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Discussion Starter · #1 ·
PD150 which had camshaft problem. Camshaft replaced along with injectors followers etc. and at same time EGR valve removed and replaced by Allard kit. Engine also has a Revo Technik remap to 195 bhp for last 3 years.

Car goes like a rocket. BUT when the car has got warm it will not start. From cold, first thing in the morning the car starts fine - every time. However, stop top fill up with diesel, go shopping and get back in and it will not start.
Turn the key the engine turns and fires on all four cylinders, gets to 625 -650 rpm and just cuts out. If you keep cranking the engine to get it past 650 rpm on the starter, the engine picks up and runs fine

Right - here goes. The following have been replaced:

the MAF sensor, the temp sensor,
the injector wiring harness,
the fuel filter,
the fuel filter nrv,
Dual Fuel pump
The pump in the fuel tank has been checked and is ok

There are no faults visible on VAG Comp
And I am now totally stumped.

Anyone got any ideas on a fix......????
 

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Discussion Starter · #3 ·
XOne, thanks for the quick reply, Forgot to say crank sensor has already been replaced. what/where is the 109 relay? Also can you give reasons why the starter motor and battery would give this problem...??

Thanks in advance
 

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I know the 2.0 BKD lumps suffer from bad hot starting which is a very common fault. the solution = new starter motor.

If, after some research, you can not find people with the 1.9 with a similar issue, I would personally begin with changing the starter motor, battery less so but still a possibility.
 

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I've just had the same problem, and it tuned out to be the engine speed senor (crank sensor) cost me 60 quid for a new one been good as gold since!

if you have vag com, then scan the car when its not startaing and i bet it will show

engine speed sensor (crank sensor) no signal

but mines is on an AGU
 

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109 relay is under the steering wheel, you'll need to take off the housing plastic under there to get to it, A quick way to check it's working is to unplug the engine coolant temp sensor and start the car when it's up to temp, if theres still an issue then it'll be your battery, or a pants starter motor.
 

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Discussion Starter · #8 ·
Guys thanks for the replies. As mentioned the crank sensor has been replaced and vagcom checked and no problems indicated. The battery is giving all the right voltages - and has just been and checked. The starter motor appears fine, and kicks it over well. So why would the starter motor cause the problem,,,???
 

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Guys thanks for the replies. As mentioned the crank sensor has been replaced and vagcom checked and no problems indicated. The battery is giving all the right voltages - and has just been and checked. The starter motor appears fine, and kicks it over well. So why would the starter motor cause the problem,,,???
"There is one main reason for a starter to fail when it is hot - worn bearings, especially in the tailshaft. The heat generated in the starter by the engine and the exhaust pipes (sometimes) causes the armature to expand. If the bearings are worn then the armature drags (actually contacts) on the stator causing a short circuit and a high friction drag. Sometimes just replacing the bearings can fix the problem."

http://www.misterfixit.com/starttst.htm
 

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Discussion Starter · #11 ·
Xone am going to have to try disconnecting the coolant sensor tomorrow, as have to go out in about 5 minutes, but will sort it tomorrow morning after i get to work and let you know then.

Thanks for all the help so far [:D]
 

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Discussion Starter · #12 ·
Xone, [:D] have just been and disconnected the coolant sensor and the car started first time every time when hot ! So a new relay has been ordered and will be collected after work and fitted & I will run it for a while & confirm that this has fixed the problem.

As an aside how does disconnecting the coolant sensor confirm the problem..??? (Been trying to work out the logic on that one!)
 

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Discussion Starter · #14 ·
Well the 109 relay has been replaced. All was well for the first few hot starts [:D] but now the same problem has returned. [:mad:]

Stop, turn the engine off, go to the shops. Come back, start the engine, it fires picks up to 625-650 rpm and then dies.

To get the engine to run i need to keep the starter turning the engine over until it gets to 650 rpm and then picks up and runs normally.

Am now totally confused! Looks like trying new starter - BUT it doesn't seem like a starter problem as the starter sounds/seems to work properly.
 

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Discussion Starter · #16 ·
My battery is the original one! 9 years old now, but has been checked and is absoulutely fine, no weak cells and has 14 v on charge!

The car was fine before the cam was replaced. since then the bloody thing just won't start first time when it gets hot! The battery will kick the starter over for ages.

If you kick it over it fires, picks up to 625-650 revs and dies. keep the engine kicking over with the starter and the engine revs go past 625-650 it starts - put it on Vagcomp and no failures are shown.

Therefore i am loathe to splash out on a replacement starter just yet. I really think it is fuel but i don't know what else it can be, as the relay seemed the obvious solution, particularly after disconnecting the temp sensor as you said and it started first time every time.
 

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This is becoming a bit clearer. Who undertook the work changing the cam? sounds like it may be an injection timing thing that may need to be adjusted with vcds. Although this is a PD engine so maybe not. Get the injector loom looked at, there may be an issue with that as well. But hot start issues are normaly related to what has been pointed out already so it may be the crank sensor but yos say that this is new.
 

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Discussion Starter · #18 ·
The car has been looked after regularly by my friend who owns a garage specialising in vw. The head was sent away and rebuilt by a firm specializing in heads in Inverness. The head was put back and the timing set up using the approriate guages. The injector loom has been replaced, and the crank sensor, and just about anything else you can think of - apart from the battery - which has been fully checked, and the starter motor, which as i said in my previous post seems to work fine.

It has also been checked by an independant diagnostic specialist - who after 2 hours walked away saying he couldn't find anything wrong with it. Which is why my friend and I am open to any ideas, and the 109 relay seemed to be the solution - as no one had mentioned that previously - BUT that hasn't worked.

Fixing it will most likely be a quick solution - ONCE I CAN FIND the blooming problem. The difficulty is currently finding it.

As to adjusting the timing using vcds, i thought that the timing was set up manually using the guages to identify TDC etc etc
 

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Sorry but I think you have been given duff information, disconnecting the coolant sensor will cause the glow plugs to stay on for the maximum time, this causes excess compression which makes the car fire up easier.

Timing cant be adjusted.

If you have VCDS you might want to log the cranking speed (engine speed) when cold and hot to see if the starter is slowing when hot.
 

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Discussion Starter · #20 ·
Aham_uk thanks for that, was wondering how disconnecting the coolant sensor would work! WIll try to log the cranking speed, but not really sure on how to do that. However, I really can't understand how the starter motor affects the starting cycle as everyone suggests, as the engine fires pciks up, but dies between 625-650 rpm. I am convinced it is fuel problem ie lack of pressure getting to the injectors during starting, but no one can tell me what the initial fuel pressures should be from starting.

Also there is no air bubbles in the fuel lines as the fuel lines were replaced with see through pipes to check! So i am still at a loss as what else to check or as to what can be causing the problem!
 
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