Occasional lumpy idle, cutting out while moving etc? - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

GTR Jon · 10th August 2006, 07:49 PM

Sorry if this is in the wrong section but i was wondering if anyone could help me with this problem.
Most of the time my R32 GTR idles perfectly and drives perfectly but every now and then it can be idling fine and then for no reason the revs drop and it sounds like its about to cut out!? If i rev it they rise but still lumpy though sometimes this fixes the problem too. Same when driving, it can be pulling well and then it will just back off and if i dip the clutch it will cut out, when i release the clutch it will fire up and sometimes then be ok and sometimes still feel like it wants to die??
I've put new plugs in last week. When i got it though the maf was not connected so i plugged it back in. Tonight when it was idling and sounded like it was gonna cut out i blipped the throttle and then the revs started sitting higher than normal, i tried unplugging the maf which caused the revs to rise a bit and then it levelled off and was fine. Plugged it back in and it was still idling perfect. Does it sound like the maf or is it more likely to be a bad earth somewhere?
Sorry for the essay though i might aswel describe the whole picture while im at it.
Anyone had this problem before?

stehub · 10th August 2006, 09:43 PM

mmm it sound like you have a loose wire maybe around gearbox is the earth strap near that, i would say its an earth related issue.

kennyc · 11th August 2006, 07:10 AM

what kind of dump valve you got?

GTR Jon · 11th August 2006, 07:11 AM

Cheers for the help mate, that confirms what someone else has told me it would be too! Best get looking.

GTR Jon · 11th August 2006, 07:12 AM

Quote:

Originally Posted by kennyc

what kind of dump valve you got?

I doesnt make any kind of chuff so im assuming its just the standard one!?

slegros · 12th August 2006, 05:26 AM

Check the coils as well, I had a bad one and the symptoms were similar although not exactly what you mention. R32's and early 33's are notorious for bad coils.

GTR Jon · 12th August 2006, 08:29 AM

Its worth a look, though it does have a very new looking set of splitfires.

tyndago · 12th August 2006, 09:06 PM

Bad MAF will do something similar. Like you suspect. Also could be small vacuum leak. Check around the base of the injectors first.

GTR Jon · 12th August 2006, 09:12 PM

Right i've checked the coil packs and all are fine, i've replaced the battery and found a loose earth but its now sorted and the problem is just getting worse. On a short run out earlier i had to put the hazards on 3 times!
When i got the car there were 2 plugs not connected which i now know are for the o2 sensors. We unplugged the sensors today and it seemed to fix the problem with putting them back on causing it to die. However while driving home without them connected it died on me again!
I can put my foot to the floor and it struggles to get over 1200 rpm, if i sit for a bit or leave engine off for a bit its ok but while driving it varies from a lack of power at times to actually slowing down when i push the throttle.
Could it be that the faulty o2 sensors are causing it to run like that and with them not being connected the same happens as there is no reading and therefore also causing it to run like sh1t.
Also it has a new idle control valve and inlet manifold gasket.
Could it be the ecu? It has a Garage Saurus sticker on it!?
This is really frustrating me so i'd be very grateful for any help at all. I've only had the car on the road a few days and its even more annoying than the weather!

stehub · 12th August 2006, 09:16 PM

oh man does the car run fine now and again then all suddenly it runs poor ?? is this what you are saying like it has mind of its own ??? sometimes runs fine then runs shit ??

could it be the plug gaps ?? but you say it sometimes runs ok ??

stehub · 12th August 2006, 09:17 PM

i think you for surely have an elctrical fault or sensor related or even vacuum leak am sure a technical gtr person on this forum will be able to help you more jon.

GTR Jon · 12th August 2006, 09:22 PM

Yeah it can run perfect and idle perfect and then for no reason just goes to sh1t. Sometimes if you rev it a bit it'll sort itself out and other times it'll have none of it. Occasionally it will also jump from idling at 1k rpm and then sit at 1200 rpm for no reason also. Though usually after it has just tried to cut out!?!?!
I would like to just take it to Abbey or somewhere, but i really dont fancy my chances as i'd probably be on the hard shoulder every 10 mins!

tyndago · 12th August 2006, 09:27 PM

Quote:

Originally Posted by GTR Jon

Yeah it can run perfect and idle perfect and then for no reason just goes to sh1t. Sometimes if you rev it a bit it'll sort itself out and other times it'll have none of it. Occasionally it will also jump from idling at 1k rpm and then sit at 1200 rpm for no reason also. Though usually after it has just tried to cut out!?!?!

90% of the time its a bad MAF. Does exactly what you are saying. Comes and goes, good sometimes, then just wont rev.

It won't throw a check engine light as its within parameters, but its normally telling the ECU a lot of air is coming in, it goes rich and dies out.

The boards in the MAF have issues.

GTR Jon · 12th August 2006, 09:36 PM

So do you suggest i just try replacing the maf? How many are there on the GTR? and any idea on the price? What about the o2 sensors is it worth changing them while i am on? Could it be possible that it is running worse now as i did not put as much octane booster in with the optimax? As it was running much better when i put more in but i ran out at the last fill up so it only got half as much! Or am i just being stupid?
Sorry for all the questions lol.

stehub · 12th August 2006, 09:40 PM

another possible cause engine temp sensor (ecu one)

10th August 2006, 07:49 PM	#1 (permalink)
GTR Jon GTR Register Member Join Date: Mar 2006 Location: Tyne and Wear Posts: 324	Occasional lumpy idle, cutting out while moving etc? Sorry if this is in the wrong section but i was wondering if anyone could help me with this problem. Most of the time my R32 GTR idles perfectly and drives perfectly but every now and then it can be idling fine and then for no reason the revs drop and it sounds like its about to cut out!? If i rev it they rise but still lumpy though sometimes this fixes the problem too. Same when driving, it can be pulling well and then it will just back off and if i dip the clutch it will cut out, when i release the clutch it will fire up and sometimes then be ok and sometimes still feel like it wants to die?? I've put new plugs in last week. When i got it though the maf was not connected so i plugged it back in. Tonight when it was idling and sounded like it was gonna cut out i blipped the throttle and then the revs started sitting higher than normal, i tried unplugging the maf which caused the revs to rise a bit and then it levelled off and was fine. Plugged it back in and it was still idling perfect. Does it sound like the maf or is it more likely to be a bad earth somewhere? Sorry for the essay though i might aswel describe the whole picture while im at it. Anyone had this problem before?

12th August 2006, 09:12 PM	#9 (permalink)
GTR Jon GTR Register Member Join Date: Mar 2006 Location: Tyne and Wear Posts: 324	Right i've checked the coil packs and all are fine, i've replaced the battery and found a loose earth but its now sorted and the problem is just getting worse. On a short run out earlier i had to put the hazards on 3 times! When i got the car there were 2 plugs not connected which i now know are for the o2 sensors. We unplugged the sensors today and it seemed to fix the problem with putting them back on causing it to die. However while driving home without them connected it died on me again! I can put my foot to the floor and it struggles to get over 1200 rpm, if i sit for a bit or leave engine off for a bit its ok but while driving it varies from a lack of power at times to actually slowing down when i push the throttle. Could it be that the faulty o2 sensors are causing it to run like that and with them not being connected the same happens as there is no reading and therefore also causing it to run like sh1t. Also it has a new idle control valve and inlet manifold gasket. Could it be the ecu? It has a Garage Saurus sticker on it!? This is really frustrating me so i'd be very grateful for any help at all. I've only had the car on the road a few days and its even more annoying than the weather! Last edited by GTR Jon; 12th August 2006 at 09:15 PM.

12th August 2006, 09:22 PM	#12 (permalink)
GTR Jon GTR Register Member Join Date: Mar 2006 Location: Tyne and Wear Posts: 324	Yeah it can run perfect and idle perfect and then for no reason just goes to sh1t. Sometimes if you rev it a bit it'll sort itself out and other times it'll have none of it. Occasionally it will also jump from idling at 1k rpm and then sit at 1200 rpm for no reason also. Though usually after it has just tried to cut out!?!?! I would like to just take it to Abbey or somewhere, but i really dont fancy my chances as i'd probably be on the hard shoulder every 10 mins! Last edited by GTR Jon; 12th August 2006 at 09:25 PM.

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10th August 2006, 09:43 PM	#2 (permalink)
stehub GTR Register Member Join Date: Nov 2005 Posts: 170	mmm it sound like you have a loose wire maybe around gearbox is the earth strap near that, i would say its an earth related issue.

11th August 2006, 07:10 AM	#3 (permalink)
kennyc GTR Register Member Join Date: Aug 2005 Location: Scotland Posts: 497	what kind of dump valve you got?

11th August 2006, 07:11 AM	#4 (permalink)
GTR Jon GTR Register Member Join Date: Mar 2006 Location: Tyne and Wear Posts: 324	Cheers for the help mate, that confirms what someone else has told me it would be too! Best get looking.

12th August 2006, 05:26 AM	#6 (permalink)
slegros GTR Register Member Join Date: Oct 2005 Posts: 149	Check the coils as well, I had a bad one and the symptoms were similar although not exactly what you mention. R32's and early 33's are notorious for bad coils.

12th August 2006, 08:29 AM	#7 (permalink)
GTR Jon GTR Register Member Join Date: Mar 2006 Location: Tyne and Wear Posts: 324	Its worth a look, though it does have a very new looking set of splitfires.

12th August 2006, 09:06 PM	#8 (permalink)
tyndago GTR Register Member Join Date: Oct 2002 Location: LBC , CA Posts: 2,400	Bad MAF will do something similar. Like you suspect. Also could be small vacuum leak. Check around the base of the injectors first.

12th August 2006, 09:16 PM	#10 (permalink)
stehub GTR Register Member Join Date: Nov 2005 Posts: 170	oh man does the car run fine now and again then all suddenly it runs poor ?? is this what you are saying like it has mind of its own ??? sometimes runs fine then runs shit ?? could it be the plug gaps ?? but you say it sometimes runs ok ??

12th August 2006, 09:17 PM	#11 (permalink)
stehub GTR Register Member Join Date: Nov 2005 Posts: 170	i think you for surely have an elctrical fault or sensor related or even vacuum leak am sure a technical gtr person on this forum will be able to help you more jon.

12th August 2006, 09:36 PM	#14 (permalink)
GTR Jon GTR Register Member Join Date: Mar 2006 Location: Tyne and Wear Posts: 324	So do you suggest i just try replacing the maf? How many are there on the GTR? and any idea on the price? What about the o2 sensors is it worth changing them while i am on? Could it be possible that it is running worse now as i did not put as much octane booster in with the optimax? As it was running much better when i put more in but i ran out at the last fill up so it only got half as much! Or am i just being stupid? Sorry for all the questions lol.

12th August 2006, 09:40 PM	#15 (permalink)
stehub GTR Register Member Join Date: Nov 2005 Posts: 170	another possible cause engine temp sensor (ecu one)