Annoying miss. 1990 RR - 3.9litre

I have this intermittent engine miss. May happen once a day over a total of
80 kilometers of travelling. Feels like a 80% loss of power. Engine will
always keep running and not stall. If I stop the vehicle, the engine idles
nicely and I can rev freely up to [say] 5000rpms. If I drive away then the
bad missing will still be there. Keep driving and it appears to go away
within a few minutes of starting. Mechanic cannot find the cause; have
swapped out the Hot Wire Air Flow Sensor, Computer, Throttle Position
Sensor, Water Temp and Fuel Temperature sensors have been checked, Spark
Plugs and leads are new, new Petrol Filter and Air Filter.

Also at times there can be a very slight miss around 2000rpms in top gear on
a level road, it to can disappear within 30 seconds of starting.

Your comments please?

Possibly a tired fuel pump.

The pump is sited in the tank but on the 1990 model you should have an
access panel in the boot floor under the carpet.

Muddy

"Milcom Instrumentation" <milcom@milcom.co.nz> wrote in message
news:ck0634$vm1$1@lust.ihug.co.nz...
> Annoying miss. 1990 RR - 3.9litre
>
> I have this intermittent engine miss. May happen once a day over a total
> of
> 80 kilometers of travelling. Feels like a 80% loss of power. Engine will
> always keep running and not stall. If I stop the vehicle, the engine idles
> nicely and I can rev freely up to [say] 5000rpms. If I drive away then the
> bad missing will still be there. Keep driving and it appears to go away
> within a few minutes of starting. Mechanic cannot find the cause; have
> swapped out the Hot Wire Air Flow Sensor, Computer, Throttle Position
> Sensor, Water Temp and Fuel Temperature sensors have been checked, Spark
> Plugs and leads are new, new Petrol Filter and Air Filter.
>
> Also at times there can be a very slight miss around 2000rpms in top gear
> on
> a level road, it to can disappear within 30 seconds of starting.
>
> Your comments please?
>
>

"Alan Mudd" <alancdmudd@spamtrapbtinternet.com> wrote in message
news:ck17l1$kth$1@titan.btinternet.com...
> Possibly a tired fuel pump.
>
> The pump is sited in the tank but on the 1990 model you should have an
> access panel in the boot floor under the carpet.
>
> Muddy
>
> "Milcom Instrumentation" <milcom@milcom.co.nz> wrote in message
> news:ck0634$vm1$1@lust.ihug.co.nz...
>> Annoying miss. 1990 RR - 3.9litre
>>
>> I have this intermittent engine miss. May happen once a day over a total
>> of
>> 80 kilometers of travelling. Feels like a 80% loss of power. Engine will
>> always keep running and not stall. If I stop the vehicle, the engine
>> idles
>> nicely and I can rev freely up to [say] 5000rpms. If I drive away then
>> the
>> bad missing will still be there. Keep driving and it appears to go away
>> within a few minutes of starting. Mechanic cannot find the cause; have
>> swapped out the Hot Wire Air Flow Sensor, Computer, Throttle Position
>> Sensor, Water Temp and Fuel Temperature sensors have been checked, Spark
>> Plugs and leads are new, new Petrol Filter and Air Filter.
>>
>> Also at times there can be a very slight miss around 2000rpms in top gear
>> on
>> a level road, it to can disappear within 30 seconds of starting.
>>
>> Your comments please?

Tracing in the distributor cap is another potential cause. Clean / New Dizzy
and rotor arm my help.

Lee D

The message <pAW8d.194$A85.158@newsfe1-gui.ntli.net>
from "Lee_D" <lee@lrproject.com> contains these words:



> Tracing in the distributor cap is another potential cause. Clean / New
> Dizzy
> and rotor arm my help.

whatever you do don't heave the rotor off, turn a slight problem into a
disaster, suppposed to break it to get it off, if you pull you seriously
cause it to come to bits inside, no recon/repair kit available.

had similar problem after Martin the mad mechanic hit the lambda sensor
with a hammer, replaced this and everything O.K again.

--
If you received this through the miracle of modern technology then all
is well; if not then situation normal.
Chris father of ( also at chrisjbarnes@openlink.org )
www.users.zetnet.co.uk/barnes_firsnorton