Getting P0231

[Turbine Doc]

i got 3.42s too. so not all k1500s got 3.73s. but for 185 hp and tall gears it has pretty good accerlation i think for a sub 6 thousand pound truck

Most of the K1500/2500s were 3:73, which is why I asked; those that have 3:42 in K form were special orders for most part as was case here.

My burb also mirrors yours in acceleration, maybe a little more than most now that it has Heath reflash, ATT,& 4" exhaust, very spry for a fullsize with 3:42, and thrifty on fuel 850+ mile range, not sure how much on the + since adding the ATT I havent run to empty on it

 

[fritz1990]

Went out and looked for the ground wire on top of the frame aft (behind) the filler neck and no such critter. Felt all the way to the back.

There is a ground strap form the filler neck to the box. There is also a wire loom there with a purple, and a brown with white stripe wire, but they go into the loom. Gotta make a trip tomorrow about 80 miles, thinking about putting spare LP on? Won't do any good though if it is a bad ground.

Thanks!

Regards, Jeff

 

[packratt]

Clean the grounds that come to the passenger side intake stud. Should be one of those 3 little wires as the ground for the fuel pump. The one on the frame rail above the fuel tank is for the sending unit.

 

[fritz1990]

I went ahead and changed the LP to my spare and cleared the codes. I will have a 50 mile round trip tomorrow and I will see what happens. I cleaned all my grounds when I R&R'd IP and Injectors 12,000 miles ago. I cleaned them really good with emery cloth and the studs too.

Thanks for the reply, I will post back tomorrow night and see what happens. If light comes back I will clean grounds again.

Regards, Jeff

 

[Turbine Doc]

Jeff I've got 98 K1500 myself, that gnd is should be where I said it is, when it's dirty or disconnected you'll have lift pump issues, I'll try to get a pic of it tomorrow. Single ring lug black wire top of the driver side frame rail.

 

[fritz1990]

Thanks! A pic would be great but I will look for it some more tomorrow when I get back. I felt around a few times from the filler neck back on top of frame on drivers side but didn't run across it. Maybe it fell off but I didn't see any wire hanging. I don't drive in a lot of mud or snow, don't mean much I know.

Pic would be great!! :hail::thankyou2:

Regards, Jeff

 

[Turbine Doc]

GND pics, angle was kinda hard to get best pic but these should give you an idea where the gnd is

 

[fritz1990]

Thanks a bunch! I will look tomorrow more closely.

I went ahead and changed LP out and went on a 50 mile round trip. I cleared codes before I left and when I got back the only ones I had were the EGR ones that I have had since blocking EGR at intake. Will look for it some more and then I have to go on a 130 mile round trip on Friday, hope to find this ground.

Will post back on findings.

Thanks again.

Regards, Jeff

 

[fritz1990]

Made my 130 + mile trip this afternoon and no P0231. All I did was R&R LP. I will look for the ground strap tomorrow that Turbine Doc mentioned. So far so good. Will see if the code stays gone. Thaks a bunch again guys!:cheers2:

Regards, Jeff

 

[buddy]

Does your LP run when you turn the IGN to ON? I would check your relay. As TD said, it runs off of either. So it could be that your OPS is working and relay is not. At IGN ON it would only run off the relay though.

The OPS can randomly cause lowered voltage if the contacts are getting fried.

So I would check out the relay.

 

[fritz1990]

Yes LP runs with KO/EO. Gonna run it for now and see if it comes back, haven't been out to check the GRD that TD spoke of but will in a couple days. will post findings.

Son is coming home from college for a couple days! :hurray:

Thanks for the reply!

Regards, Jeff

 

[Turbine Doc]

All;

FYI on the 98's and rest of OBD-II's (I'm purty sure) you have to lose both the PCM feed & OPS feed to lose lift pump power, if one or other is present lift should run, common point either way is grounding, what stuck me as odd from earlier test was voltage across both pins was low, but high side to frame he had good voltage, now it's running apparently, possibly the disconnect/replug corrected the gnd issue.

Jeff when you have a go at it again, read the resistance of the gnd side of the supply plug to gnd, it ought to be very low, closer to 0 ohm the better, report back the results.

 

[buddy]

All;

FYI on the 98's and rest of OBD-II's (I'm purty sure) you have to lose both the PCM feed & OPS feed to lose lift pump power, if one or other is present lift should run, common point either way is grounding,

Very true, except when there is no oil pressure at IGN On, Engine Off, so thats when you can see if the relay is still functional.

 

[Turbine Doc]

Very true, except when there is no oil pressure at IGN On, Engine Off, so thats when you can see if the relay is still functional.

Negative; on OBD-II with key on only, lift runs until current monitoring in the lift pump shuts off the pump, if vent is open on filter manager drain, or vent pump will run with just key in run position, or if test jumper is connected to +12v with ign on.

 

[buddy]

if vent is open on filter manager drain, or vent pump will run with just key in run position.

So yes it does run with key on engine off via relay, it should also prime during WTS if its not primed for any reason.

 

[fritz1990]

All;


Jeff when you have a go at it again, read the resistance of the gnd side of the supply plug to gnd, it ought to be very low, closer to 0 ohm the better, report back the results.

I just went out and did above test and it showed 0.08 on my digital meter grounded to the frame. I also found the GND wire that you have spoke of, pics made all the difference. I will leave it like it is for now unless someone has other suggestions. I won't be going anywhere in it until next Monday.

Thanks again! :thumbsup:

Regards, Jeff

 

[marshmello]

i have a 97 2500 6.5 just replaced lp and truck drove fine for few days then starting to lose power and seemed to be skipping, think i have a similar issue with my truck it starts blows white smoke for a few seconds then idles fine for a minute or two then seems to be loosing fuel and getting air bound but i open bleeder vent on filter and pure fuel no air, i did a few test that you guys said in here and i get 11.80v with ko/ef and it cycles w the wts light so like i was saying ko/ef i get 11.80v at lp plug across the pins then when the wts light goes off the votlage spikes to 12.30v and then when the wts light stops cycling the voltage goes to 2.63 volts and fluxuates around that min 2.58v to max2.74v any ideas?

 

[marshmello]

and im getting the same code