Starting issues

[AdzTVR]

Good Morning All,

Having a frustrating issue with my 4.0 Chimaera....it won't start! I took her out for a drive last week and after about half a mile she started to cough and splutter and then completely cut out. After 5-10 mins I managed to get her going again and made it home but she was running rough almost as if it wasn't running on all 8. Left the car for the remainder of the day as had places to be, came back to have look the next day and it wouldn't start. Kept trying and eventually it started but immediately cut out then failed to start again,the stater motor fired up but not so much as a cough from the engine. This is now all it does, 1 in every 10 times I try to start it will fire up but cut-out almost straight away. I have been through the below so far but wondering if anyone has had a similar issue or can point me in the right direction?

Battery replaced (I did try a jump start on the old one but did the same thing)
100 amp fuse checked (Both in the passenger foot well and under the car)
Replaced both ECU and Fuel pump relays
Checked all HT leads seated correctly
Check rotary arm and distributer cap

I did wonder if this could be an immobiliser issue but I can hear the fuel pump prime and was under the impression if the immobiliser was on then neither the starter motor or fuel pump would work. The car was only serviced in December and was running fine until last week, the only change I have made is re-wiring the light switches after the wires all fell off on removing the radio surround, and all lights are now working as normal.so now am i thinking could this be a coil issue? There is a spark as it will fire but could it be that it's on it ways out hence why it's cutting out? or perhaps the fuel pump is dying and it's fuel starvation, i did pop a plug out and they were wet and I can smell fuel?

Any advice anyone can give me will be appreciated, desperate to get her sorted before next weekend.

Thanks

[AdzTVR]

Thanks for the advice guys, i had already purchased a new dizzy cap and rotary arm as mine do look a little worn. I will get the multimeter out tonight and check the voltage on the coil and report back with my findings!

[AdzTVR]

So I measured the voltage at the coil and got 11.5V, also tested the king lead spark and couldn't see that it did spark! Want to try it again and was on my own last night and was slightly tricky getting the lead to stay put and turning the key at the same time!

[AdzTVR]

I did check it last night, it's on as tight as it can be and didn't see any damage to the connector on the coil. I now have a new dizzy cap and rotor arm so will pop them on tonight and see if that improves things, faling that I might look to replace the coil

[AdzTVR]

So re-tested the king lead and got a spark, still only getting 11.5v on the meter though, not sure if that matters. Replaced the dizzy cap and rotor arm as they both did look worn, but still having the same same problem. Not sure what to try next, ignition amplifier?

[AdzTVR]

So managed to get a few more bits done this weekend. Removed and cleaned all plugs, replaced HT leads. On re-testing the coil centre lead I get one spark and then nothing. Have ordered a replacement coil and ignition module so will see if that resolves the problem.

[AdzTVR]

Have now fitted a new ignition coil and module but still getting the same issue After fitting new parts on turning the ignition on I couldn't hear the fuel pump prime (First time this has happened) I check the relays and tried again and again and on the 4th/5th attempt I could hear it prime. First attempt to start car just cranked as it had been doing but didn't start, on the 2nd attempt there was a cough as if it wanted to start but failed to and then back to the just cranking.

So I have now replaced the HT Leads, Spark Plugs, Dizzy Cap, Rotor Arm, Coil and Module and both the ECU and Fuel Pump relays. The battery is brand new and properly charged so the only thing I can think of is that there is an issue with the immobiliser.....but wouldn't have the first idea of how to prove this!

[AdzTVR]

Thanks for advice chaps, will check the items mentioned tonight and see what results I get. I normally hate throwing parts at a problem but given most of mine looked pretty old and battered I thought it was worth a shot, I was deperate to get her running for the weekend!

[AdzTVR]

Boosted LS1 said:

OP, which type of dizzy have you got? If it's an early type with 8 ferrite rods embedded in a plastic disc then I've had the exact same fault.

Hi Bud, mine is the later type I believe , looks exactly this this one http://www.racetechdirect.co.uk/e2501-tvr-car-part...

[AdzTVR]

Boosted LS1 said:

So when you look inside you see an 8 point star, if so that a variable reluctor type? My one, with the ferrite rods would play up at random and prevent the car from starting. It took ages to discover it was the dizzy at fault. Once replaced with the VR type the engine ran perfectly.

Yes I have the 8 point star so assume it would be the VR type. The annoying thing is I've never had any issues starting the car before and it started fine on the day this all begun! I've managed to find a decent mobile mechanic with TVR knowledge to come and have a look next week as frustratingly I just don't get the time I need to properly test myself. Will update on what the results of his inspection is.

[AdzTVR]

Immobiliser was the issue! Paul from Kent TVR came round on Wednesday to give the car a once over and after running 12V straight to the coil it started first time. Immobiliser has since been replaced by David at HF-Solutions and she is now running perfectly. It turns out that a previous owner had bypassed the starter circuit which is why it would always crank. Anyway main thing is the car is back on the road and I've learnt a shed load about TVR electrics.