The d-jet pumps have 3 lines attached to the pump itself so that would have to be adressed. From what I understood, the cis pumps were very high pressure and rely heavily on the accumulator to limit the flow to the injectors.

I'm looking at some fine tunable regulators such as this one http://www.xenocron.com/aeromotive-a100 ... p-306.html

I have an extremely high pressure pump that came with the MSS motor. It has a 1/2" connection on it that looks like its for a truck. I want to be careful of the d-jet injectors as they are very expensive.

I have rebuilt a good number of electric motors in the past and I'm also going to try a rebuild.

It's actually not that big a deal. The 3 lines are pressure to the rail, return from the rail, and a bypass from inside th pump. Both my D-jet pumps have bad motors, which could probably be repaired, but honestly there are cheap reliable electric pumps from Summit or Jegs or wherever for $60-$70. The white car has a Russell pump or something left over from an FSAE car. As long as the pump can supply a reliable 55-60 psi under load it'll work.

D-jet regulator at the rail is like 45 psi, and CIS needs closer to 55 to be happy. Pressure isn't actually all that high.

I realized my other manual has extra stuff in it, including the d-jet document. It looks like the fuel pressure is actually around 28-30psi. Combing over the d-jet docs, it says:

On 2.0 I engine, the throttle valve switch has another function (N). Its task is to give the engine a somewhat richer fuel/air mixture at full throttle. This gives the engine an improved inner cooling at extended periods high speed driving.

However, looking at the following document, it looks like this feature may not have been available on cars destined for the US.


In any case, CIS pressure is way too high and could damage the injectors.

Those numbers are all for the triumph engines...is that what you are running? could be that the compression ratio is lower in the triumph engine and needing less fuel pressure. The B motors might need more fuel pressure.

The d-jet document refers specifically to this table. Perhaps my manual is older, and someone added in the d-jet section? Does anybody have a newer one with all of the variants. I noticed the lack of the 2 liter spec as well.

Sam wrote:I realized my other manual has extra stuff in it, including the d-jet document. It looks like the fuel pressure is actually around 28-30psi. Combing over the d-jet docs, it says:

On 2.0 I engine, the throttle valve switch has another function (N). Its task is to give the engine a somewhat richer fuel/air mixture at full throttle. This gives the engine an improved inner cooling at extended periods high speed driving.

However, looking at the following document, it looks like this feature may not have been available on cars destined for the US.


In any case, CIS pressure is way too high and could damage the injectors.

But the pressure is controlled by the fuel pressure regulator, not the pump... I'm sure it is possible to overpower a regulators return flow with a huge pump, but I've used CIS pumps many times to run LH jetronic cars and they work just fine and pressure is not changed.
The rally car runs two pumps and pressure can still be regulated at 3.0 bar with no issues.

Great, I would consider replacing the regular with an aftermarket one all the same. What is the target pressure with the regulator inline?

Sam wrote:Great, I would consider replacing the regular with an aftermarket one all the same. What is the target pressure with the regulator inline?

you could get an adjustable regulator too. I do not have a pressure number to throw at you but I can look in my pile of 99 factory manuals...maybe its listed in one.

Normal is either 2.5 or 3.0 bar on c900
The d jet regulator is actually adjustable stock.

Luke wrote:Normal is either 2.5 or 3.0 bar on c900
The d jet regulator is actually adjustable stock.

Yup. That's what the bolt with the jam nut on the regulator is for. A CIS pump should work fine.

28psi is the pressure you want. If you set it higher than that, you'll foul out plugs and the car will not run very well on less than four cylinders.

You most likely won't find a new OEM pump. I'd bet I have one of the last new ones in the country.



PaulH has already accomplished the CIS pump in a d-jet 99, and I believe he has no issue with the way his car runs.



This is where you put the gauge to check your pressure, and yes, your regulator is adjustable as Drew and Luke already mentioned.

This seems to be identical to a C900 pump. Are these also compatible?

Looks like they are not the same but just look very similar.

The later C900 pumps don't have an inlet that will take a hose, they have a large exposed boss that sits in the bottom of the pump bucket. Any universal or OEM pump that has a barb that will take the hose coming out of the tank will work though, like that CIS pump.

The ones like this also don't take a banjo fitting, you just press the nylon fuel lines down onto the barbs on the outlet.

I'd recommend a walbro gsl392 , they are threaded on both ends to take whatever adapters you require and under $100 brand new. They are very reliable and what most of the rally teams use.