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View Full Version : Hesitancy and popping on hard acceleration..


AlfaJack
30-11-08, 20:50
Today whilst out I was giving it some stick in 2nd gear, as the power was coming in nicely and at about 3500 to 4000rpm I felt a hesitancy, it is like a couple of small jolts and at the same time there is a popping/snapping noise - it sounds like it is coming from the exhaust as in unburnt fuel igniting....not 100% on that though.

I tried gunning it a few more times and it kept doing to same, I am reluctant to keep my foot in as I dont want to do too much damage.

Any ideas what it is?

Couple of things to note...I have a Squadra chip and I am running it on RON95 fuel....worse still, it has a tank of Supermarket (Sainsburys to be precise) fuel in...is this of any significance - never used supermarket fuel before)

Thanks
Jack
wrinx
30-11-08, 21:56
When were your plugs last changed? Q4s seem to be very sensitive to worn or unsuitable plugs.

What about your plug leads?

wrinx
AlfaJack
30-11-08, 22:09
Plugs have seen quite a few miles now - perhaps 12K. Plug leads looked ok when I took it all apart to paint the inlet - guess they could be breaking down inside though....
sub555
01-12-08, 06:23
id say plugs like wrinx says mine did the same thing matey with worn plugs
cuore_sportivo_155
01-12-08, 07:12
i'd check the plugs first too
Steve Webb
01-12-08, 07:31
What they said. Sounds like plugs to me.
wrinx
01-12-08, 07:40
Plugs have seen quite a few miles now - perhaps 12K.

Shouldn't they be changed every 12k...no iridium platinum coated kryptonite 60k jobbies here ;)

wrinx
AlfaJack
01-12-08, 10:17
Thanks guys. I am going to get these nice Colder plugs NGK B8EGV.
wrinx
01-12-08, 16:56
There were some reasonably priced one on ebay recently...let us know your source.

wrinx
AlfaJack
01-12-08, 23:01
Ordered from here for ?27.75 delivered. Will let you know if it solves the problem in a few days.
AlfaJack
04-12-08, 21:25
Sorry, left out the link in the above post:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=260319460955

Have not got them yet....but driving the car tonight it seems like there is nothing wrong :rolleyes::rolleyes::rolleyes:

Even had a nice rare oversteer moment on a little roundabout.
It was very cold and slippery though :D
wrinx
04-12-08, 21:43
Same price I found...let us know how you get on as I'm after some too :D

wrinx
wrinx
11-12-08, 21:02
Have they arrived yet....fitted....has it sorted the car?

wrinx
AlfaJack
11-12-08, 21:48
It hasnt done it again. I have the plugs but not fitted them yet, not planning to unless the problem comes back...bit confused as to why its like this...
Evodelta
11-12-08, 21:55
Because it's Italian.
wrinx
11-12-08, 21:58
It hasnt done it again. I have the plugs but not fitted them yet, not planning to unless the problem comes back...bit confused as to why its like this...

But if you've covered 12k since the last lot were fitted...they're due anyway.

wrinx
AlfaJack
11-12-08, 22:41
But if you've covered 12k since the last lot were fitted...they're due anyway.

wrinx

Its a guess at the mo, need to check and write up the history...job for the weekend :deal:
wrinx
12-12-08, 10:26
:D

wrinx
AlfaJack
12-12-08, 10:32
4.5 years of history, receipts (lots:cry:)and MOTs to estimate the mileage, a normal person would have entered the history in a book as it goes :doh::doh:
AlfaJack
12-12-08, 10:34
Because it's Italian.

AKA S.H.I.T - Self Healing Italian Technology :tongue2:
WhizzMan
14-12-08, 08:03
Well, running it on 95 with a squadra chip is sort of asking for spark timing retardation by the ECU (knock detected with knock sensor, retard spark a few degrees). In cooler weather you're less likely to have knocking, so that might be why it's not happening again. Good spark helps since you're more likely to burn your mixture properly and fast enough so it doesn't get a chance to knock.
AlfaJack
03-01-09, 23:29
It was hesitating quite a lot today so I fitted the new plugs. It is pulling well now - I wont say this is a fix until iv driven it a fair few more times yet as it was an intermittent problem. All is well for now and the back end is sliding round nicely in this icy weather :D
mverhari
03-02-09, 18:09
I had the same problem ,I fitted the colder ngk plugs and the problem was solved
AlfaJack
03-02-09, 19:34
I had the same problem ,I fitted the colder ngk plugs and the problem was solved


Glad to hear it. Seems pretty common with this engine.