Serious problems! please help me!

Supercharged Nat · Post by **Supercharged Nat** » Mon May 26, 2008 2:03 pm

Ok ive had the megajolt in for almost a year now, and its been faultless up until now.

I was out doing some fuel pump and regulator testing when shes popped, banged and then rolled to a stop. i was redlining it at the time. the engine is ok mechanically because it turns over ok and occasionally fires once or twice. im 99% sure it timing related due to the way it cut out and the way it behaves now.

While stuck on the side of the road i pulled the VR sensor plug, coil plug and edis plug checked them for tightness etc and reconnected them. it briefly fired up but the rev counter lepted up and down wildly, while i was reving it to trying and keep it going, but it was coughing and back firing then died again. it hasnt restarted since. during the brief period it ran and the rev counter flicked about, a couple of times you could see it go to zero while the engine was reving.

Personally im thinking VR sensor but who knows. the trigger wheel in relation to the crank has not moved. i couldnt pull a plug to see if i was getting a spark due to me not being able to find the right tool

am i right in thinking if it was a megajolt issue i would still get 10 degrees limp home? so no spark at all, or to me whats seems like a spark at the wrong time would suggest edis, or one of its components.

I really need a starting point with this one, im not sure what to check first or how to go about it. i also dont have any spare edis parts at the moment.

as a side note i had the laptop connected to the megajolt yesterday and everything seemed ok, no problems etc.
please help me! (btw the car is currently parked at my work premises- i had to push the damn thing 400m uphill to get it there!
please help

david jenkins · Post by **david jenkins** » Mon May 26, 2008 2:19 pm

A good starting point would be to unplug the megajolt connector (the Molex thing). If the car starts in get-you-home mode then the EDIS/trigger wheel/coil is OK, and there may be a fault with the MJ unit. If it doesn't start - well, you know what to look at!

Are you sure the trigger wheel hasn't slipped, or the VR sensor mount come loose? It does sound like a timing thing...

Supercharged Nat · Post by **Supercharged Nat** » Mon May 26, 2008 3:01 pm

the trigger wheel is definately in the correct position. the vr sensro is tight and hasnt moved.

im going to do some testing while cranking, but i need to know what i should be getting on the mutlimeter to make sure everythings ok.

what should i get from the vr sensor- during cranking. also what should i get from each of the 3 wires on the coil pack during cranking?

can the megajolt prevent the edis from working correctly?

any help appreciated.

Post by **brentp** » Mon May 26, 2008 4:48 pm

Try as Danny suggested by unplugging the Megajolt and testing if it operates in limp-home mode. It's highly unlikely the MJLJ would interfere with the EDIS module and prevent it from working.working.

Let us know what you find out!

MartinM · Post by **MartinM** » Mon May 26, 2008 4:59 pm

Try this post for voltages...

http://www.autosportlabs.org/viewtopic.php?t=734

Supercharged Nat · Post by **Supercharged Nat** » Sat May 31, 2008 11:40 am

thanks for the voltages post. ive been doing some testing. When i went outside it fired straight up! grrr! i did the voltagaes check, everything checked out ok, and it ran ok without megajolt connected. pluged megajolt back in and it ran ok again.

then after a couple of minutes it started acting up again. then it wouldnt start again. i disconnected megajolt, it still wouldnt go. then i did the voltage checks again, and couldnt get anything from the VR sensor. its what i suspected from the begining, so ive ordered a new one, and il see if it works. Il report back when i know more.
thanks for the help.

Post by **brentp** » Sat May 31, 2008 5:50 pm

Hm- those VR sensors are pretty robust. It's still worth checking the whole VR sensor wiring and plug assembly. If you do get it running again on the current sensor, try wiggling the connector and wiring to see if you can re-create the problem, while the engine is running- if that is safe to do, of course.

Let us know what you eventually find out.

Supercharged Nat · Post by **Supercharged Nat** » Wed Jul 02, 2008 8:30 pm

sorry to drag this one back up but i thought i should give an update: its fixed! on closer inspection of the vr sensor i realised that the crank pulley had burned through the side of the sensor and was touching the bared copper strands! i guess it was effectively shorting the sensor and hence no output. a new sensor and a rejig of the pulley, all is well.

thanks.