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Locosaki
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Joined: 03 Jul 2016
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Location: Fife


PostPosted: Sun Jul 15, 2018 4:25 pm    Post subject: Reply with quote

Hi James,

Great work mate hat off to you

Just a wild thought I had reading this, is there any type of anti hijack switch, I got caught out with this pulling an engine out my cosworth. If activated it wouldn’t allow the fuel pump to run. (Or might have been a switch to kill power to pump in the event of an accident)

Something to do with the angle I had the car at when pulling engine out but either way it would power the fuel pump

Just a thought
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Jamesx19
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PostPosted: Sun Jul 15, 2018 5:07 pm    Post subject: Reply with quote

Hi Lokosaki, thank you.

Good point. Not sure. But car locks and unlocks. And engine turns over. It was fairly level. Dont know

All the sensor's are connected up.
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deMort
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PostPosted: Sun Jul 15, 2018 5:44 pm    Post subject: Reply with quote

Another pm sent.
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Dammit
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PostPosted: Sun Jul 15, 2018 6:14 pm    Post subject: Reply with quote

I’d do all this only to discover that the tank is empty, and that the solution was a fivers worth of Super Unleaded in a Jerry can
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thecarfixer
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PostPosted: Sun Jul 15, 2018 9:14 pm    Post subject: Reply with quote

Jamesx19 wrote:
Hi Carfixer,

No, but then I have never heard a pump come on that I remember.

Is there anyone with an early cable throttle 996 that can answer that one?


I do, and it does - you won't hear it particularly loudly unless the tank is low when the fuel doesn't absorb the noise. But with the door opened you should definitely hear it, when turning to ign pos 1/ready to start.

Jamesx19 wrote:

Fuel pump seems ok. I used a jumper wire across the relay pins which switched the pump on. I could hear it running which it didn't before, and there is now fuel in the injector rail which was dry.

I tested the relay with multimeter and a fused jumper wire onto the battery. I could hear it clicking.

Is there a pressure switch in the fuel system? If not, I can't see that the pump would prime then cut off until the engine cranks?


No pressure switch.

Jamesx19 wrote:

Crank sensor next? The tachometer never flinched when cranking. Or something else you reckon?

Cheers Jim


If you've got Durametric or PST2 (or PIWIS), check the live data for cranking. The manual way of course is to pull a coil - earth the outside of the plug securely and crank to see if you get a spark.
 
  
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Jamesx19
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Joined: 10 Jul 2015
Posts: 356
Location: Brighton


PostPosted: Sun Jul 15, 2018 10:02 pm    Post subject: Reply with quote

Cheers Carfixer,

OK, only just see your post. Been under the car..

The fact that the pump doesn't prime is really whats vexing. Tested the rely pins with ignition on.

30 - 12v live
86 from fuse 4 - 12 v live
85 to DME 6.4 volts with ignition switched on. 5.8 volts when cranking. (need to check it switches to earth with a resistance check when switching ignition on, and when cranking- Cheers Demort) though I suspect it won't as that would switch the pump on to prime, and then to run.

So, no switch to earth from the DME.

I've pulled the Crank sensor and tested the pins. Signal to Grnd resistance is 909 ohms which is fine.

If there is a break in the CPS, the DME might not be seeing the correct voltage when the ignition is switched on, and hence not switch the fuel relay to earth?

Might just throw a new Crank sensor at it and see if that works.

Dammit - there half a tank!!!!
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Jamesx19
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PostPosted: Mon Jul 16, 2018 12:11 pm    Post subject: Reply with quote

Unfortunately I don't own a Durametric or similar.

New crank sensor. Still no fuel pump prime, and no start.

Still need to check whether there is a spark and/or injectors are switching.

frustrated
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infrasilver
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2001 Porsche 996 Targa

PostPosted: Mon Jul 16, 2018 1:52 pm    Post subject: Reply with quote

Have you checked for continuity between the ECU and the CPS wiring, through the wiring harness plugs in the engine bay?.
If you did snag the CPS wire it may have done the same as mine after refitting my engine, the wire across the engine had degraded and gave the same symptoms as a faulty CPS.

Is your cam sensor plugged in properly, this may also stop the car starting if the cams and cranks are not talking to each other.
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thecarfixer
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PostPosted: Mon Jul 16, 2018 2:12 pm    Post subject: Reply with quote

Does the CEL light and then go out when you turn the ignition on. That's the first start to see if the ECM is getting power and boots up properly.

Secondly, the floating voltage on the fuel pump relay seems iffy to me. It should pull down to earth smartly. Check the ECM earth is good and solid.

It was working before, so points to a power supply/earthing problem - and that's what you will have disturbed when you separated the engine management > car loom.

Might be worth checking all the contacts are clean and made properly between those big engine management > body loom connectors.

The crank sensor is just a pulse generator, it won't have any impact on the fuel pump initial prime, so I'd troubleshoot that before moving onto what is happening when cranking. Start at the basics, see that 12v is cleanly getting to the power supply pins at the ECM itself. Check the earth is good, etc etc.
 
  
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Jamesx19
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Joined: 10 Jul 2015
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PostPosted: Mon Jul 16, 2018 5:01 pm    Post subject: Reply with quote

Cheers both.

I think your right, it seems like a bad earth or supply problem.

I've had the big connectors off. They look ok. Will remove and spray in some wd40.

Good points re wiring loom and continuity check. Not able to do that on my own due to plug locations.

Carfixer, you may have something..... Just switched ignition on and waited. All warning lights have stayed on Inc engine check light.

They should go off after a few secs?

Cheers
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Jamesx19
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PostPosted: Mon Jul 16, 2018 5:07 pm    Post subject: Reply with quote

It's had no battery on the car for 5 months, as I had a small power drain. I just thought it'd be easier to disconnect and leave.

Could this have caused an issue?

Immobiliser triggered somewhere?
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thecarfixer
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PostPosted: Tue Jul 17, 2018 8:06 am    Post subject: Reply with quote

The Check Engine Light should definitely extinguish after a couple of seconds..
 
  
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deMort
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Joined: 21 Mar 2015
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PostPosted: Tue Jul 17, 2018 12:02 pm    Post subject: Reply with quote

Just a though , the cam sensor and the crank angle sensor plugs arent swopped are they ? i think they are the same plug ..

At work so not on here till tonight .
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Jamesx19
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PostPosted: Tue Jul 17, 2018 2:52 pm    Post subject: Reply with quote

Thanks Carfixer. OK It's definitely staying on. After a while the airbag, and also the brake warning and washer bottle lights go out. all others stay on.

Hi Demort, Good point. I'm pretty sure not. I left the cam sensor plugged in to the loom throughout. Also the metal clip that holds the crank sensor rotted and rusted leaving a stain on the plastic connector. So I knew which was which.

I've cranked with the spark plug out and grounded to the engine. No Spark.
Also tested the injector plug. Ignition on and cranking gives 5.6 volts, ignition off, and the 5.6 volts remains for 3 - 4 seconds before reverting to zero. (Which is the same as pin 85 on the fuel relay)

Big engine plus off, check for bent pins, spray with WD40 and refit making sure they are orientated correctly. (There are only 3 missing connections on each so its easy to see which way they should go.

I have found some threads from Rennlist talking about a similar issue. (Fuel pump no priming etc) and one of the thoughts was immobiliser kicking in due to door locks not being in sync, and a general immobiliser issue.

I've looked and unlocked the doors with the key and remote. No issues with either key or method. Both doors locking at the same time.

Infrasilver's comment above regarding the same issue he had after snagging the CPS wire is interesting. He has raised a good point in that the signal wire has to travel a long way to the DME and the signal could be weak especially if the wiring loom has a high impedance after 20 years of heat from sitting on top of the engine. Me moving it around might have been the final straw?

That could be the next place to check. ie check continuity / impedance of that wire. Trouble is not sure which one and my tester isn't blessed with long leads.

Really could do with a proper Durametric or diagnostic tester. It may come up with the answer.
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deMort
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PostPosted: Tue Jul 17, 2018 6:24 pm    Post subject: Reply with quote

Alarm immobilized and it wont spin over , there are some possible faults there but without a tester then theres no way of checking ..

Atm i think its not alarm related .

No spark , no tacho and probably no injector switch means no signal from the cps .. you will have to test this at the dme , testing at the cps wont say if the wiring is ok .

Your checking the plug so ill wait to see what you find there before continueing but the plugs and wire colours / dme pins are below .
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Jamesx19
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Joined: 10 Jul 2015
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PostPosted: Tue Jul 17, 2018 7:09 pm    Post subject: Reply with quote

FIXED!!!!!

OK, firstly very very many thanks to all of you that have come up with ideas and suggestions. Some are on this thread, and others have PM'd me with advice and offers of help and equipment. I really appreciate the assistance this forum and its members. I would not have found out my (Simple and embarrassing) error if not for you guys , so thanks.

Demort was entirely correct, I managed to put the Cam sensor plug on the Crank sensor and visa versa. DOH! nooo

Demort guessed it, but Infrasliver suggested checking continuity within the engine loom and Harv's logic that it had to be within the engine bay cemented the thought that that was the next check/test. Thank to Thecarfixer for logical suggestions as well.

As Demort has posted above, I put a wire into what I thought was the CPS plug and then checked pins in the large round engine wiring loom connectors 9,10 and 18. Not a sausage.... checked 14 "Buzzz" bingo, that one goes to the Cam Hall sensor. Swap them round and she starts!!!

I've only run her for 15 - 20 seconds. enough to circulate the oil and check for leaks. None found.

A bit nervous starting her. A bit clattery for 2 -3 seconds and then smoothed out. Increased revs to 2000 rpm and held there until switching her off 15 seconds later.

Interestingly, no fuel pump prime on initial start, but switch the ignition only back on a few minutes later and I could hear the fuel pump prime.

Thanks all again. Have to sort out stuff for work, will do the initial running in tomorrow.

Cheers
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rdodger
Monza


Joined: 08 Apr 2018
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PostPosted: Tue Jul 17, 2018 7:16 pm    Post subject: Reply with quote

thumbsup thumbsup thumbsup
Great news and well done. Glad it was something simple in the end.
 
  
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infrasilver
Fast & Furious
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2001 Porsche 996 Targa

PostPosted: Tue Jul 17, 2018 9:14 pm    Post subject: Reply with quote

Great news. Thumb

I usually run mine for quite a while when first installed after a rebuild, static with the car in the air, this allows me to check everything while the engine gets up to a hot temperature and things expand and to also allow the tappets to run quiet.


Then its time for a drive.
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wasz
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PostPosted: Tue Jul 17, 2018 9:29 pm    Post subject: Reply with quote

infrasilver wrote:


Then its time for a drive.


Bet you can't wait Drive
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thecarfixer
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PostPosted: Tue Jul 17, 2018 9:30 pm    Post subject: Reply with quote

Great news! Glad to hear it goes Smile

Don't let it idle for long so that those rings and bores bed in nicely..
 
  
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