No fuel in combustion chambers.....
Turbo Mini Forums

I'm growing impatient with the MPI now.

Got over to Dastek on the back of a recovery vehicle, and decided to let them have a look at it and see if a fresh pair of eyes could figure something out.

Here's why they said:

"car non starter. Established ECU comms, compression test: Cly4 =9 bar, Cly3=8 bar, Cly2=8.75 bar, Cly1=8.25 bar. Check spark, all 4 cylinders getting good spark. Check fuel pressure, Check injector voltage. Remove ECU, continuity test injectors to ECU, Scope crank and injector outputs. Remove intake manifold, check injector mist - very poor, require ultrasonic clean. Suggest possible supercharger problem - no fuel getting to spark plugs"

As they are suggesting possible 'charger problems, does anyone have a diagram?

I'm not sure what generation M45 I've got, but from looking at Magnuson Products web site, I found this image of a 4th gen showing a bypass valve - the chap at Dastek thinks this bypass is causing all the problems. Clicky for piccy I don't have a butterfly in the inlet, and it doesn't look like it's been filled - so no surprises in stating it's not the 4th gen M45.

Can anyone advise if there are any other bypasses on earlier M45s?

Do you think the pish-poor injector misting could be the route cause of the issues?

Was concidering buying another charger, but there's no many going about just now.

Any help, words of encouragement, slaps around the face etc are most welcome.

Oh, really need to get things sorted before 21 September when Uni starts or it's a 2 hour bus ride...... :(

"se ne estas rompita, ne ripar ĝi - supercharge ĝi."

If your running an mpi, doesn't that mean that the charger is before the injectors on the air route?? if so then it'll have nothing to do with fuel Getting into the chamber...

The MPI is a suck through system - got the injectors mounted before the 'charger.

Further research is making me think there isn't a bypass so it must be down to the shity spray from the injectors.

I noticed when searching here, Stuart Gurr apparently made some modifications to the M45's - anyone got any ideas what they were?

"se ne estas rompita, ne ripar ĝi - supercharge ĝi."

There is no bypass on the m45. The mods that Stuart does is 1.He reshapes the output side of the charger to allow the air to flow right over to the edge of the output (if that makes sense?) Basically it is because the charger is so far off centre to the inlet manifold it is wasnt opened up it would leave a very small gap. The other thing he does is blank off the small pipe that I believe is for the servo on the bini's. i have a pair of these that I bought from Coupe on here a couple of months back. If they are any help I will happily stick em in the post for you to try?
(Last up is a pair of 650cc Siemens Deka low impedance top feed injectors
Again approx 1000 miles use - these were bought from 5-0 Motorsport in the US. )

Whilst I'm no expert on a supercharger (having gone down the turbo/fuel injection route) the statement
"Remove intake manifold, check injector mist - very poor, require ultrasonic clean. Suggest possible supercharger problem - no fuel getting to spark plugs"
would worry me.....

The injector(s) should give a healthy squirt when cranking, not just a mist.

This has nothing to do with the supercharger (as they suggest) as the supercharger will have little effect on the MAP at cranking speed but sounds like an ECU error or really bad injectors.

When they said they put a scope on the injector(s) did they say what the pulse width recorded was ???

What ECU are you using ???

Schrödinger's cat - so which one am I ???

Am I right in thinking you had problems in the past with your Lucas 5as? If so did you ever get these properly sorted? It is maybe a problem with that and you are only getting the fuel pump to prime on the intial key on and not pump on crank/run this would give you a short burst of fuel as the pressure relieves through the injectors...Just a thought!

Rod S I am sure it is an Emerald setup from Vmax

Edited by lockfast on 31st Aug, 2010.

Mark - that would be most helpful - let me know how much to cover and I'll sort you out. And thanks for confirming the no bypass and other mods. Yeah, had problems with the 5as, but that's all good now.

Rod S - As Mark sayz - I'm using the Emerald ECU - which has been checked for faults and is in working order, I'm not sure about the PWM - I've fired an email off to find out. As for the injector spray pattern, they should always spray atomised fuel, regardless of being under cranking conditions or normal running - and it was kinda globues of fuel - there is no harm in getting them cleaned. I'm more worried about the charger being fucked.

"se ne estas rompita, ne ripar ĝi - supercharge ĝi."

Pop me a PM with your address and I will get them in the post to you

I personaly dont think it is a supercharger issue. I think if the supercharger had seen its day you would be geting some funny mechanical noises or the car would run but you just wouldnt make much in the way of boost

Edited by lockfast on 1st Sep, 2010.

Schrödinger's cat - so which one am I ???

how well atomised also depends on the fuel pressure ..

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Mark - PM sent. Thanx fella.

Rod - gotcha. Yeah, I've had the system apart many times - dirt ingress could be part of the problem. I'll see what they say about startup enrichment.

Robert - The fuel pressure is set to 3 bar, so that should be fine.

When I was watching the injectors firing - they definately weren't atomising the fuel.

"se ne estas rompita, ne ripar ĝi - supercharge ĝi."

Like others have said, it all depends what you mean by atomising

these were perfectly ok to start and run the car since http://www.youtube.com/user/16vKVan#p/u/27/oTGenScQ8uc

Edited by Rod S on 1st Sep, 2010.

Schrödinger's cat - so which one am I ???

Yeah, the injectors were nothing like any of the videos - it was more like a spit than a spray.

"se ne estas rompita, ne ripar ĝi - supercharge ĝi."

Sounds like a good ultrasonic clean is in order first (as they suggested).

If you use a reputable company they will replace the internal filters as a matter of course (they won't bother to try to clean them) as well as the ultrasonic clean, then they will flush at high pressure and then test the injector to confirm it is producing the correct spray pattern and flowrate.

Or beg/buy/borrow some known good ones to try out.

Schrödinger's cat - so which one am I ???

Good ones to try are parcelled up and ready to go! Should be at the post office within an hour. Let me know when you get them and if they sort out your problem

Nice one Mark.

Will let you know how it goes.

"se ne estas rompita, ne ripar ĝi - supercharge ĝi."

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

The MPI injectors do not atomise fuel esp at low duty when cranking etc. From first hand experience with the DON as we use these inj. They give out a distinct "line squirt" of fuel, can't think of any better way of describing it.

I use the same generation Lucas injector as The DON, The MPi Mini, Jimster, Matty, Andre to name a few, and they certainly have a more distinct squirt, rather than mist. granted all the above are injecting direct into the port, but other charger conversions work with these injectors.

One question, have you had this started and running? and if so, it has to be something more obvious and simple?

Edited by Sprocket on 1st Sep, 2010.

Thanx for that Tom - a line squirt seems to be a good description of what I was seeing - but it was still kinda spitty (if that makes sense).

Sprocket - yeah, the MPI was running (no fine as still needed a mapping session), but running - I managed to blow the pipe of the take-off for the boost gauge that's when the problem first started.

Before taking it to Dastek, I had a look over myself and discovered that the IACV was fucked, so replaced that then she started up, took her for a test run, got about 100 yards from the hoose there was a miss-fire, a stall and non-starting commenced.

"se ne estas rompita, ne ripar ĝi - supercharge ĝi."

Sounds like you might have a really big air leak somewhere to me?

Are those injectors in yet? did they solve it?

I'm heading up tomorrow.

I'll see what's what then.

Thanx for sending them - really appreciate it.

"se ne estas rompita, ne ripar ĝi - supercharge ĝi."