2000 V8 power/fuel issues even after tune up.

[Hawk]

Bought my second LS about a year ago with around 100,000 original KM.
It had been neglected from the previous owner(s).

The project has been on hold for many months. I just started working on her again.
I have since cleaned her up pretty good and completed a major tune up with Motorcraft: battery, alternator, coils. NGK spark plugs, Fel-Pro VCG's, oil pan gasket and serpentine belt.
Cleaned throttle body, K&N air filter, MAF sensor, oil change.

-When I start the car and the RPM's drop to idle around 650-700, the vehicle shakes. If I give it some gas it will go away.
- Accelerating with a light throttle past 2000+ RPM feels like it hesitates and doesn't want to go any higher. It will just stay there, unless I press harder on the gas pedal, then it will jump up a bit then shift. The problem seems to not be as bad if I really step on it.

The following codes shows up with a KOEO using Forscan:
U1131 - Lack of fuel pump status response
U1262 - SCP Data Link Fault (IC and ABS)
C1805 - Mismatched PCM and/or ABS/TCS Module
C1963 - Stability Control Inhibit Warning
P1233 - Fuel pump driver module offline

My research has pointed me towards the secondary fuel pump or jet pump.
Before I go and replace that. Do you think that is the culprit for the U1131, P1233?

 

[joegr]

...My research has pointed me towards the secondary fuel pump or jet pump.
Before I go and replace that. Do you think that is the culprit for the U1131, P1233?

No, I wouldn't think so. Those codes relate to the electric fuel pump. The jet pump is purely hydraulic, and couldn't set those codes. Those codes are saying that the PCM isn't communicating with the electronic driver for the fuel pump. That driver is in the REM. Since there is a communications problem with the ABS module as well, I would start by looking at the data bus wiring. You might also try disconnecting modules and seeing if that allows comms with the remaining modules. Clear codes and unplug the ABS module, do the fuel pump codes come back? Reconnect the ABS, clear codes, disconnect the REM. Do the ABS codes come back? (Engine won't run because no fuel pump.) May have to try unplugging other modules.

 

[Hawk]

"No, I wouldn't think so. Those codes relate to the electric fuel pump. The jet pump is purely hydraulic, and couldn't set those codes.
Those codes are saying that the PCM isn't communicating with the electronic driver for the fuel pump. That driver is in the REM."

Okay. I will not replace the jet jump.

"Since there is a communications problem with the ABS module as well, I would start by looking at the data bus wiring."

Does that mean visually inspect? or check voltages with a multi meter?

"You might also try disconnecting modules and seeing if that allows comms with the remaining modules."

Maybe my Elm327 adapter doesn't support ABS. Would that have anything to do with it?


"Clear codes and unplug the ABS module, do the fuel pump codes come back?" Reconnect the ABS, clear codes, disconnect the REM. Do the ABS codes come back? (Engine won't run because no fuel pump.) May have to try unplugging other modules.

The codes were all returning after about 100+km.

On another note. There were 2 other DTC's that stood out to me that has not been back yet.
-C1284 - Oil pressure switch failure
-U1130 - Invalid or Missing Data for Fuel System

I think my oil pressure switch is leaking, would that trigger C1284 from the oil pressure not being adequate?

I will try what you suggested. I have the ECU's memory clearing right now. I have not done that yet since sealing a vacuum leak. Will see if that smooths out my rough idle. Maybe it needs to re-learn the new air ratio.

 

[RigsLS]

Change out the fuel filter in drivers side wheel well also. Partially clogged filters are no good for pumps. Ends up working too hard.

 

[joegr]

I think that C1284 is triggered if the oil pressure switch (it's just a switch, not a sensor) indicates pressure when the engine is not running, but I am not positive on this.

 

[Joshawa]

on a separate note, how do you do the koeo koer on forscan? ty

 

[Hawk]

Update:
Since clearing the memory of the PCM, the car no longer shakes at idle.

I do need to fix something in my front suspension, it clunks over bumps. I noticed one of my motor mounts is worn out too.

Replaced fuel filter yesterday with OEM.

Will be doing the tests with modules unplugged today sometime.

 

[AmsterDutch]

Check your front outer tie rods. Check for play in front wheels when car is jacked up as you probably already know. Hopefully this is the problem and not something more serious.

Update:
Since clearing the memory of the PCM, the car no longer shakes at idle.

I do need to fix something in my front suspension, it clunks over bumps. I noticed one of my motor mounts is worn out too.

Replaced fuel filter yesterday with OEM.

Will be doing the tests with modules unplugged today sometime.

 

[RigsLS]

... something in my front suspension, it clunks over bumps.

Possibly: Front sway bar bushings worn out.

The inside of the hard rubber bushing, which is the inner part that wraps around the bar, it hardens over time, when it creates enough space/slack, it will start making a mild thumping sound when the front end travels slowly over uneven surfaces. The bracket and the bushings are stationary and the bar bangs around.

Note the bolts holding the brackets through, are long, to the point you think it's Christmas before it comes out.

Clean the dirt up around the bar where the bushings clamps down and a smear of silicon lube all inside the bushings. Grease the thread on the bolts. Some of the brackets bolts are more easily managed from the top, with long extensions and a swivel.

The DCCV needs to be moved slightly out of the way. It has two bolts, only one needs to come completely out, the other, I think it was the top one, only needs to be loosened as the DCCV bracket is hooked around it. As you loosen the bolt a few turns, the DCCV on it's bracket can be lifted up and around away from the bolt.


FYI: the ES bushings and brackets are too narrow and will slide end to end.

More here ( Sway bar bushings- sport or non-sport ) on why I do not like the ES bushings. You can work the collar to keep them in place or simply just get the right size bushings and be done with it.


There is a solution for the GEN 1 using the OEM brackets and obtaining the Jaguar Rein #XR819697 bushings from FCparts.

Jaguar Sway Bar Mount Front(S-Type XJ8 XK)- Rein XR819697 | FCP Euro

NOTE: These are the 30mm bushings needed for a Sport model, You'd need Qty x2
only grab these if your 1st GEN V8 is indeed a Sport. Base model any year, uses a smaller swaybar and these would not work.

The sport front sway bar is 30mm, the non-sport base model is not. The REIN Jaguar bushing would sit slightly loose on any non-sport LS. The REIN bushings are more suited for the 30mm Sport model.


Clean up original brackets and hardware and reuse.

... Also, do check your front swaybar outer end links. Moog's are a solid and cheaper replacement for those. Greasable. Same P/N fits both L & R side. Rears uses two different P/N's due to L & R angles. Available on Rock Auto.




.

 

[EJay58]

Replaced the rear left and right sway bar links on my 2006 LS this morning with Moog upgrade links. Living in Germany and driving average speeds of 100mph on the Autobahn I didn't feel too comfortable with the extremely thin OEM stock links. After installation and driving back home I could definitely feel the extra support when making lane changes at high speeds. The wishy-washy rear end feel was definitely gone. I couldn't get the nuts off the front links with the small equipment I had, so can't wait to get it into a Shop Bay with access to professional tools.