Savannah and Spike555 you have been of great help more than you know plus going the extra mile with a replies plus your own vehicle's fuel reading postings. More useful than other replies.
I also asked on the "LandRover Exchange web" back in 1-30-12 and so far a zero reply. This I find really strange as Mike Green a Rover factory trained mechanic gone independant (he hates dealerships with a passion plus how they ripoff customers). Mike owns "Rover's West" in Livermore Calif. app 26 miles from me plus plans and teaches off roading. From stock to wild builds, he's not a parts swap until fixed problem person. Mike is usually rather busy on the above forum plus test rode my 4.6 D1 12 years ago after the dealership engine install. He was impressed with the results and RPI chip plus agreed it was slightly out of balance but within spec of later Rover production engines. I added my mods later he'll get another road test with my mods, I can't let him drive a stumbling mess at this time.

I have a burning question about Airtex pumps, one is app price plus after reading this; Airtex Fuel Pumps - Buyer Beware - Car Forums and Automotive Chat i'm a bit worried about their pumps.
Other "known good brands" available plus prices?

Savannah and Spike555, your help was way more than Disco Mike's reply of "do you know where and how to read your fault codes?". Yeah Mike we BS'ed many years together in the past on this forum, i'm a little disappointed this time as your replies were helpful to many members.
I get that "dealership service tech" feeling and answer from you.
Had that from a dealership after a rear main seal install, it took 4 quarts to drive 21 miles to the dealership within hours of a seal replacement number three.
Service TECH report," customer thinks has an engine oil leak developed".
Parked it out front a stream of oil flows out at their pretty overhead area.
Yeah "thinks" when they changed the seal three times with all failures, my "thinks" are not a guessing game.

This BS because I was still under 7/100K warranty. Disabled D1 parked at the dealership outside in the rain sunroof open, boxes on hood in shop dragged across hood paint damaged, tranny lift shoved against rear quarter panel paint damaged, their electric push unit caved in the spare tire cover, "was that way when delivered", hood lifted vertical to remove engine, rear of hood now 1/2" higher than fenders due to sprung hinges, gear face ticking in transfer case after one of their many road tests. Complain and get a "it was that way when road tested it.
Reused old heater hoses, blew (split) one apart at 400 miles after the factory new 4.6 install. Billed for a new water pump when the original one had 67 total miles from new I installed a day before, I asked for the old one back, "it went out with the scrap aluminum collector".
Sorry off topic rants , just had to mention my experience with factory trained Rover tech and service. My faith in "Tech" is rather low, they did it to themselves like replacing parts until problem cured then bill all the not required parts to "Customer Pays" at the bottom of the bill. This i've seen with other Rover owner repair bills.

With rain today plus no known quality brand name fuel pump yet to order this will be a delayed repair, i'll keep those that helped updated. Sort driving on a 1 x 4 mile island or within walking distance home.
.....~~=o&o>.....

 

So it would be a safe bet that you already dealt with any microscopic cracked vac hose to the fuel pressure regulator, and perhaps replaced that? Seems like that if key is turned to where pump runs, you would have pressure, and without engine running, no vacuum. So if twitching with just pump running that points one way, and if twitching starts after regulator gets vacuum (engine running), that might point a different way. As far as the pump, a number of posts on here of people installing them. As you can see, it is unlikely that people on this forum hold back on much, except where a new roof rack is on super blow out sale....

 

That's because it is the first thing you should look for. And since you never said anything about codes, that was a perfectly normal question/suggestion. Had you informed us that you had already checked for codes and there were none, you would not have been asked. I was planning on asking the same thing because too often people ask questions about symptoms and never bother checking their codes. Okay, I'm done with that.

As for Airtex pumps, the problem I've seen with them has mainly been installation problems. Every bad new Airtex pump I repaired was bad because the installer took shortcuts and reused fuel lines and/or clamps or didn't position the pump correctly. Just small details they overlooked. When corrected, the pumps worked perfectly for many years.

I reread the posts, and couldn't tell, does the needle twitch both during key on/engine off and key on/engine on, or only during one or the other?

 

Note: Mine doesn't twitch on either condition, and the gauge I am using is too cheap to be oil filled and dampened.

 

Forgot one other part, if it twitches key on/engine off, does it do it while the pump is energized, when the pump is off, or both?

Answers to these questions should help us narrow down the culprit.

 

Pressure gauge did flutter only when engine was running, engine off cycling the key powering up the boosting pressure from 24 psi to 31 psi after 4 hours was a steady needle rise.

I just got back from a 20 mile highway torture run talking 5,000 50 mph in 2nd, 75 in 3rd with 5,400 rpms reached in 4th, 5th it was still pulling hard past the 115 mph and climbing. I ran out of safe speeding road area. I sure miss the airport taxi ways we used to speed run on, Feds and new laws stopped our track fun days.
CHP in my area are jerks hence I had to drop down to sub normal speeds.
Now parked hot idling the fuel pressure 31 psi and rock steady no gauge flutter. What happened? i'll let it soak 10 minutes then restart to see if the fuel gauge needle will flutter plus the restart stumbling problem.
At a 10 minute wait with ignition on, fuel pressure went from 31 to 33 psi with a steady needle climb, started engine had a slight stumble 2-3 cylinders for 4-5 seconds then cleared up with a solid idle as well the fuel needle holding solid now at idle even after throwing revs to 3,500, yeah right now what? Crap in the pump got cleared out or a self healing pump?

I'm also working on the "mods" photos I promised,
here they are: Fuel Injector Cleaner Project and Intake Risers pictures by BeemerNut_photos - Photobucket

I'll try to explain thes photos from top L to R;

1) Completed engine with Bosch 4-hole injector replacements (wow should of done this many years ago what a difference).
Intake to lower plenum 1.500" milled spacer as well .250" spacer under top plenum cover.
Lines and hoses to hide this addition to pass smog visuals. It does.

2) Two 3" dia 45* rubber intake hoses off 87 Mustang 4 cylinder for an offset of dry cold ram air behind the left headlight. Snorkel reinstall 30 seconds for smog tests.
That Master Lube Pre-Oiler is a 3 qt. unit hard piped to near the oil filter. Flex stainless hose to a modified sandwich adapter holding a gauge sensor plus a low oil pressure EFI switch to trigger a relay then delay timer. Wet cold starts of 28 psi even after an overnight drain drain plus installing a 9" long filter dry installed. I saw too many dry start rattling Rovers with bearing damage, not on this new 4.6 install if I can help.
3)Bridgeport milling the top plenium for the .250" spacer added allowing me to use the original allen bolts.

4) Injector cleaner, ultra sonic with PWM, Hz plus timer to vary the cleaning and injector testing process.

5) Intake extension 1.500" tall with .250" plenum top spacer. This allows end trumpet air clearances of 0.723" vs 0.473 of stock.
The 1.500" spacer reduced max TQ of 3,100 by 386 rpm's doing the math, I can live with 2,714 max TQ and can feel it.
No worries it still pulls hard past 5,900 rpms, beyond common sense of these motors. By 5,200 it'a all over unless port and exhaust work. Port matching alone is a massive improvement on these engines without a wild porting job. High flow cats plus Borla exhaust has also helped wake it up besides the great sound like a 289 on Glaspacks. A remap is a must, I selected a RPI Tornado chip and the best choice in my book as the 4.6 required remaping.

6) IAC mount just clears the firewall cowling with IAC installed.

7) Front view of plenum top & bottom with spacers installed. Now easy to remove or service injectors.

8) Ram tubes with base with extension.

9) Ram tubes with base without extension.

10) Basic stock intake with plenum vs photo 7 to compare height differences.

11) A 4-hole Bosch injector being checked for spray pattern after flushing, note all 4 holes digging equally into the liquid.

12) Flow pattern checking. It doesn't take much to not have all 4 spraying an equal amout of pressaure and volume, trust me seen on "good but dirty 4 holes".

13) Low pressure testing will show up on slightly plugged holes.

14) The pressure chamber with regulated air supplied from 15 to 50 psi.
Scrap aluminum turned down on the lathe for the "O" ring grooves, cut wine bottle body for the chamber, add bits and parts at hand.

15) Cleaning solution chamber.

16) Old Ford fuel rail section put to use.

17) The early dram stages of the build after cutting the glass, this was my main worry.

18) Top of pressure chamber with fuel filter.

19) Bad dark photo, oops!

20) Bad photo of PWM driver with Hz control with timer for long and short injector volume balance testing.
Testing at 200 rpm's (engine speeds) at 5% duty cycle to 90% duty cycle at 17,000 rpm's plus 100% duty of full time open.

21) Start of pressure chamber.

22) PWM, Hz and timer unit to control the injectors during testing.

23) Complete injector flushing, cleaning, spray pattern with forward and backwards flushing with fuel rail with adapters.

24) Ready for cleaning duty.

25) Reverse flow flushing with PWM, Hz and timer.

26) Double photos sorry.

This is the best I came up with vs sending out injectors to be cleaned and sent back with a chart still not a balanced set.
I have a balanced set plus my own ideas on engines and what they require to run the way I want them to run.

Now i'm not a 29 year Rover service tech person so maybe ignore what I have posted, your wish to read and learn should you decide to open your mind to better ideas than what Rover offered to you.
Call me a wise ***, this is my results with photos backing up the mouth.
Prost and enjoy.
Carl.....~~=o&o>.....

 

I'd start looking at the regulator then. Possibly a bad hose(can't remember if you said you replaced/checked it or not) or sticky regulator. The regulator should stay closed during key on/engine off. Only time it should open is while running. And it it is gummed up, or worn, it could be opening and closing erratically instead of smoothly. I should check mine just for fun. I'll try to tonight and see what happens.

 

I bought a Airtex fuel pump for my truck 3? years ago, but I bought the whole assembly and not just the pump.
It works great and so far my only complaint is that the fuel gauge reads lower than actual fuel level BUT this is because of the ethanol in the fuel, the more ethanol the lower it reads.
So for example, with the original pump the low fuel light would come on and I would have approx. 5 gal of fuel left.
Now when it comes on I have close to 10 gal left, again this varies with the amount of ethanol in the gas.

 

Hoses are like new, replace often something I learned about owning a Rover their hoses as crap.
Hell check their vacuum advance units, 80-90% of them are shot plus the small weak signal lost hence no advance action.
Power steering HP hose give it 100% a leaker every Rover has rust control on the left front like their valve cover gaskets.

With the vacuum hose removed regulator pressure will rise from 31 to 39 psi, mouth vacuum applied will increase it to 41 psi.
Pinched shut return line 78 psi pump pressure hence pump isn't dead yet.
Slowly pinching fuel feed rail hose engine will idle down on 9 psi. I must add 4-hole Bosh injectors are great.
With regulator speced out 33.99 to 38.00 psi range, below or above "replace regulator" per Workshop Manual.
Seems other Rover owners also only read 30 to 31 psi regulated pressure, these all below spec.
Add the crazy asking price of a regulator and if it has the same below spec pressure readings this would be a pisser and waste of money.
A fuel pump is cheaper to replace, last resort a regulator but not before rechecking the injectors for flow and balance again. They are 2 years old with under 1,500 miles on them from last installed all within 3/4% balanced flow checked.
Any bump start with a full charged or low battery would take a 2' bump and fire. Bless 5-speeds vs automatics.
Never would Lucas injectors ever start or run a smooth and clean as these later 4-hole bosch injectors. Called progress with injector designs as well tighter smog laws to be matched.
My observations playing with and keeping a 95 D1 running the past 12 years with intrest in it running its best.
Nuff ramblings.....~~=o&o>.....

 

Hey your honest and speak the truth.
I wanted a V-8 as I installed a 3.5 Rover motor into a 1962 P1800 Volvo back in 1973, always liked that engine. A fun project besides I had faith in the aluminum engine when it became available used.
Ask my wife she'll call garbage pickup to remove the eyesore LandRover she hates it with a passion due to too many road failures and walking home with her replacement knees. Starter failures as it would be started 30 plus times a day. This on a 1 x 4 mile island, think of failures way out in the bush or Bum Screw India? "Limey Lemon" dad named it. Resale value zip i'm told, amount of money sunk keeping it alive don't ask. I'd part it out when the time comes, engine for a 914 Porsche project with Webers installed I keep telling the Rover.