Discussion
I know this been covered a million times, but i'm stuck with a serious misfire and am at the limit of my knowledge. so, it seems, is my mechanic!
at about 3000 revs, the engine stops firing almost all together, then the revs drop off, and its sweet as a nut again. ive changed the ignition coil, temp sensor, rotor arm, fuel, found a hole in a fuel line so changed those at the back.. also fiddled with the ecu connector which is very tight. did notice some hot relays in there though... could it be connected?
I'm stuck. a 390 without revs about 3.5k souldnt be allowed on the road!
at about 3000 revs, the engine stops firing almost all together, then the revs drop off, and its sweet as a nut again. ive changed the ignition coil, temp sensor, rotor arm, fuel, found a hole in a fuel line so changed those at the back.. also fiddled with the ecu connector which is very tight. did notice some hot relays in there though... could it be connected?
I'm stuck. a 390 without revs about 3.5k souldnt be allowed on the road!
Problem sounds electrical to me.
As well as the obvious, I would also check:-
Distributor cap for arc marks on the inside earthing to distributor body. (Replace cap)
High tension jumps at high revs so check leads are not touching or close to anything metal. (better visible in the dark when engine running)
Distributor advance, including weights within the distributor and it's advance mechanism.
Tony. TCB.
As well as the obvious, I would also check:-
Distributor cap for arc marks on the inside earthing to distributor body. (Replace cap)
High tension jumps at high revs so check leads are not touching or close to anything metal. (better visible in the dark when engine running)
Distributor advance, including weights within the distributor and it's advance mechanism.
Tony. TCB.
When I had my 350i I had an intermittant problem which literally came on and off like a switch.
Started fine then once warmed up (like a switch) ran like a dog
Someone suggested the ECU so I got a friend to join me at my mechanics and swapped them easily
and fault instantly cured
A kind Wedge friend (who likes to remain anonymous)re soldered all the joints of my ECU and the problem was resolved
HTH & good luck
Trickie
Started fine then once warmed up (like a switch) ran like a dog
Someone suggested the ECU so I got a friend to join me at my mechanics and swapped them easily
and fault instantly cured
A kind Wedge friend (who likes to remain anonymous)re soldered all the joints of my ECU and the problem was resolved
HTH & good luck
Trickie
Thanks guys. spent the afternoon with my head under the front looking for problems. Dizzy was done recently so think i'll leave that as an unlikely possibility and leave till last. when i start her up, there is what sounds like a crack... a spark perhaps from somewhere, but im bu**ered if i can see where its from. Theres no hope of hearing it once shes running, but i suppose it could still be there. could be one to look into inthe dark.
anyone point me in the right direction for an ecu? hopefuly wont need one, but if i required s newby, is fleabay best?
Stu
anyone point me in the right direction for an ecu? hopefuly wont need one, but if i required s newby, is fleabay best?
Stu
Trickie Dickie said:
When I had my 350i I had an intermittant problem which literally came on and off like a switch.
Started fine then once warmed up (like a switch) ran like a dog
Someone suggested the ECU so I got a friend to join me at my mechanics and swapped them easily
and fault instantly cured
A kind Wedge friend (who likes to remain anonymous)re soldered all the joints of my ECU and the problem was resolved
HTH & good luck
Trickie
So is this something I need to watch out for Rich!! ;-)Started fine then once warmed up (like a switch) ran like a dog
Someone suggested the ECU so I got a friend to join me at my mechanics and swapped them easily
and fault instantly cured
A kind Wedge friend (who likes to remain anonymous)re soldered all the joints of my ECU and the problem was resolved
HTH & good luck
Trickie
evening all, a quick update on progress....
after a lot of tinkering and ruling out, i discovered a problem with the connector on the ignition amp, which was causing a weak spark when hot. fixed and the problem is now 99% sorted.. pulls like a train and the 390se is a beast as reported. i realised this when i saw the back of the car making a cencerted effort to overtake the front in todays slippery conditions!
one problem left to be classed as fully fixed, she still has a brief stutter when accelerating hard, not a cut out or misfire, more like lightly flooded. could it be as simple as plugs? i ask as she ticks over a little fast (i think) about 1200rpm and does smell petroly.
also, the misfire has put a strain on the clutch which is very high on the pedal, i assume this cant be altered?
Stu
after a lot of tinkering and ruling out, i discovered a problem with the connector on the ignition amp, which was causing a weak spark when hot. fixed and the problem is now 99% sorted.. pulls like a train and the 390se is a beast as reported. i realised this when i saw the back of the car making a cencerted effort to overtake the front in todays slippery conditions!
one problem left to be classed as fully fixed, she still has a brief stutter when accelerating hard, not a cut out or misfire, more like lightly flooded. could it be as simple as plugs? i ask as she ticks over a little fast (i think) about 1200rpm and does smell petroly.
also, the misfire has put a strain on the clutch which is very high on the pedal, i assume this cant be altered?
Stu
What was the problem exactly, was the connector loose or corroded, or was the crimp onto the wire bad? For future reference.
For your last remaining problem try driving it for a long run it might go away on its own when the plugs get the crud burnt off.
As for the clutch well high is good probably - as long as it doesn't slip. TO text this, stick it in 4th at about 30-40 with a nice long road in front of you, and floor it. If the revs rise suddenly during the acceleration then it's started slipping and you may need a new pressure plate.
For your last remaining problem try driving it for a long run it might go away on its own when the plugs get the crud burnt off.
As for the clutch well high is good probably - as long as it doesn't slip. TO text this, stick it in 4th at about 30-40 with a nice long road in front of you, and floor it. If the revs rise suddenly during the acceleration then it's started slipping and you may need a new pressure plate.
corroded it seems, I can only imagine that someone managed to get something on it that should be there and it ate away at the connector. whatever the cause, its miles better, just not perfect.
clutch seemed ok today, but i'll do a check on it tomorrow (in the sunshine hopefully). assuming theres nothing cheap about a new plate?!
Looks like ill take a few trips around the island tomorrow then. It used to end up in a visit from the rozzers with the chim so no doubt ill have a whole response team tomorrow!
clutch seemed ok today, but i'll do a check on it tomorrow (in the sunshine hopefully). assuming theres nothing cheap about a new plate?!
Looks like ill take a few trips around the island tomorrow then. It used to end up in a visit from the rozzers with the chim so no doubt ill have a whole response team tomorrow!
Hmm I can see a problem then testing the clutch - the A9 out of St Helier going north is straight-ish but only for a mile and then you're in the drink! However looking on google streetview I spotted a "notional speed limit" sign so at least you can give it some welly. Guernsey has similar problems - Forest Road looks straight-ish for about a mile.
Clutch pressure plates are only about £25 - £30 but it's the fitting that costs (unless you do it yourself - about 8 hours?)
Clutch pressure plates are only about £25 - £30 but it's the fitting that costs (unless you do it yourself - about 8 hours?)
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