Won't start, first time

Is your car playing up? Section includes conversion advice, temperature control, ECU and ignition problems.
golf-reub
L-Driver
Posts: 7
Joined: Sun Feb 10, 2019 8:32 pm
Drives: 1989 MK2 Golf GTi

Won't start, first time

Postby golf-reub » Sun Feb 10, 2019 9:08 pm

Hey! I've recently acquired an '89 MK2 GTi. 150k, new clutch, starter, battery, fluids, dizzy cap and rotor.

So far it's been amazing, but it has an odd starting problem - would be great to get some advice on it.

So here's what happens:
- from cold, when i start it, it turns over nice and quick but just doesn't fire at all. I can turn it over for 30 seconds, nothing.
- turn the ignition off, back on and start it. Catches immediately, and runs a treat.
- from hot, if i turn the engine off, it will start again no problem.

Generally it runs really nicely, it will just never start on the first try. Does anyone have an idea of where i should start to investigate?
0 x

User avatar
Monkey
Site Admin
Posts: 2568
Joined: Tue Sep 28, 2010 12:42 pm
Drives: VWs, lots of them!
Location: Somerset
Contact:

Re: Won't start, first time

Postby Monkey » Mon Feb 11, 2019 12:20 pm

It kinda sounds like a fuel issue.
can you hear the fuel pump prime when you turn the ignition on before firing the car?
0 x
Mk2 Driver
Mk2 Silver 8v
Corrado G60 Turbo
Mk2 Red 8v
Mk2 Grey 16v
Mk2 BBM ABF
Bora 20vt
Mk2 Green VR6
Mk2 Green ABF
Mk2 BBM 20vt
3.2 TT Roadster
Mk2 Red 16v
225 TT Coup
3.2 TT Coup

Mk2 BBM R32
Mk4 Anni Derv

golf-reub
L-Driver
Posts: 7
Joined: Sun Feb 10, 2019 8:32 pm
Drives: 1989 MK2 Golf GTi

Re: Won't start, first time

Postby golf-reub » Mon Feb 11, 2019 2:02 pm

Hey monkey, yes I can hear the fuel pump buzz then stop after a couple seconds, every time i turn the ignition on.
0 x

User avatar
Monkey
Site Admin
Posts: 2568
Joined: Tue Sep 28, 2010 12:42 pm
Drives: VWs, lots of them!
Location: Somerset
Contact:

Re: Won't start, first time

Postby Monkey » Mon Feb 11, 2019 3:14 pm

Ok, if we go back to basics, an engine only needs air, spark, fuel, compression and timing to start.
We know that you have timing and compression as it starts and runs on the second attempt.
It'll have the air as it'll probably splutter if there wasn't enough.

So it's either the fuel or the spark being dodgy.

If your pump is running, there probably is fuel getting there, leaving us with spark.
One thing I have just thought of, it could be the ignition switch, maybe on the first attempt, the switch can give the starter life, but not the ignition system. When you crank from cold, watch the dash, all the red lights should come on.
If not, your problem could be your switch, bit fiddly to install, but they're only about a tenner online.
0 x
Mk2 Driver
Mk2 Silver 8v
Corrado G60 Turbo
Mk2 Red 8v
Mk2 Grey 16v
Mk2 BBM ABF
Bora 20vt
Mk2 Green VR6
Mk2 Green ABF
Mk2 BBM 20vt
3.2 TT Roadster
Mk2 Red 16v
225 TT Coup
3.2 TT Coup

Mk2 BBM R32
Mk4 Anni Derv

golf-reub
L-Driver
Posts: 7
Joined: Sun Feb 10, 2019 8:32 pm
Drives: 1989 MK2 Golf GTi

Re: Won't start, first time

Postby golf-reub » Sat Feb 23, 2019 7:15 pm

Thanks for the suggestion Monkey.
I had some time to investigate today, pulled the injector rail and injectors out, cleaned them up and looked for any dodgy connections. Also triple checked for vacuum leaks in the intake boot and vacuum lines. Changed the plugs because they looked pretty old.

When i turn the ignition on, i get the oil pressure light, then i attempt to start it, and it goes out after a second or two.
I also pulled the plugs, and confirmed that i'm getting a good spark on all four, when cranking.
I also checked that i'm getting fuel to the rail when ignition is on, by loosening the hose clamp. Fuel sprays out under pressure.

So really it looks like it must be an intermittent fuelling issue - what do you think?
It's like the injectors are just not firing when i first crank the engine, then they start firing the second time round. Could it be an issue with fuel pressure maybe, like the first prime doesn't quite get the pressure for the injectors to work? But second time around, they are.

Any help is much appreciated, i'm kind of pulling my hair out on this one!
0 x

User avatar
Damien.wrl
Site Admin
Posts: 8100
Joined: Fri Nov 05, 2010 8:14 pm
Drives: an armchair
Location: Cornwall

Re: Won't start, first time

Postby Damien.wrl » Sat Feb 23, 2019 10:16 pm

No expert......... think the k jet wur can cause starting issues, also are both fuel pumps working? You aren’t using a bit of throttle to start??
0 x
Image

1988 Alpine White 35k mile OCD MK2 GTi ".................. viewtopic.php?f=12&t=128

golf-reub
L-Driver
Posts: 7
Joined: Sun Feb 10, 2019 8:32 pm
Drives: 1989 MK2 Golf GTi

Re: Won't start, first time

Postby golf-reub » Sat Feb 23, 2019 10:52 pm

Ah, it's an 8v digifant, so not k-jet.
When I turn the ignition I can hear a fuel pump under the floor prime then stop. Then when it's running I can hear the one in the tank humming. Throttle or no throttle doesn't seem to make a difference.

Once it's running, it's faultless. It's just starting that's a problem.
Cold start takes two or three attempts, hot start is slightly more reliable but still not right.
0 x

golf-reub
L-Driver
Posts: 7
Joined: Sun Feb 10, 2019 8:32 pm
Drives: 1989 MK2 Golf GTi

Re: Won't start, first time

Postby golf-reub » Wed Mar 06, 2019 1:40 pm

Update! I've found that although there's 12v to it, the pump in the tank isn't running at all. The pump under the rear seat is though.
To confirm, I've unplugged the pump in the tank, it continues to run exactly as before (hard to start, then fine when running).

I have a new pump coming today, will let you know if that fixes it.
0 x

golf-reub
L-Driver
Posts: 7
Joined: Sun Feb 10, 2019 8:32 pm
Drives: 1989 MK2 Golf GTi

Re: Won't start, first time

Postby golf-reub » Wed Mar 06, 2019 10:41 pm

So i replaced the in-tank fuel pump this evening, and i can now hear both pumps prime when switching ignition on. It's not fixed the starting problem though!

I'm going to summarise, as there's a few posts before now:
- crank from cold or hot, starter spins the engine, but will not fire at all
- loosen the rubber intake boot, spray a tiny bit of easy-start into the throttle body, and it starts right up
- 1989 8v GTi - Digifant, engine code PB. 155k miles.

Once running it runs perfectly, idles smoothly, pulls well through the gears. I've checked for vacuum leaks and the coolant temperature sensor.

I'd really appreciate some help - does anyone have a list of things that i could check please?
0 x


Return to “Engine & Gearbox”

Who is online

Users browsing this forum: No registered users and 4 guests