Specifically what is the truck doing that makes you say the engine is running great now but the truck overall isn't?
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Sent from my FlashScan V2 using Tapatalk
2001 lb7 duramax fuel issues.
- Thread starter Arlo75
- Start date
Is a knock after it gets to operating temp and under load. Have rebuilt fuel filter head, changed MAF sensor (which got rid of a lot of engine probs), replaced fuel lines, used fuel supplements, and have had a scanner hooked to it. The scanner shows everything to be fine as I'm told by the mechanic. Engine is actually running and sounding as good as when I bought it last November. Now the transmission is getting hot and started slipping yesterday along with the knock. Don't know which way to turn. Have been told that an injector could cause all of these problems. Pulling hair out.
Warm the engine up and run it hard until you make it knock then pull over immediately and check balance rates at idle.
You'll want to log the truck when it does it. Could be dropping rail pressure, causing extremely long pulsewidth, which can do all sorts of weird stuff.
Low rail pressure can be caused by worn injectors returning too much fuel, or a weak CP3, or a leak.
But without a scan tool and taking some logs, we are just going to be guessing. I would log desired and actual rail pressure, main fuel rate, fuel temperature, coolant temperature, MAF, and baro.
Low rail pressure can be caused by worn injectors returning too much fuel, or a weak CP3, or a leak.
But without a scan tool and taking some logs, we are just going to be guessing. I would log desired and actual rail pressure, main fuel rate, fuel temperature, coolant temperature, MAF, and baro.
I don't have a scanner. Been having a friend of a friend come over with his. I don't think borrowing it is an option. But I just looked at balance rates immediately after the issue started and one injector was almost -4.0. Would this cause my prob? I know you are asking for more info but this all I have for now. Sorry and thanks for all the input gents.
describe this "transmission slipping". your truck is pretty good about monitoring slip and when it starts to actually slip a clutch, it will put you in limp mode. it wont run like you are saying.
What im guessing is the truck is starting to hang gears? as in, you are hard on the throttle and it seems to hit redline but wont up shift, that sound correct?
What im guessing is the truck is starting to hang gears? as in, you are hard on the throttle and it seems to hit redline but wont up shift, that sound correct?
Slowing down it wants to downshift hard, almost barking the tires and the other day it seemed to be slipping as it was loosing ground coming up steep hills unless I gave it throttle. Trans temp was up around 170 in no time at all.
Negative numbers means one or more cylinders is producing more power then the rest and the ECM is trying to pull fuel to balance it all out. It could be from a leaking injector which is causing that cylinder to output more. -4 isn't usually enough on it's own to be something to worry about but can help in narrowing down where to look when you do have an issue
Seems to me that without a scanner and someone that knows what the hell is going on I'm just pissing in the wind. The guy that does have a scanner isn't what he thinks he is best I can tell.
I've had a problem for over a month now. Have had numerous people look at it and numerous opinions. Everything from air in the fuel, cracked flex plate, injectors, ECU, cp3, FPR, among other things. No closer to pinning down problem now than I was when it first started. This not pointed at anyone in this group. I know you guys have been trying to help. But I'm going to have a nervous breakdown over this. Lol.
10-4, dropping the transmission pan and taking a pic of what is in the botton of the pan (fluid drained out) and then splitting open the transmission filter or even just a pic into the pickup hole of the trans filter can tell us alot. if you changed the filter and fluid already, sadly we just lost all our health info. doesnt sound like you have gone that far yet though?
any vehicle from 97 on up really needs a decent scanner to be diagnosed properly. if its not this truck, it will be your next. otherwise your best bet is a truck with a warranty and thats a whole nother ball game and hoops you will have to deal with if you actually have to use it.
i can understand because based on the info we have here, its very little and hard to fix over just pic and text. relaying the issues you have is not your strong suit because you are new to this and its nothing against you, just means it will take more time to extract the correct info to diag this properly.
if it were me, i would start with one issue at a time. start with the knock. get a good scanner that can shut down individual injectors and go run it hard to get the knock back. soon as its back, start shutting down each injector and then turn back on listening for the knock to go away. if shutting down one specific one kills the knock, well that is your smoking gun on the injector that is bad. if it happens to be inj 4, the balance rate also confirms its the issue. if it does not change when an injector is being shut down, we have more to investigate.
as for trans, you gotta drop the pan like i stated. we are looking for high amount of material in the pan. being that thing is tuned, its likely the c3's or even converter are starting to go. it will plug the filter and cause temp issues.
once you have a decent diag on it, you can decide to either fix it or sell it.
Can I shut off injector 4 and drive it without a scanner? To be honest I think I would do better troubleshooting this with you guys only instead of Mr. Knowitall and his scanner.