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Non starter

B

BCOSTELL

New member
1987 Model Carrera won't start. Starter Motor is turning the engine over. I am working through troubleshooting steps outlined in Bentley Manual .
History of the problem was I had the car off the road and every couple of weeks I would start it up to keep it running , then after a couple of months it failed to start.
Inspection of the Distributor found marked points and some signs of tracking etc, so I ordered a new rotor and distributor , and DME relay to boot. After installing these no change. No start
I have identified a problem with open circuit on spark plug lead number 3, I will order a new one, however I would not have thought one faulty cable would have prevented the engine from starting.
I have tested the speed and reference sensor which are fine, and the solenoid is within spec.

I will continue to trouble shoot. If anyone has experienced a similar foot print I would be grateful for any advice .
Brian
 
Hi Brian, It could possibly be the flywheel sensors, if they need replacing the car will not begin to start, so it may be worth checking these out. good luck Glenn
 
See if you can borrow a spare ECU from somewhere. Just swapping the sensors is expensive if you are not sure, I've been there and done that and ended up buying a secondhand ECU. Problem with the sensors is that if they are not faulty you'll certainly b*gger them up trying to remove them and possibly damage the ali bracket trying to press them out. Before you know it you could be nigh on £200 out of pocket and still have a non starter. Check all earthing points too, the one form the gearbox to body often fails. Its cheap and easy to replace/clean earthing straps. Are you getting fuel? Is the fuel pump working? Is the fuel fresh. On another point. I've always understood that just running a 3.2 at idle for a few minutes so is a bad thing whilst its off the road. They run rich from cold and are ideally started up and driven. Idling on the driveway will create prolonged periods of running rich, which will soon wear your valve guides. I think if I were to keep mine laid up for a period of time I'd be tempted to turn it over by hand (or on the starter) a few times rather than running it.
 
Thanks Valvebouncer and Big_nige I have checked the speed and reference sensors and they are within the specs outlined in the Bentley manual. Have you seen these being faulty even when within spec? I will try cleaning the earthstraps this morning and see how I get on. I was not aware if the issue of running rich, valve guide wear if just running the engine at a standstill, I will bear that in mind in the future......if I can get it started again
 
I had an intermittent fault that the engine would just stop, would still have electrics, would usually start again after a few minutes of cranking, then wouldn't happend for a few weeks or months until it totally gave up. Swapped out the DME relay, cleaned all the earths, new cap and rotor, changed both speed sensors only to find the ECU was faulty. It wasn't damaged by water or anything, other than just old age. Whereabouts are you Brian, its only a 10 minute job to swap ECUs for a known working one. Any independents local to you to advise? I'm sure if you only run it occasionally it'll do little damage, its the habit some people seem to have of letting the car warm up 5-10 mins before a journey. Best thing is to start and drive it straight away, keep it gentle until everything is up to temp. The engine will warm up much quicker by doing this.
 
I would put at least two cans of fresh fuel in the tank before you go buying any parts. BTDT [:)] These cars are great, it's me that's stupid... My car started with only 3 spark leads connected recently. I was inspecting the plug connectors and I forgot to connect the whole right hand side but he still started and ticked over [:)] Did I mention I'm stupid... [:D]
 
Thanks ... I didn't get back to it that day. Well not in detail I think maybe the sensors could be the problem , the digital fluke meter I have may not have the range to test that the sensors resistance is higher than 100,000 ohm I am sourcing another meter , with some hope of eliminating the sensors alltogether. I have a raft of problems that are showing up now[:(]. Accelerator pedal is now staying stuck to the floor as well ......I am starting to think valvebouncers advice is the best "if you rest you rust" , having gone through some of my old porsche posts I will look at the pedal bushings etc. but would like to get it started before digging any deeper. I had a sniff of the petrol (short sniff) and is still smells of petrol (a lot of internet sites metion that if the petrol is evaporated it will smell like paint thinners) but I will get a pressure guage and test the fuel side as well, maybe flush it through . I may well add some fresh petrol to the tank, but without draining the tank totally , how long would the good petrol take to get to the injectors? I am in Ireland , I didn't want to go down the ECM route just yet......is there any chance that I could damage someone elses ECM while testing it????? I don't want to have to pay for two. Thanks for the responses Brian
 
Sticking throttle is quite common on cars not used often... It is normally down to the linkage on the transmission... You should easily be able to check this with the passenger (N/S) rear wheel removed... Depending on how bad it is, you should just be able to fix it with some lubrication and keep it free with some silicon or copper based grease. As for your starting issue... You have done the obvious... DME, crank sensor, head temp sensor on No3 etc etc.. and I assume you actually get a spark..? I would say a quick test of the fuel pressure... followed by the recommendation of trying a different ECU... many specialist would lend you one.. Durning/before my engine rebuild... everything was fine... on reassmbly, the car would only run for 10 seconds, then stop... this turned out to be the ECU, they can be fine on day, broke the next..? Adam
 
Managed to get back to it the weekend. I was a bit concerned about the result I was seeing on my Fluke 77 when measuring the Flywheel sensors, one of the measurements were in spec (I think 1 to 3 )reading 1023 (spec is 960 +/-96 Ohm approx) however two other measurements were Overload.....meaning broken circuit. As I didn't know the range of my meter I mailed Fluke in USA who replied with the following "The Fluke 77 can read values up to 32,000,000 ohms, and should show 100,000 ohms as 100K ohms. If the meter is in autorange mode and shows O.l, this indicates a value over 32M ohms. " Armed with this information :: I can now be confident that both flywheel sensors need replacing. Information I dug out of my mountain of Porsche magazines found a users question regarding these sensors. The response was that when these usually go its due to the mounting bracket crushing them which is due to corrosion of the bracket, the advise was that trying to remove the sensors will damage this bracket anyway and a new one should be ordered with the sensors. Thanks to everyone for their advise.......i may still need it later. I will let you all know how I progress with the repairs PS Even though I have been a member for PCGB for three years I am still classified as a guest [:)]
 
Hi,Both of these sensors are the same and also carry the same part number.They come already housed in the mounting bracket.I ve heard others on the forum commenting on how crucial it is to set the gap on these,when i fitted mines i just tightened it up ,plugged it in and the car fired up straight away.Hope its as simple for you.
 
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