After between 20 and 30 mins running and after a period of part or very little throttle the engine will suddenly feel unresponsive then cut out, it recovers intermitently, runs rough or cuts out, then after a few mins returns to normal.
I have changed Plugs, leads and coil pack to no avail.
The cutting out of the engine is coupled with the Tacho dropping to zero as if switched off.
The Tacho feed is from the MegaJolt V2.
I intend to make a new loom as the one that came with the complete engine is a little bodged here and there.
From what i can see so far the sheilded wires shielding is not earthed and there is no capacitor fitted, the wires to the VR sensor are also not shielded.
Anything else i should be looking for?
As always any help advise appreciated.
Tacho suddenly drops to zero
Moderators: JeffC, rdoherty, stieg, brentp
Hi Paul:
A bit more context would be helpful. Was this an existing installation that was running well and then started having problems? Is it a new vehicle for you for which you have no history?
In any case, yes- it's recommended you re-wire the VRS and PIP/SAW lines with properly shielded wire.
Out of curiosity, you can run the engine without the MJLJ connected to see if you still see the problem. If you do, then your problem is may be around the VR sensor. Check sensor placement, bracket design (it should be very rigid) and of course, wiring.
Let us know what you find out!
A bit more context would be helpful. Was this an existing installation that was running well and then started having problems? Is it a new vehicle for you for which you have no history?
In any case, yes- it's recommended you re-wire the VRS and PIP/SAW lines with properly shielded wire.
Out of curiosity, you can run the engine without the MJLJ connected to see if you still see the problem. If you do, then your problem is may be around the VR sensor. Check sensor placement, bracket design (it should be very rigid) and of course, wiring.
Let us know what you find out!
-
snapperpaul
- Posts: 13
- Joined: Mon May 02, 2005 9:43 am
It was on a complete bought in engine package from a Sierra, i saw it running and installed the whole lot only changing the sump and fabricating a new VR sensor mounting plate (more substatial than before).
I will run the car without MegaJolt just using EDIS and see what happens.
I will look at the VR sensor plug which always seemed a little loose.
Thanks for the tips its just this sort of help that takes me from " Where do I start" to "Lets try this first then that" etc
Thanks BrentP
I will run the car without MegaJolt just using EDIS and see what happens.
I will look at the VR sensor plug which always seemed a little loose.
Thanks for the tips its just this sort of help that takes me from " Where do I start" to "Lets try this first then that" etc
Thanks BrentP
Is there a possibility that the VR sensor to wheel spacing is too large(and marginal) when cold? Then when the engine warms the sensor is moved far enough away to no longer get a strong enough signal for a reference? Seems reasonable to me since the tacho drops to zero, i.e. no pulses, when the engine warms up.