MR2 Owners Club • Constant Ticking before trying to fire engine
Page 1 of 2

Constant Ticking before trying to fire engine

Posted: 29/05/21 22:40
by GraemeC
Hi,

my son and I picked up a 1990 G-Limited Mk2 a while back. Was an old barn find that hasnt run for over a decade. First thing we noted was the fuel pump was dead, so removed the tank and replaced it. New one works fine. We also took the inlet gubbins and fuel rail off to clean the injectors. We finally got it all back together today and when putting the key to the ON position, before trying to fire the engine, there is a loud and constant rapid ticking noise coming from what seems to be the fuel rail/injectors (although I cant be sure of this) - if I remove the plugs there is a spark and a smell of fuel, so presumably fuel is getting to the rail/injectors but when you do try and fire up the engine it just turns over with no real inclination to fire.

I thought it could be a problem with one of the ground wires not re-attached properly but have checked all of them and they all appear OK.

Any thoughts ore help would be much appreciated.

Cheers
Graeme.

Re: Constant Ticking before trying to fire engine

Posted: 07/06/21 11:46
by GraemeC
Update to this - turns out its nothing to do with the fuel rail or injectors! Stripped back the inlet manifold and the constant ticking is coming from the ACIS vacuum tank bolted to the inlet manifold. Presumably I reconnected the vacuum pipes incorrectly or there is a blockage somewhere. If any has a diagram of the vacuum pipe order that would be fantastic.

However I did crack open the fuel pipe to the fuel rail to check on fuel - and nothing. The fuel pump is working (connected FP and B+) but is just blowing out air - no fuel. WHen I put the fuel tank back in I added a gallon of fuel - surely thats enough for the fuel pump to sitting in fuel and therefore pumping fuel to the fuel rail isnt it? Or am I being really stupid and I need to add a lot more fuel?

Re: Constant Ticking before trying to fire engine

Posted: 07/06/21 15:50
by jimi
This any use for the ACIS? https://www.mr2oc.co.uk/know-your2/mk2/ ... ystem.html
If you tank was emptied I think I'd be adding more fuel first ;)

Re: Constant Ticking before trying to fire engine

Posted: 08/06/21 10:11
by GraemeC
Thanks for the ACIS stuff - v helpful! I'll try more petrol tomorrow and see where we go!

Re: Constant Ticking before trying to fire engine

Posted: 15/06/21 12:03
by GraemeC
Thanks for the help so far. Here is a bit of an update. I've discovered the ticking noise isnt the fuel rail or injectors - its one of the solenoids attached to the vacuum tank bracket (green electrical connector) and the orange engine light on the dashboard ticks at the same time!

I've tested all the injectors for resistance - all fine. I've checked the wiring harness to the injectors and all getting 12 volts. I've also changed all the spark plugs but still absolutely NO SIGN of the car wanting to fire. It just cranks over.

I'm going to do a compression test later.

When I removed one of the new spark plugs there was pretty much no smell of petrol (even though I know fuel is being pumped to the fuel rail) - so could it be that the ECU isnt sending a signal to actually open the injectors and therefore they arent spraying fuel into the engine? Is there a way I can test that the injectors are getting the signal to open?? I know they're getting power but that doesnt necessarily mean that they're operating correctly. So how can I test that?

And what on earth is that ticking solenoid and warning light on the dash about!?

Re: Constant Ticking before trying to fire engine

Posted: 15/06/21 14:46
by Deleted
Did you check the timing belt?As you've mentioned that the car never ran for a long time and it's barn find.

Re: Constant Ticking before trying to fire engine

Posted: 16/06/21 14:49
by GraemeC
I've not checked it yet - to be honest the view down the side of the block looks a little restricted so was building up to it! Is it possible to remove the upper timing belt cover and check the timing markings without removing the engine?

Re: Constant Ticking before trying to fire engine

Posted: 17/06/21 12:11
by Deleted
GraemeC wrote: 16/06/21 14:49 I've not checked it yet - to be honest the view down the side of the block looks a little restricted so was building up to it! Is it possible to remove the upper timing belt cover and check the timing markings without removing the engine?

You can replace or check T.belt without removing the engine. Also did you try to spay easy star in the intake to see if the car starts? It would tell you if you have a fueling issue or something else.

p.s Is the aftermarket alarm has been fitted to the car?

Re: Constant Ticking before trying to fire engine

Posted: 17/06/21 20:15
by GraemeC
OK - so just tried easy start into the intake and car fires up - so obvs no fuel getting through the injectors. Yes - it does have an aftermarket alarm - its a pain in the butt as keeps immobilising. Do you think it might be something to do with the alarm system thats preventing the injectors operating??

Re: Constant Ticking before trying to fire engine

Posted: 17/06/21 20:41
by MRHAPPY62
Could be as some alarms cut feed to the fuel pump

Re: Constant Ticking before trying to fire engine

Posted: 17/06/21 20:43
by Deleted
GraemeC wrote: 17/06/21 20:15 OK - so just tried easy start into the intake and car fires up - so obvs no fuel getting through the injectors. Yes - it does have an aftermarket alarm - its a pain in the butt as keeps immobilising. Do you think it might be something to do with the alarm system thats preventing the injectors operating??
Yes it's highly likely. Check if the wires go to engine bay fuse box underneath. I would remove alarm completely and wiring everything back to original. Thanks

Re: Constant Ticking before trying to fire engine

Posted: 20/06/21 13:12
by GraemeC
Really quick update. I've not fully removed the Cobra alarm system, but I did try starting the car with the fuel pump bypass in place (FP - B+ ?) - pump definitely working and still no firing of the engine. Could there be a immobiliser type circuit on the alarm system preventing the injectors firing??

Re: Constant Ticking before trying to fire engine

Posted: 20/06/21 22:00
by Deleted
GraemeC wrote: 07/06/21 11:46 However I did crack open the fuel pipe to the fuel rail to check on fuel - and nothing. The fuel pump is working (connected FP and B+) but is just blowing out air - no fuel.
There should be 40psi of fuel pressure in the rail. Also have you changed fuel filter? Or removed the banjo bolt from the bottom of fuel filter and see if you got any fuel pressure.

Re: Constant Ticking before trying to fire engine

Posted: 21/06/21 10:42
by GraemeC
Thanks - yeah that lack of fuel was just me being stupid! I hadnt filled the tank enough for the pump to pump any fuel! It is now and there is pressure and fuel to the rail (brand new filter fitted too) - so at the moment I have fuel pressure, I have 12v to the injectors, the injectors have resistance, and the car fires using easy start direct to the intake - but wont even think of firing trying a normal start....