2000 S40 bad FPR or fuel pump??

jared455 · Sep 2nd, 2011, 03:59

I was driving last night and all the sudden the car started cutting out. Whenever I would give it gas the rpms would drop. It seems like the car went into limp mode. I had to stop at a red light and the car died. Luckily it started back up and I was able to limp it home which was only about a half mile away. I took off the throttle body and gave it a good cleaning this morning. Also cleaned the TPS and the IAC. I then replaced the fuel filter. Put it all back together and the car will barely start, but if I give it enough gas right when started it will run at high rpm fine for about 5-10 seconds then the rpms drop and cannot get them back up and the car eventually dies. Sometimes it will start up and seem to idle normal but when I touch the throttle it starts bogging and eventually dies. Checked the fuel pressure and it is at 8 when the ignition is on and at 10 when the car is running. The car has had a rough idle since I bought it about a month ago and has always kind of lagged off idle. It seems like a definite fuel problem, but would it be a fuel pump or the fuel pressure regulator? Has anyone had a FPR go out and if so what are the symptoms before it goes?

Any help would be much appreciated, I need this thing fixed ASAP.

veryloudv40 · Sep 2nd, 2011, 05:26

Check your coil packs. One bad coil pack can cause 2 cylinders to miss. This may be intermittent depending on temperature. Also, the connectors to the coil packs tend to have problems. You can check and see if this is the problem by unplugging spark plugs one at a time and seeing if they change how the car runs. You can see if it's a connector because the wire or silicon sleeve around the connector will be slightly scorched. I never replaced my connectors, just bent them to a point where they made a good connection. The problem never recurred. Good luck

peynut · Sep 3rd, 2011, 00:56

i just had replace fuel pump on mine as it had siezed up and i also replaced coil packs as they went to lol. when my coil packs went the car would still run even on 2 cylinders but it would make an awful noise.. when fuel pump wen it did like what your describing... try putting some petrol in the tank .. so the pump "if it is that" doesnt have to work so hard to pump fuel, the car will run better if its that. i aint no expert i am just suggesting from my own experience

veryloudv40 · Sep 3rd, 2011, 17:33

You're right peynut. You still want to check the simple stuff, first. It would suck to replace your fuel pump just to find out the problem was caused by a loose wire on a coil pack.

jared455 · Sep 3rd, 2011, 19:17

Well I've replaced the fuel pump which is not very time consuming since my s40 has an access panel for the pump under the rear seat. I took the plugs out and cleaned them and checked all the wiring to and from the coils and ran the car and checked the plugs again and they are all getting spark. I'm just trying to see if anyone has had pretty much the same exact issue so they can tell me what to do!! I've been on sites and reading forums for the last 3 days now and cannot figure this thing out. I wish I had a knight rider car that could just tell me exactly what needed to be fixed...

peynut · Sep 6th, 2011, 18:04

did u try to see if the plugs were getting sparks when the engine is hot , as the coil packs tend to only play up when they are hot and expanded. mine used to be fine when it was cold but as soon as car got hot it would start playing up

Sep 2nd, 2011, 03:59	#1
jared455 New Member Last Online: Sep 4th, 2011 03:06 Join Date: Sep 2011 Location: st george ut	2000 S40 bad FPR or fuel pump?? I was driving last night and all the sudden the car started cutting out. Whenever I would give it gas the rpms would drop. It seems like the car went into limp mode. I had to stop at a red light and the car died. Luckily it started back up and I was able to limp it home which was only about a half mile away. I took off the throttle body and gave it a good cleaning this morning. Also cleaned the TPS and the IAC. I then replaced the fuel filter. Put it all back together and the car will barely start, but if I give it enough gas right when started it will run at high rpm fine for about 5-10 seconds then the rpms drop and cannot get them back up and the car eventually dies. Sometimes it will start up and seem to idle normal but when I touch the throttle it starts bogging and eventually dies. Checked the fuel pressure and it is at 8 when the ignition is on and at 10 when the car is running. The car has had a rough idle since I bought it about a month ago and has always kind of lagged off idle. It seems like a definite fuel problem, but would it be a fuel pump or the fuel pressure regulator? Has anyone had a FPR go out and if so what are the symptoms before it goes? Any help would be much appreciated, I need this thing fixed ASAP.

Sep 2nd, 2011, 05:26	#2
veryloudv40 Junior Member Last Online: Feb 17th, 2012 22:11 Join Date: Aug 2011 Location: Lexington	Check your coil packs. One bad coil pack can cause 2 cylinders to miss. This may be intermittent depending on temperature. Also, the connectors to the coil packs tend to have problems. You can check and see if this is the problem by unplugging spark plugs one at a time and seeing if they change how the car runs. You can see if it's a connector because the wire or silicon sleeve around the connector will be slightly scorched. I never replaced my connectors, just bent them to a point where they made a good connection. The problem never recurred. Good luck

Sep 3rd, 2011, 00:56	#3
peynut Member Last Online: Oct 19th, 2018 01:34 Join Date: Dec 2010 Location: Leigh/Wigan	i just had replace fuel pump on mine as it had siezed up and i also replaced coil packs as they went to lol. when my coil packs went the car would still run even on 2 cylinders but it would make an awful noise.. when fuel pump wen it did like what your describing... try putting some petrol in the tank .. so the pump "if it is that" doesnt have to work so hard to pump fuel, the car will run better if its that. i aint no expert i am just suggesting from my own experience

Sep 3rd, 2011, 17:33	#4
veryloudv40 Junior Member Last Online: Feb 17th, 2012 22:11 Join Date: Aug 2011 Location: Lexington	You're right peynut. You still want to check the simple stuff, first. It would suck to replace your fuel pump just to find out the problem was caused by a loose wire on a coil pack.

Sep 3rd, 2011, 19:17	#5
jared455 New Member Last Online: Sep 4th, 2011 03:06 Join Date: Sep 2011 Location: st george ut	Well I've replaced the fuel pump which is not very time consuming since my s40 has an access panel for the pump under the rear seat. I took the plugs out and cleaned them and checked all the wiring to and from the coils and ran the car and checked the plugs again and they are all getting spark. I'm just trying to see if anyone has had pretty much the same exact issue so they can tell me what to do!! I've been on sites and reading forums for the last 3 days now and cannot figure this thing out. I wish I had a knight rider car that could just tell me exactly what needed to be fixed...

Sep 6th, 2011, 18:04	#6
peynut Member Last Online: Oct 19th, 2018 01:34 Join Date: Dec 2010 Location: Leigh/Wigan	did u try to see if the plugs were getting sparks when the engine is hot , as the coil packs tend to only play up when they are hot and expanded. mine used to be fine when it was cold but as soon as car got hot it would start playing up

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