Intermittent Code 44.

[Gander]

First off, no scanner, no ALDL cable, no Windows 7 or Windows 10 laptop and I won’t be able to have any of that stuff anytime soon. Wish I had that stuff because it sure would be easier to figure this stuff out.

OK, so random code 44. Only seems to do it if I’ve shut the truck off hot like at a gas station or a store if I haven’t been in very long. I’ll start it back up, drive off, and as I’m driving off the SES light would come on. Just did it again today and as it happened it felt like I was pressing the gas pedal but it was hardly feeding the motor any fuel. Fuel pressure regulator and spring is new, injectors are reconditioned, TPS is new. Checked the voltages there. IAC is new and so is the connector. I don’t think it’s a fuel pump issue since this happens regardless of which fuel tank I’m using and each tank has its own pump. Fuel filter is new. Any ideas? Tell me where to look and how and I’ll start checking. BTW, when I shut it off and turn it back on the light is gone though the code is stored, I can pull it up when I jump A&B on the ALDL. This is an intermittent thing. I can go a week without it happening and then have a week where it happens once a day. Just can’t figure it out.

 

[gmbellew]

If it is intermittent, I would guess the O2 sensor is flaking out. 44 is lean condition, closed loop (O2 voltage low for too long). Or something that is causing the O2 to read low in closed loop.

 

[YakkoWarner]

I get this too but not in the same conditions you describe, mine happens when I'm driving either up a long gradual hill or on a highway with a speed limit 70 or more. I had the data log running the last time it happened and saw an anomoly - right before the error triggered both the MAP and TPS readings went very high much quicker than could be achieved with pedal manipulation.

In your case, I would almost suspect a partial vapor lock since it only happens when you shut down the truck while hot and then restart. Some of these trucks had an extra fuel "hot start" pump control module that would run the fuel pump longer before cranking in order to circulate cooler fuel into the throttle body before startup. An experiment to try would be to turn your key on for 10 seconds, then off, then on again for 10 seconds 3 or 4 times before actually starting - that would do the same thing in terms of moving cooler fuel thru the lines. Is your truck a small block or big block? I have that hot start thing but I have a BBC, I don't know what caused some trucks to get it and others not but maybe they didn't put it in SBC trucks?

 

[Gander]

I get this too but not in the same conditions you describe, mine happens when I'm driving either up a long gradual hill or on a highway with a speed limit 70 or more. I had the data log running the last time it happened and saw an anomoly - right before the error triggered both the MAP and TPS readings went very high much quicker than could be achieved with pedal manipulation.

In your case, I would almost suspect a partial vapor lock since it only happens when you shut down the truck while hot and then restart. Some of these trucks had an extra fuel "hot start" pump control module that would run the fuel pump longer before cranking in order to circulate cooler fuel into the throttle body before startup. An experiment to try would be to turn your key on for 10 seconds, then off, then on again for 10 seconds 3 or 4 times before actually starting - that would do the same thing in terms of moving cooler fuel thru the lines. Is your truck a small block or big block? I have that hot start thing but I have a BBC, I don't know what caused some trucks to get it and others not but maybe they didn't put it in SBC trucks?

5.7tbi. I’ll try the 10 sec trick on hot startup and looking forward to any other ideas. Thanks!