal engine operation.
Electronic Spark Control (ESC) Circuit ."

Now with this engine still cold, I'm assuming it read a knock signal during startup and while running for the few seconds before it triggers the code, or the newish ESC went bad, somehow.

Would this ESC or knock issue, cause this bad of an idle just off throttle like it is. I'm not getting ANY other codes except for the MAP sensor reading low on vacuum, which usually only triggers when the idle drops way down to rumble status.

I haven't been able to check the fuel pressure just yet, need to get my adapter hose fixed, but that is always on the list when something happens to these things with me I was thinking possibly a fuel problem from sitting in a climate that seriously changes, non running for the past 3 years with not much fuel in it, may have done something to the pump in this thing. I haven't had the best of luck with the pumps in this truck.

Any, any insight to something else I can check with it, as mentioned, I just started looking into this thing, pops took off back to Indiana this past Sunday, so now I have time to tinker

Thanks guys.

 

[4X4HIGH]

Your rough running just off idle sounds like an EGR issue.

 

[4xcrazy]

I'll check that out tomorrow. It was replaced several years ago, but was not an OEM style replacement.

 

[4xcrazy]

Alright, so I FINALLY went out there today and checked a few things out. I looked up the correct position for the vacuum line feeding the EGR off of the vacuum switch, it was on wrong, not sure if it matters, but after starting it normally, it fired right up, idled normally and got up to a normal operating temperature.

So I then tinkered with the throttle a bit with the foot. I was pushing it down slowly to see if it'd bog down and run like a hopped up dragster. I couldn't get it to do that at this time.

I did however notice anything above 1000rpm, it would have a slight surge to it, level out for a few seconds then surge some more. I took some video, hope this helps anyone with any ideas on this.

The CEL did NOT light up at all this time either..


Thanks.

 

[offshore]

put a ohm meter on the TPS and with the key off open and close the throttle very slowly by hand. the resistance should go up and down in very close and gradual measurements. if jumps around or has a flat spot that could be the problem.

 

[4xcrazy]

I was thinking about that thing the other day too, I'll be checking that out along with some other stuff as well, also with the way it runs, I'm thinkin about changing out the plugs and wires, it just sounds like it has a random misfire and even with true dual exhaust, I can't determine which side, because it actually sounds like both sides have a random misfire. Weird.

new plugs and wires are on the list as well.

Crazy thing ran great though, 3 years ago before the coil wire issue, so I'm not sure what would have happened to little things while it was sitting mostly. It was started now and then, when it would stay running for a bit, so it's not like it was dry for 3 years straight. The fuel pump was brand new when it went down, I had posted pics of the split hose from that little ordeal a few months before the wire problem, so I'm wondering if that thing isn't too happy from sitting that long with minimal fuel in the tank.

I dunno... again, not horribly annoyed with it, because it's here...