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MG MGB GT V8 Factory Originals Technical - EFI OS2 Sensors
|Fitting 1995 3.9 Range Rover Efi to 3.5 motor. I have complete wiring harness and manifold, pelum etc from Aussie doner car, I now have 3 questions plus a diff??.|
1.no OS2 sensors came with wiring I was told that sensors were only on the 4 and 4.4 motors. IS THIS SO.
2.Do I need "Fuel Injection Fault Display " or is part of the 14cux ecu unit?
3. I have a Lucas 4FP fuel pump from a XJ6 Jag, pump numbers 0580 464 014 is this suitable for my conversion if so what other parts do I need to feed the efi injectors?
4. I have a 5 lug XW ford/ mustang lsd diff what and how do i convert my 4 lug front hubs to match or do i convert rear to 4 lug.
|Tony - if you are not fitting the oxygen sensors you may have to change the resistor in the loom - they are colour coded - what colour have you ? I seem to recall an earlier version of the system had a function tell-tale - my 94 version does not - a diagnostic plug only. The Jag pump seems to have a Bosch number - probably Ok but if it's not a sucker you may want to incorporate the standard MG pump and a swirl pot (or large filter) - you need 40 PSi and a return line - lots in the archive. Can't help with hubs - you need to choose - I have a couple of MGC hubs if you get stuck.|
|Tony- Baker electric sells a o2 spoof and a square wave spoof for VATS if you have that. However, the o2's in front and behind the CAT will be important for the PCM to dial in your fuel mix! Cheers, Vic|
|Tony, I bought two bosch o2 sensors for my 3.9 to use with the rover electrics. They are 3 wire and are the correct replacement type except for the plug. I have decided to use a totally different system and are not using them. I paid 42.00 dollars each for them. I am willing to sell them for 70.00 for the pair. They are brand new in the box. the plug will need to be changed to match the original rover plug.|
|First fuel pump|
If you don't want to change the tank and stick with off the shelf gear then;
Buy a very late model MGB fuel tank sender. This has it's own independent fuel uptake line. All the older style tanks (and new replacement ones) have a separate fuel uptake located about two thirds of the way back on the RHS of the tank. That gives you an uptake line and a return. The senders cost about $50 new. You could also just put a pipe through the existing sender since you are able to remove it to a safe distance and weld/solder etc.
First- Petrol is not like water (no surprise there). It does not siphon well, having a high vapour pressure.
This means you need to be careful setting up your fuel supply.
High pressure, high volume, run all the time, roller vane pumps deliver good pressure, but have very poor suction and will cavitate unless gravity fed, and be very noisy and wear fast. Problem, there is no room anywhere around the standard MGB tank to gravity feed anything. The solution is to keep the high pressure pump supplied with a good suction, high volume, run all the time, roller vane, low pressure pump (you can't get both good suction and high pressure, physics issue)
I'm using a Bosh high pressure Roller vane pump that is fed by a pierburge roller vane Low pressure pump. The low pressure pump sucks (through a big filter) from the tank outlet on the new fuel sender. The big filter acts as a very effective surge buffer. I use the old outlet as the return from the engine inlet.
You can put the filter and two pumps in the boot if you want.
pg 75 and 76 KP.05288.50.0 as far as I can tell
The bosh one is the same as in the rover
Bosch 0580 254 909 or 0580 254 949
I got mine from petroject in Melbourne. $100 for the peirburg and $150 for the bosh. Your jag pump is probably a bosh.
The petroject (03 9873 7006) At the time their catalogue number was 12001, this might have changed.
I did try a variety of set ups, internal swirl pots etc, all sorts of expensive attempts. I found that this cheap and easy approach of
tank--late sender--big filter--supply pump--HP pump--engine--tank again
has worked quietly, faultlessly and with out any surge supply problems for over 50,000 kms now
The filter is a standard rangerover, or rover one. About the size of a soup can. You can get them in K mar for about $20.
As an alternative,
There is a guy in America making a very nice EFI fuel tank. I'd get one of those if I was local. http://www.mgexperience.net/phorum/read.php?40,747959,747959#msg-747959
All hot wire EFI came with O2 sensors, but you don't need them. I don't have any ('94 EFI) and I get a solid 10km to the litre @110km/hr (melborne to Sydney). It's a 3.9 (or 4.0L) Just plug in a new resistor as Roger suggests. A 446 to 494 ohm resistor. I got mine from Dick smiths for about $2. My resistor was in the loom near the computer. A blue plastic plug with a resister in a bit of shrink wrap.
Or you can fit the O2 sensors, up to you. It might improve millage.
I Don't have a display on my computer, just a plug.
|Hi guys as usual thanks heaps for input.|
Roger thanks for the offer of the hubs, postage will probable knock me out, will try local first.
Jim I will give consideration to the OS2 sensor offer. cheers.
Peter can I have your email for direct contact please. email me at firstname.lastname@example.org.
This thread was discussed between 16/06/2008 and 23/06/2008
This thread is from the archive. The Live MG MGB GT V8 Factory Originals Technical BBS is active now.