Hi, I have installed the MJLJ on my rover V8 powered MGB and following several errors on my behalf (ford vs rover v8 firing order difference etc), have managed to get it running. However.....
I have used a generic map to get it going but, no matter what values I use for the advance it will not tickover properly (lumpy huffing n puffing). If I put the distributor back it runs like a dream. It seems to get better the more the engine is revved, but it runs rougher low down, I have a good idea of the correct advance from various sources but even just keeping the revs at say 1000rpm no matter what advance i stick in, it is rough.
It has v3.0 config software, using a MAP sensor fed from the carb.
I have rechecked the wiring and all is good. I have checked 8cyls selected and they were not, changed this and it still ran rough, just a different sort of rough. It has the USB timeout problem but i manage to get 10ish seconds of feedback (RPM load advance change etc) so is well here (apart from timeout error but it still runs).
I have used dual shielded wire for the VRS and earthed as per instructions....
I have spent 3months fiddling and am at the point of ordering a mallory distributor (as my Lucas DLM8 has now got a hot running fault too so I have no useable ignition).
If anyone can help get me and my MGB to SIlverstone, running on EDIS-MJLJ for June 21st, I will buy you a pint of beer!
Thanks.
Duncan
rough running problem -help!
Moderators: JeffC, rdoherty, stieg, brentp
rough running problem -help!
V8 MGB
Hi Duncan,
A couple of ideas for you:
1. have you tried it running disconnected with the EDIS-8 only? With the MJLJ disconnected the EDIS should run the engine fixed at 10 BTDC. Verify timing is fixed at 10 degrees BTDC under these conditions.
2. Are all of your coil packs firing? Do you have the correct firing order connected? A classic rough running scenario could involve a plug or two not firing correctly.
Let us know what you find out.
A couple of ideas for you:
1. have you tried it running disconnected with the EDIS-8 only? With the MJLJ disconnected the EDIS should run the engine fixed at 10 BTDC. Verify timing is fixed at 10 degrees BTDC under these conditions.
2. Are all of your coil packs firing? Do you have the correct firing order connected? A classic rough running scenario could involve a plug or two not firing correctly.
Let us know what you find out.
As Brent says, you have to prove the EDIS installation first.
The best way is to demonstrate that the EDIS is capable of giving you good idling when it's doing its limp-home mode of 10 BTDC. So disconnect the MJLJ completely and start and run the engine. Most engines will start at 10 BTDC and run smoothly.
If that doesn't work, then you need to work on the EDIS installation.
If that works OK, then re-introduce the MJLJ while the engine is running and see if it immediately starts running rough.
Have you used a timing light to check the advance - if its showing as steady but running rough, then it's likely its still a lead problem...that's if you are quite sure it's not a fuelling problem.
Keep persevering and report back - we'll help as much as we can...
The best way is to demonstrate that the EDIS is capable of giving you good idling when it's doing its limp-home mode of 10 BTDC. So disconnect the MJLJ completely and start and run the engine. Most engines will start at 10 BTDC and run smoothly.
If that doesn't work, then you need to work on the EDIS installation.
If that works OK, then re-introduce the MJLJ while the engine is running and see if it immediately starts running rough.
Have you used a timing light to check the advance - if its showing as steady but running rough, then it's likely its still a lead problem...that's if you are quite sure it's not a fuelling problem.
Keep persevering and report back - we'll help as much as we can...
More thoughts...although re-reading your post, it does seem to be an EDIS installation problem rather than a MJLJ problem
With the MJLJ connected, disconnect the vacuum feed from the carb - any change?
Dialling in different advances (within a reasonable range) at the idling usually only makes a difference to rpm - so if you notice nothing at all then there's something wrong somewhere!
You could upgrade your software to V3.2.1 to take advantage of all the latest facilities (including better noise immunity), but that's not the normal panacea to getting smooth tickover.
You could fit some temporary lights to the programmable outputs to see if the MJLJ thinks that the rpm is "all over the place" (TM), which is indicative of installation faults/noise problems.
With the MJLJ connected, disconnect the vacuum feed from the carb - any change?
Dialling in different advances (within a reasonable range) at the idling usually only makes a difference to rpm - so if you notice nothing at all then there's something wrong somewhere!
You could upgrade your software to V3.2.1 to take advantage of all the latest facilities (including better noise immunity), but that's not the normal panacea to getting smooth tickover.
You could fit some temporary lights to the programmable outputs to see if the MJLJ thinks that the rpm is "all over the place" (TM), which is indicative of installation faults/noise problems.
Thanks for the quick help, I am back home tomorrow eve so will try:
1) Recheck that I have Coil A firing 1+6, B firing 8+5, C firing 4+7 and D firing 3+2 (rover timing 18436572 (but pretty sure this is ok.
2) Will run in limp home mode with mj unit disconnected to see what happens.
3) Check coil packs are firing (remove HT leads to see if any difference).
4) If I can follow the instructions I will download V3.2.1 aswell.
(I have tried runng with MAP pipe disconnected -no difference)
(when i saw the rpm when it gave feedback for 10secs, the rpm values looked ok/sensible)
Will let you know after tomorrow night.
Thanks
Duncan
1) Recheck that I have Coil A firing 1+6, B firing 8+5, C firing 4+7 and D firing 3+2 (rover timing 18436572 (but pretty sure this is ok.
2) Will run in limp home mode with mj unit disconnected to see what happens.
3) Check coil packs are firing (remove HT leads to see if any difference).
4) If I can follow the instructions I will download V3.2.1 aswell.
(I have tried runng with MAP pipe disconnected -no difference)
(when i saw the rpm when it gave feedback for 10secs, the rpm values looked ok/sensible)
Will let you know after tomorrow night.
Thanks
Duncan
V8 MGB
Duncan,
I found that whilst my Rover V8 would start from cold with 10deg advance (ie no MJLJ connected) it would not start hot with that much advance. Backing it off to 6deg (now with the MJLJ connected) and it started fine hot and cold.
I'm sure I saw it written down somewhere on the forum about a special calibration value box for a starting advance. I just need to find it!
BTW I also scratched my head for a bit about the difference from Ford to Rover firing orders.
Regards,
Cliff
I found that whilst my Rover V8 would start from cold with 10deg advance (ie no MJLJ connected) it would not start hot with that much advance. Backing it off to 6deg (now with the MJLJ connected) and it started fine hot and cold.
I'm sure I saw it written down somewhere on the forum about a special calibration value box for a starting advance. I just need to find it!
BTW I also scratched my head for a bit about the difference from Ford to Rover firing orders.
Regards,
Cliff
Folks,
Thanks for all the help.
Just got back tonight and managed to try the following (before the heavens opened -MGB is relegated out of garage by mini at mo...):
1) Disconnected MJ unit and tried to start, it was very reluctant to start and even managed a muffled backfire. I then reconnected the MJ unit and it started much easier although still running rough. I can only assume that the MJ unit is working fine then. The 10deg advance must be too much to start engine, I have 6deg in 'no throttle'-'lowest rpm' column-row, as per Cliff's V8.
2) Checked the firing and I have the right leads to the right coil packs and the right pins on EDIS unit to the coilpacks, for the rover timing.
So, I now need to check to see if I have a duff coilpack and then download v3.2.1 to see if this helps...
Back tomorrow eve to ket you know...
Thanks.
Duncan
Thanks for all the help.
Just got back tonight and managed to try the following (before the heavens opened -MGB is relegated out of garage by mini at mo...):
1) Disconnected MJ unit and tried to start, it was very reluctant to start and even managed a muffled backfire. I then reconnected the MJ unit and it started much easier although still running rough. I can only assume that the MJ unit is working fine then. The 10deg advance must be too much to start engine, I have 6deg in 'no throttle'-'lowest rpm' column-row, as per Cliff's V8.
2) Checked the firing and I have the right leads to the right coil packs and the right pins on EDIS unit to the coilpacks, for the rover timing.
So, I now need to check to see if I have a duff coilpack and then download v3.2.1 to see if this helps...
Back tomorrow eve to ket you know...
Thanks.
Duncan
V8 MGB
Hi Duncan
I'd strongly suggest you get a timing light rigged up and see what's going on with the advance even though it's running rough.
For example, an error in setting up the trigger wheel/sensor/TDC combination by even half a tooth will give a constant 5 degree advance error from the EDIS (which the MJLJ will never know about) and if you're debating whether your engine will start/run better at 6BTDC or 10BTDC then 5 degrees set up error could be very significant
No amount of firing order/wiring/coilpack testing or checking, or MJLJ firmware updating will identify that sort of fundamental problem
Also, given you've probably had the engine running roughly at idle-type rpms for some time, it would be worth checking the plugs - they might be heavily sooted and not working properly (a gentle wire brush will sort them out), or if you have a coilpack error and are getting no sparks in a cylinder, you will find them rather clean!
Good luck
Martin
I'd strongly suggest you get a timing light rigged up and see what's going on with the advance even though it's running rough.
For example, an error in setting up the trigger wheel/sensor/TDC combination by even half a tooth will give a constant 5 degree advance error from the EDIS (which the MJLJ will never know about) and if you're debating whether your engine will start/run better at 6BTDC or 10BTDC then 5 degrees set up error could be very significant
No amount of firing order/wiring/coilpack testing or checking, or MJLJ firmware updating will identify that sort of fundamental problem
Also, given you've probably had the engine running roughly at idle-type rpms for some time, it would be worth checking the plugs - they might be heavily sooted and not working properly (a gentle wire brush will sort them out), or if you have a coilpack error and are getting no sparks in a cylinder, you will find them rather clean!
Good luck
Martin
Totally agree- If you haven't checked your static timing- that's the first thing we suggested and the first thing you should do on an installation.
So yes- do stop all other troubleshooting else and verify what your static timing is! After that, you could connect the MJLJ and verify whatever advance MJLJ is signaling is actually what you are getting on the crank, by comparing the runtime screen with your timing light reading.
So yes- do stop all other troubleshooting else and verify what your static timing is! After that, you could connect the MJLJ and verify whatever advance MJLJ is signaling is actually what you are getting on the crank, by comparing the runtime screen with your timing light reading.