JLDickmon
Bo Duke
so I get a call from the kid about two weeks ago.. truck won't start. Luckily, it's in the driveway at home, and it's nearly closing time at the shop. I grab my MODIS and drag it home with me.
I hook it up to the truck, arm the movie, and hit the key; the truck roars to life. Hmm.
Ok. F/F two days; we're loading up to go to a horse show. Fire up the truck, back up, hook up the trailer, pull it out into the driveway, shut the truck off, go back in and finish my coffee.
Come back out to leave, truck cranks over, won't fire. No smoke. Obviously not getting fuel. Open the PDC and remove the fuel pump speed relay (had trouble with this before), pitch the old one as far as I can into the weeds, grab a new one from the door (me smart!) drop it in, truck jumps to life and away we go.
Hook MODIS to it during a break at the show, throwing a MAP code. Look at serial data, it's measuring pressure, but it's not showing any frequency response. Interesting, indeed.
Leaving the show grounds that evening, truck does the same shenannigans it did in the morning. Only now, I'm wishing I had simply swapped the relay out, instead of heaving the old one. Pull the fuel pump speed relay and jump it up & down in the socket a few times, trucks finally convinces itself to start.
Kid says, "...this thing has been a real MUTT the last few days..."
I noticed that too. Acting reluctant to make any power. I hook the MODIS back up, set it to data disply and arm the movie... away we go down the road. Never once did the MAP show any frequency response, although it showed reasonable pressure numbers on the display (0-22psi depending on load).
I've since changed it out, but due to the lateness of the hour never did scan the data again, and it hasn't given me any trouble since.
But it still perplexes me (and several other techs as well) as to why I can get a PSI reading out of [the old one], but no frequency response (0 Hz solid).
Anyone ever seen anything similar to this?
I hook it up to the truck, arm the movie, and hit the key; the truck roars to life. Hmm.
Ok. F/F two days; we're loading up to go to a horse show. Fire up the truck, back up, hook up the trailer, pull it out into the driveway, shut the truck off, go back in and finish my coffee.
Come back out to leave, truck cranks over, won't fire. No smoke. Obviously not getting fuel. Open the PDC and remove the fuel pump speed relay (had trouble with this before), pitch the old one as far as I can into the weeds, grab a new one from the door (me smart!) drop it in, truck jumps to life and away we go.
Hook MODIS to it during a break at the show, throwing a MAP code. Look at serial data, it's measuring pressure, but it's not showing any frequency response. Interesting, indeed.
Leaving the show grounds that evening, truck does the same shenannigans it did in the morning. Only now, I'm wishing I had simply swapped the relay out, instead of heaving the old one. Pull the fuel pump speed relay and jump it up & down in the socket a few times, trucks finally convinces itself to start.
Kid says, "...this thing has been a real MUTT the last few days..."
I noticed that too. Acting reluctant to make any power. I hook the MODIS back up, set it to data disply and arm the movie... away we go down the road. Never once did the MAP show any frequency response, although it showed reasonable pressure numbers on the display (0-22psi depending on load).
I've since changed it out, but due to the lateness of the hour never did scan the data again, and it hasn't given me any trouble since.
But it still perplexes me (and several other techs as well) as to why I can get a PSI reading out of [the old one], but no frequency response (0 Hz solid).
Anyone ever seen anything similar to this?
