Cranks but does not start, sometimes starts but then shuts off

Tiny
KIDROS
  • MEMBER
  • 2006 VOLKSWAGEN POLO
  • 1.6L
  • 4 CYL
  • 2WD
  • MANUAL
  • 9,941,939 MILES
Hi folks, My name is Keith and I am new to the forum. Please help me with the below:

I have the vehicle listed above comfortline, and for about three weeks my EPC light came on and went off and in that same time I would lose throttle completely even while driving on the freeway at high speeds. It would feel as if I lifted my foot from the gas but I did not. I will then simply lift my foot and drop it again then it goes fine. Last week when EPC light did not go off and I lost throttle completely. Towed the car home because it would not accelerate of course. I then tried to start when I got home and would not start, just swing and swing but would not take, Left it and tried the next day, it then started and idled erratically then switched off. During this time still no throttle.

I have tested my accelerator pedal in a Polo Vivo and it works but the Vivo one also did not work in mine. I have put on a different throttle body (also from a Vivo) and it does the exact same that mine does. Car just idles for about ten to fifteen seconds then switches off (as if timing was off). But timing was never an issue before the throttle issue, then the starting/idling issue.

Plugged it onto VCDS and it picks up - Accelerator pedal position sensor 1/2 (P1639).

on a second diagnostic it speaks about map sensor (manifold absolute pressure). Also mentions something to do with injectors, now I do not know if this is the case because of a faulty map sensor.

Please shed some light as to where to start first without spending too much unnecessary money. I have already spent about R1500 in diagnosis and still cannot be pinpointed to the problem.
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Saturday, February 17th, 2018 AT 1:55 AM

19 Replies

Tiny
KEN
  • ADMIN
Hello,

The P1639 is the clue. I would replace the throttle position sensor on the gas pedal a used one will be fine. Once you have replaced the sensor clear the codes and retry the car.

Check out the diagrams (below).

Let us know what happens and please upload pictures or videos of the problem.

Cheers, Ken
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Monday, February 19th, 2018 AT 11:31 AM
Tiny
KIDROS
  • MEMBER
Hi Ken,

Thanks for your reply reply, just to confirm, the the TP sensor sits in the pedal itself? Or is it the plug(wiring) that plugs into pedal?

Just an update, after spraying my accelerator pedal switch and plug with electric contact cleaner, removing battery terminals for about two days, last night the car started fine but idled erratically and the throttle seems to have re-appeared. (Do not known if that spray helped),

After five minutes of erratic idle (not very bad almost like hiccups but I would not drive it) it stalls and switches off. Then it would not start again, only swing swing swing. We then tested the petrol pump because when I turned the key on at times I would hear the pump and other times I do not. We ran a cable from pump to battery and car started. Still had the erratic hiccup idle but seems there is a short in the wiring from fuel pump?

Thank you very much for your responses and pictures this far.

I will post pictures or videos if I can but still not certain about the erratic idle now? Perhaps a bad map sensor and plug leads. (My plug leads does seem to be buggered).

Thanks again.
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Monday, February 19th, 2018 AT 10:08 PM
Tiny
KEN
  • ADMIN
Can you upload a video of the way the engine is running so I can see? You can upload it in your response.
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Tuesday, February 20th, 2018 AT 12:04 PM
Tiny
KIDROS
  • MEMBER
HI Ken, I will do that later today for you. Thanks for listening.

I have taken a picture of the battery last night I noticed that on the battery where all the connections are, there is about three of the plates that no more makes contact but looks like the previous owner just connected it with a copper wire. Any idea what these are for? As in what is connected to it?

See picture attached.
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Tuesday, February 20th, 2018 AT 9:39 PM
Tiny
KEN
  • ADMIN
Oh man, yes you should not have them like that because it is a fire hazard. It looks like the second one from the top is broken? I would replace these with new and see what happens from there.
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Wednesday, February 21st, 2018 AT 9:39 AM
Tiny
KIDROS
  • MEMBER
Is it hey? Well then it has to be done fast.
I actually phoned Goldwagen and battery Centre to try and get the metal plate where I turn the 10mm bolts onto. Apparently they are so scarce and I should make my own using copper. I have made them all make contact with each other with the copper wire. But as you say, I should try to get that plate first.

Left the battery terminals on overnight and during today and tried to start and nothing. Only swing. A very strong swing so battery is good I would think. There are so many things that it could be but no one is sure. It is frustrating spending money on something you did not need to replace. But I am taking it in to an auto electrician this weekend and I am praying for the best. I will post the video of the idling tomorrow after I have left the terminals off overnight.

Thanks Ken.

Keith
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Wednesday, February 21st, 2018 AT 10:28 AM
Tiny
KEN
  • ADMIN
Hi Keith

A video would be best. Please let me know.

Cheers, Ken
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Wednesday, February 21st, 2018 AT 6:30 PM
Tiny
KIDROS
  • MEMBER
Morning Ken, see attached video. This time around it sounds a bit weirder than before. Let me know what you think? Thank you.
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Wednesday, February 21st, 2018 AT 8:55 PM
Tiny
KEN
  • ADMIN
Looks like you are not getting fuel into the engine. Lets do a fuel pressure test to see what you have.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

You can also crack a fuel line loose at the engine and then turn the key on and it should spray from the loose fitting.

Can you spray carburetor cleaner in the throttle bore will the engine run?

Thanks for the video really helps.
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Thursday, February 22nd, 2018 AT 11:40 AM
Tiny
KIDROS
  • MEMBER
Thanks, the electrician have connected a wire from the fuel pump directly to the battery and the car started. But when it idles it does so really bad. Like a hiccup idle, then shuts off as if timing was off and mechanic told me timing was okay.

I have cleaned the throttle body before with carburetor cleaner, do you suggest I spray it whilst the engine is on and idling as badly as it does?

I will do fuel line thing too and check. But if we tested with the wire to battery would you say there is a wiring problem here? Perhaps making contact with another?
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Thursday, February 22nd, 2018 AT 11:58 AM
Tiny
KIDROS
  • MEMBER
I will also do the fuel pressure test should all fail. But if I am taking it to an auto electrician they should be able to pick up what s happening and sort it. Thank you
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Thursday, February 22nd, 2018 AT 12:01 PM
Tiny
KEN
  • ADMIN
Lets do a compression test instead, I think the timing chain could have jumped. Just check two of the easier cylinders.

https://www.2carpros.com/articles/how-to-test-engine-compression

let me know
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Thursday, February 22nd, 2018 AT 12:08 PM
Tiny
KIDROS
  • MEMBER
Howzit Ken, thanks for your response once again.

So I took the car to an auto electrician to see what they say and take it from there.

Apparently my comfort control module has blown? Says water went into it and that s the reason the car is not starting or doing whatever it s doing? No idea how water went in there?

I have attached a picture of what this unit look like. Please reply with your thoughts.

Thanks,
Keith
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Friday, February 23rd, 2018 AT 7:56 PM
Tiny
KEN
  • ADMIN
Water in the module will definitely cause the issue. So they replaced it and now the car runs? I would make sure water can get to the new module do you live in rainy weather? Make sure the car is sealed up tight.
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Saturday, February 24th, 2018 AT 10:58 AM
Tiny
KIDROS
  • MEMBER
Thanks Ken,
So I bought the part and he fitted it and that seems to have sorted the starting problem I think. No idea how water could have got in there though. That sits under the steering wheel? He has mentioned that the erratic idle is still there and took out spark plug number 2 and says it seems wet. Also the exhaust is blowing like water. No idea what that means. But I m waiting for a call today and hopefully be told that it s sorted and ready. Thanks for all your help this far. I will let you know outcome.
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Sunday, February 25th, 2018 AT 9:52 PM
Tiny
KEN
  • ADMIN
The windshield seal is usually the culprit
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Monday, February 26th, 2018 AT 12:03 PM
Tiny
KIDROS
  • MEMBER
Awesome thank you, I will definitely have a look a that when car comes back. After replacing that module the car seems fine with starting but he still finding some wiring issues.
Will give you a full and final update in the next day or so,
Thankful.
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Monday, February 26th, 2018 AT 7:08 PM
Tiny
KIDROS
  • MEMBER
Hi Ken. I want to thank you for your replies and expertise so far.

Thanks for the windshield advice, noticed some areas where water definitely seeps in. Will sort that soon.

Please shed further light on me with some new problems that arised after the car came back from electrician.

So remember the problem it initially had before going there? (No starting, erratic idle, switching off. Also accelerator pedal didn t respond). Changed the blown control module and that sorted out starting and idling problem. It now has no power, when I drive in low revs it hesitates very much unless I rev a bit harder. On higher revs and faster speeds it still doesn t feel normal but the car moves ok. I changed plug leads last night, took it for a test and still hesitates a lot at take off?

Furthermore, I noticed a water leak coming from something that Sits just behind the thingy that the plug leads come out of? I don t know if that s the coil? But the leaking thing is behind what I think is the coil. (Video attached) please tell me what this is called and how the leak can Be fixed?

This trial and error is killing the pocke but I guess there s no other way.

Look forward to hearing from you again.
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Wednesday, February 28th, 2018 AT 7:45 PM
Tiny
KEN
  • ADMIN
I will be glad to help you but because this is a different issue we must start a new thread.

Please copy and post your question here and re-upload the video please.

https://www.2carpros.com/questions/new

Cheers, Ken
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Thursday, March 1st, 2018 AT 10:53 AM

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