Porsche 924 white

[bigfella2]

I thought this might have happened.

[inconsistant]

So it wouldn't start. I tried 10-15 times and it just turned over but didn't fire. Battery and oil light on when I turn ignition. In the absence of mechanical knowhow or problem solving ability I kept going back to it every few minutes thinking it might have sorted itself out but to no avail.

 

Received various suggestions from the Owners Club forum, which gave me a steady stream of things to check or confirm as working or tested.

 

I'd put the distributor on wrong. Spent the evening reading up about it and watching awesome youtube vids about setting up distributors, and realised my mistake. Next morning I went out, re-fitted confident that was the problem, but it wasn't.

 

I was getting a spark from all plugs, tested on the cam cover, which was a new trick I learned. I pulled out the injectors and could get them to squirt into a bottle giggity by pushing the air metering flap up, but when I turned it over and then checked the plugs they were dry, and when I pulled an injector out, put it in a bottle and turned the engine over it didn't squirt giggity goo. Bridged the Fuel Pump Relay, and proved that the fuel pump worked ok, and undid the fuel line connections from the fuel distributor and confirmed fuel was getting that far.

 

3/4 of a tank of fuel, battery charged, brand new plugs, brand new injector seals, crank and cam set at tdc and rotor arm pointing at plug lead no1, checked and double checked everything. Turned over easily, but not even a splutter.

 

Mechanical friend who said he'd help popped by and went over everything I'd done and it all looked ok. He thought the spark was weak, so we put a spare coil on that he had in his van but no better, worse if anything. It started to rain and was getting dark so he left, and I got in the car, shut the door and sat there cranking it thinking I'd just keep going until the battery was flat and it started. And I got excited, and I videoed it:

 

 

And then after about a minute loads of smoke came billowing out of the engine, there was a funny smell, and I panicked, and turned it off. Not sure if smoke is normal and is just stuff bedding in, or if maybe it's the exhaust manifold paint smoking as it cures from the heat (manifold definitely got hot enough) or something worse, so I thought I'd play it safe and turn it off.

 

Tried a few times to start it again so I could see if the smoke returned and to get a vid of it, but it wouldn't go and I pretty much ran out of daylight. At least I know it WILL run.

 

Next day I popped out there but t didn't start so I jump started it and it ran for a while, about 15 mins. Enough time for the smoke to die down (it WAS the paint) and for the engine temperature to get up to normal and for everything to settle down nicely.

It's idling quite fast, about 1500rpm, and once up to temperature the exhaust is reassuringly steam free. I went to drive it forward to park and it stalled, and then I couldn't start it. I tried jump starting it again but it wouldn't go, so I left it for the evening.

 

The thing that was adding loads of pressure was that there was a Porsche 924 Owners Club get together at Brooklands on Saturday (6th June) and because Brooklands on New Years Day was where I broke down and things started to go wrong, I really really wanted to have it running by then so I could go back with it working. I'd booked an MOT for during the week, but it wasn't looking hopeful...

 

Having jump started it, my handy mechanical neighbour, who had been following my progress with interest, had offered to pop over with his timing gun to get it running nicely so I could get it round the corner for it's MOT the next day. But we couldn't get it to start. Nothing worked. We were out there until about 11.30pm just trying to work out why it wouldn't run. We went methodically through many, many checks to see what was up. My neighbour saw it as a challenge to get it going and very reluctantly gave up when we couldn't see what we were doing any more.

 

 

So I called the MOT off, did some more reading up on the owners club forum, and found out that I'd fitted the distributor wrong again. Finally understood properly what I was supposed to line up with what, and the next morning went out there before school and fitted it properly. But definitely properly this time.

 

 

I had to line these two notches up and line up plug 1 at tdc. Derp. Idiot. But it still didn't start. Also got a new rotor arm just in case, but no change.

 

Wouldn't fire with me turning over the ignition, wouldn't start being jumped from other car, wouldn't start with the Fuel Pump Relay bridged. As before, getting sparks, but plugs dry. Fuel pump noises when bridged so pump works, but no pump noises when ignition is turned on. Fuel is getting to the fuel distributor. I'm getting pissed off with it all. Can't believe that the most difficult bit of doing a head gasket is getting it to run afterwards!

 

Saturday morning came, and in a last ditched attempt to get to Brooklands, I had booked an MOT for 11am, and a helpful 924 owner/guru who was coming past on his way popped in ridiculously early to try to get it going, so I would get it round to the garage, fingers crossed , they would issue an MOT and I'd be Brooklands bound. That was the plan...

 

He got it to start a couple of times, but it wouldn't run for long, then it was difficult to start. He worked out pretty quickly that the 5th injector/Cold Start Valve/CSV doesn't seem to be working. We checked the Thermo Time Switch/TTS and it's connected OK, so he earthed the red/white wire into the CSV (which I think was to bypass the TTS) and that got it to start a couple of times, but it was hard to keep it going for long. The mixture and idle speed, along with the timing is out and it's affecting the running. Unfortunately he ran out of time, and had to head over to Brooklands. On his own. And I popped around to the local garage to cancel my MOT. And bought a donut from the bakers to cheer me up. But it didn't.

 

I'm in a bit of a catch 22 in that it won't stay running long enough to warm up so we can adjust the idle & mixture, which will make it easier to start. Anyway, I missed Brooklands so there's no rush or pressure to sort it. I've been reading up on the 924OC forum to try to understand better what the WUR, AAV, TTS, FPR and CSV all do and how they work. It's becoming clear that I'm not the first person to experience this sort of thing. I've been out this evening to run some tests and I've pretty much confirmed that the Cold Start Valve (which sprays extra fuel into the intake manifold to aid cold starts) isn't working, which is why it won't start. This is known as the 'cold start problem'. That's all for now. I've run out of ability to sort it myself. It's really frustrating because I know I'm SOOO close. 

It's been a disappointing week and a bit. Also gutted that I couldn't get to Shitefest because it looks like it was awesome. Really want to go next year. Might be running by then...

[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.