DI - Fuel Pump Readings/Modifications
#11
06-27-2010, 09:05 PM
OZ, I installed an air-tex 3270 pump for the same reason.(similiar pressures)
Runs much better.
I don't know that I'd change the reg until I confirmed it was bad.
I agree, change the fuel filter (cut the crimps off the steel-to-rubber connections & install a different filter w/clamps)
luck,greg
Runs much better.
I don't know that I'd change the reg until I confirmed it was bad.
I agree, change the fuel filter (cut the crimps off the steel-to-rubber connections & install a different filter w/clamps)
luck,greg
#12
06-27-2010, 09:27 PM
Baja
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I think you're chasing that elusive dream, how is jacking the fuel injection pressure going to accomplish anything.
Also better ensure the integrity of your fuel lines. My 97 DI had such badly corroded fuel lines that they sprung leaks at the clamps when the fuel lines were repositioned to get to the starter mounting bolts. I had to replace them from the fuel tank to the engine bay. If yours are weak, they will leak when you start handling them, especially with a jacked up psi applied.
Good luck boosting it in HP.
Also better ensure the integrity of your fuel lines. My 97 DI had such badly corroded fuel lines that they sprung leaks at the clamps when the fuel lines were repositioned to get to the starter mounting bolts. I had to replace them from the fuel tank to the engine bay. If yours are weak, they will leak when you start handling them, especially with a jacked up psi applied.
Good luck boosting it in HP.
#14
06-27-2010, 10:02 PM
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Yes, 3rd gear when pulling the trailer...it still seems to be heading into a very strong headwind.
We use to see this condition when fuel pump pressure was low, or when the cats started to stop in the GM vehicles???
#15
06-27-2010, 10:05 PM
#16
06-28-2010, 10:58 PM
luck,greg
#17
06-28-2010, 11:04 PM
Thanks Greg!!!
That was my rational...you could have unlimited pressure from the fuel pump, the regulator will hold the fuel system to factory specs...it would just be nice to bump it another 2-3psi to help the bosch injectors???
Another thing that I notice when pulling 2-3 mile grades is from around 2200-3400 rpm's the engine seems flat (like driving into a hard wind)...then it seems to pull out of it from around 3500 rpm's and higher...according to articles I've read, this seems to be a well-known problem with the stock 4.0L Rover engines???
My thought was the camshaft from a 4.6L (or crower replacement from D&D Fabrications) would help provided I opened up the exhaust side a little bit...again, still looking for 30 horses, or so..thanks!
That was my rational...you could have unlimited pressure from the fuel pump, the regulator will hold the fuel system to factory specs...it would just be nice to bump it another 2-3psi to help the bosch injectors???
Another thing that I notice when pulling 2-3 mile grades is from around 2200-3400 rpm's the engine seems flat (like driving into a hard wind)...then it seems to pull out of it from around 3500 rpm's and higher...according to articles I've read, this seems to be a well-known problem with the stock 4.0L Rover engines???
My thought was the camshaft from a 4.6L (or crower replacement from D&D Fabrications) would help provided I opened up the exhaust side a little bit...again, still looking for 30 horses, or so..thanks!
The ecm pulse-width controls the injectors for the mixture, so you'll get nothing from bumping the pressure up or larger flow injectors.
I too, run new style injectors (Ford's 19lb.) and I don't have the loved 2500rpm flat spot, but I'm inclined to say it's from cleaning my MAF.
luck,greg
#18
06-29-2010, 12:36 PM
This instrests me, ive also got a '98 4.0.
No idea how the rover v8 handles 'em, but I swapped more aggressive injectors (from a mustang) into my BMW without any other mods and noticed an instant improvement in power, throttle response, and even a few mpg's.
It's about increasing the atomization of the fuel into the mixture. The old injectors were more of a squirt than a fine mist. Increasing fuel pressure and running larger injectors is only really useful for FI situations afaik.
What does the 4.6 cam do? Just more aggressive timing? I thought you needed the whole 4.6 bottom end to make it worthwhile. If not, sign me up!
No idea how the rover v8 handles 'em, but I swapped more aggressive injectors (from a mustang) into my BMW without any other mods and noticed an instant improvement in power, throttle response, and even a few mpg's.
It's about increasing the atomization of the fuel into the mixture. The old injectors were more of a squirt than a fine mist. Increasing fuel pressure and running larger injectors is only really useful for FI situations afaik.
What does the 4.6 cam do? Just more aggressive timing? I thought you needed the whole 4.6 bottom end to make it worthwhile. If not, sign me up!
#19
06-29-2010, 02:52 PM
While the LR lucas injectors are a single-pintle design, they have tri-cone barrel inside, atomizing the fuel very well.
They also don't use inlet filters.
Being a single pintle, they also tolerate crappy substandard fuel better than a four-hole disc like I installed.
My originals leaked, causing a stinky rich sooty idle, I could have cleaned, refurbed them, but I can't leave things alone.
luck,greg
They also don't use inlet filters.
Being a single pintle, they also tolerate crappy substandard fuel better than a four-hole disc like I installed.
My originals leaked, causing a stinky rich sooty idle, I could have cleaned, refurbed them, but I can't leave things alone.
luck,greg