dweller

My truck is an '02 HO with 6 speed. Dealer replaced LP with intank pump at about 90K. Shortly after that I forced them to replace the VP44. The truck was cutting out at any rpm lower than 2000. The new VP44 cured the problem and the truck ran great.

Now, at 105K, its doing the same thing as before. I put in a new fuel filter, reset the APPS, cleared the old codes, but none of the above helped. The problem seems worse when the truck is cold. Pulled the codes and got:

1693
0380

The 0380 is intake air heater grid relay, I think. 1693 is companion code, so I don't really know what it means. Could a faulty grid heater be causing these symptoms? Or is my warranty VP44 already taking a dump with only 13K on it?

Thanks

dweller

Anybody? What's weird is that I'm not getting the 0216 code like before when the IP failed, even though the symptoms are exactly the same.

What is the most common thing to go bad with the grid heater? The relay?

Thanks

Tate

Well, cold air isn't going to create as much heat when compressed as warmer air will. So a faulty grid heater would make it run poorer when cold. Does it run fine once its up to temp? Search for a video by MCummings, its of his 24v starting when cold. He doesn't have any grid heaters, and runs really rough. Get those fixed, and then see if your problem goes away. A VP dying at 13k isn't the most common, but its not unheard of either.

dweller

OK, I went through the process of checking the grid heaters and relays. I have continuity in all cables, the relays are working fine. I cleaned all grounds and checked ECU connections. Disconnected the batteries with key on for about an hour. The heaters come on for the right length of time before starting, and then cycle as they should when truck is cold. I don't think the heaters are the problem.

So I drive the truck for 30 miles and it runs like crap under 2000 rpm. Stop, run errands, then drive another 30 miles. Its running fine, go figure. Checked codes and am still getting the 1693 and 0380. I don't get it.

Barry St John

This is a long shot but I've heard some wierd things happening with bad batteries. Are your batteries both in good shape?