Electrical problem 940

[Laird Scooby]

Before you go any further on the diagnosis, pull fuse #1 out for about 30 seconds and then refit it. Give that a try and see if the inability to rev to maximum goes. Also does it make any difference whether it's hot or cold?

Lastly, have you got a spare battery you can try? A known good battery from a correctly working car or even renew the battery. It's surprising just how much grief a failing/failed battery can cause, even if it still starts the car!

Just had to renew a battery on one of mine for this reason, just out of the guarantee as well

[Ammorack]

Originally Posted by Laird Scooby

Before you go any further on the diagnosis, pull fuse #1 out for about 30 seconds and then refit it. Give that a try and see if the inability to rev to maximum goes. Also does it make any difference whether it's hot or cold?

Lastly, have you got a spare battery you can try? A known good battery from a correctly working car or even renew the battery. It's surprising just how much grief a failing/failed battery can cause, even if it still starts the car!

Just had to renew a battery on one of mine for this reason, just out of the guarantee as well

On cold and warm engine. It won’t rev past 3000. I checked yesterday to be sure. Since tachometer bounces so it’s kinda hard to see. But it’s max rpm is 3000.
I got a spare battery. It would be funny how a battery could cause this lprobkem. I would be so happy.
Pulled fuse 1 for 1 30 second. Didn’t seem to make a difference.

[Ammorack]

Originally Posted by Laird Scooby

Is that certain limit about 3000rpm and when it gets there, does it die and then rev up again?

It doesent die. It just stays at 3000rpm backfiring and such. It constant. So it stays there.

[Ammorack]

Originally Posted by aardvarkash10

change the exhaust pipe.

Its as logical as what's happened so far.

Exhaust system are brand new

[Ammorack]

Originally Posted by taiwan740

Feels like a grounding issue, probably a cable breaking down somewhere, or battery connections.

I'm gonna science and say there's some lead that's barely making a connection, but given extra load the pixies have more energy to leap across the Chasm of Despair (a break in the cable) therefore you get slightly better performance.

It's something simple, but it's hiding. Also don't scrap, there's always some sucker on here (me) that buys junk and calls it a 'laff'

Haha yeah it must be some cables hiding underneath.
It’s just hard to find.this remains a mystery 🤣

[Laird Scooby]

Originally Posted by Ammorack

On cold and warm engine. It won’t rev past 3000. I checked yesterday to be sure. Since tachometer bounces so it’s kinda hard to see. But it’s max rpm is 3000.
I got a spare battery. It would be funny how a battery could cause this lprobkem. I would be so happy.
Pulled fuse 1 for 1 30 second. Didn’t seem to make a difference.

Try the other battery and let us know..

[aardvarkash10]

what the hell. I'm doing nothing else for the next 28 days.

Anorak - If its too much trouble to take the battery out and put another one in, just use jumper leads and connect a known, good battery (even one still in another car) to your car. Check and see if you still have the 3,000rpm problem.

If the problem resolves, disconnect the earth lead on the battery in your car so your battery is completely out of the circuit and try again with the jumper leads connecting the other battery to your car. Check and see if you still have the 3,000rpm problem.

If the problem is resolved, its LIKELY that your battery is the problem. To confirm, remove the second battery, reconnect your battery and check the 3,000rpm problem. If its back, the problem is almost certainly your battery

Let us know, and DO NOTHING ELSE.

[Ammorack]

Originally Posted by aardvarkash10

what the hell. I'm doing nothing else for the next 28 days.

Anorak - If its too much trouble to take the battery out and put another one in, just use jumper leads and connect a known, good battery (even one still in another car) to your car. Check and see if you still have the 3,000rpm problem.

If the problem resolves, disconnect the earth lead on the battery in your car so your battery is completely out of the circuit and try again with the jumper leads connecting the other battery to your car. Check and see if you still have the 3,000rpm problem.

If the problem is resolved, its LIKELY that your battery is the problem. To confirm, remove the second battery, reconnect your battery and check the 3,000rpm problem. If its back, the problem is almost certainly your battery

Let us know, and DO NOTHING ELSE.

Hm, seems like the problem is still there. I tried your solution, with the batteries. But it’s still there. 🤷*♂️

[Laird Scooby]

Originally Posted by Ammorack

Hm, seems like the problem is still there. I tried your solution, with the batteries. But it’s still there. 🤷*♂️

Did you remove the earth connection from your vehicle battery as part of the last test as Ash said?

[aardvarkash10]

Originally Posted by Ammorack

Hm, seems like the problem is still there. I tried your solution, with the batteries. But it’s still there. 🤷*♂️

colour me unsurprised.

Next thing.

Disconnect the battery wire from the alternator, tape it and clamp it so it CANNOT touch anything, and check your 3,000rpm fault. If the fault has gone, reattach the B+ terminal and check the 3000rpm problem again. If its BACK the problem is POSSIBLY very weirdly associated with the load the alternator imposes on the engine.

Do nothing else - tell us what happened.