Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 / 930 Turbo & Super Charging Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 3,562
fuel system issue

Hi Guys. been gone a while. Car has been sitting for about 7 months. Was running fine when last parked up.
Now I go to start it and it has a fuel issue. First - my near new 044 front pump had seized. Just replaced with a new one. Both pumps working. But my WUR pressure is low (cold pressure) and I cant get a proper diagnosis of the pressures or flow rates because every time I pull the airplate switch plug , the injectors are squealing and pumping fuel. I have backed the idle mix screw off a couple of turns now, and same result. I wanted to test fuel flow rate, but can't while the cylinders are filling with fuel.
Any ideas why the injectors won't stop flowing fuel?
Thanks
Alan

__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 02-16-2021, 01:04 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 14,357
Garage
Is the air meter plate free?
Could be the piston seized after all the pressure blead down over time.
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 02-16-2021, 03:26 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 3,562
Hi Brian. The airplate is free as. I wonder if it is a bit soft. Which is why I was wanting to check the flow and pressures. I wonder if enough fuel is flowing to push it completely home. But it seems to be sitting in the right place - but very small variation in plate height before injectors usually open.
I have a permanent pressure gauge on the WUR and am only getting around 1 bar CP. With current temps should be nearer 2 bar.
Regards
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 02-16-2021, 03:49 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered
 
Join Date: Sep 2002
Location: Westchester County, NY
Posts: 2,248
Garage
For fuel to leave the head, your slotted piston must not be seated all the way. Do you guys use ethanol in your gasoline there?
I’m not sure of any proven methods to unstick one besides removing it.
__________________
Ken
1986 930, 1969 Mach1, 2003 540 Sport, 2016 R1200RS
Old 02-16-2021, 03:58 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 3,562
Yes Ken. Agree. I am wondering if somehow the metering piston is stuck fully open. Have just checked again - without the pumps running. The airplate bounces back to the top, from fully depressed. I am not really feeling any resistance when I depress it. Pumps not running - but I thought I should at least feel the weight of the metering piston and it doesn't feel like it.
No ethanol in this fuel.

"I’m not sure of any proven methods to unstick one besides removing it."

Have you heard of a hammer?
Will give it a sharp tap on top of the head and see what happens.
Regards
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 02-16-2021, 05:48 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 3,562
The hammer method didn't improve things. Wondered about going up a size in hammers, but decided to pull the FD instead.
Brian nailed it first off. The piston is jammed part way up the metering bore.
Now to get it out without splitting the head :-)
Soaking inWD40 right now.
If I had to pay someone to look after this beast I doubt I would own a house anymore.
Regards
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 02-16-2021, 07:03 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 14,357
Garage
Turning the fuel distributor upside down and placing a small amount of mineral spirits pooled on top of the piston overnight should free it up.
I suggest to folks storing their 930 on a charger to run the fuel pump once a month allowing fresh fuel to circulate. You don't need to start the car just run the pumps.
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8

Last edited by RarlyL8; 02-17-2021 at 06:15 AM..
Old 02-17-2021, 06:13 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered
 
mark houghton's Avatar
 
Join Date: Jul 2008
Location: Central Washington State
Posts: 3,893
As Ken mentioned above: "For fuel to leave the head, your slotted piston must not be seated all the way..." I suspect this is the problem that I have.

I've always had fuel flowing through the injectors as soon as the pumps come on like when pulling the air plate switch. My switch is either defective or I have a wiring fault to where it doesn't matter if the switch is unplugged or not, my pumps always come on with the key turned on.....and my injectors can be heard squealing. My air metering plate moves freely.

I've just lived with it, the only real issue being that I dare not leave the key on for any length of time or it will fill the cylinders with gas.
__________________
Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, stock everything else. The result of a massive Pelicanite good will fire recovery effort. Truely an open book, ready for the slippery slopes to modification.
Old 02-17-2021, 06:17 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 3,562
Brian - two bits of good advice. Turning the pumps over is a convenient solution. Unfortunately - I was out of the country for about 5 months. But that is a good plan.
I currently have the FD upside down with WD40 soaking the metering piston o/night. Yet to check. If not working will try mineral spirits.
Mark - the idle mix setting will do the same - it only has to be out about 1/4 turn. You could try backing it off half a turn and see if the problem goes away (anti clockwise).
Or your airplate sw has been bypassed in the earth circuit.
The silly thing is my SC fired up straight off, ran like a watch. Basically same CIS system and same fuel in the tank.
Would the 930 ever think of behaving like that of course not. Wouldn't be a 930 then.
Regards to all
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)

Last edited by Alan L; 02-17-2021 at 10:56 AM..
Old 02-17-2021, 10:25 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered
 
Join Date: Sep 2002
Location: Westchester County, NY
Posts: 2,248
Garage
Sounds like you’re on the right track, Alan. I’ll mention it just for the heck of it here since you’ve already removed it, but a partial engine drop (by removing the two rear engine mount bolts and lowering the engine 3-4”) makes the R&R of the fuel distributor much easier and saves a lot of skinned knuckles and cuss words.
__________________
Ken
1986 930, 1969 Mach1, 2003 540 Sport, 2016 R1200RS
Old 02-17-2021, 01:06 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 14,357
Garage
Have you checked the plate height? Could be that with your modified system the plate height may need to be adjusted a touch to bring the piston to full bottom when the pumps are off. I've not seen that before but it seems plausible. The air meter assemblies do wear to the point of being out of tolerance. Had one that wouldn't allow the engine to keep running when warm unless you pushed down on the plate.
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 02-17-2021, 01:13 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 3,562
Ken - I pulled the IC. Plenty of room. Not too hard to remove . I have a K&N air filter. FD is quite exposed.
Brian - it was running fine when I parked it. The metering piston is stuck at something like full flow.
Which is a bit weird. Thought it would be fully shut (dropped). With no pressure on it, the plate sits fully shut. Pretty sure the plate height is correct - but if I have an issue when I re install the FD, that will be something to check.
Regards
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 02-17-2021, 03:44 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
Registered
 
mark houghton's Avatar
 
Join Date: Jul 2008
Location: Central Washington State
Posts: 3,893
Quote:
Originally Posted by Alan L View Post
Mark - the idle mix setting will do the same - it only has to be out about 1/4 turn. You could try backing it off half a turn and see if the problem goes away (anti clockwise).
Or your airplate sw has been bypassed in the earth circuit.
Alan
Alan, per your suggestions: The first thing I did years ago was to back off the screw, i.e., lean out the idle mixture. That reduced the amount of fuel flowing as evidenced by less injector squealing, but screwing it out any further dropped the idle being too lean. I don't have an AFR, so just have to tune by ear. And yes, I suspect a bad ground for the switch. Just have to go through the effort of tracing and finding it.
__________________
Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, stock everything else. The result of a massive Pelicanite good will fire recovery effort. Truely an open book, ready for the slippery slopes to modification.
Old 02-18-2021, 05:51 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 3,562
Hi Mark,
Then the Q really is, in you case, can you back the idle screw off enough to stop the injectors squealing? If so, that is where the screw needs to be. That solves one issue - fuel pumps running with key on. Then you need to figure why it idles so lean under such conditions. Air leaks?
My current progress report - soaking the fuel piston with WD40 o/night did nothing. So I switched to mineral spirits. O/night, no progress. Have left to soak longer. Will be a few days before I get back to it now.
Regards
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 02-18-2021, 08:20 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 3,562
Progress report.
Nil.
After soaking the metering piston in mineral spirit for several days on/off, it still wont budge. tried gently tapping the end with a hammer. Nope. But I think it is fully seated in the open slit position - fully inserted. Tried compressed air on the WUR port. Nope.
May have to split the head.
Will report back.
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 02-22-2021, 01:17 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 3,562
Well I ended up splitting the FD. Tapped the piston out from the inside. Came out quite easily. Not sure why the compressed air didn't free it. Wasn't badly stuck, but slight resistance by hand to move it in the metering barrel. I have a few 930 FDs and one of them had a spring on top of the metering piston. I had left the spring off this one - as others had no spring. May have made a difference if the spring was in. The piston would have been at rest in the closed (extended) position, rather than fully inserted in the bore. Would have been able to grab the end of it and pull it out.
In process of reinstalling now. then I guess I will have to recal the injectors etc. Sigh. A days work all round, at least.
Brians advice of turning the pumps over regularly is a good one.
Regards
Alan

__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 02-23-2021, 02:15 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 10:27 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.