Hello!
I'm new to the forum and would appreciate a bit of help with a couple of questions The story goes like this;
I've just completed a Megajolt installation using TPS on a Ford Crossflow with twin 40 Webers in a moderate state of tune (stage 2 head, Kent 234 cam). The car starts, idles and revs smoothly.
On connecting the PC I can see a response on the load dial when pressing the throttle while the engine is not running.
When I start the engine the load dial stops responding to throttle input but I can still see RPM responses and ignition advance.
I believe that engine load is not influencing the ignition advance (on the basis of watching the map 'live' while changing engine revs).
Can anyone tell me why the TPS input seems to cease when the engine starts and what I should do about it?
Secondly, any recommendations for a suitable 'Cranking advance' setting for my crossflow?
Thanks in advance for any help.
Cheers,
Simon
Load (TPS) response stops when engine starts
Moderators: JeffC, rdoherty, stieg, brentp
Hello-
That is an odd issue with the TPS. If you disable the coil pack power and just *crank* the engine, does it still happen?
With the engine off, does the TPS move smoothly, or does it have any jumps or jerkiness? You should definitely check all of the connections, including the ground connection for the TPS- make sure it's grounded back to where the Megajolt itself is grounded.
Finally, are you using resistor or non-resistor spark plugs?
That is an odd issue with the TPS. If you disable the coil pack power and just *crank* the engine, does it still happen?
With the engine off, does the TPS move smoothly, or does it have any jumps or jerkiness? You should definitely check all of the connections, including the ground connection for the TPS- make sure it's grounded back to where the Megajolt itself is grounded.
Finally, are you using resistor or non-resistor spark plugs?
Brent,
Thanks very much for your rapid response. To answer some of your questions;
The TPS response is jerky/jumpy (with the engine off - there's no response with the engine on).
I have a single earth to the chassis which covers all earthing requirements, so MJ and everything else is earthed in the same place.
The current plugs are Bosch Super RO 762. My assumption is that the 'R' implies resistor, but I could be wrong.
I am yet to try the 'disable the coil pack' approach, primarily because......
there is another twist to the tale. I have found that the engine will fail to start on numerous occasions and then, in the face of no apparent change, will start.
This is beginning to feel like a loose connection-type problem. The 12V feeds are all as solid as a rock, so any further pointers around where I should be looking would be very welcome.
Thanks again.
Cheers,
Simon
Thanks very much for your rapid response. To answer some of your questions;
The TPS response is jerky/jumpy (with the engine off - there's no response with the engine on).
I have a single earth to the chassis which covers all earthing requirements, so MJ and everything else is earthed in the same place.
The current plugs are Bosch Super RO 762. My assumption is that the 'R' implies resistor, but I could be wrong.
I am yet to try the 'disable the coil pack' approach, primarily because......
there is another twist to the tale. I have found that the engine will fail to start on numerous occasions and then, in the face of no apparent change, will start.
This is beginning to feel like a loose connection-type problem. The 12V feeds are all as solid as a rock, so any further pointers around where I should be looking would be very welcome.
Thanks again.
Cheers,
Simon