I'd say this will eventually happen, I was in Elizabeth City @ the C&H Oyster Bar on Monday. I blew by you last Thursday, one my way back from Savannah, I caught the last ferry to Ocracoke for the evening. I headed out on my Motorcycle at the end of Sep for Alabama, then over to Georgia, and back up the coast. Wasn't on much of a schedule, was going to PM you, but after a few thousand miles on the bike, I was ragged out.

 

Oh man yeah that's a lot of travel, I can imagine you were worn out after that! Sounds like a blast though! I've heard about C&H before but never been. Another good one to try is T&W, right outside of Cape Carteret if youre ever out that way

 

Okay I just played with the throttle stop screw and got it to a comfortable position, as closed as I could get it without binding. Read the voltage on the DG/LG wire and got 0.862 vdc, so that's good. Just a quick question, do I need to have the truck to operating temp before I perform the idle speed procedures (minus the adjustment like we said)? Or is that what step 2 on those procedures is for: "Start the engine and run it at 2500 rpms for 30 seconds"

 

Yeah, have it fully warmed up.

 

There are multiple Scenarios/Strategies programmed into the EECM, so you want to get past the Cold Start/Warm Driveway strategies. @ fully warmed, the EECM operates on a minimum idle. Until then, the EECM is adding more fuel, increasing timing, turning off smog/EGR flow, etc..

 

Well yesterday didn't go as well as I was hoping. After adjusting the throttle stop screw (before starting the truck or procedures) and getting 0.862 vdc on the DG/LG wire, started the truck up and seemed to idle pretty well right around 700+/- 50 rpm. Hit the throttle a few time, and it would get hung up around 1000-1400 rpm. It seemed to be about 50/50 whether it would idle around 700 or the 1000-1400. I decided after that, that I would go ahead and try the procedures and adjust the throttle stop screw "by the book". After going through the procedures and getting the idle where I wanted it, let the battery sit unplugged for 5-10 minutes, started the truck back up and the same thing, it would keep getting hung up and never go completely back to closed throttle...seems like I might need to pull the throttle body off and clean it real well. What do you think?


If that is the case, yall wouldn't happen to have a link for removal and installation of the throttle body? Best I can find are threads just for cleaning but never removal. From looking at it, it seems like all I have to do is unplug the TPS, disconnect the throttle cable from the throttle body "arm", remove the four front facing bolts and pull it off. Sound right? Is there anything I need to worry about flying out? Got any tips/tricks? Or is this a fairly straight forward job?


Another weird thing: It really seems to run better when the motor is cold vs operating temp, and it really seems to run best when it is cold outside....coincidence? Or could this be related to my issue?

 

It’s a low percentage for that procedure to be the ultimate fix, and as previously stated, it is more of a fine-tuning step.

Your goal was to get your new stop screw back close to where it should be.

Did you go for a 5-10 mile run?

Never hurts to clean and check/inspect parts, but the TB doesn’t get very dirty unless Air Filters are missing. The soot in the upper and lower intake usually comes from the EGR flow over years.

If you remove your TB, check the Valve fit inside the TB, photo it well for all to see.

Removal is as you explain, may be a few water hoses in the way, use a new Gasket on reassembly.

 

Yeah I drove it to friends house about 30 minutes away and back. On the way there, it was a little rougher running than on the way back. But it was about 60 degrees outside vs about 75 degrees on the way there. Not sure if that bit of temp change could make a difference. I'm driving it today to Greenville for a wedding so I'll update if it's driving any better.

Yeah I really want to remove it so I can inspect the valves to see if there is any damage or loose parts. I will make sure to take many pictures. Do you know of anywhere to buy new springs and such for the throttle body? Or any new parts? Im going to check rockauto again but i dont remember seeing anything

 

Hey, will you pop over to Farmville and cut the grass for me, it will save me a trip in the morning.... (Just kidding)

Is the The Skylight Inn in Ayden catering the wedding.....

 

Haha if I didn't have this wedding I sure wouldn't mind as much as you've helped!!

I misread that at first, the dinner tonight is actually at the Starlight cafe in downtown Greenville. I'm not sure who is catering it honestly, I just know I'll be eating a nice ribeye tonight

 

Don't know what you are using, but I like to add a bit of 93 octane, when troubleshooting to eliminate any low octane issues.

 

I'm just running 87 currently, I've tried 89 but couldn't tell a for sure difference. Sometimes it seemed to run better, sometimes the opposite. I already filled the front tank today with 87, I'll throw some 93 in the rear and try it out. Unless you're saying mix a little 93 into the 87 and not just straight 93?? I couldn't see that making much of a difference just mixing a little in but I've been wrong before haha

 

Just for a while I would run 93, while troubleshooting, yeah, just some in one tank will do, then you can switch to that when you are under the hood.

 

Warm/Cold Engine issues can be EECM control (Assuming EEC is operating correctly) or Mechanical issues.

When you are Cold Cranking, the EECM is dumping in loads of fuel, the Air Bypass is wide open, timing is fixed.

When the engine is Cold Started, determined by the ECT & ACT primarily, the EECM uses a predetermined strategy to rich up the fuel delivery, modifies the Air Bypass from 100% cranking open, to less open, advances the timing, turns off Smog/EGR operation (assuming no leaking mechanics). The EECM is looking at ECT, ACT & MAP input sensors.

So, Cold Start for the 30 seconds or so, you get that High Idle, then for the next 1 minute or so the next Strategy sets a Part Throttle, cuts back the Air Flow, keeps the Timing Advanced. The EGR will flow if throttle depressed(not in your case, Blocked) The EECM continues to monitor the ECT, ACT & MAP input sensors. For the next 2 minutes or so, same thing until the ECT reaches about 1v, then the O2 kicks in.

So, “run better when the motor is cold” = Cold Start = Cold Strategy Rich Mode mixture for about the first 2 1/5 minutes.

Obviously, a Fully Warm engine (195degF) is the normal operating condition for the engine, and the Input Variables are; Intake Air Temp (ACT), O2, ECT, MAP, EVP, KS, TPS.

It is good to understand and keep track of what’s going on in a timeframe & rpm perspective.

Troubleshooting processes try to eliminate possibilities by trying to prove each part is installed and operating correctly.

 

Well I ran 93 most of the way to Greenville, I switched back and forth a few times to see if I could tell a difference and I feel like it ran a little stronger with the 93. Not a huge difference by any means, but just seemed smoother. Im not quite sure what that entails. I did notice however, on both octanes, the idle fluctuation have subsided for the most part. It was sitting steady at about 700 rpms the majority of the time i sat at stop light and such, so that's good. The times that it didn't idle at 700, it would flutter around 900 +/- 75rpms really quickly. It happened when i got to greenville so i stopped and popped the hood to check my fuel pressure and noticed the fuel pressure was bouncing around +/-2 psi really quickly as well. I really feel like that could be the throttle cable hanging up, I may go ahead and replace the cable, I feel like that's a cheap and easy thing that won't hurt