mk1 leon, starting issues - intermitant

[pugparcels]

ok, hope this is in the right section and someone has an idea what cuold be the issue....

our 2000 reg mk1 leon cupra ( 63000 miles ) has developed an intermitant starting fault.

From cold & hot she starts fine but if you have been out for a run, leave here and come back to her when she is warm ( temp would display around 70deg ) she really struggles to start.

it is as if she suffering from fuel starvation or as if there is no spark to ignite the fuel. i checked the plugs the other day and they were a bit ropey ( ngk pfr6q i think is the code off the top of may head) these were replaced with the exact same brand new plugs

the car is 100% standard engine wise. when she did start after 10 -15 seconds with a bit of throttle work to help she high idle'd at around 1200 - 1500rpm for around 6 - 8 seconds untill she settled down and then it was as if there was nothing wrong.

my other thoughts are looking to the coil packs? ( how do you check them )

maybe the battery? ( bit of a long shot )

dirty injectors? ( bit would this cause intermitant issues ? )

any help / sugegstions would be a great help as this is our only car and i really dont need the wife being stranded with the kids.

 

[pugparcels]

to add to this, our fuel economy seems to have gone through the floor. i am now wondering maybe a air flow meter / sensor?

if she is high idling, to burn off extra fuel ( if this is the case ) maybe the sensor is not allowing enough air through to balance the mixture?

or an issue in the pipe after the sensor - hence the reason no warning lights on the dash?

again i am running a completley standard engine, no k&n filters etc or anything like that.

 

[pugparcels]

think i am getting to the bottom of this...have plugged a fault code reader into the car and the codes i have got are:

16486 - Mass or Volume Air Flow Circ Low Input

&

16502 - Engine Coolant Temperature Circuit - High Input

so would a faulty air sensor combined with a faulty engine temp sensor cause the car to struggle to start as mentioned above? no other fault codes showing.

looking in the engine maf sensor easy to find, i think the engine sensor is just to the right of the head, remove the top 20vt cover and then the second plastic cover held in again by those quarter turn screws which goes around the front of the block by the dip stick and up the right hand side....sound about right?

 

[itfben]

my 1.6 Mk1 has been start badly, today it though the battery went flat cos i kept trying it 30mins later se started up fine. WTF is going on, runs fine. Seems to do it when it feel like it, the clocks sometimes reset (clock and trip)

i have a Powertec filter, which might be a bit dirty. but i wana change this anyway to K&N typhoon so cba to clean it.

Let me know what resolves you problem.

 

[Steely]

temp sensor fault for sure, im on my 3rd one now, its the 4 pin type sending 2 seperate signals to bothe the dashboard temp gauge and the ecu,

you'll find its over fueling, and your mpg will be down, can be had on ebay for 8-10 posted

be careful when putting back the c-clip it had a tendency to snap easily,

 

[itfben]

@steely is that for me or pug?

 

[Steely]

@steely is that for me or pug?

@ pug mate,

but yours im not sure,

Struggling to start as in turn the engine over, or do you mean it wont fire up?

 

[itfben]

ok you turn the key and you might not here anything, then it will start to turn but will not fire up (so it can be drive) eventually it will start and you can drive it. The time these steps takes vary at what seems to be at random

 

[pugparcels]

temp sensor fault for sure, im on my 3rd one now, its the 4 pin type sending 2 seperate signals to bothe the dashboard temp gauge and the ecu,

you'll find its over fueling, and your mpg will be down, can be had on ebay for 8-10 posted

be careful when putting back the c-clip it had a tendency to snap easily,

exact symptoms. i have ordered a new engine temp sensor & maf sensor as they both are showing faults and the wife needs the car for the kids etc so i need to get it fixed asap and hope both of these bits solve the problem.

should be here in 2 -3 days so can get them wipped in and touch wood all will be well again!

steely - how often have you replaced your temp sensor if your now on your third? how long hav you have her? my brother never had this issue on his 1.6 leon, does the fact we have the turbo model make this a more likely part to fail is it just one of those things and you have been very unluckly?

 

[itfben]

Video I just uploaded to youtube of me tryign to start my car: http://www.youtube.com/watch?v=c8rv9kP2t0M

It just wont start today

2nd video on its way, where it actually sounds like its trying to start (taken 40minutes later)

 

[itfben]

2nd vid here: http://www.youtube.com/watch?v=6Ypy9UXmEh4

 

[pugparcels]

right, i have replaced the temperature sensor ( old black for new green ) & replaced the maf sensor.

here is the scary part.

took it down the road, at low speed 30mph not and issue ran beautifully. decided to go up the dual track to ensure power all of the way through the range, that the turbo still kicked in etc, etc.

30mph, 40mph all fine. put my foot down and just as the turbo is about to kick in - then no power, plums of black smoke out the back and she started die. ( whilst im in the outside lane of the dual track )

managed to get to a bus stop, checked under the bonnet all looked fine. limped home, was a bit concerned something had gone major wrong. had no fault codes on the car....

decided it cant be the new green sensor, so i replaced the new maf sensor with the old. checked the ecu and had the same warning codes as in the begining ( the reason for buying a new sensor )

took her up the road, the turbo kicked in with no issues, no smoke ran beautifully. have spoke to the place where i had the sensor back, they will have it back and issue a refund.

question is apart from the old sensor throwing up the warning code

16486 - Mass or Volume Air Flow Circ Low Input

she runs perfectly, power through all of the gears everything i would expect from her. should i be concerned about the warning code? what does it actually mean?

 

[itfben]

Mines all good now, replaced the battery and she fired straight up then did the spark plugs too while i was getting grubby

 

[HallycupraR]

16486/P0102/000258 - Mass Air Flow (MAF) (G70): Signal too Low
Possible Symptoms
Probably no serious malfunctions
Loss of power
Possible Causes
Wiring and/or connections (short circuit?)
Mass Air Flow (MAF) (G70) defective
Possible Solutions
Check wiring and connections
Check / Replace Mass Air Flow (MAF) (G70)
Special Notes
In MY 1995-2002 (?) in Europe at VW-diesel-cars G70 had the bad reputation of slowly losing his performance, causing loss of power
From ross tech site so def a defective MAF

16502/P0118/000280 - Engine Coolant Temperature Sensor (G62): Signal too High
Possible Symptoms
Difficulties with starting a cold engine.
Starting the engine when engine is warmish or warm, idle rpm immediately is 1200 - 3000 rpm.
RPM at idle is irregular.
With all engine temperatures idle rpm will often vary between 900 - 1000 rpm.
With engine warm (90 °C) the engine temperature suddenly drops (70 °C) and slowly comes back to 90 °C.
Bad acceleration during warm-up.
Diesel Engines: Glow plug indicator may be on for a longer than normal time or at ambient temperatures where it shouldn't come on at all.
Possible Causes
The electrical signal coming from G62 is too low
Wiring and/or connections faulty (short circuit?)
Engine Coolant Temperature Sensor (G62) faulty
Possible Solutions
Check wiring and connections
Check / Replace Engine Coolant Temperature Sensor (G62)
And i would of said keep the green sensor in

hope it helps alittle

 

[pugparcels]

thanks for that, the engine temp sensor is working great. she has started each time since it was replaced! well chuffed ( means the wife aint stranded )

on the maf sensor side of things,

Loss of power - non that i have noticed
Possible Causes
Wiring and/or connections (short circuit?) - have checked all connections and look good
Mass Air Flow (MAF) (G70) defective could be the issue, but the new one was worse than the original!
Possible Solutions

think i will run as is, keep an eye out to see if i notic any loss in power etc. if this appears then maybe try the maf sensor again, looks like i need to replace the cam chain tensioner on my fireblade now so i will put the cash towards that first.

thanks again

 

[HallycupraR]

Im sure someone as said before on here if u tink ur maf is a prob dissconect it an drie downthe street an if it feels worse then there is nothing wrong with it

 

[scarface]

Im having a similar problem to you now, car doesnt start first time when warm, but only now and then. ALso after filling with petrol it over revs for few seconds and when driving off its like there is a delayed reaction to putting foot down and power coming out, but that all levels out after a few mins.

Ive had an engine management light on for 3mths with the following codes:

17704 P1296 - Cooling System Malfunction:
ECT Sensor, engine coolant thermostat

19534 P3078 - Throttle Control System - insufficient air flow at idle speed:
Throttle vavle housing requires cleaning, intake leak, wiring, maf sensor, TP sensor, Throttle control unit, ECM

Reading above it seems i also have a thermostat problem.

Once i buy the part, where and how do i fit it?