Sketchy battery / idle misfire problems .

[robrado974 1]

Afternoon everyone .

Just sitting here , just thinking about my dodgy idle /misfire problems . Ive just read online about the battery causing these problems . Now ive not tested the battery , but it is over 4/5 years old , it has been recharged at least 6 times because of me working on the car or crappy weather has meant i cant drive the car so the battery has been flat . Ive been reading about the fuel pump not working how it should do , bad fueling etc . Sometimes the car will have no throttle response and then burst into life a few seconds later . Maybe its time for a new battery ?.

[Keyo 47]

Afternoon everyone .

Just sitting here , just thinking about my dodgy idle /misfire problems . Ive just read online about the battery causing these problems . Now ive not tested the battery , but it is over 4/5 years old , it has been recharged at least 6 times because of me working on the car or crappy weather has meant i cant drive the car so the battery has been flat . Ive been reading about the fuel pump not working how it should do , bad fueling etc . Sometimes the car will have no throttle response and then burst into life a few seconds later . Maybe its time for a new battery ?.

 

If the battery is displaying the correct output I would be amazed if it was the battery, wouldn't do no harm to clean the contacts though with a wire brush if they are looking grubby. Have you changed the coil pack at all , I had the problem you had and it was the coil pack, Vince at stealth said the coil pack was that bad that it even enabled for two cylinders to be working intermittently. If you have a cheap one on well worth swopping out for a Beru coil pack. If you have misfueling this should show up as a fault code on VAG as mixture adaption or lambada code code because it cant work in its tolerance. Recommend a Vgate off ebay if you don't have one pretty cheap £30 something.

 

Bad fuelling could also be injectors choked and need to be refurbished, also fuel pump on its way out as you mentioned.

 

My first port of call would be sparks and leads if not changed.

Coil Pack

Fuel pump

Injectors refurbished - If going to do this let me find out who he uses because he mentioned to me other Owners of Rados had them done elsewhere and caused big problems as the refurbisher didn't do them correctly and they did some sort of damage to the cars .

 

Also worth checking that you have no air leaks in the intake and exhaust system.

Edited April 28, 2019 by Keyo

[robrado974 1]

Sorry keyo , should have mentioned I’ve checked the usual suspects in a previous post. The injectors haven’t been checked yet .

[Keyo 47]

You know for sure its not your coil pack as that would be my number 1 prime suspect.

[robrado974 1]

I’ve got a coil and dizzy set up , it’s an early VR . I’ve changed the coil for another one I had spare .

[Keyo 47]

Still you can eliminate both coil packs are working correctly as this does sure sound like a coil pack misbehaving.

 

I would just work your way through the parts mentioned as it will do your car good anyhow.

[Dox 23]

Has it passed an MOT with the lumpy idle?

[robrado974 1]

I’m not sure Dox ?, I can’t remember if it was like it or not .

[fendervg 32]

Won't be battery, as with the engine on it will be running off the alternator - it might be a dodgy earth connection though. Have you checked voltage output across the battery with engine on/off?

 

Then there's the usual suspects:

- dizzy hall sender

- cap and rotor arm and leads

- crank sensor

- vacuum leak

- dirty intake manifold

- injectors and fuel pressure

 

It's a real pain and sometimes very expensive getting to the bottom of rough running on a VR. Did you scan for fault codes as well?

[robrado974 1]

I’m going to book the car in when time and money allow me too . Or try and do some more digging myself.

[Dox 23]

If there's a misfire emissions will be affected hence why I asked about the MOT.

 

 

I'd spend time looking for air or vacuum leaks - servo, breathers, idle circuit, gaskets, damper, various hoses and injector seals etc.

 

Spraying easy start around various joints can sometimes find leaks, other times it just gets to the cylinders too slowly to increase the idle enough to confirm a leak.

 

You could try misting water around the ignition system on a dark evening to see if sparks are jumping to other places than the plugs.

[dr_mat 0]

You might be onto the fact that your battery is a bit low on capacity (as opposed to voltage), lead acid batteries degrade rapidly if they're allowed to discharge and left discharged for any period of time, and it sounds like you've recharged it a few times. (You've done well, I've never got more than 3-4 years out of a battery in a VW..)

 

A poor battery won't just cause issues starting, it does also provide a huge reserve of current for spontaneous loads during normal use. I would be surprised if it could cause lumpy idle on its own however.

[robrado974 1]

Thank you for the replies chaps. As I have said the usual suspects (most of them ) I have checked. Vacuum etc . I’m going to have to book it in if I can’t find it , I think a vagcom and a multi meter are needed to be honest.

[dr_mat 0]

You need an old fashioned load tester for the battery, not a multimeter.

[Dox 23]

If the battery will crank a 6 cylinder engine to the point it will fire up there’s not much wrong with it

[robrado974 1]

Yeah that’s true about the battery. I just stumbled across the battery problem online and thought you never know I’ve tried and tested loads of other parts .

The multi meter was for testing the parts of the ignition system not just for the battery. I’m pretty good with mechanics when the time allows me to do stuff . It’s the electrical side of things I don’t get .

[Keyo 47]

Unfortunately if vag don't reveal anything it's just one of those have to go through the part list, however I can honestly say after going through similar car not running right and sorting it, I drove to Derbyshire today and my VR was growling down the carriageway and all the BMW 2.0 crew got an arse slapping, Im going to put a ASBO on my RADO if this carries on .

[robrado974 1]

Lol . I’m sure I will get to the bottom of it . I have a show coming up in June and then there’s the CCGB run out in Devon , she has to be ready by then .

[seanl82 23]

Where are you meeting everyone Rob, I didn't see your name on the list on the CCGB?

 

Gutted I'm not in a position to attend, and the route taken kind of loops all the way around me!

 

If anyone going fancies a detour on the way home, take the A396 from Tiverton to Minehead. Its the first time I'd driven the road last weekend, and I was absolutely blown away. Incredible scenery, and phenomenal undulating and twisty roads that were an absolute joy to drive. I can't wait until my car is back on the road so I can drive it through there again! :thumbleft:

[robrado974 1]

I’ve taken that road Sean , not in the corrado but in the mrs BMW . Great road as you say . The not on the hotel list Sean . I will be meeting up with everyone during the trip .