Fuel injection help , not Jaguar!

Injectors are from my Mr Turbo ZZR
I have tested them off and on the bike , and sprayed brake cleaner in them ,
On the bike , fuel system hooked up and a 9v battery connected , fuel pump running , the fuel sprays out rapped ,
In the vid is how it would be on the bike , I am no expert and just don’t know if there is enough fuel passing the injectors ,
The problem is bike will run on easy start , then dies , I guess when the easy start runs out , think the pressure is ok , you can feel the fuel hoses going hard , and like said , when a 9v battery is connected there is a continues flow of fuel , in a strong jet mist !

I thought there is a probe type test light you can purchase to determine if the injectors are receiving their ‘pulse’ signal?
im sure I have read this somewhere.

Yes its called a noid light, you insert it between the injector and the plug.

I have tested that side of things , all look’s ok to me , I am just not sure what and how much the injectors should spray out :thinking:

ZZR1100 Mr Turbo - YouTube

Does it die when you release the key? The injectors seem to spray well so let’s assume they work. Either they do or they don’t. Yours spray nicely and don’t leak. So the signal is there and anything after and likely including the computer seems to work.

Maybe your pump or ecu are only powered in ‘crank’. Maybe the pressure is just too low so the hoses stay hard but it dies. Or it’s set too lean electrically which is why it runs with starter fluid. Or it thinks the engine is hot.

What is the history of the injection systems and what inputs act as modifiers on the mixture?

I don’t know how much you know about fuel injection but what goes into the engine is determined by the fuel pressure drop (manifold vacuum/ boost pressure against fuel pressure in the lines) and the time the injector stays open.

Faults for too lean could be the pump, the pressure regulator, the metering device (air flow or mass meter), the air temperature, coolant temperature, and engine speed as well as the lambda feedback and associated trim depending on the ecu you have. And vacuum leaks of course.

If you had it too rich before what happens if you enrich it little by little?

Thank you for the feed back David ,
It’s a 1990 Mr Turbo system and very basic , it has sat in my shed for a good 15 years , When I got it it had sat for over 7 years , bike and the Turbo kit has a bout 16k miles on it
I have replaced the hoses , fuel , oil , and pressure .
Only other thing I have done is replaced the 2 coils for stick coils to each spark plug
I was getting a nice blue spark , on all 4 plugs , with engine turning , 2 plugs spark at a time , the engine has to be turning fast to get a spark !
All I was getting was back fires in the exhuast , even when spraying the easy start into the inlet .
My dad suggested I change the spark plugs , that made a world of diffrence , engine will run now but only on the easy start , then dies ,
The power supply is live when the ignition is on , I tested that with a bulb , did notice the bulb goes dim a little on cranking the engine !
The timing cant be out , run’s so compression should be ok
There is a fuel regulator after the Bosch car fuel pump , that run’s all the time , with a return too the tank
I have turned the engine over by hand , with a test bulb too the injectors , that lights up with the piston going down , so should be sucking fuel into the bore
There is 5 small pressure pipe , 2 too dump valves , 1 too the boost gauge , 1 too the pressure regulator , and 1 to the ECU ,
I just can’t understand , if engine run’s for a few seconds on easy start , with that fuel being injected into the engine you would think it would at least fire .
I do have a injector service kit on its way , with new filters ,
I did try blocking off the fuel return too the tank , so the fuel rail had more pressure , still the same
The other thing I noticed , the injectors , inject a splash of fuel , when they first get power , and the engine has to be cranking fast before the coils get power , so I thought maybe the plugs are getting too wet to fire , so I put a on and off switch too the power supply to the ECU , then crank the engine , then turn on power to injectors , made no diffrence

Ian I know nothing about bikes at all, but after a google search a couple of guys had starting problems with your bike model and reported a fix from

  • New battery (insufficient voltage when cranking to supply spark)

  • returning the stick coils to original type.

Just for my own knowledge do you have a crankshaft position sensor?

I‘ll think about it. Good luck you‘ll get this running. I looked up the old reviews and this is one mad bike.
The splash of fuel when the machine powers up, I‘ve seen that before. All I can offer for now is that I‘m sure the injectors themselves work just fine and fuel is delivered in a way. The new filters won’t change anything and the pressure should be checked. Any details in the turbo kit? Ignition and voltage per Phil could be more promising.

Phil , I am using a car battery from jump leads , and I do charge it up , but worth checking the volts , I am getting a strong spark on all 4 plugs , of course that is with the plugs out , As the engine will fire with the easy start , they must be sparking when in the head .
I did change back to the original coils , after replacing the HT leads with copper , spark was the same !
There are 2 sensors for the fuel injection , in the left hand engine case !

David , mad bike is right , I did have it on the road , last time I brought it back to life , after laying dormant for over 7 years before I got it
Pull’s Wheelies at over 150 on the clock
see 180 on the clock
Not sure what speed I was doing but the engine cut out on one high speed run , the deceleration was so great my balls hit the fuel tank , fast :scream: :sob:

Turbo is a RayJay FF40 , off a light Aircraft , had that rebuilt by Arrow Aviation

Am a bit lost really , have strong spark , look’s like the injectors are working at least enough to start the engine .

2 things come to mind as I type this out , I said the engine cut out at high speed , when I slowed down it was fine , getting the bike home , I found I had pinched the fuel pipe , and it could not deliver enough fuel , that would suggest to me the pressure too the injector rail would not be so great .
The other thing is the fuel , I have about 11lt in the tank , with a mix of about 10% fuel injection cleaner , wonder if the cleaner has lowered the octane :thinking:

I have a ultrasonic cleaner on its way , so will stick the injectors in there after I have stripped them down ,

Will look at the pressure regulator as well , try and test it , see what pressure I am getting !

If nothing else it has kept my mind busy in this second lock down , thank’s again for your input , it’s good to communicate :+1:


I just tested the regulator , think it’s ok !
Striped the injectors down , filters clear !

It’s got to worth a try with fresh fuel.

That’s what I thought Phil , I did drain all the old fuel out , then added around 11lt off 97 ron fuel and added 100 ml of fuel injection cleaner , not a great deal but must be strong stuff , as they say add 400ml to a tank full of fuel .

I bought an xjs that had stood for a long time, wouldn’t start. I added a large bottle of Aldon octane booster (when you could buy it online) it started straight away!

try some new petrol.

I have done quite a few bike injectors. What is the number on the side of the injector ? Injector made by ? Post it and I may have the flow rates or can look them up. I also need to know what fuel pressure your bike operates at ? And what year ? make ? model ? Is the turbo stuff add-on or OEM ? What HP does the engine develop at full throttle ? That determines what size (flow rate) injectors your engine needs. If the bike starts on starter fluid, all the electrics have to be good. If it starts on starter fluid, and starts but stops when attempting to accelerate, almost sure it is the injectors clogged up. The ultrasonic cleaner can clean them up, but the definitive way to know if they are flowing to spec is have them flow tested on a bench tester. I would find a shop in the UK and send them out for testing. SD Faircloth www.jaguarfuelinjectorservice.com

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No name on injectors , The Turbo is a kit from Mr Turbo , Huston Texas !
The set up is the same now as when I had it on the road , some 15 years back , only diffrence is the stick coils I added , did refit the 2 coil system , made no diffrence .
I have a service kit , come today for the injectors , I pulled the filters out , they are clean !
I think Terry (Mr Turbo) may well have ground the name off the injectors , so you did not know what they come off , have been told they are Bosch , and the supplier of the kit confirmed this , and the parts are the same !

s-l500 (2)

It is a Bosch injector. Red top are generally considered to be 30 # injectors…unless modified (which most shops do not do). 315cc at 3 Bar…60 second static flow. The MrTurbo website appears to be shut down.
Swapping injector filters will usually not do anything for flows…unless the fuel system ( mostly the tank) is rusty/contaminated. The injector tips need to be cleaned to get any flow difference. SD

Since all the injectors spray evenly and can put out a lot of fuel, isn’t a problem with the mixture or ignition more likely? I assume you know better than I and there would still be variations on the flow bench, but it seems to die and not fire at all…
My thinking is that it is unlikely that all clog up at the same rate, still spray well and are not visibly contaminated inside. Since it runs on starter fluid it either won’t ignite well (plugs, bad fuel) or the mixture is way lean. Or the plugs get wet immediately.
There must be a way to roughly calculate the required flow for a given rpm for the engine size. Or a base setting :thinking:

The volume can be checked against the figures, but it will not tell us what the ecu is calculating for pulse length.

Is 3 bar a set operating pressure and his 3.4 bar too high?

Thanks for the feed back gents , like I said , it was running fine , I have not changed any settings .
If it run’s on easy start , then dies , with the injectors working , then I can’t see anything , only the fuel that is the problem , tank is clean , I added new fuel , with the injector cleaner ,
Tank is now empty , and will have just 97 ron fuel in it , not 100% sure yet , but thinking the fuel injector cleaner may have made the fuel weak .

Hope to find out in a few days , when it is back together !

From the short video ,it’s really not possible to tell how much fuel is squirting out. The 50 psi on the gauge for pressure looks about what bikes use…but that’s a way too general statement. The regulator is Bosch and there is a partial number stamped on the side. A research of that Bosch injector number should indicate the pressure range.

And yes, there are formulas available to calculate HP.

I don’t want to overdo what may come off as a sales pitch, but my contention on bikes is…for a four cylinder bike injector…and specifically this Bosch injector, which is very similar to what Jag uses in the HE V12’s, my price to do them would be $20 x 4 = $80 and you’re done with them. If it resolves the problem, it was a cheap fix, and if it doesn’t, you know the injectors are now good, and you move on with some other test. Putting in new filters and the spraying of injectors onto a cloth is pretty much a waste of time and effort. SD