CPR bodge

[Rottbott]

My car starts up really badly in the cold at the moment (so much that it flattens the battery without starting here in Lancaster), and I'm pretty sure it's due to the CPR which has been causing problems for a while. Right now it's Christmas and I won't be able to get any new parts delivered for a while, but I have a lot of driving around to do, which means I need to make the dratted thing start, so...

Martin told me a while ago there's some sort of bodge you can do to make the engine start properly despite a dodgy CPR, but I can't remember the details. Can anyone tell me how to do it?

[stunned_monkey]

I think I was talking about the cold start valve. In the workshop we get them started up by manually enriching on the screw but this is hardly something you can do every morning.

CPR is £195 and even you could change it yourself

[stunned_monkey]

sorry, that looked ruder than I meant it! It's two 5mm allen keys and a 12 and 14mm banjo bolt plus one vac hose. Simple

[NickT]

Rottbott Wrote:My car starts up really badly in the cold at the moment (so much that it flattens the battery without starting here in Lancaster), and I'm pretty sure it's due to the CPR which has been causing problems for a while. Right now it's Christmas and I won't be able to get any new parts delivered for a while, but I have a lot of driving around to do, which means I need to make the dratted thing start, so...

Martin told me a while ago there's some sort of bodge you can do to make the engine start properly despite a dodgy CPR, but I can't remember the details. Can anyone tell me how to do it?

Have you had a fuel pressure check to see if it is the cpr that is duff?

Check that you get 12v on the grey plug with the engine running

Resistance across the cpr electrical pins should be approx 30 ohms

there is also a wire mesh in the cpr where one of the banjo bolts in.
this can get dirt behind it. blast it out with an airline

nickt.

[NickT]

classic bodge is to remove the blue plug (cold start valve)
remove the grey plug from the cpr
put the grey plug on the blue cold start valve
crank engine for approx 5 seconds
put the plugs back in the same positions
start engine

the 12v from the cpr while engine cranking will open the cold start valve injecting some fuel into the inlet manifold

fixing the problem in the first place is easier

good luck

NickT.

[Rich H]

I think I may have been guilty of telling you the "bodge".... When we were at Phill & Claires, you tryed to show me the fault, but it started on the button!

Take off the the air filter box to expose the fuel metering flap

Push the flap down by a couple of **millimeters** and crank the engine - you'll either need inredibly long arms, an assistant, or something to hold the flap down slightly that won't fall into the inlet manifold!

Don't press the accelarator while cranking.

From what you were describing to me, it sounded like your CPR is blocked and not enrichening your mixture (the equivalent of trying to start a cold engine without any choke). Pushing down the flap does the job of the CPR, once the engine has warmed up a bit, you can release the flap and put the airbox back on.

[Dan Howarth]

What i did was get 2 cpr's. 1 from a volvo and one from an audi. I took mine off and split all 3 of them into their 3 parts. You need the bottom piece of your 'd' the middle piece off the audi and the top piece off the volvo cpr's, i think it goes that way round but put it all back together and that should work. It'll probably only take you about 15 minutes to do but you need to go to your local scrap yard. The bits will only cost you about £5- £10. Thats what i did and mine works fine now. no more hot/cold start problems for moi. The reason you need 3 cpr's is that the volvo's middle or top isn't the same as the 'd' and the audi's middle or top isn't the same as the 'd'. but with all 3 cpr's you can make one the same as the 'd'. Be methodical when taking each one apart though. Springs and stuff might go all over the place so open them carefully and lay them all out individually.

[Rottbott]

I can fix it fine given a whole new one, I've had it out before when doing rocker cover gaskets. The problem is that there's no way I'm getting any parts through the post in time for my trip from Lancaster to the Isle of Wight so I have to get it running as it is!

NickT's suggestion sounds very similar to what Martin was telling me, but I remember Rich telling me about the metering flap one now -- I think it was in the context of testing to confirm it really was the CPR at fault. Anyway, that's a couple of things to try now so hopefully I can get it running and fix it properly after Christmas :). Thanks all.

[stunned_monkey]

Cold start valve bodge will only cause the valve to fire.... which it should do anyway if the engine's cold. This is usualyl a fix for a hot start problem. From what you're saying it might not be working as well as the CPR having messed up. at the top left of the water pump there's a brown connector - is it plugged in?

[NickT]

A fuel pressure test will show quantitatively that the fuel system is working within specifications.

I've given Bozzy a volvo k-jetronic fuel pressure test I got from ebay for the club to use, should save guessing.

Test for cold start valve is to put multimeter cables across the pins on the blue plug.
With the engine cold (i.e. not run for at least 8 hours) there should only be 12 volts at the blue plug for approx 7 to 12 seconds with the engine being cranked only. You can prevent the car from starting by unplugging fuse no.1 if my memory is right.
This is controlled by the thermo start switch that is on the left of the water pump as martin said by refering to the brown connector.

Good luck,

NickT.

[steve.s]

Hi

i wouldn't assume this is the cpr, i did and bought one and the car was exactly the same.

This could be what i think mine was....a poor coil connection.

try cleaning the coil connections/or recrimp.

Also easy to clean the cpr...and i don't thing they go wrong much.

what is it doing exactly?.

steve

[Rottbott]

A while ago it started taking more cranking than usual to start in the cold. Then it would start (after a while), but run badly and die as soon as I applied any throttle. Then last time I tried (when I posted this) it was so cold it wouldn't start at all. I heard fuel going bang for a few seconds but it didn't catch, even though it kept cranking for a very long time.

That's one point, those batteries of yours Martin must be magic... despite my dodgy alternator and permanently-on cooling fans, that battery turned the engine over for an incredibly long time before it ran out.

[steve.s]

Hi

this could be a number of things i think.

try jumping the cold start valve. and don't try accelerator, but hold the fuel flap down 5 mm or so.

this is how mine ran...rough and would cough and die

if you can get it to run a minute...would it then idle ok?.

Regards

Steve

[stunned_monkey]

steve.s Wrote:Also easy to clean the cpr...and i don't thing they go wrong much.

I agree.... and disagree. I've only known one CPR that "went wrong" on a working car, and that was mine!! Usualyl we supply them for cars that are being resurrected after years standing still. In those cases, I've tried to clean them out myself and failed miserably.

[Rottbott]

It wasn't too cold today (just wet) and it decided to start fine, so I haven't had the opportunity to try any of the suggestions yet -- hopefully I won't have to. I've got them noted for the other end of my upcoming car ferry trip though!

Steve, I never got it running just by leaving it running badly without applying throttle. I assume it would have eventually warmed up enough to run. A better solution seemed to be to keep the starter motor going until it caught properly while giving it full throttle, then letting go of the starter and keeping it above 1500 rpm for a while to warm up.

After the new year when everything's settled down I'll have everything out that seems relevant and clean it all up.