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Rough idle and pinging

sreidmx

sreidmx

Fortify Offroad
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Hey guys I am working on my wife's truck 92 k2500 350/4l60
It started to ping a lot under part throttle, it also has a semi rough idle. Initially I thought the egr valve was bad and it was, I replaced it and the solenoid. I still have the pinging and rough idle. I checked the coolant temp sensor just to see if it was pulling fuel from a bad sensor, I unplugged the tps and o2 while running and no change.. I cleared the codes and drove around and still not getting the 32 like it had probably cause I don't have any level ground around here. I don't know what to do and I don't have much experience with tbi so not sure where to look from here.
 
Those symptoms still point to an EGR stuck open?

Also now that the error 32 is gone the symptoms could be low fuel pressure!

Also check timing set to 0* with bypass wire disconnected.

These small cap distributors are also known to burn up the button in cap that contacts rotor, which causes all sorts of these issues.

Anyone with an EFI vehicle needs to have a scan tool... but then you also need a lot of knowledge to use the data it shows. The other tool is a data logging cable and software TunerPro. This way you can data log, save the file, post it and I or others can take a look.
 
I'll check fp it runs up the rpm without stuttering. I also checked the new egr valve and it stumbles when vacuum is applied at idle. Could a bad knock sensor cause this?
 
Very unlikely... pull the cap and check the rotor for black tracing and look at button in cap to see it is spring loaded and pushing down.
 
That datalogging tool looks awesome im definately going to get that, i checked timing its at 0 i also verified that the knock sensor is not pulling timing. Hammer to block test while checking timing. Checked wiring and sensors for faults so all thats left is fuel filter and knock/ spark related...
 
Checked cap and rotor thay were fine, also changed fuel filter. Checked spark plugs they look fine also. Changed knock sensor and pigtail also. Could the ecs module be going bad?
 
If you mean the ESC? Again highly unlikely, just like the knock sensor. They pull timing, not add timing to create Pinging.

Although it pulls fine through RPM. This is still all typical of low fuel pressure.

Just like a scan tool or data logging, fuel pressure is something you need to know when working on these. The ECM has no way to know what fuel pressure is! It expects it to be correct. If it is low? It can adjust fueling to compensate, but only so much. There are boundaries, it can not perform miracles except within set guidelines.

We are still chasing pinging part throttle and rough idle?

Have any codes set during this time?
 
Ok I'll check fp and yes still chasing the rough idle and pinging. And esc what what i was referring to. I have a friend who has the aldl cable and program so were going to check it also. Would low fp be in tank pump or fpr?
Thanks again
 
Anything under 12 just starts to run worse. 13 is better and when adjusted to that a stock motor runs better and data is better.

These TBI systems have barely enough fuel to start and run a stock motor.

If you can data log with TunerPro RT (Free to use, please pay $39 if you decide to keep) I can review data log.
 
Will it tell what fuel pressure is?

If your going to rebuild your TBI... for unknown reason? Then send the injectors to be serviced. It is the most important part of the TBI rebuild. Second would be the fuel pressure regulator included in kit. Then third would be have the throttle blade shaft rebushed to avoid vacuum leaks... also not included in kit.

Why did you buy the kit? :dunno:
 
While i do not disagree with your logic its time consuming and wont lead me immediately in a correct direction, if the fpr is bad and i fix it with a 27 dollar set of gaskets so be it. There is no idication of air leaks in my tb, they are just like carbs they wear out and if i was going to refurbish it i might as well buy a brand new or completly rebuilt one. I am not that far into it yet just troubleshooting and tying up loose ends. All of the parts i have replaced so far needed it so money hasnt been wasted. This truck sat for some 10 years only being driven occasionaly..
 
here is the log

BTW it has a superchip for a 49 state truck
 

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  • 20131115_191621_LOG.txt
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I'll see if I remember how to change a WinALDL txt file to a spreadsheet file so it can be read...

But the real answer is TunerPro RT, read the tutorial in Injection Section, files needed for your truck are in the thread and I wrote them, download the program and get a real data log! :waytogo:
http://coloradok5.com/forums/showthread.php?t=302680

In the Tutorial all you need right now is the ADX file data logging, the other stuff is for tuning!
 
I can help you with this here is the spreadsheet. Remove .txt from the end of the filename..
 

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  • 20131115_191621_LOG.xls.txt
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Soooo. I think I have a bad ESC module. I can see knock values in the aldl program so I know the knock sensor is working, however the ESC is not pulling timing, I tested this by watching the timing with a timing light at idle and tapping the block with a hammer, this is how it says to test in the manual.. and it doesnt retard timing at all..

I also drove around a little with the timing bypass unplugged and at WOT it runs normal so I doubt this is fuel related or else It would happen regardless of timing controls.

70 dollar part hope it fixes it..
 
Depending on your chip calibration... vehicle has to be over 700 RPM and 2 MPH for Knock sensor to enable spark retard.

Save your money...
 
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