intermittent rough running
Discussion
Hi All
After some advice. My S2 seems to intermittently run rough. symptoms are it seems to stutter and missfire, rev counter goes crazy. This generally clears itself after a time and normally (but not always)seems to start during slower town driving.
Since having the car I have changed:
Spark plugs, HT Leads and Ignition unit
Distributor Car and rotor arm.
Throttle pot and Idle control valve
Earth strap from Alternator to main chassis earth.
I also bough a can of the BGK44 stuff as I thought it might be a blocked injector.
My car has already had the yellow connector under the steering wheel changed. I have inspected the main wiring loom connector under the ignition unit and it looks in good consition.
The only other thing I can think might be connected with this fault is that occasionally when I turn the ignition on the fuel pump doesn't alsways stop priming after a few seconds (is alwayss fine when i run the ignition off and on again). Also my fuel pump continually buzzes when driving (has been like it since I got the car and hasn't failed in the 2000 odd miles I've driven it.
This fault is really starting to annoy me and can ruin otherwise perfect drives in the car.
Any ideas???
After some advice. My S2 seems to intermittently run rough. symptoms are it seems to stutter and missfire, rev counter goes crazy. This generally clears itself after a time and normally (but not always)seems to start during slower town driving.
Since having the car I have changed:
Spark plugs, HT Leads and Ignition unit
Distributor Car and rotor arm.
Throttle pot and Idle control valve
Earth strap from Alternator to main chassis earth.
I also bough a can of the BGK44 stuff as I thought it might be a blocked injector.
My car has already had the yellow connector under the steering wheel changed. I have inspected the main wiring loom connector under the ignition unit and it looks in good consition.
The only other thing I can think might be connected with this fault is that occasionally when I turn the ignition on the fuel pump doesn't alsways stop priming after a few seconds (is alwayss fine when i run the ignition off and on again). Also my fuel pump continually buzzes when driving (has been like it since I got the car and hasn't failed in the 2000 odd miles I've driven it.
This fault is really starting to annoy me and can ruin otherwise perfect drives in the car.
Any ideas???
Hi,
This sounds very similar to the problem on my car (also an S2), except that I tend to get a massive stutter under hard accelaration, which after a while can also turn into the symptoms you describe in town...
I've tried similar things to you, am due to try some injector cleaning stuff this weekend. I'm beginning to think it must be fuel related on my car too. Haven't noticed any strange symptoms from my fuel pump, but I am beginning to suspect it could be:
1) Fuel pipe membrane loose inside? Could cause the pipe to block intermittantly and starve fuel
2) Fuel filter - this was changed recently before the problem started
3) Bits in the fuel tank - beginning to block the pipe that sucks the fuel from the tank
Mine gets much worse in extreme heat, but I wonder if this is just fuel vaporisation exaggerating the effect.
Sorry I can't be much help! If I haven't got it fixed before our S Scotland trip, I was planning on picking a few brains there....Please let me know if you get to the bottom of it though!
Andrew
This sounds very similar to the problem on my car (also an S2), except that I tend to get a massive stutter under hard accelaration, which after a while can also turn into the symptoms you describe in town...
I've tried similar things to you, am due to try some injector cleaning stuff this weekend. I'm beginning to think it must be fuel related on my car too. Haven't noticed any strange symptoms from my fuel pump, but I am beginning to suspect it could be:
1) Fuel pipe membrane loose inside? Could cause the pipe to block intermittantly and starve fuel
2) Fuel filter - this was changed recently before the problem started
3) Bits in the fuel tank - beginning to block the pipe that sucks the fuel from the tank
Mine gets much worse in extreme heat, but I wonder if this is just fuel vaporisation exaggerating the effect.
Sorry I can't be much help! If I haven't got it fixed before our S Scotland trip, I was planning on picking a few brains there....Please let me know if you get to the bottom of it though!
Andrew
I've had similar problems on two occasions in the past.
Rough running when driving/accelerating but ok when stood still in neutral.
If I turned off the engine then restarted it was ok for a while.
Full description and advice received can be viewed here
One time this turned out to be rust in the fuel tank ~ similar but worse to what Russ had.
You can check the small filter with the tank in situ.
Drain tank and remove bung ( blanking plate ) in bottom of tank. The filter will be inside pushed onto the fuel outlet pipe.
Note ~ it may not be present, I have seen a tank without one.
It may be broken ~ It is only made of plastic and on mine the screen had ripped.
Once you take the bung out you may get an idea whether there is any rust in the tank.
If there is rust, and it is getting past this filter you will find that the inlet of the fuel pump gets blocked.
Take the hose off the pump ~ on mine there is a small thimble shaped filter in the pump inlet ~ this was blocked with rust particles.
Note that the "proper" fuel filter is after the pump and therefore will not stop crap getting to the pump.
As I said all of this can be done with the tank in the car ~ you just need to drain it down and look inside.
If the tank is rusty you have no choice but to either replace or repair it. Even if you fit an inline between the tank and the pump it will only be a matter of time before that gets clogged too. ( As I have found)
Taking the tank out is easy enough
This is what I did ~ tank repair
Holdens now have a video on their site about the product Holdens
(I still have a spare (refurbished) tank in storage here which I am happy to talk about.)
Your local garage would probably do the job of removing the tank but I fear that most would prefer to replace the tank rather than repair it.
The following spring I had similar symptoms. I knew it couldn't be the tank but was truely stumped for ages.
In the end it turned out that it was a loose connection in the fuel relay ~ the small resistor was not firmly pushed in.
That problem took months to find, was eventualy diagnosed by the "waggle" test and a star tester diagnostic tool.
It too half a second to fix!
I hope this helps ~ there are a couple of threads around at the mo with similar symptoms.
Most tanks are now around 20 years so it's a problem that we may hear about more often now
Cheers
Tim
Rough running when driving/accelerating but ok when stood still in neutral.
If I turned off the engine then restarted it was ok for a while.
Full description and advice received can be viewed here
One time this turned out to be rust in the fuel tank ~ similar but worse to what Russ had.
You can check the small filter with the tank in situ.
Drain tank and remove bung ( blanking plate ) in bottom of tank. The filter will be inside pushed onto the fuel outlet pipe.
Note ~ it may not be present, I have seen a tank without one.
It may be broken ~ It is only made of plastic and on mine the screen had ripped.
Once you take the bung out you may get an idea whether there is any rust in the tank.
If there is rust, and it is getting past this filter you will find that the inlet of the fuel pump gets blocked.
Take the hose off the pump ~ on mine there is a small thimble shaped filter in the pump inlet ~ this was blocked with rust particles.
Note that the "proper" fuel filter is after the pump and therefore will not stop crap getting to the pump.
As I said all of this can be done with the tank in the car ~ you just need to drain it down and look inside.
If the tank is rusty you have no choice but to either replace or repair it. Even if you fit an inline between the tank and the pump it will only be a matter of time before that gets clogged too. ( As I have found)
Taking the tank out is easy enough
This is what I did ~ tank repair
Holdens now have a video on their site about the product Holdens
(I still have a spare (refurbished) tank in storage here which I am happy to talk about.)
Your local garage would probably do the job of removing the tank but I fear that most would prefer to replace the tank rather than repair it.
The following spring I had similar symptoms. I knew it couldn't be the tank but was truely stumped for ages.
In the end it turned out that it was a loose connection in the fuel relay ~ the small resistor was not firmly pushed in.
That problem took months to find, was eventualy diagnosed by the "waggle" test and a star tester diagnostic tool.
It too half a second to fix!
I hope this helps ~ there are a couple of threads around at the mo with similar symptoms.
Most tanks are now around 20 years so it's a problem that we may hear about more often now
Cheers
Tim
Edited by Elfit on Tuesday 29th March 07:46
Rev counter going crazy says that you have either a duff rev counter, or an ignition fault. (Just to add to the complexity - the rev counter can fail in a way that induces an ignition fault.) So I would re-check all the ignition-related things you already checked. If it was me, I'd also put a tell-tale lamp on the coil +ve so I can confirm it's getting power, and across the coil so I can see that the ignition amp is still working when this problem happens. Do you have access to disconnect the rev counter?
I have been thinking about this some more and given the intermittent nature of the fault I'm not convinced it's a mechanical problem with the fuel supply (though could still be electrical). For example I drove back from Wales to London on the m4 a couple of weeks ago and I don't think it happened once on te motorway.
My rev counter works perfectly till the car starts missing would this be the case if the rev counter was faulty?
The last part of the ignition to check would be the distributor itself. Otherwise all I can think is an intermittent injector fault or perhaps dodgy wiring to the fuel pump.
Strange that me and Andrew both report that the problem is worse with heat
My rev counter works perfectly till the car starts missing would this be the case if the rev counter was faulty?
The last part of the ignition to check would be the distributor itself. Otherwise all I can think is an intermittent injector fault or perhaps dodgy wiring to the fuel pump.
Strange that me and Andrew both report that the problem is worse with heat
jonesy80 said:
Strange that me and Andrew both report that the problem is worse with heat
Could be that there is less fuel than there should be and the heat is vapourising what fuel there is in the fuel lines? Hence exaggerating the problem but not actually causing it....maybe. Any in my case I think that it could be more to do with the 'time engine is running' (backing up the filter blocking theory).
Have booked mine in at XWorks Service in Preston (very helpful) and agreed for them to do a pressure test, remove tank, repair tank, replace tank carrier (needs doing anyway!). Think I will provide a Holdens Kit for them to use (subject to agreement). Booked in for April 28th so will be able to report back then.
Andrew
GreenV8S said:
The rev counter playing up tells you that it is an ignition problem. I think you're barking up the wrong tree looking for problems on the fuel supply side.
My rev counter goes mad too when the missfire happens on mine. I put this down to the fact that the signal going to the rev counter is inconsistent!!! It's fine at as long as the car is stationery (not sure if that's pens and paper or not moving). I am going to replace the coil on Friday and look at that. Them check the rotor arm and cap as well as unplug all fuses and relays and generally give all conections a clean. I did give my mass airflow a clean but only with contact cleaner. Might give it a blast with carb cleaner then contact cleaner to see if that's better. All this doesn't take too long to do it's the taking it for a 5 mile drive only to find it not working that's a pain. Especially as from cold it's often fine for a few miles.I know you have changed the yellow connector but the symptoms are very similar to yellow connector problems. After I changed my yellow connector I had a repeat of the same symptoms which turned out to be a loose soldered joint on the back of the ignition switch. The various earths are also worth a check as they are mostly open to the elements.
Rob.
Rob.
Doesn't help your mis-fire but stationAry is not moving. StationEry is paper and stuff. I always think E for envelope to remind me.
Gary
[/quote]
I recall going into a post office and asking the assistant " do you keep stationery ? " she replied " I do for the first five minutes, then I go like hell !!! "
couldn`t resist.
Gary
[/quote]
I recall going into a post office and asking the assistant " do you keep stationery ? " she replied " I do for the first five minutes, then I go like hell !!! "
couldn`t resist.Griffinr said:
I know you have changed the yellow connector but the symptoms are very similar to yellow connector problems. After I changed my yellow connector I had a repeat of the same symptoms which turned out to be a loose soldered joint on the back of the ignition switch. The various earths are also worth a check as they are mostly open to the elements.
Rob.
Actually the yellow connector was changed by a previous owner not by me soni think checking this will be a very good place to start.Rob.
By the way anyone got any theories on why very occasionally my fuel pp continue to prime non stop instead of stopping after a few seconds? Is this just somethin they all do?
Griffinr said:
I know you have changed the yellow connector but the symptoms are very similar to yellow connector problems. After I changed my yellow connector I had a repeat of the same symptoms which turned out to be a loose soldered joint on the back of the ignition switch. The various earths are also worth a check as they are mostly open to the elements.
Rob.
Actually the yellow connector was changed by a previous owner not by me so I think checking this will be a very good place to start.Rob.
By the way anyone got any theories on why very occasionally my fuel pump continues to prime non stop instead of stopping after a few seconds? Is this just somethin they all do?
Where does the yellow connector usually reside? I was under the impression it is under the steering column. If so it aint there for me. I am amazed how tidy the wiring is though and under the glovebox. Someone in the past spent a long time sorting it out. There is an odd cable under the steering column with a 1amp fuse in it but I can't work out what it's for, any ideas?
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