non-start issue, poss electric to fuel pump?

[_Absinthe_]

Hi All, need a little help & advice

I have one of the original 420SE's which formerly belonged to my uncle (SteveHall).

It won't start. Turns over fine, there's a spark (not great, but a spark nonetheless) but it won't fire up. There doesn't appear to be any fuel getting to the engine. (I think I may have stupidly let it run too low, so suspected a blockage somewhere along the way). I've changed the fuel filter, but still no juice at the engine.

I've checked the fuel pump fuse, which looks fine. Checked the relay too using 12v power supply and multimeter, and as far as I can tell it's working correctly. (low resistance across the control/solenoid windings, clicks appropriately when powered. When powered, resistance across switched terminals drops from infinity to negligible). So I was thinking the pump itself must've got gunked up and failed, but I checked the pump terminals expecting to find a voltage there with the ignition on, and nothing

Am I right in thinking I should be trying to trace the wiring for the pump next and testing that? (Not something I'm looking forward to, the sum total of what I know about repairing cars has been self-taught from the Steve Heath book my uncle gave me with the car!)

[adam quantrill]

Flapper? Ignition on, push in the flap half way (carefully) and the pump should start whirring.

[gmw9666]

I guess you got your engine rebuilt in the end then? http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[mrzigazaga]

Its possible that the pump is dead..I did the same thing by letting my fuel get a bit lower than usual..Almost to the point of it stalling..Filled up got 300 yards and the car died...New pump fitted and normal service resumed.

The only other thing which it could be is the "Steering relay"...The only red one amongst the relays..The car will not run if this is nadgered as I'm sure it supplies a feed to the fuel pump...Rimmers sell them if needed.

Cheers...Ziga

[mike various]

I had exactly the same problem with mine after it had been stood for app 12 months 3.9 SE
If you turn the ignition on does the fuel pump start wirring for a few seconds then cut off ?
You will hear it inside the car as you turn the ignition on.
If not there are two possible causes, one the fuel pump has gone, or the fuel pump relay has gone under the glove box.
What i did to check the pump and it's not very health and safety !!! is to disconnect the fuel pipe from the fuel rail.
Turn the ignition on and if fuel spurts out then the pump is working.
I ended up with both the relay going and the fuel pump, it would click when the power was applied to it but not pump fuel.
Replaced both of them and no problems since.
What i have got to do is put a filer BEFORE the fuel pump to stop it sucking the crap from the fuel tanks into the pump.

Mike

[_Absinthe_]

Thanks for the super-quick responses all, very much appreciated.

"Flapper? Ignition on, push in the flap half way (carefully) and the pump should start whirring." - will try this, just as soon as I figure out what a flapper is! Well, in the car sense of the word anyway!

"I guess you got your engine rebuilt in the end then?" Certainly did took a fair while longer than expected, but the chap did have plenty of other commitments and was doing it for a very fair price, so couldn't really complain.

"The only other thing which it could be is the "Steering relay"...The only red one amongst the relays.." Saw that one when I was looking for the pump relay. Will test tomorrow, thanks.

"If you turn the ignition on does the fuel pump start wirring for a few seconds then cut off?" Ah, this helps in a rather fundamental way! I was only listening for the relay clicking to be honest, and didn't realise the pump would deactivate after a few seconds, so by the time I got under the car and got the multimeter leads on it, it would already have gone off. So there may be power to it (and a knackered pump) after all. I checked for fuel at the engine in the same way!!! Pipe end hanging in an old fashioned chunky pint glass with an handle, to catch any go-go juice I read in the Steve Heath 'bible' that some folks put a filter before the pump, may get that done while I've got it up on axle stands, as well as replace some fuel pipes at same time, dread to think how old they are.

Thanks again for the replies guys, very much appreciated. Have the next few days off work so will let you know how the above suggestions go

[CAPP0]

Does the car eventually start? I picked up a 3.9 EFI RR a few months ago with "starting problems" - sometimes it will start first or second churn, other times it will churn and churn and churn until it flattens the battery.

I've been through all the basics (there is a thread of mine on here in the LR section) plus most of what's been written above here and still not cracked it. I have the software and cable for the ECU (can't remember the name offhand) and there are no faults showing. It has a new fuel pump, amongst multiple other new items. Due to other commitments I haven't touched it for 2-3 months but I did have a eureka moment re the fuel filter last week and have been trying (unsuccessfully so far) to find one locally; I'll order one shortly if no luck tomorrow. So, fuel filter and also check whether the pump is clogged?? Will watch this thread with interest for any solution and let you know if I find one this end!

[_Absinthe_]

CAPP0 said:

Does the car eventually start? I picked up a 3.9 EFI RR a few months ago with "starting problems" - sometimes it will start first or second churn, other times it will churn and churn and churn until it flattens the battery.

I've been through all the basics (there is a thread of mine on here in the LR section) plus most of what's been written above here and still not cracked it. I have the software and cable for the ECU (can't remember the name offhand) and there are no faults showing. It has a new fuel pump, amongst multiple other new items. Due to other commitments I haven't touched it for 2-3 months but I did have a eureka moment re the fuel filter last week and have been trying (unsuccessfully so far) to find one locally; I'll order one shortly if no luck tomorrow. So, fuel filter and also check whether the pump is clogged?? Will watch this thread with interest for any solution and let you know if I find one this end!

Nope, doesn't start at all. In the lead up to this, it had been getting quite tricky to start, used to take a while and started quite hesitantly. But it did start, every time, until the last time when it stalled not long after starting, since then it won't start at all. Embarrassingly it was only at that point where I thought, hang on, I've not put any petrol in it for a while, st!!! (It's been off the road for about 18 months now, although run for 20-30 mins every 2 weeks, and backed out the garage for some three point turns in my yard.)

[mrzigazaga]

Fuel filters..

Post filter..
http://www.google.co.uk/aclk?sa=L&ai=CoeG_z4Vr...
Different fitment...Rimmers
https://www.google.co.uk/url?sa=t&rct=j&q=...
There are these which are pre-filters..
https://www.google.co.uk/url?sa=t&rct=j&q=...

[_Absinthe_]

mrzigazaga said:

Fuel filters..

Post filter..
http://www.google.co.uk/aclk?sa=L&ai=CoeG_z4Vr...
Different fitment...Rimmers
https://www.google.co.uk/url?sa=t&rct=j&q=...
There are these which are pre-filters..
https://www.google.co.uk/url?sa=t&rct=j&q=...

Thanks for this, much appreciated, saves me searching and asking further questions!

[CAPP0]

_Absinthe_ said:

mrzigazaga said:

Fuel filters..

Post filter..
http://www.google.co.uk/aclk?sa=L&ai=CoeG_z4Vr...
Different fitment...Rimmers
https://www.google.co.uk/url?sa=t&rct=j&q=...
There are these which are pre-filters..
https://www.google.co.uk/url?sa=t&rct=j&q=...

Thanks for this, much appreciated, saves me searching and asking further questions!

Thanks from me too, ECP sold me something yesterday which LOOKS like your second item (which I'm pretty sure us what I need) but is about 3 times larger!

[Wedg1e]

A common cock-up that happens when the fuel injection has been disconnected is that the connections to the fuel rail are re-made the wrong way around, in which case the car won't start. Th fuel pump feed should go directly into the fuel rail, with the low pressure return coming from the fuel pressure regulator. On most cars the LP return is in rubber hose while the HP feed from the pump is in copper.

[_Absinthe_]

Wedg1e said:

A common cock-up that happens when the fuel injection has been disconnected is that the connections to the fuel rail are re-made the wrong way around, in which case the car won't start. Th fuel pump feed should go directly into the fuel rail, with the low pressure return coming from the fuel pressure regulator. On most cars the LP return is in rubber hose while the HP feed from the pump is in copper.

That's excellent info about the direction of flow and likely copper/rubber tubing, thanks. Was having problems figuring out which was the feed and which was the return, but it's very clear now, thanks. If only me uncle were still around, I'm sure he'd have shown me how to sort this out straight away, only had time to tell me so much though unfortunately. The Injectors haven't been removed, can't see how they could be without taking what I assume is the intake manifold off the top, leading to gasket replacement etc.? That's a bit beyond my confidence level just yet

[Wedg1e]

_Absinthe_ said:

The Injectors haven't been removed, can't see how they could be without taking what I assume is the intake manifold off the top, leading to gasket replacement etc.? That's a bit beyond my confidence level just yet

I was working on the fact that you said the engine had been rebuilt; to do that you'd usually have to remove the inlet manifold and that would tend to mean disconnecting the fuel supply and return.

Now I've skimmed back through the thread it looks like your fuel pump is getting no 12V feed hence not pressurising the fuel rail. If you can rig up a temporary feed with a length of thick wire directly to the pump from the battery (+) and the pump runs straight away, that tells you the pump is (a) working and (b) earthed OK, which just leaves you with the missing 12V feed to sort. If you get a shower of sparks when you touch the wire to the battery and the pump doesn't run, it's probably seized (and drawing a lot of current, hence the sparks).

Now, if you pull the fuel pump relay out (as you seem to know which one it is) and make up a short link wire to poke in the 30 and 87 terminals (usually the top and bottom ones in typical relay sockets), with the ignition on the pump should run all the time and the car ought to start. If the pump doesn't run, use your long test wire between the battery (+) and either the top or bottom terminals as just discussed; once you have it in the 'output' side of the relay socket the pump should run (even with the ignition off).
If the pump now runs then you have a 12V feed to the 'input' side of the relay socket missing or the relay itself is kaput, which can usually be proved by swapping it for an adjacent one as they're usually the same type.

[Wedg1e]

_Absinthe_ said:

"The only other thing which it could be is the "Steering relay"...The only red one amongst the relays.." Saw that one when I was looking for the pump relay. Will test tomorrow, thanks.

Watch this, it's not a relay at all but a collection of resistors and a diode, so it won't test like a relay. If you poke voltages into the wrong termninals you'll probably blow the diode.
IMHO the steering module is the least likely part of the system to give trouble, which is not to say yours could be the exception to the rule.

[Wedg1e]

_Absinthe_ said:

"If you turn the ignition on does the fuel pump start wirring for a few seconds then cut off?" Ah, this helps in a rather fundamental way!

It might not help if your car has 'flap' rather than hotwire injection (and I don't thnk the SEACs had hotwire though I could be wrong) - it's only the hotwire cars that prime the fuel pump for a few seconds, the 'flappers' don't do it.

[_Absinthe_]

That's all fantastic info, thanks for taking the time, I greatly appreciate it. Re: the rebuild, that was a few years back and it's run fine since then, so no concerns there.

I'd considered putting a feed directly to the pump but wasn't sure of the voltage/current requirements, and hadn't had chance to look it up, so decided to leave well alone til I had further info. In addition to the other testing to do, I'll pop out and get some suitable cable to run from battery.

And thanks for the heads up on the red 'relay'! I'm guessing it therefore doesn't have the usual relay circuit diagram stamped on it, which I'd like to think would have made me stop and think, but warnings always appreciated. I'm figuring it out as I go along as never really worked on cars before so steep learning curve, trying to play it cautious for fear of screwing it up worse. Give me a server room full of IT infrastructure and I'm in my element, but practically no experience with car stuff

Edited by _Absinthe_ on Monday 1st June 02:06

[Wedg1e]

No problem, it's a fairly simple system to understand. As far as IT goes, I was at school when 'Computer Studies' was introduced as an examinable subject but my forte was languages so I never really got past going into Dixons and typing into a Spectrum/ VIC20 etc. something like:

10 CLS
20 LET X=INT(RND*256)+1
30 PAUSE X
40 PRINT "BOO!"
50 PAUSE 50
60 GOTO 10

[hallsie]

40 PRINT 'BOO!'

Yeah right, as if you got it to print 'BOO!'



Stu

[V8 Fettler]

An auxiliary toggle switch to operate the fuel pump for trouble shooting and priming purposes should be added to the bank of auxiliary toggle switches.