Argghhh, can anyone point me in the right direction here ? My car has suffered with bad idle problems for ages, so I removed the ISV and cleaned, cleaned all breather pipes and changed air filter. Still no improvement. I then Fixed a small hole near my back box for the MOT, and when I start it it idles perfectly. I let it run for about 30 mins or so, switch off, get coffee. come back to it about 5 mins later, car starts runs for about 3-4 mins dies aftering spluttering. Car now wont start. Happened to me twice now. Leave it for a while and it starts again. It's getting worse at running though now and will only go for a few minutes before stalling. When it wont start there is no spark from coil, engine diagnostic code reader shows engine speed sensor fault after car stalls G28 sensor. However I also have another problem with the fuel relay constantly clicking and re-priming the fuel pump, it goes crazy. So from spending days on google its one of three things, the crank sensor is either naff or its wiring is, fuel relay or ECU control relay. I would possibly think the coil but when I do get a spark it's a nice blue/white strong spark. Could any body here help me decided which way to proceed first ? All usual stuff checked, vaccuum leaks, bad earths on sensor loom, coolant temp sensor seems ok resistance wise. Any help would be masively appreciated. Also nearly forgot it gets stuck at a high idle around 1600 rpm when you rev it, taking a minute or so to come down to about 1000 rpm.
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I understand very little of this link;
http://tech.bentleypublishers.com/thread.jspa?threadID=16138&tstart=0
However the following excert from it seems to make sense and matches a no start when hot, with the G28 error code;
Re: 16706 - Engine Speed Sensor (G28): No Signal - Troubleshooting help!!
Posted: Oct 5, 2006 2:32 PM
Reply
Great write up Art.
"it started fine when cold, but when it gets to normal operating temperature and dont wanna start,i have to wait 1 to 2 hours"
These sensors are magnetic sensors as Art have already pointed out. The rpm sensor produce an AC current as the teeth passes over the sensor, but as we all remember from high school physics "A magnet loses it magnetic properties once it get hot". This will explain why the engine will not start until it has cooled down, the signal is missing with a hot engine,
Re: 16706 - Engine Speed Sensor (G28): No Signal - Troubleshooting help!!
Posted: Feb 5, 2007 3:14 PM
Reply
Replace the sensor. We have seen a few bad sensor that reads correct.
Hope this helps!
http://tech.bentleypublishers.com/thread.jspa?threadID=16138&tstart=0
However the following excert from it seems to make sense and matches a no start when hot, with the G28 error code;
Re: 16706 - Engine Speed Sensor (G28): No Signal - Troubleshooting help!!
Posted: Oct 5, 2006 2:32 PM
Reply
Great write up Art.
"it started fine when cold, but when it gets to normal operating temperature and dont wanna start,i have to wait 1 to 2 hours"
These sensors are magnetic sensors as Art have already pointed out. The rpm sensor produce an AC current as the teeth passes over the sensor, but as we all remember from high school physics "A magnet loses it magnetic properties once it get hot". This will explain why the engine will not start until it has cooled down, the signal is missing with a hot engine,
Re: 16706 - Engine Speed Sensor (G28): No Signal - Troubleshooting help!!
Posted: Feb 5, 2007 3:14 PM
Reply
Replace the sensor. We have seen a few bad sensor that reads correct.
Hope this helps!
Relays are cheap and easy to get out of scrappers, so first call. then the coil as that can overheat and stop sparking when its had it
Also can anyone tell me which number relays are the fuel pump and ECU relay. I think the ecu is 30 cause I read a problem on a VW forum earlier that produced similar problems no spark from the coil. Would a faulty ECU relay cause the pump relay to repeatedly go on and off e.g cause the ECU is constantly re-booting ? Also which fuel management system was fitted to the ABF 16v Ibiza's, I was originally under the impression it had a hybrid like digifant controller but when I looked at the ECU it's made by Siemens, isnt that a SIMOS controller ? I am gonna bridge the ECU control relay as suggested on another forum I was looking at to see if the relay is at fauly. Problem is Im very short on money at the moment so want to try and replace parts logically if possible. I know I could end up replacing all sorts but want to do it in a logical manner. Relays first I think. Followed by crank sensor because I found a problem on another forum that is identical and as suggested above the crank sensor loses it's mangetism when it gets hots. Cold started engine runs fine for 5-10 mins then all the problems start occuring as the engine gains temprature. It's driving me crazy. Tommorrow I am going to check the earthing and wiring to crank sensor because the car never had any problems like this until it spent a year not being started on my drive. Just thrown by the fuel relay going mental, does anybody know what else is powered by fuel pump relay or is it just fuel pump ? Absolutely any help will be appreciated.
Did you say it hasnt been started for a year?
If this is the case you could have bad fuel? The water etc and fuel can seperate, might be worth checking that?
If this is the case you could have bad fuel? The water etc and fuel can seperate, might be worth checking that?
duncagr
Guest
if it turns out to be the engine speed sensor then i have a brand new one from vw that i don't need.
pm me if ur interested.
cheers
gordie
pm me if ur interested.
cheers
gordie
I think the engine speed sensor (G28) is a good one to change.
However, whatever you end up doing, i would suggest cleaning all the electrics, throttle body etc afterwards as well as clearing fault memory by disconnecting the battery.
However, whatever you end up doing, i would suggest cleaning all the electrics, throttle body etc afterwards as well as clearing fault memory by disconnecting the battery.
clowntype
Guest
I have a similar problem, struggles to start when its warm, and now its just started dieing on me at speed, like 60mph and the thing dies, rev counter drops like a stone, it did it quickly a couple of times and this morning i tapdanced it down a dual carriage way for about a mile before it came back into life!!
any ideas would be great before i pull out in front of a truck and it dies!
oh its a 2l 16v abf engine p plate
any ideas would be great before i pull out in front of a truck and it dies!
oh its a 2l 16v abf engine p plate
clowntype - First thing is to post a new thread ;-)
The easiest one when warm is distributor cap, if its cracked it expands and mucks things up.
check all the basics;
dizzy cap for cracks, also carbon rod inside should be smooth/intact, points inside clean
ignition coil - cracks, scoring, marks
spark plugs and leads - clean and check plugs, also colour, are they carboned up (overfuelling)
vacuum hoses and air hoses - dont think it will be these but check anyway.
throttle body - can cleaner only £4 ish, give it a good clean. Unlikely to be tb but good to do anyway.
air filter - unlikely to be this, but good to check it.
Doing above helps narrow it down.
If it does the same after above it might be worth buying a fault code reader, about £30 off ebay, i use one and its really helpful. Might single out a sensor etc.
The easiest one when warm is distributor cap, if its cracked it expands and mucks things up.
check all the basics;
dizzy cap for cracks, also carbon rod inside should be smooth/intact, points inside clean
ignition coil - cracks, scoring, marks
spark plugs and leads - clean and check plugs, also colour, are they carboned up (overfuelling)
vacuum hoses and air hoses - dont think it will be these but check anyway.
throttle body - can cleaner only £4 ish, give it a good clean. Unlikely to be tb but good to do anyway.
air filter - unlikely to be this, but good to check it.
Doing above helps narrow it down.
If it does the same after above it might be worth buying a fault code reader, about £30 off ebay, i use one and its really helpful. Might single out a sensor etc.
clowntype
Guest
cheers for that,
changed dizzy cap, leads, spark plugs, rotor arm(had to cut it off!! they cant have changed that at the last service!!)
no code on the reader, just the speed sensor but i have read that you get that when the engine isnt running.
problem still happened, i'll go through the other things next couple of days.
There does seem to be a leak/or just wet at the elbow which leads into the fuel rail, could it be a problem with the fuel pressure sensor(is that what the round thing held on with a simple clip on top of the rail is?)
spark is a bit weak coming out of the dizzy too
changed dizzy cap, leads, spark plugs, rotor arm(had to cut it off!! they cant have changed that at the last service!!)
no code on the reader, just the speed sensor but i have read that you get that when the engine isnt running.
problem still happened, i'll go through the other things next couple of days.
There does seem to be a leak/or just wet at the elbow which leads into the fuel rail, could it be a problem with the fuel pressure sensor(is that what the round thing held on with a simple clip on top of the rail is?)
spark is a bit weak coming out of the dizzy too
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clowntype
Guest
Fixed engine cutting out abf
replaced the g28 sensor (dealer £150, ecp £90(they do a cheaper one but not worth the saving in my opinion))
tools
sockets 10mm,13mm longwall, 16mm,17mm big sockets 3/4 drive various extensions
allen key 5mm to fit in end of socket
long flat screwdriver
put jack under bellhousing/engine join
undo 3 starter motor bolts
(take 2 off 13mm nuts off that secure cables/clips(one on top bolt one on front bottom bolt)
then you have 2 off 16mm bolts(top and bottom to rear of car, and 1 off 17mm closest to front of car)
jack up approx inch
remove 17mm bolt from top of engine mount(long extension in from the top)
take 10mm bolt off bracket( holds cable/pipe control clip)
bit of jiggery pokery and that bracket will come out through the top allowing you straight in to the sensor
i would take the time to clean the area all around the sensor so you're not pushing crap back into the hole with the new sensor
then you need a 5mm allen key on a medium extension go over the front crossmember and under the 2 hoses, you'll see the position off your new one if you're not sure
undo the bolt and then you'll need a bit of leverage against the engine just to 'pop' the sensor out (long flat screwdriver should do it)
then remember the routing of the cable when you remove it for putting the new one in.
put the new one in the hole it should be loose, spin it to locate the bolt screw the bolt in until it just takes the tension then use a lever against the cross member to 'pop' it in(i used a long socket extension) then tighten the screw
assemble in reverse
DONE
replaced the g28 sensor (dealer £150, ecp £90(they do a cheaper one but not worth the saving in my opinion))
tools
sockets 10mm,13mm longwall, 16mm,17mm big sockets 3/4 drive various extensions
allen key 5mm to fit in end of socket
long flat screwdriver
put jack under bellhousing/engine join
undo 3 starter motor bolts
(take 2 off 13mm nuts off that secure cables/clips(one on top bolt one on front bottom bolt)
then you have 2 off 16mm bolts(top and bottom to rear of car, and 1 off 17mm closest to front of car)
jack up approx inch
remove 17mm bolt from top of engine mount(long extension in from the top)
take 10mm bolt off bracket( holds cable/pipe control clip)
bit of jiggery pokery and that bracket will come out through the top allowing you straight in to the sensor
i would take the time to clean the area all around the sensor so you're not pushing crap back into the hole with the new sensor
then you need a 5mm allen key on a medium extension go over the front crossmember and under the 2 hoses, you'll see the position off your new one if you're not sure
undo the bolt and then you'll need a bit of leverage against the engine just to 'pop' the sensor out (long flat screwdriver should do it)
then remember the routing of the cable when you remove it for putting the new one in.
put the new one in the hole it should be loose, spin it to locate the bolt screw the bolt in until it just takes the tension then use a lever against the cross member to 'pop' it in(i used a long socket extension) then tighten the screw
assemble in reverse
DONE
clowntype
Guest
Thats a bloody expensive magnet lol
good stuff
was there much crap inside when you took it off? im wondering if that might create a slightly bad signal without a fault code creating similar issues?
good stuff
was there much crap inside when you took it off? im wondering if that might create a slightly bad signal without a fault code creating similar issues?
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clowntype
Guest
the sensor was clean,
the intermittent will be i think beause the actual fault is the wires break away from the housing and wear throught the sleeving causing them to short, there will be a point i am sure where it is sending border level signals before it goes completely s/c.
heat obviously makes all the plastics and the copper softer allowing the wires to flex more and allowing them to move and short more easily.
that's my guess anyway
the intermittent will be i think beause the actual fault is the wires break away from the housing and wear throught the sleeving causing them to short, there will be a point i am sure where it is sending border level signals before it goes completely s/c.
heat obviously makes all the plastics and the copper softer allowing the wires to flex more and allowing them to move and short more easily.
that's my guess anyway
nice one, that info helps people know what to look for, something the haynes book of 'go to a garage' advice wont tell you!
clowntype
Guest
just hope it helps someone
one great tip is if you don't have a garage do it in summer,
it's f***ing freezing out there and all the metal including the engine and sockets are dumb and dumber cold.
one great tip is if you don't have a garage do it in summer,
it's f***ing freezing out there and all the metal including the engine and sockets are dumb and dumber cold.
clowntype
Guest
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