Hi,
I've fitted an TPS Megajolt, bought as an assembled unit, to a ford crossflow.
I checked everthing at each stage, except that my timing light won't work with this, so I hadn't checked the timing.
The Edis unit worked fine before I installed the Megajolt, and the configuration screen let me load and amend maps, and showed how the revs, advance & load changed in real time, when the Megajolt & TPS were connected.
The car started easily & ran for over 100 miles to run the rebuilt engine in. All seemed well.
But, when I took it to a rolling road their timing light showed that despite the laptop display showing everything was fine with revs, advance & load changing as they should according to the map, the timing is actually fixed at about 9 degrees, or limp home mode.
We double double checked all the wiring connections, but all seemed right.
I have had to refit the coil, electronic ignition etc temporarily as I had to compete in a sprint yesterday, but I appear to have a problem.
Any ideas please.
Steve
It doesn't do what it says on the screen
Moderators: JeffC, rdoherty, stieg, brentp
...and when you did the 100 miles it seemed OK? It is fairly easy to tell if the EDIS is in limp home mode as the engine should have felt pretty awful....
If the Configurator is showing all is OK (i.e. TPS moving, revs moving and load bins moving) but timing stayed fixed at 9 BTDC then you have to prove:
1) the SAW pulse is actually coming out of the MJLJ (the Configurator display is fed from a data stream from the MJLJ that indicates what the MJLJ thinks it's doing, rather than actually measuring the SAW output)
2) the SAW pulse is reaching the EDIS
3) the EDIS is taking notice of the SAW pulse.
Did you just visually check the connections or electrically test them?
You could, to test the above 3 items in the same order:
1) wire it all up again, start it up and measure the SAW line at the Molex end of the MJLJ, ideally with an oscilloscope. If you don't have one, or access to one, you could use a voltmeter set to DC - it should measure non-zero (without measuring it I'd expect around 2 volts) and the voltage should decrease with increased advance (usually increased rpm)
2) whip the top off the MJLJ and use a continuity checker to test between pin 5 on the inside of the Molex connector and as close as you can get to pin 3 of the EDIS - there should be a direct connection
3) swap the EDIS, if you have a spare
Have a go at those, don't give up, and report back....
Martin
If the Configurator is showing all is OK (i.e. TPS moving, revs moving and load bins moving) but timing stayed fixed at 9 BTDC then you have to prove:
1) the SAW pulse is actually coming out of the MJLJ (the Configurator display is fed from a data stream from the MJLJ that indicates what the MJLJ thinks it's doing, rather than actually measuring the SAW output)
2) the SAW pulse is reaching the EDIS
3) the EDIS is taking notice of the SAW pulse.
Did you just visually check the connections or electrically test them?
You could, to test the above 3 items in the same order:
1) wire it all up again, start it up and measure the SAW line at the Molex end of the MJLJ, ideally with an oscilloscope. If you don't have one, or access to one, you could use a voltmeter set to DC - it should measure non-zero (without measuring it I'd expect around 2 volts) and the voltage should decrease with increased advance (usually increased rpm)
2) whip the top off the MJLJ and use a continuity checker to test between pin 5 on the inside of the Molex connector and as close as you can get to pin 3 of the EDIS - there should be a direct connection
3) swap the EDIS, if you have a spare
Have a go at those, don't give up, and report back....
Martin
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Stevedspeed
- Posts: 4
- Joined: Mon Jan 22, 2007 10:45 am
Thanks Martin,
I'll do that, but it won't be this week as I've got 2 sprints this weekend & I don't want to be refitting the distributor system at 10pm the night before, as I did last week.
In fact when I do it I'll leave the distributor as it is, & just change the 12v feeds & plug leads. Then I can switch from one system to the other without having to retime the distributor every time.
Steve
I'll do that, but it won't be this week as I've got 2 sprints this weekend & I don't want to be refitting the distributor system at 10pm the night before, as I did last week.
In fact when I do it I'll leave the distributor as it is, & just change the 12v feeds & plug leads. Then I can switch from one system to the other without having to retime the distributor every time.
Steve
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Stevedspeed
- Posts: 4
- Joined: Mon Jan 22, 2007 10:45 am
Martin,
I have now got a spare Edis, VR sensor & coil pack, with all connectors. Last night I refitted the original system to the car, in limp home mode it started 1st time & ran ok. I checked & the timing didn't vary with revs. I swapped Edis units & the result was the same.
Then I fitted the MJLJ unit in 2D mode. Again it started & ran, but with no change in timing with extra revs. I swapped Edis units & the result was the same.
By now it was getting late, so the only other check I did was to check the connection from inside the MJLJ unit at pin5 to pin 3 in the inside of the connector on the Edis with a meter & there is a connection.
When it's running in fixed advance mode, according to the timing light it's at 12 degrees. I assume that this is because the toothed wheel is not in quite the right position, but it's not adjustable. I know some systems have a facility to key this variance in to correct this. With MJLJ do I just have to correct all the map values by 3?
Tonight I will check the SAW with a voltmeter, and do the other checks as detailed in the set up instructions.
If you have any other ideas please let me know.
Regards
Steve
I have now got a spare Edis, VR sensor & coil pack, with all connectors. Last night I refitted the original system to the car, in limp home mode it started 1st time & ran ok. I checked & the timing didn't vary with revs. I swapped Edis units & the result was the same.
Then I fitted the MJLJ unit in 2D mode. Again it started & ran, but with no change in timing with extra revs. I swapped Edis units & the result was the same.
By now it was getting late, so the only other check I did was to check the connection from inside the MJLJ unit at pin5 to pin 3 in the inside of the connector on the Edis with a meter & there is a connection.
When it's running in fixed advance mode, according to the timing light it's at 12 degrees. I assume that this is because the toothed wheel is not in quite the right position, but it's not adjustable. I know some systems have a facility to key this variance in to correct this. With MJLJ do I just have to correct all the map values by 3?
Tonight I will check the SAW with a voltmeter, and do the other checks as detailed in the set up instructions.
If you have any other ideas please let me know.
Regards
Steve
-
Stevedspeed
- Posts: 4
- Joined: Mon Jan 22, 2007 10:45 am
Hi,
The saga continues. My apologies if this post seems to drag on, but I've done all the things suggested & here are the results:
1. With the engine running in 2D mode, the DC voltage on the SAW line is O.01 volts at tickover, INCREASING to 0.02 at approx 3000 revs, but the timing stays exactly the same.
2. There is a direct connection between pin 5 on the inside of the MJLJ and pin 3 of the EDIS
3. I have tried another EDIS & the results, on every test are the same
EDIS fault finding tests:
VR sensor voltage across the VR sensor pins at the EDIS main connector, disconnected from the sensor, is 0 volts AC stationary, and 0.8 volts AC when cranking. These figures do not change if the MJLJ is connected or disconnected.
PIP pulse, the DC voltage at EDIS pin 1, with the main connector connected to EDIS, is 12 volts stationary, and 6 volts cranking. These drop to 9.3 volts and 4 volts if the MJLJ is connected.
SAW pulse, the voltage at EDIS pin 3 with the main connector connected to EDIS and SAW output connected to the MJLJ, is 0 volts Ac or DC stationary, and 0.03 volts DC cranking. I cannot get an AC reading when cranking.
I have checked the 12v feeds to the EDIS and MJLJ, and they are fine. The only other voltage going into the MJLJ is the 12v on the PIP wire into the MJLJ when stationary. This was measured at the molex plug.
Checking the DC voltages at each of the molex terminals inside the MJLJ unit with ignition on, stationary shows:
Term1, tach, 12v term2, PIP, 9v term3, prog, 0v term4, option, 2v term5, SAW, 0v term6, Vref, 5v term7 +12v, 12v
term8, gnd, 0v term9, TPS, 5v term10, prog, 0v term11, prog, 0v term12, shift, 0v term13 rev lim, 0v term14 prog, 0v
Does any of this prove anything?
The saga continues. My apologies if this post seems to drag on, but I've done all the things suggested & here are the results:
1. With the engine running in 2D mode, the DC voltage on the SAW line is O.01 volts at tickover, INCREASING to 0.02 at approx 3000 revs, but the timing stays exactly the same.
2. There is a direct connection between pin 5 on the inside of the MJLJ and pin 3 of the EDIS
3. I have tried another EDIS & the results, on every test are the same
EDIS fault finding tests:
VR sensor voltage across the VR sensor pins at the EDIS main connector, disconnected from the sensor, is 0 volts AC stationary, and 0.8 volts AC when cranking. These figures do not change if the MJLJ is connected or disconnected.
PIP pulse, the DC voltage at EDIS pin 1, with the main connector connected to EDIS, is 12 volts stationary, and 6 volts cranking. These drop to 9.3 volts and 4 volts if the MJLJ is connected.
SAW pulse, the voltage at EDIS pin 3 with the main connector connected to EDIS and SAW output connected to the MJLJ, is 0 volts Ac or DC stationary, and 0.03 volts DC cranking. I cannot get an AC reading when cranking.
I have checked the 12v feeds to the EDIS and MJLJ, and they are fine. The only other voltage going into the MJLJ is the 12v on the PIP wire into the MJLJ when stationary. This was measured at the molex plug.
Checking the DC voltages at each of the molex terminals inside the MJLJ unit with ignition on, stationary shows:
Term1, tach, 12v term2, PIP, 9v term3, prog, 0v term4, option, 2v term5, SAW, 0v term6, Vref, 5v term7 +12v, 12v
term8, gnd, 0v term9, TPS, 5v term10, prog, 0v term11, prog, 0v term12, shift, 0v term13 rev lim, 0v term14 prog, 0v
Does any of this prove anything?
The 12V at the PIP line (with the engine not running) is suspicious. Do you measure this on pin 1 of the EDIS module with the MJLJ disconnected? It's normally a 0-12V square wave, triggering on each ignition event.
Other things to try:
Find someone with an oscilloscope (buddy at an auto repair garage?) and visualize proper PIP and SAW pulse behavior.
Find someone nearby with a working MJLJ installation and swap MJLJ units as a test.
Other things to try:
Find someone with an oscilloscope (buddy at an auto repair garage?) and visualize proper PIP and SAW pulse behavior.
Find someone nearby with a working MJLJ installation and swap MJLJ units as a test.