Suburban towing stuff

[jniolon]

and I got to say thanks for all the responses... tried some other boards and one vague response from one and crickets on the other...you guys rock

 

[Geotrash]

any real test for fuel pump problem other than checking pressure... and that is a static snapshot test and not real time during the tow, right ??

You can use a Tech2 scanner to monitor fuel pressure in real time, and log the data. There could also be other causes though, such as a loose injector wire.

A lot of folks will replace their fuel pump proactively after X number of miles just to ensure they don’t run into problems.

 

[wsteele]

thanks WSteele
I had new engine installed 35K ago due to the great idea chevy had with the V-4 - v-8 mode and he did new plugs since the old ones had 130K on them... hard to believe it was a plug misfiring but I've seen stranger things... so, you think this nothing to worry about or is there something I need to do ? BTW, you have any kin around Bham, Al ??

I am sure I have relatives in Bham, but I don't know them. We do breed like rabbits though...

I think if you can figure out what the random/multiple misfire is (P0300), you may have addressed the Stabilitrack/Traction Control messages.

A random/multiple misfire can be a challenge to diagnose when it is happening consistently. Being intermittent just makes it harder. Dave (@Geotrash) makes a good point on the possibility of a fading fuel pump. Unlike my 2007, he is right that with your 2008 you can monitor fuel pressure real time (both commanded - what the truck wants and actual - what the fuel pump is delivering). With a smart enough scan tool, you can watch it under load. There are a number of other parameters that can give you some hints, like MAF, MAP, Miss-fire counts (can help you zero in on what cylinders are miss-firing and what aren't, like if they are all on one bank (even or odd) or on both banks). That kind of thing can help you isolate the problem. If it is only on one bank, you can of put the things that might cause miss-fired on both banks aside and concentrate on candidate causes that might be bank specific.

 

[jniolon]

you guys are way above my pay grade... my diagnostic tools are timing lights and dwell meters . But, I've got a friend with a good scan tool and some knowledge and he might be able to give me some help. I have a cheapo obd reader that showed the P0300 and I cleared that. I'll bet that litte device doesn't do much clearing the other codes so maybe his scanner will show some stuff mine doesn't , eh ???

my question on kin ?? I've got a good friend named Steel that was from west virginia, thought it might be a cuz or sumthin

john

 

[wsteele]

you guys are way above my pay grade... my diagnostic tools are timing lights and dwell meters . But, I've got a friend with a good scan tool and some knowledge and he might be able to give me some help. I have a cheapo obd reader that showed the P0300 and I cleared that. I'll bet that litte device doesn't do much clearing the other codes so maybe his scanner will show some stuff mine doesn't , eh ???

my question on kin ?? I've got a good friend named Steel that was from west virginia, thought it might be a cuz or sumthin

john

The tool Dave mentioned above (the Tech 2) is one that can talk to the Fuel Pump Control Module and see all the various fuel related parameters, like pressure both requested and delivered, fuel trims, etc. Many high end scan tool can read the same modules. Your ODB reader might be able to see the fuel pressure sensor values. If it has an "All Sensor" mode, it will show all the sensors it can monitor If the fuel pressure value is displayed in the "All Sensor" request, you can at least watch that value. You should see about 43.5 psi. It shouldn't drop a lot from the 43.5 psi under heavy load.

You can also probably watch MAF, MAP, miss-fire counts (by cylinder). If your odb reader has a "live mode" or something like that, look for the above values. You might be able to narrow it down some.

Another thing to try as you move down the diagnostic path of the P0300, buy some MAF sensor aerosol cleaner and clean it up. There are many YouTube videos on the do's and don'ts of that process, many by the guys that make the stuff, like CRC, etc.