73 replies to this topic

[Chris P Duck]

This is an average start, it gets a lot worse as this caught first time, sometimes takes 3 attempts with a little longer cranking.

[CHILL Gone DUTCH]

What's the hissing during priming ???

[CHILL Gone DUTCH]

Should start like this

[Chris P Duck]

Hmm. They do sound different don't though. The Walbro has always sounded like that. I've not really listened to anyone else's as as people say they're noisy pumps I assumed it was normal. Anyone else with a Walbro care to comment?

[CHILL Gone DUTCH]

Mine is walbro I'm thinking smiley could be on to something

[Chris P Duck]

I guess it would explain the poor starting, the fuel trims being erratic and the injectors running a higher duty cycle than they should. Balls, I thought I'd got away with not having to cut a bigger inspection hatch! Fuel pressure gauge has been posted so will be here tomorrow I guess. That should let me know for certain. So I ended up with a vacuum leak, a coolant leak (from the CC), an oil leak (from the SC) and a dodgy fuel pump. FFS, glad I took the path well trodden, imagine if I tried to push the limits or do anything pioneering! Still as long as it works in the end I'll be happy!

[Chris P Duck]

Fuel pressure gauge turned up.

 

Again this wasn't a bad start (possibly as it primed when I turned the key to disengage the steering lock so I could push it out the garage to film in the light)

 

http://youtu.be/icDfhqe897o

 

Observations are:

It's very slow at building up pressure                          (but I've nothing to compare this to, can anyone that's measured there's say if its different or link to a vid)

Idle pressure is 3.4bar not 3.8                                    (but I don't expect a gauge that cost <£30 inc plenty of adaptors and postage to be super accurate)

pressure fluctuates when revving even without load  (I'm guessing this is really not right, but again I've nothing to compare it to)

 

Basically I think this is telling me the pump is fooked, but I want to be certain. I don't want to spend >£100 on a pump and spend a day of my time to find out I've changed something there was no problem with and still have problematic starts!

[CHILL Gone DUTCH]

It may not be the pump chris but one of these pipes leaking which makes sense of the noise it's making

[Chris P Duck]

The pipes which are famous for being oh so easy to change, oh joy! Still it would be cheaper!

[Chris P Duck]

Fuel pressure gauge turned up.

 

Again this wasn't a bad start (possibly as it primed when I turned the key to disengage the steering lock so I could push it out the garage to film in the light)

 

 

Observations are:

It's very slow at building up pressure                          (but I've nothing to compare this to, can anyone that's measured there's say if its different or link to a vid)

Idle pressure is 3.4bar not 3.8                                    (but I don't expect a gauge that cost <£30 inc plenty of adaptors and postage to be super accurate)

pressure fluctuates when revving even without load  (I'm guessing this is really not right, but again I've nothing to compare it to)

 

Basically I think this is telling me the pump is fooked, but I want to be certain. I don't want to spend >£100 on a pump and spend a day of my time to find out I've changed something there was no problem with and still have problematic starts!

 

To save a click

[smiley]

Lifting the pump housing just to check costs nothing.

(other then dremel time, and if you have an early generation clip system, the connectors may struggle back a bit before coming unloose.)

 

I would say rule of thumb is that the pump housing should go back in the tank and compress with almost no pressure needed. 

if not, you are forcing something. 

 

[Bargi]

I can very confidently say that is way, way to slow to build up pressure.

When I had Nicks pressure tester (which is identical to yours) it jumped up immediately turning the key on and even when starting almost instantly jumps up to 3.8

 

It seems once it's up to pressure it's ok and when you rev it raises as it should ok also.

Have you done any track days and found it running out of puff or it running lean on WOT when logging?

 

My guess would be leak, but I guess the pump is always a possibility.

 

Could you pull the whole pump and gubbins out and run it in a bucket and see if any of the pipes are leaking?

 

Edited by Bargi, 28 February 2015 - 09:49 PM.

[Bargi]

looking again, when you rev it doesn't even got over 3.8 which doesn't seem right

When I had my car on the dyno it went well over 4, but you are just revving without load so maybe it doesn't go up as much

 

[Bargi]

I'm an idiot, I took a video when I had the gauge, even with the obligatory heavy breathing!

clicky

 

Your pump only primes to 3 while mine reaches 4

Much slower to prime

Drops off much quicker

 

The dropping off quicker I think points to a leak.

 

 

Edited by Bargi, 28 February 2015 - 10:21 PM.

[pete-r]

Have you tried priming the car more than once before starting? Listen for the pump to whizz, click off and repeat. After the pump has primed there should be not much priming being done. Then start it. If it starts then you know the rail isn't getting enough fuel on the first prime and you can stick a pressure gauge on it to see what's happening. Pump, lines, leaks, electrics. If it's not starting cleanly after several primes then your looking at more involved stuff like ECU or injectors etc.

[Chris P Duck]

I'm an idiot, I took a video when I had the gauge, even with the obligatory heavy breathing! clicky   Your pump only primes to 3 while mine reaches 4 Much slower to prime Drops off much quicker   The dropping off quicker I think points to a leak.    

Cheers Bargi, exactly what I was after . I had a long chat with Gaz at Spitfire and got plenty of things to check. He said it's very unlikely to be the pump as its so basic there's not a lot to go wrong. Almost definitely a split internal hose. Now to buy some more Drexel bits and find some time.

[Chris P Duck]

Have you tried priming the car more than once before starting?

Yeah I tried this some time ago, no difference it just throws the EML (something to do with the immobiliser, I guess it doesn't t like the ignition going on and off too many times without starting)

you can stick a pressure gauge on it to see what's happening.

Done this as well, that's what the video is of.

Edited by Chris P Duck, 28 February 2015 - 11:36 PM.

[pete-r]

The gauge dropping pressure after the pump primes would indicate a leak, if those pipes split then it's pumping fuel back into the tank. What happens when you stop the engine? There shouldn't be a sudden drop when it stops worth checking. On the plus side it's pennie to fix but the pump is an ass to remove.

Edited by pete-r, 28 February 2015 - 11:38 PM.

[Chris P Duck]

Yeah all I need to do now is pull my finger out and knuckle on with it* I'm 99% certain it's now diagnosed (so thanks everyone) just wish it was something easier to get at! *as soon as my eBay circlip pliers turn up anyway

Edited by Chris P Duck, 28 February 2015 - 11:43 PM.

[smiley]

That spring is not so strong, and can be done one side at a time with a bodkin or something.