Loss of Power (Updated)

[redmaestro]

Hi All,

Just to update you on my problem on my car. I changed the temp sender as Dave suggested (tricky job too!!), and it didn't work!!:mad: I drove about 5 miles earlier this afternoon and it still happened - same prob as before. Sudden loss of power then "judders", revs upto 2000rpm then falls to just under 1000. This happens anything from a few seconds to a few minutes. Mighty annoying when trying to pull away from junctions etc

Please, please any suggestions? Or is my baby destined to the great scrap heap in the sky??

[talkingcars]

Please, please any suggestions? Or is my baby destined to the great scrap heap in the sky??

:(

If you get to that point offer it for sale.

Before you get to that point though have you checked the signal from the temp sensor is reaching the ECU?

Is the new sensor faulty, it happens!

[talkingcars]

However reading the symptoms I do wonder if you have an air leak?

It maybe that the engine is intermitantly drawing more air than the ECU thinks it is.

When you next have the problem lightly spray the airlines with WD40 and see when the revs settle correctly and inspect this part for damage.

[G Force]

Hi RedM did you not find anything wrong with the crank sensor wiring?

When you changed the plug leads and rotor arm did you use genuine rover parts? It is possible that there is a problem with these new parts.

Check the connections are tight on the coil also check there is no corrosion inside the coil HT connection.

When you say the revs go upto 2000 then drop to 1000 is this whilst in gear trying to pull away, or with your foot on the clutch whilst trying to rev the engine?

You also mentioned in your other post that if you were stationery and you gently put your foot on the throttle pedal the engine revs would rise and fall on there own. This is almost definitely the throttle pot setting out of adjustment and can cause a flat spot when pulling away.

Gary:)

[redmaestro]

This problem happens randomly - I can drive 10 miles without a problem, then a few days later on the same route it can happen. It happens in all gears and also in neutral. Infact, it hasnt done it for about a week and then yesterday it was doing it all the time.

I didnt check the crank sensor thingy - i dont know what it looks like nor where it is

[G Force]

I didnt check the crank sensor thingy - i dont know what it looks like nor where it is

Its a little awkward to reach but as you look at the engine bay from the front of the car it is between the engine and bulkhead and half way down the gearbox adapter plate (the plate where the engine joins to the gear box. It might be easier to see if you remove the large hose from the throttle body and look down the back of the engine in that area.

[redmaestro]

Its a little awkward to reach but as you look at the engine bay from the front of the car it is between the engine and bulkhead and half way down the gearbox adapter plate (the plate where the engine joins to the gear box. It might be easier to see if you remove the large hose from the throttle body and look down the back of the engine in that area.

Is it to the left of the starter motor?
[just checked for air leaks and seems ok]

[G Force]

Is it to the left of the starter motor?
[just checked for air leaks and seems ok]

Yes & just below, usually a blue plug but sometimes black. The sensor is in the adaptor plate & the plug is on a bracket slightly above and left of it

[talkingcars]

just checked for air leaks and seems ok

Did you do this while the car was producing the symptoms?

[redmaestro]

Yes I did. As luck would have it, as I was revving the engine from under the bonnet it started doing it. I couldn't see any air leaks.


Now my girlfriend has called this problem "Juggering".:banghead:

Interesting thing tho, I drove into into town last night for a takeaway, and it started up again just as I got to a red traffic light. As I waited for the lights to change, I revved the car to try and get past the dreaded 2000rpm. Just as the lights changed, I managed to rev it hard, around 5000rpm. Now this may be a coincidence, but it never happened on the drive home....

[G Force]

As I waited for the lights to change, I revved the car to try and get past the dreaded 2000rpm. Just as the lights changed, I managed to rev it hard, around 5000rpm.....

While you were sat trying to raise the revs to above 2000rpm does the rev counter needle sit quite steady at 2000 before the revs eventualy rise, as apposed to jumping up & down erraticly?

This is quite helpful to know when trying to diagnose your problem as it can rule out or point to the area where the fault may be.;)

Cheers Gary

[redmaestro]

While you were sat trying to raise the revs to above 2000rpm does the rev counter needle sit quite steady at 2000 before the revs eventualy rise, as apposed to jumping up & down erraticly?

This is quite helpful to know when trying to diagnose your problem as it can rule out or point to the area where the fault may be.;)

Cheers Gary

When it "juggers", the engine will only rev upto 2000rpm, then falls to 1500rpm, then rises again. It happens as quick as that. The length of time it takes to jugger varies. The longest has been about a minute. Does this help?

[G Force]

When it "juggers", the engine will only rev upto 2000rpm, then falls to 1500rpm, then rises again. It happens as quick as that. The length of time it takes to jugger varies. The longest has been about a minute. Does this help?

It does help a little:confused: ;) If the revs fluctuate from 2000rpm to 1500rpm it sounds like the engine is running as it does on overrun. If the revs are smoothly surging up and down rather than spluttering and missfiring I would think you have an intermittant throttle pot fault or the wiring between the throttle pot and fuel injection ecu.

You can test this with the multi meter as in the setting procedure I described. The voltage output from the throttle pot should rise steadily from 325mv at idle to 4.5v +-0.5v at full throttle ignition on engine not running. If these voltages are in tolerance the throttle pot is OK and you would need to recheck them at the ecu to check out the wiring.