options please

[Andy70]

Hi all, the Chim has been off road all summer due to prioritising other projects so haven't had the time to sort it, now i best find the time to look at it. I posted a thread regarding it not starting earlier in the year, It's fueling ok, fuel pressure in fuel rail, fuel pump priming, good spark, but there is no fuel getting to the cylinders, the plugs are dry and no smell of petrol. One suggestion was the ECU, as far as I know there is no fuse or relay connected to the injectors, looking at the ECU it's clearly seen better days (see pics) but I can't identify it..

So options are to send it away to get it looked at but the company i called wanted 45 quid to post it back if they can't find anything wrong, yeah right!!, or up to 350 quid to repair it if it is faulty. Option 2 is see if i can find a second hand one to see if it sorts the problem out (bare in mind i'm doing this blind as I'm not sure for definite it is the ECU) or is there an upgraded one that will just plug in and work?.. Before anyone says to get a mobile auto electrician around, I've tried and finding it hard to get anyone to reply as soon as you mention it's a TVR, the one that did call back suggested it could be the ECU but is too busy to come out, me thinks if they can't plug it in to their little machines they are stumped and don't want to get involved in good old fashioned problem solving.

The reason why I mentioned a second hand one is there is one going on facebook for 170 quid and might be worth a gamble (provided it works and that it is the correct one)... So where do I go from here?

[Andy70]

[url]|https://forums-images.pistonheads.com/238620/202509257322927

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[Andy70]

sorry, had problems uploading the pics

[Loubaruch]

It is the condition of the ECU inside that matters not the case. The ECU is sealed with a rubber gasket so it may be OK
You can inspect the circuit board by carefully unscrewing the 4 bolts (Torx heads) and lifting the top off.

[Andy70]

Loubaruch said:

It is the condition of the ECU inside that matters not the case. The ECU is sealed with a rubber gasket so it may be OK
You can inspect the circuit board by carefully unscrewing the 4 bolts (Torx heads) and lifting the top off.

Yeah I'll have a look, but no idea what I'm looking at, but what else could be causing the car not to start when everything else seems in order?

[Belle427]

Ideally you need to carry out some basic testing, checking for the permanent 12 volt feed to the injectors which comes from the main relay on the brown/orange wire with ignition on.
If that is present you could try a noid light next which plugs into the injector connector to see if they are being switched by the Ecu.
The Ecu needs to see feedback from the coil to turn on the fuel pump and fire the injectors, wiring at the coil should be checked especially the 2 small resistors that should be present here, the one on the white/blue wire is the feedback from memory.
The resistor should measure roughly 6.8 k ohm when tested, if this is open circuit then it wont have the feedback.
I would take care buying second hand Ecus off facebook unless its from a fellow TVR owner.
If you wanted a hand let me know, im happy to pop over for a few hours and have a multimeter and noid lights.

Edited by Belle427 on Friday 26th September 07:19

[blaze_away]

Belle427 said:

Ideally you need to carry out some basic testing, checking for the permanent 12 volt feed to the injectors which comes from the main relay on the brown/orange wire with ignition on.
If that is present you could try a noid light next which plugs into the injector connector to see if they are being switched by the Ecu.
The Ecu needs to see feedback from the coil to turn on the fuel pump and fire the injectors, wiring at the coil should be checked especially the 2 small resistors that should be present here, the one on the white/blue wire is the feedback from memory.
The resistor should measure roughly 6.8 k ohm when tested, if this is open circuit then it wont have the feedback.
I would take care buying second hand Ecus off facebook unless its from a fellow TVR owner.
If you wanted a hand let me know, im happy to pop over for a few hours and have a multimeter and noid lights.

Edited by Belle427 on Friday 26th September 07:19

I'd echo everything belle says and take his very kind and generous offer to help. If you do need an ECU call Joolz at kits and classics in Chesterfield he's a TVR man and well loved and trusted here. He does lots of aftermarket ECU upgrades.

[Andy70]

The reason why I was looking for am auto electrician is because I've no clue with electrics, I don't even own a volt meter nor no how ton use one lol. I'll dig deeper then, see what else Google throws up

[Loubaruch]

Good advice from Belle as always. The only reason I suggested looking into the ECU was to check for corrosion to the circuit board as you suspected the case looked in poor condition . If the circuit board inside is stll shiny with no obvious damage do not touch anything as small charges from your hands can destroy semicinductors put the top back locating the rubber gasket correctly and look elsewhere.

[Belle427]

Lloyds specialist developments are in Warminster so may be an option to speak to them if all else fails.
Obviously will cost you but these cars do need money spending on them now and again.

[Andy70]

Yeah I know of them but it's getting the car there. There is a garage that do the odd tvr at the other end of town to me but they don't provide a mobile service

[Belle427]

If you have a look on facebook you can generally find car transport services that will move it short distances for not too much money.
Just try to find someone fairly local as they will charge extra for travelling to you.

[Andy70]

Yeah fair point

[Andy70]

Loubaruch said:

It is the condition of the ECU inside that matters not the case. The ECU is sealed with a rubber gasket so it may be OK
You can inspect the circuit board by carefully unscrewing the 4 bolts (Torx heads) and lifting the top off.

i had a peek inside the ecu and without risking damaging anything, the back came off and could only view theback of the ecu, I couldn't quite see how to look at the other side

[Loubaruch]

It just rests on the other part of the case, put the cover back without the torx screws and lift the back off. From what you saw If the circuit board looked ok then chances are the ECU is fine, damage if bad would affect both sides of the printed board.

[Andy70]

where are you based Belle427?

[Belle427]

Near Newport.

[Andy70]

Belle427 said:

Near Newport.

well id appreciate a visit, id cover your time and a very large drink if you're available

[Belle427]

Pm me your mobile number and we can communicate that way. Happy to pop over and try and figure it out.

[dogbucket]

definitely check the two resistors which are on spade terminals and taped into the loom near the coil. try swapping them as one is in line with the ECU and other to the rev counter. ECU one was open circuit on mine and although the fuel pump would prime it was not being turned on when cranking.