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 > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
Join Date: Jan 2004
Location: Texas
Posts: 11,257
Need some quick and serious help

Just put Brother's engine back in the car. Started up on the first try but doesn't run for long. Bogs down and is real rough. Plug wires should still be going on the same way. Pumping the throttle barely changes the rpm and then will cause a backfire and stop the motor.

Any ideas?

Exhaust is cool. We adjusted the valves, but didn't make a big enough change to warrant this. (I think)

Please help!!!

Old 03-06-2005, 09:06 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Still Doin Time
 
asphaltgambler's Avatar
 
Join Date: Nov 2004
Location: Nokesville, Va.
Posts: 8,225
You need to provide more complete info
__________________
'15 Dodge - 'Dango R/T Hauls groceries and Kinda Hauls *ss
'07 Jeep SRT-8 - Hauls groceries and Hauls *ss Sold
'85 Guards Red Targa - Almost finished after 17 years
'95 Road King w/117ci - No time to ride, see above
'77 Sportster Pro-Street Drag Bike w/93ci - Sold
Old 03-06-2005, 09:14 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Make My Day
 
wowzer911's Avatar
 
Join Date: May 2003
Location: Northern NY
Posts: 1,305
Distributor been out? Possible solution, try rotating distributor 180 degrees.
__________________
74 911S Targa ROW
Building Designer/Business Owner
Old 03-06-2005, 09:18 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Designer King
 
Paulporsche's Avatar
 
Join Date: Mar 2004
Location: Toronto, ON Canada
Posts: 5,499
What year?

If CIS, check WUR and AAR, and control pressures.
__________________
Paul
Yellow 77 Sunroof Coupe/cork interior; 3.2L SS '80 engine/10.3:1/No O2; Carrera Tensioners; 11 Blade Fan; Turbo tie rods; Bilstein B6; 28 tube Cooler; SSI, Dansk; MSD/Blaster; 16x7" Fuchs/205/50 Firestone Firehawk Indy 500s; PCA/UCR, MID9
Never leave well enough alone
Old 03-06-2005, 09:26 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
Join Date: Jan 2004
Location: Texas
Posts: 11,257
There is some valve noise coming from #1. I think I boofed the first Valve adjustment. I might have rushed it. I barely adjusted them though and they seemed tight before so I didn't think it would have this effect. I can coax the idle up to 1000 by holding the throttle but then it starts to backfire. The distributor is back on and the wires match up correctly. I didn't change any timing (that I know of). It idles at 740 RPM now.
Old 03-06-2005, 09:53 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered
 
Join Date: Jan 2004
Location: Texas
Posts: 11,257
Quote:
Originally posted by Paulporsche
What year?

If CIS, check WUR and AAR, and control pressures.

80. I don't have the tools for that.
Old 03-06-2005, 09:54 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered
 
blue82coupe's Avatar
 
Join Date: Oct 2003
Location: Louisville KY
Posts: 493
Rikao4.Just because the plug wires are installed correctly, doesn't mean the distributor is is installed right. The rockers need to be on the base circle of the cam, with piston atdc on #1 cylinder.Dan
__________________
I have plenty of lead for my pencil... just not enough paper to write on..

82SC with 95 993 engine
2004 Ford Powerstroke
Old 03-06-2005, 10:11 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered
 
Join Date: Apr 2004
Location: Harvard, MA
Posts: 29
Garage
I just reinstalled the engine in my wife's 1977 911S. Same symptoms. Poor starting, rough running, although after sitting 24 hours, last night it started and ran better but still not right.
I did not do any internal work to the engine while out except adjust the valves. I took it out primarily to install a new clutch and exhaust systems.

What is the WUR and AAR referred to in Rikao4's post ? I think I need to be troubleshooting the fuel sysem, but I'm open to any suggestions.

Prior to this, the car would sometimes run a little rough like this but clear up within 30 seconds or so and run smoothly. Could happen hot or cold.

Thanks !
__________________
Chris Ryan
1996 993 Coupe C2
1984 Carrera Targa
2002 Boxster
1976 911S Coupe (Sold)
Old 03-09-2005, 11:22 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Designer King
 
Paulporsche's Avatar
 
Join Date: Mar 2004
Location: Toronto, ON Canada
Posts: 5,499
Chris,

Do a search for the Warmup Regulator (WUR) and the Auxiliary Air Regulator and Valve (AAR and AAV). They control the mixture while the engine is running (WUR) and keep the revs up during warmup (AAR).
Usually rough running, especially while warming up, is caused by a malfunctioning one of these.

Rickao4 and Chris,

You will need a fuel pressure gauge (about $60 from Whitney) to check the control pressures, which will tell you if the WUR is OK or not.
__________________
Paul
Yellow 77 Sunroof Coupe/cork interior; 3.2L SS '80 engine/10.3:1/No O2; Carrera Tensioners; 11 Blade Fan; Turbo tie rods; Bilstein B6; 28 tube Cooler; SSI, Dansk; MSD/Blaster; 16x7" Fuchs/205/50 Firestone Firehawk Indy 500s; PCA/UCR, MID9
Never leave well enough alone
Old 03-09-2005, 11:39 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered
 
Join Date: Apr 2004
Location: Harvard, MA
Posts: 29
Garage
Thanks for your reply, Paul

Also, out of curiosity in case the CIS system checks out oK, is it possible that an error in valve adjustment could be causing this ? I just pulled each spark plug connector with the engine running and it sure seems that cylinders # 2, #4, and #3 are not firing (no RPM drop) while disconnecting the others exhibits a noticeable drop. They happen to be sequential in the firing sequence. Does this point to a possible valve adjustment issue ? Although I am pretty confident the valve adjustment was done properly, I have to ask ... Can an error in valve adjustment result in piston-valve contact ?? Or am I just looking at re-adjusting ?
__________________
Chris Ryan
1996 993 Coupe C2
1984 Carrera Targa
2002 Boxster
1976 911S Coupe (Sold)
Old 03-09-2005, 06:18 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered
 
Join Date: Nov 1999
Location: Las Vegas, Nevada, USA
Posts: 646
Hi Chris,

You might also check to see if you installed the ignition wires "backwards". Note that some distributors rotate clockwise, others counter-clockwise. I thought I knew which way mine rotated, but when I first re-installed my rebuild, I had gotten them "backwards. The car ran very roughly, and when I put the wires on correctly, it now runs quite nicely.
__________________
Andras
1983 911SC The Chocolate Kiss
1998 Audi A6 Quattro (Family Car)
2002 Audi TT Roadster (Wifey's Car)
1992 Mazda Miata (Daughter's Car)
1991 Honda VFR750F Interceptor
1982 Honda VF750S Sabre
Old 03-10-2005, 04:06 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered
 
djmcmath's Avatar
 
Join Date: Nov 2003
Location: West of Seattle
Posts: 4,718
When I re-installed my engine, it started on the first go but ran very poorly -- extra-super-rich. Turns out I had almost, but not quite, plugged in one of the wires. Check through your engine bay to make sure you actually plugged everything in -- it only takes one loose connection to make the whole thing not work.

Dan
__________________
'86 911 (RIP March '05)
'17 Subaru CrossTrek
'99 911 (Adopt an unloved 996 from your local shelter today!)
Old 03-10-2005, 05:52 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
 
JOT MON ABBR OTH
 
Groesbeck Hurricane's Avatar
 
Join Date: Feb 2001
Location: USA
Posts: 3,238
Just a question: What would be the effect of having too little clearance on the valves?
__________________
David
'83 SC Targa (sold ) MANLY babyblue honda '00 F250 7.3L (MINE!)
'15 F250 Gas (Her Baby) '95 993 (sold )
I don't take scalps. I'm civilized like white man now, I shoot man in back.
Old 03-10-2005, 06:31 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered
 
buster73's Avatar
 
Join Date: Feb 2004
Location: Wine country, Germany
Posts: 596
Garage
When disconnecting and reconnecting the fuel lines it is possible that dirt comes loose and blocks fuel lines or filter. Some fuel still reaches the engine but not enough to keep it running properly.
__________________
Regards,
Guenter

73.5 911T, mod
Old 03-10-2005, 09:38 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered
 
pookie's Avatar
 
Join Date: Dec 2001
Location: Knoxville TN
Posts: 779
What else was done to the engine while it was out of the car?

I would check all the connections from the engine removal i.e. all the wires, hoses and grounds. I also have to agree with the earlier post that the distributor may be off, happened to me and you can chase down every wire before you realize that was the problem. Also check the rotation of the distributor and make sure your ignition wires are in the correct firing order.
__________________
1976 911 S Targa 3.2
Old 03-10-2005, 09:49 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Designer King
 
Paulporsche's Avatar
 
Join Date: Mar 2004
Location: Toronto, ON Canada
Posts: 5,499
Why not check your valve adjustment? Then you can move on to other things.

And if you can get your hands on the fuel gauge that would tell you about the WUR.

Do you have a popoff valve in your airbox?

Have you checked for air leaks?

Are your ignition wires, cap and rotor good?

Have you checked the mixture? How old is the fuel filter?
__________________
Paul
Yellow 77 Sunroof Coupe/cork interior; 3.2L SS '80 engine/10.3:1/No O2; Carrera Tensioners; 11 Blade Fan; Turbo tie rods; Bilstein B6; 28 tube Cooler; SSI, Dansk; MSD/Blaster; 16x7" Fuchs/205/50 Firestone Firehawk Indy 500s; PCA/UCR, MID9
Never leave well enough alone
Old 03-10-2005, 12:58 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Registered
 
Join Date: Apr 2004
Location: Harvard, MA
Posts: 29
Garage
To PaulPorsche et al

I took the advice and re-checked the valve adjustment. Sure enough, the exhaust valves on the three non-firing cylinders were mis-adjusted so those valves were not seating. I readjusted them, checked all the others, and the engine runs smooth as silk. Guess I wasn't as careful as I should have been while adjusting the valves the first time ... but will be next time ! Thanks for all the feedback. Hope Rika04's situation is as easy a fix.
__________________
Chris Ryan
1996 993 Coupe C2
1984 Carrera Targa
2002 Boxster
1976 911S Coupe (Sold)
Old 03-10-2005, 06:39 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
Registered
 
Join Date: Jan 2004
Location: Texas
Posts: 11,257
Thank you all for the input / note from the shop

1. we broke a grounding wire in the back harness which disabled the "frequency valve"= fuel regulator fritz
2. valve job was blessed and deemed worthy
3. the # 2 intake runner not seated completely=leak
we did it backwards / should have tighten the runner 's first, then the clamps for the boots (me)
Brother scored a "duck" from this misfortune / got tagged by a F350 last week. I'm still going to do mine, have no fear the Pelicans are near.
Rika

Old 03-11-2005, 05:53 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 07:21 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 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.