Porsche 924 white

[mat_the_cat]

High idle says you must be getting air in *somewhere*, either a bona fide air leak, or the AAV which raises the revs when cold, doing it when it shouldn't. Good luck and well done for getting this far!

[Danblez]

Gah so close! Don't lose the faith!

 

As the wur is the only thing you have tinkered with I would be tempted to whip it off and check it's working proprley. Don't go chasing new issues as it's possible but unlikely!

 

Also check inlet and vacuum pipes for leaks splits as per mat the cats suggestion.

 

Good luck!

[inconsistant]

Honestly , I have endlessly checked for vacuum pipe leaks! Endlessly...

Didnt really do anything to the wur other than clean the outside of it.

Did a test of the csv/5th injector last night and i couldnt get it to squirt which sounds like it might be the problem. I left it on the inlet manifold when I cleaned it up so I wonder if I damaged it then?

[Vince70]

I don't think in this weather it would make much difference once the car is initially started if it was the cold start injector or not as it should carry on running...

 

I had a problem once on my dads old 2.0 petrol Audi A6 (100) which wouldn't start which was the opposite to yours as it over fuelled due to the cold start injector continually pumping in petrol and called the AA out..

 

The guy disconnected the electrical connector to the injector and it started immediately and I used it for about a week like that a few summers ago till I managed to obtain a couple of coolant sensors (There was two to replace one for the gauge ( which didn't work before) and one for the engine management) I just replaced both as I think it was less than a tenner for each sensor.

 

I really hope you get this sorted after all that hard work you've put into the car. I really was hoping it would start 1st turn of the key after all that effort.

[Taff]

you're close, mate, stick with it. Sometimes the smallest thing can cause endless heartache and frustration, but when it's done you will feel like a dog with two dicks. More so given your relative inexperience with the spanners.

[Asimo]

For someone doing this for the first time, you are doing great. Overcoming these setbacks is how experience and expertise are made.

[Skizzer]

I kept reaching for the like button in that last update then backing off as each thing you tried didn't fix it… really feeling your pain here.

 

It'll be something tiny.  You'll kick yourself (or possibly just the car).  Keep the faith brother.

 

 

Great thread, at least 

[colino]

I wouldn't have thought that the porky would need the extra cold start in this weather.  As others have said, you have done all of the hard work, it is now down to finding the gremlin!  As it has actually fired up, the timing can't be massively out, a little play with it when it was running either way would have satisfied any queries, but before checking fuel pressure etc., I'd be checking all of the electrical connections, especially the polarity of the coil.

[The Reverend Bluejeans]

K Jet is a pain in the rectum - i'll be a wrong plug on somewhere.

 

You've done a bloody fantastic job so far, feel proud/pat on back etc.

[mercedade]

I love this thread. I'm willing you on with absolutely no helpful suggestions whatsoever, but a whole lot of enthusiasm.

[inconsistant]

 

Great thread, at least 

 

 

I love this thread. 

 

Yeah, thank goodness I'm shite at keeping chod running. The alternative would be a one post thread:

 

-----------------

 

 

 

A thing went wrong with my mota.  All fixed now.

 

 

 

*no one likes a post you made, you dull competent.

 

 

.

[worldofceri]

I think you're being a bit hard on yourself.  This thread is highly compelling even when things are going well.  I'm pretty sure I'm not the only one who finds it inspirational, coming from a position of not really having the time and/or skills to be a more committed chod-botherer.  Taking the time to explain the meaning of terms like TDC is incredibly useful to novices who, I'm sure, can follow what you're doing more closely than some other blogs that might have sentences like "... and then I lobbed on a fresh timing belt, cleaned out the MAF sensor and blanked off the EGR valve...".

[mat_the_cat]

I think the reason so many of us like the thread, is that it appeals on a number of levels. It's inspiration for people who may never have tackled anything like this, but also a reminder to those who have, of *their* first 'big' job. And so they can appreciate the sense of achievement once it's all sorted

[forddeliveryboy]

^^ This is so true - most of us have been there, in the pouring rain/at night if not both! Is the cam timing deffo right?

 

Once sorted, all your pain will be your gain since you'll know about things you wouldn't have had a clue about if all had been straightforwards.

[Parky]

You have done extremely well here - the fact it has started and run ok with no odd noises is a sign your handiwork is good. It will be something ridiculous like a tiny short or a split vacuum hose or something else minor.

 

Did you try revving it when it was running? Did it react normally or did it seem to pause before revving up? That could point at the timing but if it was that far off it wouldn't start at all.

 

You WILL crack it!

[garethj]

I feel your pain, in fact I lived through most of it when I was trying to fix that ignition coil. Have you got a Haynes manual for it? There's a very good section on the fuel system, I made a fuel pressure gauge that you need for some tests, you're welcome to it.

 

I only vaguely remember the WUR but I agree with the others that the cold start valve isn't needed in this weather, try and find why the plugs are dry.

[Parky]

Have you thought about rigging up a gravity feed fuel tank as a temp measure? Bleach bottle or similar. Might help confirm if fuel is actually making it from the tank. It could be a clogged filter after all this mullarkey!

[Danblez]

Can you see the brown wire with ring on the end on this pic? At about 2pm by the block. Is this defiantly connected back to earth? I had similar sounded issue after my head rebuild I had forgotten about and I had missed that wire. It was shorting on earth and making it run of sorts occasionally.

[inconsistant]

Is the cam timing deffo right?

 

Yes, but the more times I go over the basics the less confident I am that I know what I'm doing.

 

 It will be something ridiculous like a tiny short or a split vacuum hose or something else minor.

 

Did you try revving it when it was running? Did it react normally or did it seem to pause before revving up? 

Endlessly checked the vacuum pipes.

 

Revved OK when running and settled down to idle nicely.

 

Have you got a Haynes manual for it? There's a very good section on the fuel system, I made a fuel pressure gauge that you need for some tests, you're welcome to it.

 

I only vaguely remember the WUR but I agree with the others that the cold start valve isn't needed in this weather, try and find why the plugs are dry.

 

I have a Haynes manual, but my feeling is that it's not a good book for beginner level learning, as it assumes a certain basic knowledge. Will have a look though.

Via the owners club I have got hold of all the bits to make up a fuel pressure testing kit. Will assemble and use once I have worked out what to do.

 

Have you thought about rigging up a gravity feed fuel tank as a temp measure? Bleach bottle or similar. Might help confirm if fuel is actually making it from the tank. It could be a clogged filter after all this mullarkey!

Not considered this. 

 

Can you see the brown wire with ring on the end on this pic?  Is this defiantly connected back to earth? 

Definitely put back on.

 

 

^^^ and this is my problem, at least for the moment.

I've had endless good advice both here and on the owners club forum, and I check and re-check stuff that I've gone over already but it doesn't make a difference. I truly thought that I was beginning to understand how an engine worked, and that I was heading in the right direction with suspecting the CSV, but in truth I'm really just stabbing in the dark.  I've no idea what's up, and although I've checked and double checked my work, the timing, and hoses, connectors and the like I'm just going round in circles and making no headway at all. I've made the decision to give up and pay a mechanic to look at it, because I'm out of my depth.

 

This might sound daft but while changing the head gasket I was following a procedure where I took off a whole load of stuff, some of which was easy and some was hard, and then I put it all back together again. Because I can be quite methodical I managed to do it without messing it up. I didn't need to know what things were, how they worked or what they did in order to complete the task. Getting the car to start is a completely different game, because I don't have the ability to diagnose or make judgements. When I'm alongside someone who knows their way around an engine and they are having a go then I feel like I'm learning loads because I'm watching, asking questions and filling in the gaps of what I understand. 

 

I reckon I've now spent more hours trying to diagnose why it won't start than I did re-assembling everything, and the frustration and irritation is overshadowing the sense of achievement that I felt when I'd got everything back together and turned it over for the first time. On the plus side I've got the car to the point where it will be easy for someone who knows what they're doing to diagnose and fix the problem, and as much as I'd love it to have been me that gets it running, it's not going to be, because I've can't. I've tried, and I can't. 

[inconsistant]

I'm guessing that you are going to reply suggesting that I give it some time and come back to it, or go methodically back to basics and go over everything from the start again, or that it might just be this or that, but definitely to have another go. I've been away from the car for a couple of weeks and took the time to methodically go back over all of the advice I've been given and try to understand what might be the problem.

 

 

What I've replaced:

New set of sparkle plugs, New rotor arm, New injector seals, Replaced oil, Replaced coolant, Battery charged, Fuel tank 3/4 full.

 

Where I got to:

Wouldn't fire with me cranking the ignition, wouldn't start being jumped from other car, wouldn't start with the Fuel Pump Relay bridged. Getting sparks, but plugs are dry. Fuel pump noise when bridged so pump works, but no pump noises when ignition is turned on. Fuel is getting to the fuel distributor.

The car has been running, 3 or 4 times. Longest was about 15mins, shortest was about 2-3 mins. It either cranks and doesn't start, not even a cough or splutter, or it starts and runs for a few minutes minimum. Started once on it's own (ran for 4-5 mins), started once when jump started (ran for 15 mins up to temperature, all fine and stalled when I tried to move it) and started a couple of times when a 924 expert earthed the CSV (2-3 minutes each time).

 

Because I've changed the head gasket it might be easy to assume I know more than I do about engines, so I'm going back to the very basics of why my engine won't start. I understand that it needs fuel, air and spark to work. If one or more of these is missing then it won't start. Here's all of the advice I've been given so far, roughly grouped into those three areas, so I can go back over it all like some mega to do list:

 

 

Suggestions to test for Fuel

 

check fuel pump works

 

check fuel getting to fuel distributor

 

check fuel getting to all 4 injectors

 

check spark plugs are wet

 

Take out the fuel pump relay and bridged it, and check the fuel pump runs ok.

 

With one injector in a jar, get it to squirt fuel by pressing up on the metering flap (check they start squirting after about 1-2m of movement on the flap)

 

With one injector in a jar,  turn the ignition on and check there's no fuel squirting out

 

Adjust the mixture, clockwise 8th of a turn at a time up to a half turn and back again.

 

Perhaps adjust the mixture a bit closer to the cut-off threshold?

 

After cranking and trying to start the engine with everything installed as it should be (fuel pump relay, injectors, all hoses etc), remove one of the spark plugs and see if it's wet with fuel. If it's wet you are getting fuel, if it's dry you're not.

 

After cranking and trying to start the engine, if plug is wet, clean it and dry it with carb cleaner and a cloth and do the same to the other 3. Then try and start it again.

 

Ask the wife to crank the engine with a bit of throttle and you lift the air flap just a touch, this should get the injectors to spray and help it to start.

 

Check if the 5th injector (blue electric plug on the back of plenum chamber with fuel hose banjo on it) remove that but leave it connected and see if it sprays fuel during cranking for a few seconds.

 

5th injector might have had a dodgy connection - fairly common, sometimes the contacts slide backwards or sometimes just dirty.

 

Put an injector in a bottle again, jump the fpr relay and redo mixture so it is only just cuts fuel off, it needs to be very close for small amount of airplate lift at cranking.

 

Remove plug and insulate Cold Start Valve, remove CSV and wipe nozzle, remove HT lead from Coil, Ignition on & crank engine to operate fuel pump for 1 min, and check no fuel is dripping from the CSV during this time

 

Put nozzle in clear container, reconnect plug to CSV, remove Thermo Time Switch plug, jump the 2 TTS plug terminals, switch on ignition & crank engine, check spray pattern
 

Make sure engine is cold, remove plug from CSV, put voltmeter across plug contacts, remove HT lead from coil, turn ignition & crank engine for 10+ seconds
check for volts to register for 3-10secs then cease to register
 

If the car can start but not run long enough to tune it, it seems to me that the wur is at fault

 

 

Suggestions to test for Air

 

You may have a vac leak, With raised idle speed, an air leak is likely. Check vacuum hoses and connections for any splits.

 

Possible vac leak. Check all the pipes on the back of the inlet manifold are intact.

 

Check every air connection is perfectly sealed (cling film them if in doubt).

 

Have you tried feeling if the metering plate moves when it is cranked?

 

Lifting flap trick can work but its very easy to lift it too far, only a tiny lift needed

 

Check oil breather hose for cracks even if it looks good.

 

Spray Easystart or carb cleaner or brake cleaner etc around all the joins and hoses that are part of the intake system, the engine will stumble or change it's rpm if the spray gets sucked in through an air leak.

 

 

Suggestions to test for Spark

 

Check battery charged

 

Check timing: TDC at crank and dimple on rear (head side) of cam

 

Check distributor set correctly with rotor arm pointing at nick in metal and to lead for cylinder no1 at TDC

 

Check distributor is in the correct position its not just a matter of having the rotor pointing at number one, the ignition timing needs to be roughly in the range of 0 to 10 degrees as well which is only a five degree window at the distributor.

 

Green wire on the distributor: check the contacts are clean and pushed home

 

Check leads are 1 3 4 2 clockwise

 

Check for spark, plug against block and crank engine

 

Check the earth on the ignition amplifier box/ECU. If the mounting screws are rusty this will interfere with the spark as the ECU is earthed through its mountings and not via wiring.

 

 

Suggestions to test for Mixture/Timing

 

Timing and fuel mixture likely to need attention

 

An engine will run with 80% too much fuel, but won't run if about 20% too little so the other thing to try is adjusting the mixture screw quite rich say 2 or 3 full turns and try that.

 

If the car can start but not run long enough to tune it, it seems to me that mixture too weak.

 

The mix is wrong too weak or too rich

 

Valve timing slightly out?

 

 

Suggestions for other things to test

 

Put everything back as it was.

Check cam timing

 

Check lead order

Try for a start and report back exactly what happens. Start then die is mixture

 

Check the plugs if they are wet with fuel then it's too rich turn it down by 1/8.
If they are dry then turn it up by 1/8.

Could be WUR but you won't know until it runs.

 

Coughs but no start after long cranking is Cold start. No coughs at all is ignition or fuel delivery

check plugs, if it's ignition the plugs will be wet with fuel, if no fuel the plugs will be dry.

 

With CSV removed but with fuel line connected, I'd jumper the fuel pump relay with ignition on (not cranking) so pump is running, then I'd put a + & - wire from the battery direct to the CSV. It should spray fuel, if it doesn't it's faulty and needs changing.

 

If that sprays, I would test the 2 CSV plug terminals (wiring harness side) whilst cranking that it gets 12v. It might only be brief as the TTS will cut it after a few secs in this weather but it should give power for a moment or 2.

 

Then (or in which ever order you fancy) I would check the TTS for 12v same as above. (These 2 power tests can be done with no pump relay or jumper wire for safety if you want but it doesn't matter).

If that checks out I would look at the WUR and test the system pressure.

 

 

I'll be working my way through this list over the next few days, a making no assumptions. If it's still not running then I'll definitely give up and book my mechanic to come and sort it out.

[Skizzer]

I've made the decision to give up and pay a mechanic to look at it, because I'm out of my depth.

 

I'm guessing that you are going to reply suggesting that I give it some time and come back to it, or go methodically back to basics and go over everything from the start again, or that it might just be this or that, but definitely to have another go.

 

I for one am not going to suggest any of those things.  Calling the cavalry at this point sounds fair enough to me.  You've done the laborious part, respect for that, and now need to rent some hands-on expertise:  sensible decision.  

 

Me, I'd have sacked the whole thing off long ago.

 

Good luck!

[Parky]

If you are an AA member, couldn't you get them round to help get it started? They might diagnose the fault for you, saving the bother of getting it to a mechanic?

[garethj]

I feel your pain.  I wrestled with the car only running with an incorrect ignition coil, the correct coil would leave me stranded.  Turned out to be the feed to the coil which came from the alternator, can you check that the wires are good and clean all the way along there?  Peel back the insulation because the exhaust is close and the copper can get charred from the heat and won't conduct enough.

[worldofceri]

I think we need an Autoshite delegation to head down and get this sorted.  I'd be no help, obvs, but I could make the tea and sweep up or summert.

[Pillock]

I was just about to ask where you were, and whether we could organise a posse to come and randomly stab at stuff. It might work, worst case scenario you rule out even more stuff and it'll be a morale building experience.

[Parky]

That's a good idea, I would be happy to come along and sympathise

[Bobthebeard]

Sorry if this has already been suggested/checked, but DME relay ? (if it has one)

[Asimo]

Valve clearances ok? Apologies if you mentioned it already. Compression test - if valves are not completely closing etc.

[inconsistant]

Gents, some news/progress with this...

 

This afternoon a recommended mobile mechanic came and had a look. After checking the basics he noted there was a very weak spark. I had a new coil arrive the other day from Frazerpart so he fitted that but it made no difference. There's good voltage leaving the battery, but low voltage at coil. Eventually after much hunting it was traced to a damaged pin on the connector block at the ignition amplifier box. Not related to the work I did, and he suggests it's probably been like that since before I had the car. Prongs were fixed, and a strong spark was restored. Engine still cranking and not firing, but at least now with a strong spark.

 

After a little more searching it became apparent that there is no live feed to the Cold Start Valve because the Thermo Time Switch doesn't work. The suggestion is that this was likely to have been damaged by the engine overheating due to the head gasket failing. By forcing the CSV to fire we could get the car to start fine (as Stephan from the 924OC did when he came over and got it to start).

 

Once running for a few minutes and turned off, the car then starts fine, I assume because it's warm and doesn't need the CSV to fire.
It also needs a tune, and apparently I've fitted the cambelt too tight which is why so it's whining so much.

 

 

I feel happier than I have done for ages. The diagnosis makes sense to me based on how far I'd got with it. I noted that the CSV wasn't firing and had checked the feed to the TTS but hadn't got as far as checking the TTS itself. When my AA patrolman chum came around to help he noted the weak spark but we never got it pinned down. We checked the earth to the ignition amplifier but not the connector terminals. I wonder if that might have been why GarethJ was having so many problems with starting it? £60 well spent I reckon.

 

Anyway, my TTS is faulty... I need a new TTS.

[alf892]

Sounds like bloody good value for £60 does that........too few people capable of logical fault diagnosis/tracing. maybe one for the Limeflower thread?