Random power loss and kangarooing
Discussion
The last few times I've been out in the Chimaera I've experienced some random power loss which results in some violent kangarooing as the power falls off and then on again - more off than on. I've just managed to limp home. It has happened at different times - so not necessarily when I've been gunning it, or been on a hill, or anything else in common I can think of.
I've been told my accelerator is stiff, which potentially indicates a rusty throttle cable, but I don't think this is it because the problem occurs when the revs / power drops to nothing, rather than me squeezing the throttle and nothing happening.
Can someone have a guess at what could be wrong? Fuel pump? Choke?
Much appreciated (I'm gutted cos the weather is amazing today and I wanted a run out in the Peaks as I'm back to work tomorrow
)
I've been told my accelerator is stiff, which potentially indicates a rusty throttle cable, but I don't think this is it because the problem occurs when the revs / power drops to nothing, rather than me squeezing the throttle and nothing happening.
Can someone have a guess at what could be wrong? Fuel pump? Choke?
Much appreciated (I'm gutted cos the weather is amazing today and I wanted a run out in the Peaks as I'm back to work tomorrow
)If you have access to Rovergauge i'd connect that and see if it tells you anything. Failing that I'd look at the "usual" suspects (rotor arm, dizzy cap first), if it's a "total" loss of power rather than a feeling that it has less than usual then fuel pump relay and fuel pump would be next on my list. If it's a drop in power I'd look at the HT Leads, extenders & plugs.
It'd be hard to diagnose from your description though - is there a smell of fuel when it happens?
It could be any number of things including the injectors, a collapsed air intake hose, vaccum advance issue, coil breaking down/overheating, ignition module, fuel pump relay, fuel pump overheating, fuel filter blocking, distributor failing (or loose). It could even be a collapsed Cat in the exhaust (assuming they are still there)...MAF, TPS...ECM it's quite a long list of things to check.
Start with the basics - for example when did you last service the car and did you replace the Rotor arm, if so did you use an OEM one? If you have a spare coil, rotor arm, dizzy cap and HT Leads I'd be tempted to chuck them on and see if that does it, then narrow it down from there..
It'd be hard to diagnose from your description though - is there a smell of fuel when it happens?
It could be any number of things including the injectors, a collapsed air intake hose, vaccum advance issue, coil breaking down/overheating, ignition module, fuel pump relay, fuel pump overheating, fuel filter blocking, distributor failing (or loose). It could even be a collapsed Cat in the exhaust (assuming they are still there)...MAF, TPS...ECM it's quite a long list of things to check.
Start with the basics - for example when did you last service the car and did you replace the Rotor arm, if so did you use an OEM one? If you have a spare coil, rotor arm, dizzy cap and HT Leads I'd be tempted to chuck them on and see if that does it, then narrow it down from there..
I wouldn't say I notice a smell of fuel especially.
It had a really detailed service last October when I bought it. Done about 3500 miles since then and I was going to get a service this October.
It's a total loss of power. It happened on a roundabout today and the car basically stopped and limped for a bit - so there was some power at least - then came back to life on and off for a bit until I got it the last quarter mile home...
It had a really detailed service last October when I bought it. Done about 3500 miles since then and I was going to get a service this October.
It's a total loss of power. It happened on a roundabout today and the car basically stopped and limped for a bit - so there was some power at least - then came back to life on and off for a bit until I got it the last quarter mile home...
andyg1 said:
I wouldn't say I notice a smell of fuel especially.
It had a really detailed service last October when I bought it. Done about 3500 miles since then and I was going to get a service this October.
It's a total loss of power. It happened on a roundabout today and the car basically stopped and limped for a bit - so there was some power at least - then came back to life on and off for a bit until I got it the last quarter mile home...
If I had to guess, I'd guess at fuel related (pump, relay) changing the relay is easy and cheap (I always carry a spare) so try that first. Unfortunately it could also be ignition related but you'd be looking at a "common" component for a total loss (Rotor, Dizzy Cap, Coil, Ignition module, ECM).It had a really detailed service last October when I bought it. Done about 3500 miles since then and I was going to get a service this October.
It's a total loss of power. It happened on a roundabout today and the car basically stopped and limped for a bit - so there was some power at least - then came back to life on and off for a bit until I got it the last quarter mile home...
Julesprivate said:
If I had to guess, I'd guess at fuel related (pump, relay) changing the relay is easy and cheap (I always carry a spare) so try that first. Unfortunately it could also be ignition related but you'd be looking at a "common" component for a total loss (Rotor, Dizzy Cap, Coil, Ignition module, ECM).
Most times a "total" loss of the ignition side means the car cuts out, you haven't mentioned it stalling so I assume that as you coast down to the roundabout it seems OK but when you press the throttle to pull away it "coughs", hesitates and then accelerates really slowly?One last - really stupid - question, you have plenty of fuel in it don't you? I know mune get's quite prissy at below quarter of a tank as the tank appears not to be baffled and the fuel sloshes away from the pickup..
It could also be a partially blocked tank vent/carbon canister or a problem witht he fuel lines (and the return)
Edited by Julesprivate on Tuesday 27th August 13:48
Perhaps it was misleading of me to say "total loss of power" as it doesn't stall, no, but it doesn't matter how hard you press the accelerator there's no response. The car just rolls under its own momentum. Then it'll pick up again, if it wants. There's no action or any change in environment e.g. hills, that will determine if it will or not.
Yes, there's plenty of fuel in the tank. 3/4s full.
Funny that fuel pumps / relays were mentioned as I've been feeling lately that the fuel pump hasn't sounded the same i.e. in the moments you hear it when you first turn the ignition. This could be just in my head though and I wouldn't want to mask the real problem if stating that leads the conversation down the wrong route...
Yes, there's plenty of fuel in the tank. 3/4s full.
Funny that fuel pumps / relays were mentioned as I've been feeling lately that the fuel pump hasn't sounded the same i.e. in the moments you hear it when you first turn the ignition. This could be just in my head though and I wouldn't want to mask the real problem if stating that leads the conversation down the wrong route...
Another thing I've noticed is that it has been idling high. It normally ticks over at 1000rpm from cold on a summer's day but more often than not lately it has been up to 1400rpm at random times - so not always from cold, sometimes just at the lights.
Might that also indicate:
If so then (dumb question) where would I find the air flow meter to disconnect and reconnect? Thanks
Might that also indicate:
Robert Lees said:
Kangarooing at steady revs , turned out to be AFM. Disconnected, reconnected.. Fine ever since...
??If so then (dumb question) where would I find the air flow meter to disconnect and reconnect? Thanks
It's the gadget that is in the big air trunking that runs down the passenger side of the engine bay, from the front of the car to the top of the engine. It's in the straight bit, before the bend, attached to the wing by a bolt and a bracket. It measures the Air Flow (=AF Meter) and tells the ECU how much petrol to send to the injectors.
The high idle can be a sticky stepper motor, amongst other things. Mine used to do it when hot.
The high idle can be a sticky stepper motor, amongst other things. Mine used to do it when hot.
Found the AFM, unplugged it and plugged it back in. The connector and the wires all look fine. Not to say whether the instrument itself is working.
Took it for a couple of laps round the block after a couple of minutes sat warming up. No high revs, but that was intermittent anyway.
Whilst I didn't experience the kangarooing I suspect it is still there and will reveal itself on a longer journey. Feels this might be a job for the garage to have a look at just to get it fixed and get some peace of mind...
Took it for a couple of laps round the block after a couple of minutes sat warming up. No high revs, but that was intermittent anyway.
Whilst I didn't experience the kangarooing I suspect it is still there and will reveal itself on a longer journey. Feels this might be a job for the garage to have a look at just to get it fixed and get some peace of mind...
As I've had similar symptoms recently I'm going to go with a suggestion of Throttle pot sensor.
It is all really just guess work until as Jules says you get Rover gauge, confirm fault codes and readings from the sensors, or take it to a TVR specialist.
If it is the TPS symptoms may be intermittent as apparently when the ECU sees no signal it will not let the engine rev over 1500 rpm. Putting your foot flat or at least down further may allow a signal to come through and the problem will clear.
It is all really just guess work until as Jules says you get Rover gauge, confirm fault codes and readings from the sensors, or take it to a TVR specialist.
If it is the TPS symptoms may be intermittent as apparently when the ECU sees no signal it will not let the engine rev over 1500 rpm. Putting your foot flat or at least down further may allow a signal to come through and the problem will clear.
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