Need Help on 5.8fsi Couple of Issues

ChrisinPHX

Seaman
Joined
Jun 9, 2013
Messages
71
I've got a 5.8Fsi. Anti Siphon Valve is the #1 culprit for fuel starvation on these. Clogged pickup tube is #2. ECM relay is #3. Fuel Pressure regulator is #4.
Sounds like it's not limp mode related as in 3 seconds I doubt you're getting to 2,700 rpm.

EDIT - Well since you did mention 2,500 rpm originally. Oil pressure switch is the #1 cause of going into limp mode.

All my # rankings are based on a shared database of Correct Craft owners that all have fuel injected 5.8L Fords with GT40 heads, same as the VP 5.8 Fsi's. Incredibly minute differences in between them.
 
Last edited:

Briha1978

Cadet
Joined
Jul 29, 2020
Messages
24
Did some progress on the boat tonight.
Bypassed the boat’s tank to a 2 gallon tank. I can see the fuel being pulled to the pump. Boat still starts and runs for 3 seconds and dies. My fuel pressure tester broke so I can’t get a reading. I also hooked up 12 volts directly to the pump while it was running and still the same issue. What else could I try? I’ll see if I can borrow a fuel pressure tester. I have inspected every hose and I don’t see any cracks or cuts. Please let me know.
 

dubs283

Vice Admiral
Joined
Jul 27, 2005
Messages
5,322
You need to find out if you are loosing fuel or spark. You say you connected 12 volts to the pump and same results. You mentioned in an earlier post two pumps? Did you 12 volt both? Have you checked for loss of spark?
 

Briha1978

Cadet
Joined
Jul 29, 2020
Messages
24
I just gave the constant power to the low pressure pump only. I will check for loss of spark later tonight when I am able to get out there. It’s Texas and it got hot fast here. Thank you alldodge, dubs, and everyone else who is trying to get me back on the water.
 

Briha1978

Cadet
Joined
Jul 29, 2020
Messages
24
Update. Checked out the hi pressure pump and put 12 volts to it. It works as well. It took some time with turning and priming the pumps and finally got fuel out of both pumps. Still started and died. Well I said wth I took the carb/choke cleaner while it ran because I thought I heard a vacuuum leak. I do. It’s between the throttle bottle and the gasket. When I kept spraying the boat idled for more than 3 seconds. Now to track down the two gaskets. Any ideas?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,054
Go to ling in post 25 and back to the 4shared link from DonS. Says its a parts breakdown for the Fi and Fl
 

ChrisinPHX

Seaman
Joined
Jun 9, 2013
Messages
71
Between the throttle body and which gasket? The upper and lower intake gasket? The upper to lower gasket is a known leaker, and there are also a number of vacuum lines on the bottom side of the upper intake that are known to leak as well if the lines and caps dry rot. You can't see them without pulling the upper intake. These photos are from an automotive application but you will have different lines and possibly some capped off ports as well. Your setup will probably look slightly different than these.
l4NZ6R.png
 

Attachments

  • 1intake vac.jpg
    1intake vac.jpg
    75.9 KB · Views: 2

Briha1978

Cadet
Joined
Jul 29, 2020
Messages
24
Updated? Replaced the throttle body gaskets. TPS, and redid the gaskets for the IAC on throttle body. Boat ran but was surging. But was running with all sensors hooked up. For the hell of it. I unplugged the MAF and wow it ran beautiful. No missing, stalling, or anything. Except it has an idle of 1300 rpm. Also I don’t know what idle speed should be? Any help on where to go from here?
 

Briha1978

Cadet
Joined
Jul 29, 2020
Messages
24
Chrisin I found out I had an intake leak upper to be correct. I redid the upper gasket yesterday. Like I said now I am running great no vacuum leaks but I have the MAF unplugged and my idle is at 1300 rpm. You were correct about the upper intake leaking.
 

ChrisinPHX

Seaman
Joined
Jun 9, 2013
Messages
71
The MAF sensor is reporting incorrect airflow into the engine. The computer adds the amount of fuel it expects the engine will need, but if it is significantly off, the engine runs poorly.

The hot wire in the MAF sensor is probably dirty. You can Google how to clean the MAF sensor. If cleaning doesn't make an improvement, you may need to replace the MAF sensor.

Have you bothered to pull codes?
 

Briha1978

Cadet
Joined
Jul 29, 2020
Messages
24
Well got two vacuum leaks again. Redid the plenum gasket again. Chrisin is right about these not sealing up
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,054
Well got two vacuum leaks again. Redid the plenum gasket again. Chrisin is right about these not sealing up
Were the heads ever milled?
Milling other then a few thousandths can create a need to mill the intake because the gasket is no longer think enough to seal it
 

Briha1978

Cadet
Joined
Jul 29, 2020
Messages
24
I’m not sure. It seems the lower intake doesn’t want to seal. I redid it yesterday just the plenum so I’ll let you know if I have any other leaks.
 

ChrisinPHX

Seaman
Joined
Jun 9, 2013
Messages
71
Who's gaskets are you using? Have part numbers? Are you using any sealant in conjunction with your gaskets? Can you pinpoint your leaks using starting fluid or brake cleaner?
 

Briha1978

Cadet
Joined
Jul 29, 2020
Messages
24
Alldodge. So the TPS was changed due to code 63. The map sensor was changed due to code 22. Now the thing won’t idle. Before the parts. I can disconnect the map sensor entirely. It would run smoothly but idle at 1000rpm. I am seriously at a loss. Good thing is was able to get the codes out of the computer.
 
Top