Engine starts but cuts out-fuelling problem help please!!
Turbo Mini Forums

I'm having trouble getting my new engine started and i'm a bit stumpped to be honest!!

The fuel pressure is set at 4psi

The jet is a smidge lower than the "level" height.

The megajolt is connected with a 1293 turbo map

I have new plugs and leads and a spark on each

Connected correctly, corresponding cyl. to at the coil pack.

The sensor is mounted 90deg BTDC, about 1mm from trigger wheel

The engine is earthed properly to the body

Turns over really fast on the starter with the plugs in.

I get 60psi oil pressure on cranking.

Fuel is fresh and theres plent of it


I can't think why its not starting, this is my first build and i'm not really sure what to look for. As I say it turns over really well, but doesnt seem to have a hint of it actually trying to start it just turns and turns.

I have some LED things which connect between the HT lead and the plug and they flash when I crank the engine over.

Fuel is definately getting into the cylinders as the plugs have been getting wet to the point where i've had to crank it with the plugs out to clear the petrol out the clyinders.

I've mentioned in another thread that when testing my fuel pump originally, I realised that the plenum was filling up with fuel. I thought this was me overfilling the carb as I left the pump on too long (its on a switch, not a relay off the oil switch etc).

I've been told that the plenum filling with fuel could be to due to a split diagphram (which i've checked, its fine), or a wedged open needle valve in the carb. I've not had the carb off yet to check this as I thought seeing as the plugs are getting wet I thought it would at least sound like it was going to fire?

Any help would be great, sorry for all the questions recently but as I say, my first/new build and my first time starting (or attempting to!!).

Ta

Edited by richminiturbo. on 13th May, 2009.

if its turning over really fast, have you checked the tappet clearances? you may have the valves open all the time?

I've done the valve clearances and theyre all ok.

Just held the plug against the engine and cranked over, it did spark a few times but I'm unsure if I could call it a "strong" spark or not?

Will go and double check my earths.

I know sweet FA about megajolt, but it sounds as if yours is not behaving as it should either in spark intensity and/or timing.The experts on here will soon put you right.

Lets have a pic of your crank sensor arrangement.

check the compression too just to be absolutly sure youre getting all 4 ingredients

Edited by Monkeh on 9th May, 2009.

check you have the wires connected right on the vr.
see if it fires without the mj, the engine will still run on the coilpack, check and re-check the firing order1-3-4-2

Thanks for the replys fellas.

Just spent some more time looking at it, now for some reason the little LED things arent lighting up when I crank the engine over? Somethings not right..

Checked all the earths, which are all solid and clean.

The leads are in the correct order, 1-4 from the timing end plugged into the corresponding numbers on the coil pack.

Cant find the adapter for my hi-gauge but when i do i'll post the compression figures up.

Here is a pic of my VR sensor setup (which by the way im 95% sure I wired the correct way round).



The missing tooth is inline with the keyway on the crank pulley, in the pic cylinder one is at TDC, looking at it the angle of the sensor isnt too clever, what do you think?

Cheers guys keep it coming, i feel so close!

Edited by richminiturbo. on 9th May, 2009.

It's very easy to wire up the coil so that the firing order is wrong.

Just test by swapping HT leads around, 1 with 2 and 3 with 4.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

No luck after changing the leads round.

However I wont rule that out as those LED testers arent flickering anymore!!

From what you said above, it sounds like you have wired the +12v power incorrectly. Both jolt and EDIS require power while cranking, and if the LED goes out on jolt when your cranking, this is your problem.

You can either use the wire which use to supply the coil with +12v, or take a feed from the fuse box (i cant remember specifically which fuse off hand sorry)

I did only very quickly skim your posts so sorry if this is not helpfull.

Edited by Carl S on 9th May, 2009.

Ahhh thanks soapsud.

I just checked and the LED on the megajolt does go out whenI crank the engine!

When wiring my megajolt/edis setup, I linked the coil +12v and EDIS +12v together and ran them off the feed from the fusebox, second fuse down which supplys +12v independantly of the ignition.

I then ran my +12v for the Megajolt off the 3rd fuse down, "operating from ignition position one or two".

I remember reading now that the coil+edis aswell as the megajolt should be run off the same +12v circuit, so I will fix that, running both coil+edis+megajolt off the switchable 12v feed.

But this doesnt explain why the car doesnt fire with the megajolt disconnected?

I'm confused as to why my HT lead/spark plug testers where working earlier but arent now?

I havnt buggered something like the coil or edis by wiring the 12v wrong like that have I?

Appreciate your help guys!

i doubt you have buggered the coil pack, sounds like you need to check the wiring again. Do you have in line fuses, these should be 5v

No fuses in the megajolt/edis system no.

No idea what the problem is, i'll run the lives off the same circuit and see what happens.

Dont think it will make a difference as to why it isnt sparking, as it wont spark with just the edis gubbins connected?

If you are not getting a spark then it could be the VR sensor wired back to front.

yes as miniboo says, a common cause of no spark from EDIS is the VR sensor being wired the wrong way round, switching the wires should fix this.

Ok, will have a go!

But as I say my plug/lead testers where recording sparks earlier on today so god knows.

Will report back tomorrow!!

Thanks for the inpu guys, appreciate it!

Edited by richminiturbo. on 10th May, 2009.

Could be something simple as loose/crossed wires chap. You'l have it going in no time!

No worries, here to help!

I've just switched round my feeds to everything so theyre running off the same feed.

The green light on the jolt doesnt go out now upon cranking, got a 10a inline fuse in the jolt 12v is that ok?

So I checked my vr sensor wiring, and I have continuity between the blue/yellow at the vr sensor and blue/yellow at the edis, as well as blue/green at vr and blue/green at edis so my wiring is correct.

Ok so now i know my wiring is correct, it can be the coil, vr sensor or the edis unit itself right?

How can I test these to make sure theyre working/not working.

Should I get continuity between the the two pins on the sensor plug?

Keep it coming guys!!

Edited by richminiturbo. on 10th May, 2009.

Set your multimeter to read a nice low Voltage mate and check to see if you get a signal on the pip/saw wires like said above.

That will show you that the VR sensor is reading the missing tooth and sending a signal as it should.

i'll just go and find out what resistance you should have over the coils but when you test it you should see resistance between 1-4 and 2-3 IIRC.

again, at the coil pack, check you have voltage there

Ok, i'm getting a 12v at the coil.

What i'm not getting, is a cranking speed on the megajolt software when I crank the engine over.

I've just put a multimeter on pip and saw on setting "20".

Before cranking PIP was getting 12v, under cranking fluctuating down to 9,5,0 then back up to 12.

SAW I was getting 0 the whole time both on and off cranking.

I just tested continuity across 1+4 , 2+3 on the coilpack and didnt get anything.

Should I?

across the ht terminals?

is so no the reading shoud be about 20k ohm IIRC