S40 missfire.

billythreepuds · Jan 30th, 2008, 19:27

Hi, can anyone advise me as to what a fuel modulator is and what role it plays in the fireing of the engine.The car went in for a compression test etc, for a missfire in cylinder No3, thinking a valve or HT leads etc but a compression test was fine. The mechanic has now told me that there is an electrical fault and the Engine management system is telling him fuel modulator. I am now waiting for an Auto electricians report but i would like to know what a modulator is and where i find it and what it does. in anticipation of you help Thanks...billythreepuds

Rooster · Jan 30th, 2008, 23:04

What year is your car and is it a turbo by any chance,

The earlier s/v40 turbos suffer alot from fuel pump failure, carn't get enough fuel to engine hence the misfire under load

thebigv · Jan 30th, 2008, 23:16

I had a similar problem with a misfire under load and was told it was the modulator or fuel pump (£250) from volvo. I took it home, pulled the fuel pump out of the tank, cleaned the two absolutely disgusting fuel filters volvo told me were NOT there and it has been fine ever since. Dont know if yours is the same problem but volvo denied my car had filters in the tank. Mine is a 1.9 T4 on a T plate. The filters are plastic mesh and stop the major crud getting into the pump and lines etc. Hope this helps.

SteveP · Feb 2nd, 2008, 19:23

Sounds very similar to my S40... how do you take the pump/filters out? I don't have a Haynes to consult as yet

wa666ou · Feb 3rd, 2008, 22:33

Quote:

Originally Posted by SteveP

Sounds very similar to my S40... how do you take the pump/filters out? I don't have a Haynes to consult as yet

check here: http://s40concepts.net/forum/index.p...f3ba07454a3ab3

Jan 30th, 2008, 19:27	#1
billythreepuds New Member Last Online: Aug 19th, 2014 17:17 Join Date: Jan 2008 Location: croydon	S40 missfire. Hi, can anyone advise me as to what a fuel modulator is and what role it plays in the fireing of the engine.The car went in for a compression test etc, for a missfire in cylinder No3, thinking a valve or HT leads etc but a compression test was fine. The mechanic has now told me that there is an electrical fault and the Engine management system is telling him fuel modulator. I am now waiting for an Auto electricians report but i would like to know what a modulator is and where i find it and what it does. in anticipation of you help Thanks...billythreepuds

Jan 30th, 2008, 23:04	#2
Rooster Speed freak Last Online: Apr 3rd, 2020 22:04 Join Date: Nov 2003 Location: Yorkshire	What year is your car and is it a turbo by any chance, The earlier s/v40 turbos suffer alot from fuel pump failure, carn't get enough fuel to engine hence the misfire under load __________________ 04 XC90 D5 --- Big bus 00 pug 306HDi --- Run about 88 pug 309GTi --- Project track car 07 CB600 Hornet --- 2 wheel fun

Jan 30th, 2008, 23:16	#3
thebigv Master Member Last Online: Dec 1st, 2010 23:19 Join Date: Jan 2008 Location: darlington	I had a similar problem with a misfire under load and was told it was the modulator or fuel pump (£250) from volvo. I took it home, pulled the fuel pump out of the tank, cleaned the two absolutely disgusting fuel filters volvo told me were NOT there and it has been fine ever since. Dont know if yours is the same problem but volvo denied my car had filters in the tank. Mine is a 1.9 T4 on a T plate. The filters are plastic mesh and stop the major crud getting into the pump and lines etc. Hope this helps.

Feb 2nd, 2008, 19:23	#4
SteveP 300 Maniac Last Online: Apr 23rd, 2024 09:31 Join Date: Nov 2002 Location: Coventry View Photos By: SteveP	Sounds very similar to my S40... how do you take the pump/filters out? I don't have a Haynes to consult as yet

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