Blinking Battery Light / 1985 280i

[jeremyrgunn]

Hey everyone,

I'm trying to get my 1985 280i ready for spring but have ran into a snag. I have searched the forums, and can find multiple posts about a battery light staying on and the alternator being the culprit...but i don't believe this is the same scenario.

What happened was i went in to start her up, and noticed the battery was frozen from sitting. So i ran down to the local part store and picked up a new battery and installed it. When i went to start her, she cranked over just fine, but would not fire, so i checked spark, everything was good. So i immediately went to the fuel system and checked pressure.

After the fuel filter – No pressure
Before the fuel filter – No pressure
After the Fuel Pump – No pressure

So i tested the volts coming into the Fuel Pump and it was 10.5V (unless i had my settings wrong), You can actually hear the fuel pump click but no fuel comes through, so i thought well i guess my fuel pump froze up. So i purchased a brand new one, and same thing.

However amidst all of this, now none of my electronics work, no hazards, no blinkers, no lights, no radio, and now the Battery Light just blinks after I crank her over. She cranks over fine, and will run on Spraying fuel into the plenum, but obviously when she burns through that she dies.

So i'm at a loss at where to look, i have examined the fuses and everything "looks" good but i'm obviously missing something here.

I'm going to run 12V manually to the fuel pump to see if that works when i get home to at least test the fuel pump.

Maybe i fried something while trying to diagnose the fuel pump?

Looking for some help from all the veterans here with wedges! Cheers!

[RCK974X]

Fuel Pump - remember that the pump only runs when engine is turning - driven by the flap in the fuel metering head being off its stop - remove the plug on the side with ign on, and pump should run. Don't leave it this way for more than a few secs though. There are actually TWO relays to drive the pump, next to each other - check their bases for corrosion. Direct 12v feed is another good check.

The very late Granadas had a 'purple relay' instead which runs the pump for 2 secs, or when it gets an ignition pulse, so if you don't have a plug on the side of the metering head, look for a purple relay, and TEMPORARILY swap it for a standard relay, and the pump should run. I don't think any 2.8 wedges had this originally, but not sure.

Ignition - the blue looped wire is a ballast resistor, and they do fail - check it with multimeter, should be about 3 ohms.

Check connectors between dizzy and ignition amplifier, and its power feed too, as they can corrode whilst car is sat.
check dizzy is clean inside (I've seen spiders webs in there !!).

I found the wiring my wedge was terrible in some spots, bad earths and green connectors, cleaning them all up made a big improvement. A faulty earth can cause all sorts of weird effects - check the main earth returns to battery/engine block, and fuse panel.

Edited by RCK974X on Monday 12th May 20:13

[jeremyrgunn]

Thanks RCK974X,

I'll check all of that when I get home. I also made sure the metering head was not frozen as well as the plunger. Unfortunately the wiring on my 280i has been spotty, had to figure out a lot through trial and error. But we'll get her running again. I'll report back what I find out.

[mrzigazaga]

Hi Jeremy...I see you live in the states..So i guess you have a series 3 US version which had a different fuel cut out...(I think)...Not too familiar with the wiring but i seem to recall someone else having a similar issue stateside..As always...Show care when dealing with fuel and sparks...Sounds like some relays have failed..I had something similar on my 1982 280i but that was the big brown wire actually going to the relay board....Ziga

[RCK974X]

OOPs, thanks Zig, I should have checked that before posting !!

Yes, from threads in here it appears that the US versions had an extra cutout as required by US law...

As far as I remember it's an inertia/collision safety switch in a white box, which was also a timed safety cutout for the fuel pump.

Unfortunately an extra thing to check.....

So probably testing with 12v direct to the pump is better for you, as it bypasses all the units...
Unless where you live is very dry, I still reckon checking the earths is time well spent !!

[mrzigazaga]

RCK974X said:

I still reckon checking the earths is time well spent !!

Definitely mate....Ziga

[jeremyrgunn]

So far this is what I have discovered:

Dirty Earths

Cleaning up the earths brought back all of my electronics.

I removed and cleaned the following earth straps:

• Earth Straps coming from the Frame to the Lower Control Arms
• Earth Strap coming from middle of frame to back of transmission
• Earth Strap underneath the passenger dash.

Are there any other earth straps i'm missing? I also cleaned up the battery terminals and main ground going to the engine block from the battery.

Fuses / Diodes / Resistors

There is a weird looking diode/resistor that goes in the top right slot on my fuse box. The diagram shows that it's a Headlight Diode. However mine does not look to be in the best of shape.
Any thoughts as to where to get a replacement part? I could just make one with a diode from the local electronic shop but i have no idea what ohm/volt/etc. whatever it is.

Still No Fuel Pressure

After cranking the engine over it still will not fire, appears i'm still not getting power back to the fuel pump.
I found my engine run sensor that has the fail safe in case of accidents, is there any way to test if it's working or not? Does anyone know of any replacement part # that will work?

---

I'm going to try a few more things tonight to see if i can sort anything else out. Blew my mind how cleaning up the earths brought everything back. Thanks so much for the insight!

[mrzigazaga]

Hi Mate...Unfortunately electric's are not my bag but i think that the US cars had a frequency valve as part of the system..Although I'm not familiar with what it did.

The fuel pump relay on US cars were cream i believe and you can use a normal headlight relay to test the pump but it MUST only be used while testing..The correct relay type should be replaced afterwards.


Not sure again where you can get the spare relays...Perhaps post them up on here and see if we can get them.


Cheers...Good luck


Ziga

[Mr Tank]

RCK974X said:

Fuel Pump - remember that the pump only runs when engine is turning - driven by the flap in the fuel metering head being off its stop - remove the plug on the side with ign on, and pump should run. Don't leave it this way for more than a few secs though. There are actually TWO relays to drive the pump, next to each other - check their bases for corrosion. Direct 12v feed is another good check.

Edited by RCK974X on Monday 12th May 20:13

Hi

Have you checked to see if the flap is working i.e. Does it feel like it has a slight resistance when you lift it up. If the metering head has not had fuel through it for a while the plunger can stick. If this happens the pump will not get a signal to pump!

Andy

[jeremyrgunn]

That's actually one of the first things i checked since they can gum up, and it moves free. I can spray fuel into the plenum and it will run while it burns off.

I'm not getting any pressure up to the metering head to begin with.... Maybe it's sticking just enough to not let any fuel in...

It has been a while since i've messed with the metering head, however, does the plunger need to move in order to engage the fuel pump? or will the fuel pump engage even if it's stuck.

[RCK974X]

For the US ones, I think you should get fuel pressure for a short time (about 2 secs) immediately after turning ign on with engine stopped.

Also for info the 2 relays is the Euro setup, so may only be one on the US ones.

I guess finding the fuel pump feed wire and (temporary) bridge to battery is the fastest way to test your safety unit.

Yes, "Cleaning Up The Earths" should be the standard song for all TVR owners !!

Also check the multiplug connectors for corrosion inside.

I think there is a pressure valve in the metering head, perhaps it's gummed up. As I remember it's in the 'lump' on the side, below the actual 6 way head.

Diode can be a ordinary IN4001 - IN4007 few a few pence/cents - make sure you put it in the right way round....
(IN4001 is 50volt 1 amp through to IN4007 is 1000V (I think) at 1 amp, so any of them will do.

Edited by RCK974X on Friday 16th May 00:07

[jeremyrgunn]

UPDATE

---

So I have fuel pressure and the fuel pump is definitely working now, all the electricals are working, I found the correct diode to replace my burnt out one with. Oh, and my battery light is no longer blinking nor is it staying solid.

Car still won't start:

I have tested the following:

• Spark
• Fuel metering head plunger is not stuck
• I checked the valve below the metering head and it looks good
• Fuel pressure to the metering head and to the injectors is fine
• Since the gas has been sitting for a while I wanted to test if it's still combustbile and it's definitely able to catch fire
• Voltage going to the Fuel Pump is around 9.5-10.5 volts
• Voltage going to the Box on the front of the engine with 2 fuel lines coming out has 9.5-10.5 volts

I have not tested the following:

• Cold Start Injector
• Spark from each plug
• Injectors themselves to see if they are spraying a cone

Current Symptoms

• Engine Cranks
• I can spray starter fluid / fuel into the plenum and it will fire over until it burns off

I had this problem about 3 years ago and I had a mechanic take a look, it turned out that I was missing a wire connecting to my ignition coil (if i remember correctly), he found it, and attached it, and viola it started and ran fine. however nothing has changed in that area since.

What else can I look for that will help diagnose it not starting? I have checked everywhere I know so i definitely need a little insight there. I'm going to call the mechanic as well (he's not familiar with TVR's but just familiar with the Bosch system)

I will continue to look through the forums on anyone else with a similar problem as well.

Thanks again for everyone's help so far it is greatly appreciated.

[mrzigazaga]

Hi Jeremy...Unfortunately as i found out its not always a good idea if these or any other classic car has been sat for long periods of time...
Firstly you should check the condition of the fuel ..Not only for combustibility but for clarity also....If and i really hope it is not the case one or both fuel tanks has been allowed to rust...Or even the Accumulator can rust...Then it can get right up to the injectors...Going past the bulkhead fuel filter and passed the metering head and WUR!...

When was the bulkhead fuel filter changed?...

Please check at the plug for a healthy spark...If there is not one then this could be a faulty ignition module...Which are still available but not OEM...Intermoto only but i have heard they are ok....Cheers...Ziga

[jeremyrgunn]

Zig,

I made sure to keep Fuel Stabilizer in the car and I would start it and let it run every few months to clear out some of the fuel and make sure everything was flowing. The fuel is definitely not the best fuel since even with the stabilizer it can go rancid.

The metering head was replaced quite a while ago (I still have the original one) maybe 5 years ago, I think an appropriate move would be to drain the tanks, place new fuel in (i think there is less than a few gallons of gas in the car). I have drained the tank before thinking along the same lines as you since the car sat for so long before i got it and the car has ran since then.

It's only been a few months since it's actually ran and I put some additive in the tank 2 months ago since i knew it was going to sit. I hope it's just a matter of cleaning it all up.

[mrzigazaga]

The metering head should be fine if it was replaced a few years ago.....It might be a wise move to remove one of the injectors..This can be done without taking plenum or manifolds off but take care with the plastic fuel lines making sure you don't damage any..They can be a right pain...And check for spray...If the fuel is reaching the metering head then it should be at the injectors..However there is a return on the head unit that returns un-used fuel back to the tank so it might be wise to start with the injectors first and work your way back...I know you probably know what you are doing but i always say after giving advice over fuel issues..Please be careful where fuel and sparks come into contact..Wedges are very combustible!!...Ziga

[RCK974X]

Yeah, supporting what Zig said - if you have fuel and sparks, engine should at least 'cough' at some point, so -

Check you get sparks when cranking engine.
(check there is 12 volts on live side of coil, and also you have 12v going into ignition amplifier.)

Take out one injector and see if it sprays. (Careful ! - I would disconnect the coil, and lift flap manually, spray into a container...)

Then it should run.....even if not very well to start with.

[Mr Tank]

Hi

As Mark says check to see if you have fuel at the injectors, you can crack (Not literally) the top of a couple of injectors (One at a time) to see if you have fuel there. If you do have, then gently remove an injector and see if they are injecting fuel. If not either get them cleaned or find a new set! Off course disconect the coil so you don't have a spark etc while you do the checks.

Andy

[jeremyrgunn]

UPDATE

Hey everyone, thanks for the help thus far, wanted to give an update:

We knew we had a ground issue because the "ALT" light on the dash would glow with the ignition off and key removed.

We ran a wire from the Ground strap connecting to the crown bar up underneath the passenger side dash back to the negative battery terminal and success we got all power back to the cabin, windows, blinkers, radio, lights, everything.
And she started perfectly fine over and over, we let her idle for over an hour and noticed a fuel leak back by the fuel pump at the brass washers on the banjo fitting on the fuel pump, we cleaned them up put them back on the pump and started the car...while running we still had a very slight fuel drip and being excited and completely stupid at the same time (without disconnecting the battery) while tightening the banjo nuts, we shorted the wrench against the fuel pump wire and instantly it killed the engine. We have now lost all power again in the drivers compartment...no lights, windows, interior lights.. We still have power to the starter and it cranks and fires just like before but won't keep running...We are back to the "ALT" light glowing again on the dash. We have checked all the grounds we fixed and they appear to be fine.

So being a complete moron I've now lost all power again through a stupid move on my part. I've since tested every relay, even pulled the whole fuseboard out from under the dash and cannot figure out why I have no power to the cabin. We are back to square one, the car fires when we crank, we still have power coming in to the cabin from the brown wires, we have power to the starter, but have somehow lost everything even with the ground straps still connected and cleaned up.

Any thoughts?

Edited by jeremyrgunn on Sunday 18th May 22:58

[mrzigazaga]

Wow..The "Joy and Pain" of owning a TVR...I was really pleased for you while i was reading your post and then at around halfway down i started to feel sad...Well I'm afraid my electrical knowledge is shyte but it sounds as if you may of fried the fuel safety relay/Module.

There is a way of bridging the fuel relay so that you can turn to position 1. and the pump should work before cranking so that leaky fuel fittings/Connections can be found and sorted without introducing potential explosions and Chaos into the equation.

Your lucky to not have had a fire and burnt the car and any surroundings along with it!...PLEASE .......BE BLOODY CAREFUL...

You might be able to bridge the pump with a live feed to see if it runs but not sure if the pump can handle a straight 12V for very long if at all?....


Ziga

[jeremyrgunn]

I don't believe the car not starting is related to the fuel pump anymore, however, do you know how to bypass the Engine Run Sensor to rule that out?

I know we have some sort of ground issue because the moment I put any load on the system (even turning on a light in the car, it will trigger the battery light to come on, Do you know where all of the ground straps connect on these?

So far we've found 5

• Front Right control arm to chassis
• Front Left control arm to chassis
• Transmission to Chassis
• There is an "X" (2 straps held together by a bolt in the middle) that is by the fuse board, we originally fixed the power by fixing the side that attaches to a crossbar in the dash.

I don't know if we are missing somewhere else? The problem is that we are not getting power past the first relay to come in to the rest of the car, that is why none of my electronics work. The moment I click the light on, it's like it's tripping a breaker and the battery light won't turn off until I start the car, and then turn the key off.

Frustrating to say the least, Now I have my entire wire loom underneath pulled out, with the fuse panel and i'm tracing every wire to see if anything melted....

I guess if I had fried the engine run sensor...that would make the fuel pump not work, but it shouldn't make the rest of the car not work.