unreliable ignition

[86gti]

Nice info, but it still pulses the pump if you turn the ignition on and dont start the car.

Unshure about all systems, but 3 kjet cars ive worked on have no power out of relay or into pump at any stage of ignition being turned on unless its being cranked...may differ on some set ups.

Here is a lil more info on the relay and accumulator etc.......

PUMP RELAY

Tachometric relay...... what that means is it only responds and sends a voltage to the pump when the engine is turning over or actually running. The relay gets its signal from the negative terminal of the coil , this confirms that the engine is turning.
this rely is kind of a safety device... if the vehicle is involved in an accident when there is a possibility of a fuel line being fractured, the engine will stop due to a lack of fuel, the signal from the coil stops and then there is no voltage at the pumps.

if the car wont run, get someone to see if they can hear the pumps going while its turning over....

My relay was a bit of a bugger to find....my bentley manual said it was somewhere that it wasn't.
on my mk2 (UK) it was relay "62" as posted before.

as explaned previously bridge the 2 main pins on the relay with a switch, and a 10 amp fuse in the line too...just to be safe..
flick it on and see if it goes.lol.....
I've had a weird problem with mine of late...I park on a hill at work, and a couple of times ive just gone to roll start it..
it wont go, and then it will turn over but the pumps dont go..so i bridge the pump relay and start it, turn it off, then put relay back in and it goes....
so i havn't tried to run start for a while....might be the relay, and maybe i should change it..



FUEL ACCUMULATOR
(next to the main pump on a mk2)

It accumulates fuel......lol.
and it's the first part in the fuel system after the pump.
Its first job is to help smooth out any pulses in the flow of the fuel, this is achieved by passing the fuel through a series of baffles and into a chamber giving it smoth flow. Its other role is to maintain pressure within the system when the fuel pump has been switched off.
This is achieved by the accumulator spring and diaphragm pushing against the fuel.
When engine is running the diaphragm will be against its stop within the spring's chamber. When the engine is stopped and the non return valves close the spring pressure against the diaphragm will maintain the pressure and stop any seepage.
in most data books for this system it is shown that the critical time for maintaining these pressures is between 5 and 20 minutes. After a fang when the engine is switched off the under bonnet temperature increases, causing the fuel in the lines to heat up....this will usually make fuel evaporate.....but maintaining the pressure fixes this problem and will let it start when its been standing with a hot engine.



FUEL FILTER
(next to the main pump on a mk2)

Very good idea to change this at least every 2 years or so...
as the system is so reliant on pressure and clenlyness, you filter has to be in good condition.
not much to say about this filter....
it looks allot different to normal filters and has screw in fittings in both ends to cope with all the pressure.




For some strange reason K-Jet is something im very interested in! dont ask why, its just great idea...
Ive spent many dollars on books and referances to find out as much as i can, mostly on the mk2 set up and some saab and volvo stuff too.

[Golf Loon]

Thats a good explanation Benny and I too am a disciple of or a slave to Kjet.

The 3 kjet cars I have driven this week all pulse the pump when you turn the key on but not the engine. It runs for a sec and then switches off.

This allows you to prime the metering head and make sure system pressure is to the max before you crank it over. This is especially important on the 16vs which suck more fuel.

Also holding the pedal down sucks the most air, so it starts with a heap of fuel and a bang.

[86gti]

ahh, Ive got relay disabled at the moment, running a switch and fuse on it.
been like that for a while, cause im too lazy to put the new relay in...lol...
Doing a bit more research, it says some do actualy prime the fuel line..
some between 1 to 3 sec. some volvos run a lot of extra stuff on the system... said the tachometric relay system on the mk2 Kjet didnt tho, KEjet does however.....unshure about the mk1 tho...But yea, the Kjet system is a great set up!

[Jmac]

Yeah but all said and done these systems have a non return valve which is common as ( Me too a slave to the K,KE and KE3 jetronic - from nappies to Kjet LOL) Dont worry i stared on them when Shell 1st brought out the Magic unleaded burnt valves galore!!!!! We had 10 hoist at our dealership and every second 1 had an Audi 90 head off , sorry about the waffle but that was K jet prime time ( pardon the pun) Ahh rusted fuel pump and accumulators broken mounts making up pipes man you this country is lucky in that respect dont miss that one bit. Back to the beginning - best way as we would all agree is fit pressure gauge and crank. Then leave it and watch the holding pressure etc.
Cheers fellas im with yas all the way by the way!

[jayjay]

hey, thanks for all your replies guys. =] umm.. when it starts, the idle is fine and it drives pretty well. so does that mean that it can still be a fuel pump issue?

[86gti]

Yea, could be. I know i was going crazy a few years back in my mk2.
It would start fine most of the time. and always when cold.
some times in the heat of mid summer in traffic it would get the splutters n usually clear its self with a run on a road with no traffic...then In the worst places some times it would decide not to start!....some times i left it for a few hours and it would start. Just gradually got worse over time...went for a period of about 6mths where it was fine. Then she died...lol.
got to the point that it would pump when the pump was out of the car...and not in the car. (after 18mths of head scratching)...
I first replaced the intank pump, as that can cause a bit of trouble some times if it starves the main pump...But the main pump will GARGLE loudly if thats the case...had this happen to a mates car a while back.
But the best thing to do is to try to track down where the problem is...
Like Jimmy said it could still be the non return valve or daggy filter etc.
you really need to test all the pressures in the system.
Like I said, all my pressures were fine in the end, but the flow was down to nearly half what it should be...All cause by the main pump in the end.
Its a daunting task I know, but its a great system to get to know!!
A bentley manual is priceless If you plan on tackling it yourself.
Thanks to Andrew from Robinson Automotive for helping me out with a manual and a pressure tester when i was nearing the end of sanity with mine!.....
In the end, it could be one of many things...But i would put my money on it being pressure or flow related....
Wish i could help more!! but your to far away, haha.

[Jmac]

Yeah Benny me too mate - i would be betting holding pressure as it runs ok when started.
Cheers

[jayjay]

i spose it's time to go pressure gauge shopping then.. =P any idea on where i can get a replacement non-return valve?

oh.. i've got a bentley, it's just, it's all been a bit hectic lately so i haven't gone through it yet. hmm.. duh..

[Jmac]

Anyone with an old pump mate should be able to help they are on the fwd side of the pump mate, generally comes with the pump but can be bought seperately.
CHeers , yeah just check the pressures 1st though

[Golf Loon]

We were looking at the pump on a kjet car today and like Jimmy says there is a reduced in the end of it. And it was all clogged with cw@p.

We just drilled the middle out, so it flows good now
Some year models had the filter but some did not. I think it was an experiment by VW and is not really needed.

[Jmac]

Yeah i agree Loon but there is a ball and spring in her too to keep the pressure residual for hot starts

[86gti]

Just screws out...Keep em if you ever change a pump!

that part on lists says part number 0580 254 021
but that part number is "the pump" its self with that in the end....

please note.....the label on the pump pictured has wrong part number on sticker....
says 012 on end, and on body last 3 digits are 021.

Also Jayjay...get a specific Presure guage if you can, K-jet runs very high pressure!!! more than other inj systems!

[Jmac]

Benny Good on You mate short of piccies thats exactly what im trying to point out, Good man
Mate im sure we could write a book about Kjet, i feel you have the same passion as me mate and its good to se not a lot of it around mate.
Cheers
Have a beer with ya one day mate

[86gti]

no problems, I'll have a scotch and dry tho , haha

[86gti]

Any luck with this problemo yet jay jay???