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Considering that my chances of obtaining a new fuel filter (the one integrated in the tank) are slim to none do you think it would be an option to simply remove the fuel filter in the tank?
Or would this be asking for trouble?
Please see my post from 13 days ago for the attachment showing what’s inside the tank.
Considering that my chances of obtaining a new fuel filter (the one integrated in the tank) are slim to none do you think it would be an option to simply remove the fuel filter in the tank?
Or would this be asking for trouble?
Please see my post from 13 days ago for the attachment showing what’s inside the tank.
I just replaced the top of the SPI-unit (parts 1 to 5 in Picture014.jpg) with a second hand ditto.
I’m still experiencing rough (bouncing) idle and hesitation under acceleration.Obviously, considering that this is a second hand unit, it might be faulty, but I find it unlikely.
My local authorized Volvo workshop was unable to supply the aforementioned parts and referred me to a scrap dealer.
I’m leaning towards a faulty fuel pump or that the integrated fuel filter in the tank is clogged.
Is there any way to test if they are the cause of the fuel pressure drop during throttle snap?I just replaced the top of the SPI-unit (parts 1 to 5 in Picture014.jpg) with a second hand ditto.
I’m still experiencing rough (bouncing) idle and hesitation under acceleration.Obviously, considering that this is a second hand unit, it might be faulty, but I find it unlikely.
My local authorized Volvo workshop was unable to supply the aforementioned parts and referred me to a scrap dealer.
I’m leaning towards a faulty fuel pump or that the integrated fuel filter in the tank is clogged.
Is there any way to test if they are the cause of the fuel pressure drop during throttle snap?Eric,
Thanks for your reply. Greatly appreciated.
I’ve been reading a bit more about how the fuel pressure regulator works and how to diagnose a faulty regulator.
Seeing that the fuel pressure regulator is integrated in my SPI-unit makes it harder to troubleshoot as I can’t access the connections coming and going on the regulator. (At least not without risking destroying the membrane in the FPR)Chances are that I can’t just replace the fuel pressure regulator but I’ll have to replace the entire SPI-unit if the fuel pressure regulator is indeed the source of the problem.
I’ll check with my local Volvo workshop on monday if I can buy just the membrane inside the FPR or maybe just the 4 parts that make up the FPR.
This will allow me disassemble the FPR even further than last time (see page 2)
Last time I stopped disassembling when I reached the membrane as I’m pretty sure it will disintegrate if I try to remove it.If you (or anyone else) has any other inputs as to what I can try/test to isolate the problem further please speak up.
For instance – is there an easy way to test that the fuel pump and integrated filter in the fuel tank are ok?Thanks.
On a different note, is it possible to make a donation to this site using paypal?
I’ve been looking around but I can’t find a donate button.Eric,
Thanks for your reply. Greatly appreciated.
I’ve been reading a bit more about how the fuel pressure regulator works and how to diagnose a faulty regulator.
Seeing that the fuel pressure regulator is integrated in my SPI-unit makes it harder to troubleshoot as I can’t access the connections coming and going on the regulator. (At least not without risking destroying the membrane in the FPR)Chances are that I can’t just replace the fuel pressure regulator but I’ll have to replace the entire SPI-unit if the fuel pressure regulator is indeed the source of the problem.
I’ll check with my local Volvo workshop on monday if I can buy just the membrane inside the FPR or maybe just the 4 parts that make up the FPR.
This will allow me disassemble the FPR even further than last time (see page 2)
Last time I stopped disassembling when I reached the membrane as I’m pretty sure it will disintegrate if I try to remove it.If you (or anyone else) has any other inputs as to what I can try/test to isolate the problem further please speak up.
For instance – is there an easy way to test that the fuel pump and integrated filter in the fuel tank are ok?Thanks.
On a different note, is it possible to make a donation to this site using paypal?
I’ve been looking around but I can’t find a donate button.Compression test results are in.
Cylinder 1 dry: 180psi
Cylinder 1 wet: 185psi
Cylinder 2 dry: 165psi
Cylinder 2 wet: 170psi
Cylinder 3 dry: 180psi
Cylinder 3 wet: 185psi
Cylinder 4 dry: 180psi
Cylinder 4 wet: 185psiI added 1ml oil before performing the wet test.
Maybe I should have added some more seeing how similar the dry and wet test results are.Compression test results are in.
Cylinder 1 dry: 180psi
Cylinder 1 wet: 185psi
Cylinder 2 dry: 165psi
Cylinder 2 wet: 170psi
Cylinder 3 dry: 180psi
Cylinder 3 wet: 185psi
Cylinder 4 dry: 180psi
Cylinder 4 wet: 185psiI added 1ml oil before performing the wet test.
Maybe I should have added some more seeing how similar the dry and wet test results are.Eric,
The fuel pressure gauge was installed as seen on attachment IMG_6821.
As far as I can work out the fuel pressure regulator can only regulate the pressure “down stream”
If this is the case then I don’t think the fuel pressure regulator is to blame for the drop in pressure when I snap the throttle seeing that the pressure gauge is “up stream” seen from the regulator.
I had a look in my Haynes manual and it seems that there’s a filter inside the tank. (see attachment)
Do you think this filter could be the cause of my pressure drop problem ?I already replaced the fuel filter that’s outside the tank so I know that’s ok.
If you look at attachment “Picture 014” you can see how the Single Point Injection Unit is made up.
The attached pictures in the first post on page 2 are real-life pictures of the SPI-unit in my car.Do you agree that the fuel pressure regulator can only regulate the pressure “down stream” ?
Eric,
The fuel pressure gauge was installed as seen on attachment IMG_6821.
As far as I can work out the fuel pressure regulator can only regulate the pressure “down stream”
If this is the case then I don’t think the fuel pressure regulator is to blame for the drop in pressure when I snap the throttle seeing that the pressure gauge is “up stream” seen from the regulator.
I had a look in my Haynes manual and it seems that there’s a filter inside the tank. (see attachment)
Do you think this filter could be the cause of my pressure drop problem ?I already replaced the fuel filter that’s outside the tank so I know that’s ok.
If you look at attachment “Picture 014” you can see how the Single Point Injection Unit is made up.
The attached pictures in the first post on page 2 are real-life pictures of the SPI-unit in my car.Do you agree that the fuel pressure regulator can only regulate the pressure “down stream” ?
I’ve gotten a hold of a compression test kit so I’m hoping to get that test done this week following Eric’s video “Compression Testing and What You Can Learn From It”
When comparing the response on my pressure gauge (see video in my last post) to Eric’s gauge in the video “Solving Engine Performance Issues (Part 1)” it’s very evident that something is wrong with my fuel pressure though.
It seems odd to me though that running the engine in “limp mode” has such a huge impact on performance.Whether the fuel pressure issue is caused by a bad fuel pump or some other component misbehaving I’m not sure. Perhaps someone will comment on how to diagnose this.
I’ve gotten a hold of a compression test kit so I’m hoping to get that test done this week following Eric’s video “Compression Testing and What You Can Learn From It”
When comparing the response on my pressure gauge (see video in my last post) to Eric’s gauge in the video “Solving Engine Performance Issues (Part 1)” it’s very evident that something is wrong with my fuel pressure though.
It seems odd to me though that running the engine in “limp mode” has such a huge impact on performance.Whether the fuel pressure issue is caused by a bad fuel pump or some other component misbehaving I’m not sure. Perhaps someone will comment on how to diagnose this.
I did some more fuel pressure tests today.
The results were pretty much the same as yesterday.I also did a small video.
Link
The first 1:20 is shot with the coolant temperature sensor connected.
The remaining is shot with the sensor disconnected.
You will hear me snapping the throttle numerous times.
At 0:35 the engine stalls due to a fast throttle snap.
The engine runs much better with the coolant temp sensor disconnected as you can tell from the video.
Sorry for the poor video quality.I took a picture of my garage door following the test.
As stated in 3) in my initial post:
“It spits out, what I assume to be, unburned fuel from the tailpipe when the engine is cold (it smells like gasoline and leaves black stains on my white wall)”In respons to Woodstock.
The MAP sensor hose looked good as new and rocking the throttle body with the engine idling had no effect.I have yet to install a wire from the MAP sensor to the dashboard so I can monitor the MAP sensor while I drive. It’s on my to do list though.
I did some more fuel pressure tests today.
The results were pretty much the same as yesterday.I also did a small video.
Link
The first 1:20 is shot with the coolant temperature sensor connected.
The remaining is shot with the sensor disconnected.
You will hear me snapping the throttle numerous times.
At 0:35 the engine stalls due to a fast throttle snap.
The engine runs much better with the coolant temp sensor disconnected as you can tell from the video.
Sorry for the poor video quality.I took a picture of my garage door following the test.
As stated in 3) in my initial post:
“It spits out, what I assume to be, unburned fuel from the tailpipe when the engine is cold (it smells like gasoline and leaves black stains on my white wall)”In respons to Woodstock.
The MAP sensor hose looked good as new and rocking the throttle body with the engine idling had no effect.I have yet to install a wire from the MAP sensor to the dashboard so I can monitor the MAP sensor while I drive. It’s on my to do list though.
I don’t own a timing light but I’ll see if I can borrow one.
I did run some fuel injector cleaner through the fuel system as described in my initial post but obviously the injector might still be dirty/faulty.Preliminary fuel pressure test results are in.
I used Eric’s “Solving Engine Performance Issues (Part 1)” as a guide.Turned the key on and checked pressure (engine off) = 2,8bar
Engine idling = 2,9bar
Snap the throttle = Pressure momentarily drops to 2,5barI tested with the coolant temp sensor connected and disconnected.
The results are the same although the throttle snap will cause much more pressure fluctuation with the sensor connected.
(The pressure will jump up and down between 2,5bar and 2,9bar for a while when the throttle is snapped with the sensor connected)Snapping the throttle with the temp sensor connected really takes it’s toll on the engine.
A hard fast snap on the throttle will make the engine die.
When the coolant temp sensor is disconnected the engine runs great – snapping the throttle, no problem.My Haynes manual states that the fuel pump pressure should be 1 bar for my engine (B18U) so that’s odd.
I’ll do some more tests on the fuel pressure tomorrow – I’ll also have a look at the MAP and throttle body rubber mount.
Is it possible to post a video to this forum?
