flapper relays / diodes

sowen · Post by **sowen** » Mon Oct 08, 2007 8:49 pm

Does anyone have the part number of the diode that fits on the flapper injection loom or a source of one? I've found what looks like the jaguar equivalent of it p/n dac1861 on ebay.

Also, am I likely to have damaged anything by putting a standard relay in its place

Simon

mrcheese · Post by **mrcheese** » Wed Oct 10, 2007 10:55 am

The red one?

I looked up the Rover part number and found the same as you have. It was on the Rimmer Bothers web site.

Why do you think it needs replacing or was it just missing?

Not sure about if you have caused any damage by fitting a relay. It is possible though.

Paul.

sowen · Post by **sowen** » Wed Oct 10, 2007 7:13 pm

Yeah the red one. It was missing, and having the same spade layout as normal relays, I put a relay in there, and nothing happed

I've got one on order now for about £30

so will see if it works on Saturday.

Simon

sowen · Post by **sowen** » Sat Oct 13, 2007 1:06 pm

I've now got the red diode thingy, fitted it, turned the ignition on and only the main relay clicked. Theres no sign of life yet in it, even with the fuel pumps running directly off the battery so it looks like I've possibly fried the ecu.

Doh!

Simon

Post by **Coops** » Sat Oct 13, 2007 8:08 pm

have you installed the efi into a different vehicle and had to wire it in?
if so have you got the wiring correct?

sowen · Post by **sowen** » Sun Oct 14, 2007 8:38 am

The efi is going onto my series land rover. I've got the fuel pump working now through the ecu, seems to start kicking in when the engine spins fast enough now. The wiring all seems to be correct.

As far as I can tell after playing with the multimeter on it last night is the only fault I've got are the injectors not firing. I haven't got a fuel pressure guage but it does pump lots of fuel at pressure out of the cold start feed.

I will have another go fault finding this morning, but I'm gonna try and get a new ecu for it.

Simon

ramon alban · Post by **ramon alban** » Sun Oct 14, 2007 8:49 am

sowen wrote:The efi is going onto my series land rover. I've got the fuel pump working now through the ecu, seems to start kicking in when the engine spins fast enough now. The wiring all seems to be correct.

As far as I can tell after playing with the multimeter on it last night is the only fault I've got are the injectors not firing. I haven't got a fuel pressure guage but it does pump lots of fuel at pressure out of the cold start feed.

I will have another go fault finding this morning, but I'm gonna try and get a new ecu for it.

Simon

Simon, it may help you to review all the component descriptions and test procedures contained here

http://www.vintagemodelairplane.com/pag ... nts01.html

sowen · Post by **sowen** » Sun Oct 14, 2007 9:09 am

Thanks Ramon, thats what I have planned for today. Just a thought, the setup I am running uses a jag 4.2 airflow meter and a points type dizzy converted to lumenition, could these be my stumbling blocks?

Simon

ramon alban · Post by **ramon alban** » Sun Oct 14, 2007 10:36 am

sowen wrote:Thanks Ramon, thats what I have planned for today. Just a thought, the setup I am running uses a jag 4.2 airflow meter and a points type dizzy converted to lumenition, could these be my stumbling blocks?

Simon, OK! I'm not familiar with the characteristics of either and I dont know what your engine capacity is or what ECU you have.

So, out of left field I would hazard the following:

1 If your AFM was designed to run a 4.2 jag then its fuelling signals may not be matched to your ECU.

EG: the AFM output signals tell the ECU the volume of air and its density, so if you had a 3.5 sucking a certain amount of air and a 4.2 AFM responding accordingly, its entirely possible that the signals would be indicating a Weak mixture because the flap may not open enough.

On the other hand if the 4.2 AFM tunnel is the same size at normal then the flap open signal would possibly produce too much fuelling and then it could be too rich. Either way its a cock-up.

2 If your ignition setup does not emulate exactly the input impedance requ't and type of speed signal required by the ECU to tell it the engine is "running" then the ECU may be misinterpretting the ignition signal it receives.

Futhermore, does your ignition set up have the correct "Inline Resistor" (6.8Kohm) requirer as protection for pin 1 of the ECU.

Both AFM and the Inline resistor are covered in the link i mentioned but please bear in mind that the stuff on my website is dedicated to the standard 3.5 efi setup.

sowen · Post by **sowen** » Sun Oct 14, 2007 5:46 pm

Well I've been checking it over today, and all the injectors, resistor pack and wiring loom appear to be fine. I have the inline resistor already fitted to the negative on the coil. The lumenition kit should provide a similar signal to other electronic dizzy's as fitted to the efi engines. I maybe wrong but I can't see that being a problem by creating the wrong signal for the ecu. Maybe theres someone else on this forum thats using a lumenition kit on the efi that could confirm this?

With regards to the airflow meter, if it was either under or over fuelling the engine, there would be a smell of petrol out the exhaust, which I am definitely lacking. When the cold start injector is working, there is a slight whiff of petrol in the tailpipe, but not much. I have a good spark, so the only fault I can see is the ecu's dead.

Looks like I'm doing to dig in my pockets again to get it going, or put the old carbs back on.

mrcheese · Post by **mrcheese** » Mon Oct 15, 2007 1:23 pm

I think the EFI system needs to see a signal before it starts the fuel pump. On the 3.5 with the flapper AFM it gets it from the AFM. As the engine cranks on the starter the flap apens a little and this is the trigger.

Don't know anything about Jabs, but why would they use the same as a Rover engine? I would start by getting the correct AFM. If you can find someone near you it only takes minutes to swap the ECU and AFM over.

Paul.

sowen · Post by **sowen** » Mon Oct 15, 2007 5:34 pm

The jags used a similar lucas system to the rover, I think the main difference being the number of cylinders it caters for. The jag afm is supposed to be a direct swap for the rover unit, only differing in size, and yes it does trigger the fuel pump. I think I was getting confused with the later hotwire system which I believe run the fuel pump for a few seconds when the ignition is turned on to prime the system before starting.

I will see what I can trawl off ebay and try replacing the afm and ecu.

mrcheese · Post by **mrcheese** » Mon Oct 15, 2007 6:20 pm

Just a thought. There is supposed to be a restrictor in the fuel return line. This keeps pressure to the fuel rail at about 2 bar. Without it there will not be enough pressure to force fuel through the injectors.

It looks a bit like a vacuum advance unit on a dizzy. On mine it is fitted behind the left hand head (when viewed from the front).

Sorry if I am stating the obvious.

Didn't know that about the Jag AFMs

If I don't reply in the next few days I am not ignoring you. Going camping minus the laptop

))

Paul.

sowen · Post by **sowen** » Mon Oct 15, 2007 6:43 pm

Fuel pressure regulator? Yeah thats fitted. I bought the whole range rover efi system without ecu, airflow meter and relays, and me being stupid I plugged a relay in the diode/steering module spot on the loom. Tracing the wiring diagram I think I must have put battery voltage up the blue/purple wire into pin 20 on the ecu, and any other terminals attached to the red plug.

I can usually figure things out myself but this is the first time that I've touched efi, and I reckon I've been clumsy enough to break something delicate, only ever worked on carbs before where big screwdrivers and spanners fix things.

Well, when it runs

I should have some decent knowledge on efi.

Simon

sowen · Post by **sowen** » Sun Oct 21, 2007 6:54 pm

Today I replaced the two lucas relays with bosch relays from a spare loom, replaced the ecu and charged the battery, and had another go at starting it. The engine was coughing every few revolutions, so I measured the voltage on either side of the inline resistor to the ecu, 0.5v on the ecu side, and 7v on the coil negative side. So out with the resistor and hey presto, a running engine

Took about 10 minutes for all 8 cylinders to run acceptably smoothely with the jag 4.2 afm and lumenition set-up still in place. I just need to tidy up the installation a little and then roadtest

There appears to be a fault with the original ecu as the engine will hardly run with it fitted, but I've got another 4 spare ecu's aswell now, and they also don't want to run well either

. After replacing the brand spanking new lucas relays with old bosch relays the engine was showing signs of life? So I guess I just had a bad combination of parts and no spares to begin with.

Simon