TVR S Series Barn Find. No fuel pump or injectors

[Spacecowboyuk]

Hi all

New to the forum but not new to all things cars. Last year I pulled a TVR out of a barn but not had a huge amount of time to work on her.

Over the last few weeks I've managed to get spark back by replacing the coil and ignition module that sits on side of the dissy. I've also removed all the imboliser and alarm wiring which had itself rubbed into the main loom fraying one particular wire. That's now been fixed.

I have checked continuity across virtually all wires but I just do not seem to be able to get any signal/power to complete at the yellow and brown relays (injector and fuel pump).

The fuel pump runs fine when you squirt 12v into it via a power probe but try as I might nothing will energise the relays.

Any thoughts gratefully recieved.

[Spacecowboyuk]

Good point.

It's 2.9 cologne engine. The car is 1989 vintage. As to whether it has a cat that's a good question. I don't believe so.

[Spacecowboyuk]

I have the Steve Heath book and been glued to the wiring diagram. No joy.

Yes two mafs on this one so must be non cat.

I've also spent many hours googling up broncos and old Ford's to try to get ahead of the game but nothing seems to tally. I won't let this beat me!

[Spacecowboyuk]

I've checked the yellow plug. It does show some signs of overheating and the white wires are a little 'dark' but everything else seems to work- indicators, hazards, lights, wipers, door glass up and down etc which I understand wouldn't if the connector had had it? I have power at the fuse board.

[Spacecowboyuk]

Pretty certain yes. I mean, if there are any remnants left it's so incredibly well hidden that I'd have to take the dash apart even more than I already have.

I was given a spare engine loom so I could unstictch it and trace back all the main components in the engine bay to the ecu. I took the diode off that and reinstated it into my brown relay. I have power going to that diode and out the other side albeit it loses a little voltage on the way. Nothing on the larger black wire. Same for both injector and fuel pump relay.

The only wire that has at one time been cut cleanly and is not connected os a green wire coming out the back of the fuse board that corresponds with a green wire coming out of, I believe, some kind of dim dip module. Not sure why this has been cut but the wire coming out the module seems to be carrying power whereas the one in the board does not. Odd?

Edited by Spacecowboyuk on Monday 12th February 08:24

[Spacecowboyuk]

phillpot said:

Spacecowboyuk said:

I've checked the yellow plug. It does show some signs of overheating and the white wires are a little 'dark' but everything else seems to work- indicators, hazards, lights, wipers, door glass up and down etc which I understand wouldn't if the connector had had it? I have power at the fuse board.

If it's burnt out you will lose all ignition fed circuits, should be good if you have wipers and indicators.

Hazards, windows and sidelights are constant live.

All fuses okay?

I would try putting a live to the injection relay coil or shorting the switching contacts?

Is the Diode okay, not open circuit or round the wrong way?

Edited by phillpot on Sunday 11th February 19:10

The fuses appear to check out ok both visually and with a continuity check but I'll now replace them anyway to take it out the equation.

The diode appears to be operating correctly and I've mounted it the same way round as a photo on PH somewhere. Would it hurt anything if I tried it in reverse?

[Spacecowboyuk]

Mercdriver said:

All fuses ok said above , good point I would replace all the fuses with new unused ones sometimes they can be damaged if overheated, but still annoyingly work but do not carry the current.

Ok will try this this afternoon

[Spacecowboyuk]

v8s4me said:

Look on the underside of the fuse board to check nothing has burnt out on the back.

Remove the yellow connector and replace with a "choc-bloc" for now.

Try new relays.

Give that a go and see what happens.

Good move getting a spare loom

I've looked at the rear of the board and everything looks good. As mentioned the only wire hanging out the back which has been freshly cut sometime before me is the green wire.

I've installed a new yellow relay and a NOS brown relay (both have tested good) with no change.

[Spacecowboyuk]

phillpot said:

I would try putting a live to the injection relay coil or shorting the switching contacts?

Edited by phillpot on Sunday 11th February 19:10

I assume I can use the power probe to do this? Which pins/wires would I be hitting? If I was to short across, again which coloured wires/pins would I be aiming for?

Thanks for everyone's responses so far.

[Spacecowboyuk]

Unfortunately I ran out of light to do the things I wanted to today so these are all tomorrow jobs now.

Incidentally, does anyone know which pin/wire is the live into the ecu?

[Spacecowboyuk]

I'd love to upload some photos but PH has an odd rule that we can only post stuff after 14 days. Same as only being able to post up to 5 messages in the first 24 hrs. Seems a little archaic...

[Spacecowboyuk]

phillpot said:

Spacecowboyuk said:

I've checked the yellow plug. It does show some signs of overheating and the white wires are a little 'dark' but everything else seems to work- indicators, hazards, lights, wipers, door glass up and down etc which I understand wouldn't if the connector had had it? I have power at the fuse board.

If it's burnt out you will lose all ignition fed circuits, should be good if you have wipers and indicators.

Hazards, windows and sidelights are constant live.

All fuses okay?

I would try putting a live to the injection relay coil or shorting the switching contacts?

Is the Diode okay, not open circuit or round the wrong way?

Edited by phillpot on Sunday 11th February 19:10

I put a wire between relay pins 30 and 87 on both yellow and brown relays (tested one at a time of course) and the fuel pump will fire and the injectors click. Any ideas?

Edited by Spacecowboyuk on Wednesday 14th February 18:09

[Spacecowboyuk]

Interestingly I have power probed the ground going into the brown relay which has been poorly soldered before and it shows a feint green on the probe. So I put it to second ignition and probed it and it showed a positive to the ground? Is that normal?

Anyway I thought I'd risk it and shot a ground on the powerprobe into it and I got nice clicking injectors and the fuel pump energised for 5 seconds!

So does this mean I have a dodgy ground to that brown relay? If I ran a fresh one from the battery would that be OK? Should I be worried I get a positive on the brown when set at second ignition?

[Spacecowboyuk]

Mercdriver said:

Loosen off the pipe to an injector does it leak fuel? You say the pump operates but does fuel exit the output side of the pump? Does the car have a breathable fuel cap and someone has fitted a non breathable one? This would cause a vacuum in the tank and the pump might not pas fuel.

Can’t think of anything more to try just now, still thinking!

I get plenty of fuel up at the injectors which is good news 👍🏼

[Spacecowboyuk]

HT leads are correct. Correct I have spark. I think before I crank her over I'll put a few litres of fresh fuel in.

Will I be ok to run a fresh ground to the brown relay or should I track the fault?

[Spacecowboyuk]

It's definitely an earth. On my spare loom, if I follow it back it splits off to a thicker brown (presumably still earth) which then goes to the ecu pin 20 and the shielding grounds that are wound on the outside of the dissy module wires. The other split-off then turns into a black wire which goes into the loom connector plug.

The diagram then says the other side of the connector should be a white wire but mine is black coming out of there which then goes through the wing into the engine bay.

Anyone know where all the grounds are located in the engine bay?

Edited by Spacecowboyuk on Wednesday 14th February 18:09

[Spacecowboyuk]

Short lived excitement.

I connected a temporary ground from a spade terminal under the dash which has a strong ground to the brown wire on the injector relay. I now get both injector and fuel pump relay energising.

I depressed the schrader valve and I have yellow fuel spurting out momentarily after the pump has energises for 5 seconds. I then, probably foolishly, put 5 litres of fresh fuel down the tank and test fired her. Doesn't want to run.

Took out the spark plugs and I wouldn't say they are particularly wet so I wonder if I have gummed up my injectors or if they are just not firing.

If anyone can advise how to remove an injector to test it I'd appreciate it. They look well hidden under that intake...

[Spacecowboyuk]

I'll give it a shot. Would brake cleaner have the same effect? If that's a no go I'll go Halfords in the morning.

[Spacecowboyuk]

Good news! I managed to get her running today.

She needed a good deal of cranking over then cleaning fould up plugs then cranking again. With the help of jump leads to my A4 it provided enough resilience in the battery to give her the cranking power she needed and eventually sprang to life. She's running rough as you'd expect but she does run and sounds great considering.

Thanks to everyone for their suggestions. Now all I need to do is sort the coolant which is dry, brakes and clutch....

Is there an easy coolant drain plug on these or is it just bottom hose off? I'll consult the Steve Heath book as well when back home.

[Spacecowboyuk]

Had an hour or two today to fix a few other things:

Throttle Position Sensor: when I actuated the throttle by hand the other week the butterflys did not open fully so I gave it a little more force and I heard a 'click'. Having googled some of the rough running symptoms I was having, a good number of forum comments point to the TPS. So I have replaced that today and it does run better and the response has quickened up a touch but I do need to do more tests and de-foul the plugs from yesterday's fun. Decent enough for £20 quid from local motor factors same day. The brand is Intermotor. The one that came off was a genuine Ford item.

Flushed cooling system: I've done a couple of initial flushes but realise that clamps and some hoses will need replacing to be safe. The swirl pot is also rusty on the inside so will need to source a good replacement or one of those fancy stainless steel jobs. For now, I'll live with what I have before I sink too much in too soon.

Battery Charging: I figured out today that a quirk of these cars is that you need to blip the throttle beyond 2k rpm to put the battery light out and start the charging system. Odd but now I know.

Cylinder 5: appears to be misfiring. The exhaust header on that cylinder is barely warm compared to the all the others. I need to investigate that. The right bank headers are also more hot to the touch than the left headers in general...

Oil Pressure: currently this thing is maxing out at full 100 on the gauge! I hope it's a faulty sender or something simple and it's not really pumping out that much.

Tomorrow I plan on sorting brakes and clutch. Or at least making a start...

Edited by Spacecowboyuk on Friday 16th February 20:26