Hello - I have a 1992 5.3 XJS and need to replace the fuel pressure regulator. The part number is EBC 3387 and I can’t seem to find a new one for sale (The 1992 5.3 has a single fuel pressure regulator directly on the fuel rail). Are there viable alternatives? Can I purchase an adjustable regulator instead? Any recommendations from the group? Thank you!
I found mine easily (but for an 88) by searching for the Bosch part number instead. I assume yours is also a Bosch part too? Do you see a long number on the old one?
I installed a adjustable DeatschWerks 6-1000-FRB Fuel Pressure Reg.( $143 on Amazon, try ebay also) on my 91 XJ-S 5.3. It also has 1/4" plug for a gauge & vacuum port. I used Earls AN fittings and -6 ss braided fuel hose although I suppose you could use any type fittings & FI rating hose. I adjusted the fuel pressure to 40 psi
Why did you do that? Isn’t it supposed to run 2.5 bar?
I run at 40psi because @ 35, when the engine is hot around 210F and shut down for a short time (20 mins.) it stalls very easy. probably hot gas in the fuel rail, vapor lock etc. This car is a manual 5sp with a aluminum flywheel.
Long story short, I first adjusted it to 35 then gradually to 40. Runs, idles good and no more hot restarts/stalls
This doesn’t sound right. The V12s with the 26CU and 36CU had different hot start system that took care of the vapor lock issue.
Shamelessly lifted from Roger Bywater’s page:
" System changes.
The inlet manifolds were altered in a number of ways the most obvious being the prominent badges reading “Jaguar V12” set into the top surface in place of the previous ridged arrangement. The fuel rail and injectors were brought up to date using a single mini type fuel pressure regulator (still 2.5 bar - vacuum off) with smaller, faster acting, injectors located by O rings and sockets instead hoses as previously. These differences meant the manifolds could not be easily interchanged with the earlier type although the tracts themselves remained just the same.
In a hot start a 70C fuel temperature switch activates a 45 second timer which limits the provision of raised fuel pressure via a solenoid valve in the regulator vacuum line. A vacuum delay valve allows the pressure to decay gradually during the timer period. This all permitted the fuel cooler to be dispensed with.
Air injection was improved in detail and active for 45 seconds in any start-up, hot or cold.
As noted, over-run valves were not fitted because cut-off remains in operation at all temperatures as noted above."
If the injector pulse is calculated based on the expectation that the fuel delivery occurs at 2.5 bar and you’re running at 2.75, the mixture will always be rich(er)
on two occasions
within one tank of gas,
has acted like it’s vapor locking.
and on a seperate
it shut down altogether…
I don’t remember any hot “restart” problems before changing to manual. I know from my experience with other cars aluminum/lightened flywheel’s are more prone to cause stalling, I believe this causes my “hot engine (210F)”, easy stalling for the first 2 or 3 mins. Increasing the fuel pressure to 40psi via the adjustable regulator, worked for me. After two years, so far no spark plug filing or signs of excessive richness on the plugs or exhaust tips through mostly city driving (below 45mph), gas MPG also the same, depending on my foot…
For the record, many of the sensors were tested & tried. Also AJ6 reworked the ECU for the fuel “override” for the transmission change over.