AJP8 No Start after Top End Rebuild
Discussion
Engine turns over at the appropriate speed, definitely fueling (airbox/hoses off), then occasionally firing back through the intake.
Double checked plug lead connections, but need to confirm the following wiring loom arrangement:
Loom with Odd TP has connections for Odd bank plugs and EVEN bank Coil Pack, similarly Even bank loom has connections for even bank plugs and TP but ODD bank Coil Pack - correct?
CPS is new, if faulty would injectors fire?
Flywheel has been off but care was taken to replace with dowel in correct place.
Not checked compression, but why is it firing back through the intake?
Double checked plug lead connections, but need to confirm the following wiring loom arrangement:
Loom with Odd TP has connections for Odd bank plugs and EVEN bank Coil Pack, similarly Even bank loom has connections for even bank plugs and TP but ODD bank Coil Pack - correct?
CPS is new, if faulty would injectors fire?
Flywheel has been off but care was taken to replace with dowel in correct place.
Not checked compression, but why is it firing back through the intake?
CerbWill said:
Paul, your wiring seems correct. Have you checked you're definitely getting a decent spark on all plugs?
I recently had a couple of problems with mine caused by a poor connection at the engine bulkhead connector
Many thanks, I did remove the engine earth lead in order to put the new heat shield sleeve on the battery earth cable. I will check it again as well as put the Diags on later today.I recently had a couple of problems with mine caused by a poor connection at the engine bulkhead connector
jammy_basturd said:
Also double check the crank sensor? Though I'd imagine that would show up on the diags.
It is new, and shows as good on the Diags, as well as Crank Wiring, whatever that is.Will try swapping back the old one just in case.
Edited by ukkid35 on Monday 28th September 16:13
I used a simple light bulb spark checker on cylinder 1 and 2, all good. I did a compression test on cylinder 1 and 2, both were 230.
I checked the plug leads again, for about the forth time and they are as below.
I did find that a couple of leads were not seated properly in the coil packs and thought I'd cracked it, but no - the firing through the intake became even more enthusiastic.
What on earth have I done wrong?
I checked the plug leads again, for about the forth time and they are as below.
I did find that a couple of leads were not seated properly in the coil packs and thought I'd cracked it, but no - the firing through the intake became even more enthusiastic.
What on earth have I done wrong?
Shanksy87 said:
My experience similar to these symptoms was the result of a bad coil pack dropping spark on two cylinders.
There was no hint of ignition problems before the strip down, so I didn't even consider replacing the coil packs, but since you can now pick them up for £14 inc delivery perhaps I should have done.HarryW said:
I once had an issue with the Molded plug to one of the coil packs, an internal core had come loose at the pack end after removing and refitting. Swing through the control wires between the pack plug and the ECU. That said I think mine wasn't firing as opposed to mistimed firing.
If I put the spark tester on every plug then I should be able to rule that out.gruffalo said:
Paul,
Did you get her going in time for the Ring trip?
Sadly not, so this was my view insteadDid you get her going in time for the Ring trip?
As you can see the weather was perfect, and on the Friday we hired MTBs and cycled round the forest track that follows the circuit while watching the VLN practice, great fun! (although the uphill section from Adenau to Hohe Acte was really hard)
The AJP8 soundtrack is pretty good, but an SLS is mobile thunder - just awesome!
And this is the last time I drove my Cerbera (other than the run home a couple of days later).
It's not a great lap, quite a few little errors, as it was getting towards the end of the day and I was losing concentration. The worst is when I hit the kerb on the bridge at Adenau (Breidscheid), that's when I knew I had to call it a day.
http://vimeo.com/141834253
It's not a great lap, quite a few little errors, as it was getting towards the end of the day and I was losing concentration. The worst is when I hit the kerb on the bridge at Adenau (Breidscheid), that's when I knew I had to call it a day.
http://vimeo.com/141834253
First day working on the car since September, and still none the wiser.
Started by replacing a number of Jubilee clips with Mikalor, before refilling and bleeding the cooling system. Then I pulled the plugs and did a compression test, I had a heart stopping moment when the first came out at 150, before realising that I'd not opened the throttle. These are engine cold (obviously) and with no additional oil in the cylinders (which I had added for my original test four years ago).
1 - 220
3 - 230
5 - 230
7 - 245
2 - 220
4 - 220
6 - 225
8 - 215
So all good, and fairly even too, so I can't see how the cam timing could possibly stop the engine from firing, which it hasn't done once.
My assistant had time to press the start button while I checked that all injectors were doing their thing, but not enough time for me to check for a spark at each cylinder. That will happen tomorrow, however 1 and 2 are already confirmed.
How can I check whether the spark is near TDC?
Nevertheless, I have compression, so I can at least relax a little.
Started by replacing a number of Jubilee clips with Mikalor, before refilling and bleeding the cooling system. Then I pulled the plugs and did a compression test, I had a heart stopping moment when the first came out at 150, before realising that I'd not opened the throttle. These are engine cold (obviously) and with no additional oil in the cylinders (which I had added for my original test four years ago).
1 - 220
3 - 230
5 - 230
7 - 245
2 - 220
4 - 220
6 - 225
8 - 215
So all good, and fairly even too, so I can't see how the cam timing could possibly stop the engine from firing, which it hasn't done once.
My assistant had time to press the start button while I checked that all injectors were doing their thing, but not enough time for me to check for a spark at each cylinder. That will happen tomorrow, however 1 and 2 are already confirmed.
How can I check whether the spark is near TDC?
Nevertheless, I have compression, so I can at least relax a little.
jammy_basturd said:
Though I did have the same symptoms when I connected the coils to the wiring loom plugs the wrong way around. Even double and triple checked before I noticed!
Thanks James - I'm not really sure why I didn't pay more attention to your post before, if I had I would have been at DN13 in the Cerb. Just now I found an earlier pic of mine showing one of the coil plug cables which enabled me to differentiate between the two sides, sure enough I had swapped them. Five mins later I've swapped them back and the engine fires straight away.Obviously I'm pleased the engine is running, but a little disappointed with myself for missing that error, after working on the car almost every evening and weekend in August and September to try to get it ready for that trip.
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