1994 XJ Fuel rail

Hi all:
I’m planning on converting my 73 e-type to fuel injection. Will the fuel rail and injectors from a XJ 1994 work with the intake manifold of a 1987 XJS?
Thanks in advance,

Pepe

Dunno, but I do wonder about the question. If you’re getting the rail and injectors from the '94, why aren’t you getting the intake manifolds as well? Those would certainly work.

Thanks Kirbert. I already had the intake manifolds.

Pepe

You already had the '87 manifolds but not the rail and injectors? Do you have an ECU and sensors from either car?

Hi,

Injector flow rate is different for pre-HE and HE

Jonas

Thank you Jonas. Megasquirt can be program acordinly.

Pepe

HE injectors have lower flow rate then the ones for flat heads. I had the numbers somewhere, but can’t find it now… I’m not sure if you will have enough window gap to compensate that…
If I’ll find this info about injectors, I’ll post it here
Jonas

Not sure exactly when the change to O ring injector/fuel rail happened but l thought it was around 1994. If so the earlier manifolds may not suit the later rail.

Jaguar Injector flow data here …

Jaguar Injector Flow Data.pdf (85.3 KB)

1 Like

If someone wanted to do a bit of work and figure out which version of engine used which, I can add it to the table. (I have reproduced the source for my own documentation.)

Mark, et al,

The Stan Weiss tables have been around for years and the data accumulated from multiple sources. Unfortunately much of it is incorrect. One specific example from the Weiss table. Injector 0280150163 and 164. Same exact injector as 0280150161 and 162…not shown. Different part numbers only because they have different hose lengths attached. Used on the HE V12 from about 1983 until around 1992, when hoses on the injectors were eliminated and o-rings were substituted.

Actual flows based on my 14 years of flow testing. All four at 212 cc/minute at 3 Bar pressure, 100% duly cycle. The Weiss table shows 180.8 cc at 3 Bar. That engine during the same years referenced used a 2.5 Bar FPR, so 100% duty cycle at that pressure would be 190cc/minute.

There are multiple other flow errors in the chart, so I would caution any member to use it with caution.

And another point for those interested. For many injectors, the mfg will use 3 Bar pressure @ 100% duty cycle as a baseline reference when specing injector flows. This allows engine designers a baseline flow to then select an injector to use in a specific engine, where actual fuel pressure will likely be different, They will also determine their own max duty cycle, injector open times, and how many times per engine cycle the injector will fire.

SD Faircloth
www.jaguarfuelinjectorservice.com

1 Like

One more chart related to fuel injectors:

Makes you wonder whether those who implemented semi-sequential MSquirt fuelling achieved smoother idle results ?

There are some some cylinders there getting healthy “upstream” pulses, while others are getting horribly timed pulses during their port’s valve overlap. Must make a difference to what each cylinder is seeing.

Actually it was quite normal on early injection systems to group injectors and fire them simultaneously… although it is not perfect solution, but worked quite well. I’m guessing this was done due cost and limitations of electronics of that time.