Bizarre problem - DME fried?
Thread Starter
Intermediate
Joined: May 2012
Posts: 30
Likes: 0
From: Central Texas
Bizarre problem - DME fried?
I'll get right to it. '86 951... engine will not start, but tries. With the ignition in the ON position, I can hear the fuel injectors "ticking" randomly as well as the ICV going into spasms. A strong fuel odor is present.
Is the DME and/or KLR fried?
Is there anything else that could cause this anomaly?
With much appreciation,
Mancuso
Is the DME and/or KLR fried?
Is there anything else that could cause this anomaly?
With much appreciation,
Mancuso
Last edited by Mancuso; Jul 24, 2012 at 12:25 AM.
Rennlist Member
Joined: Nov 2011
Posts: 721
Likes: 2
From: Sydney, Australia
Does the engine turn over at all and just not start?
The strong fuel odour sounds to me like a FPR or related component failing and spilling all your high octane goodness across the engine and floor.
The strong fuel odour sounds to me like a FPR or related component failing and spilling all your high octane goodness across the engine and floor.
Thread Starter
Intermediate
Joined: May 2012
Posts: 30
Likes: 0
From: Central Texas
The engine turns over, yes, but does not start. The FPR is new. The component spasms are what's concerning me. If the DME is toast somehow, I would shudder to think that it fried my Vitesse gear.
I think it's important to point out that the car was performing perfectly this afternoon.
I think it's important to point out that the car was performing perfectly this afternoon.
Rennlist Member
Joined: Nov 2011
Posts: 721
Likes: 2
From: Sydney, Australia
If you're getting spark and obviously getting fuel, something's going hinky.
I'd try with a known good DME - If one's not available, I came across one on Lart's shop while picking up an oil cooler housing yesterday.
http://bit.ly/OkbpTW
I'd try with a known good DME - If one's not available, I came across one on Lart's shop while picking up an oil cooler housing yesterday.
http://bit.ly/OkbpTW
Thread Starter
Intermediate
Joined: May 2012
Posts: 30
Likes: 0
From: Central Texas
Thanks for the response, by the way.
Yeah, I was eyeballing that set earlier. Mainly to get a feel for the going eBay price. I would hate to immediately resort to buying a DME and KLR from eBay if it's something else.
I've searched high and low on various forums and have yet to find symptoms like the ones I described.
Rennlisters... anyone here willing to sell/trade a DME and KLR? I have many goodies. Any other suggestions?
Yeah, I was eyeballing that set earlier. Mainly to get a feel for the going eBay price. I would hate to immediately resort to buying a DME and KLR from eBay if it's something else.
I've searched high and low on various forums and have yet to find symptoms like the ones I described.
Rennlisters... anyone here willing to sell/trade a DME and KLR? I have many goodies. Any other suggestions?
Rennlist Member
Joined: Nov 2011
Posts: 721
Likes: 2
From: Sydney, Australia
I was just thinking about this a bit further,
Have you cleaned all the grounds? It's a bit of a random solution, but if the grounds are intermittant it may report a flickering similar to your issue.
Have you cleaned all the grounds? It's a bit of a random solution, but if the grounds are intermittant it may report a flickering similar to your issue.
Trending Topics
Three Wheelin'
Joined: Jul 2012
Posts: 1,563
Likes: 2
From: Chicago suburbs
I have somewhat similar issues with my '91 S2 Cabrio. Except mine won't start unless I keep the gas pedal down and then puffs rich for a few minutes after start up. I ordered a Stribel DME relay and fuel injection temp sensor that I am hoping cures the issue. I replaced fuel pump/filter, spark plugs and wires, fuel pressure regulator, distributor cap/rotor, etc.
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
Porsche's Top 5 Most Questionable Naming Decisions
Verdad Gallardo
Pogea Racing's 964 Porsche 911 Reimagination Stands Out in a Crowded Field
Verdad Gallardo
6 Convertible Top MYTHS Most People Don't Understand!
Michael S. Palmer
2026 Porsche 911 Club Coupe is Spectacular, And Everything Wrong with the Porsche Market
Joe Kucinski
Talos Takes Your 991 Porsche 911 GT3 to the Next Level for a Cool $1.13 Million
Verdad Gallardo
9 Vehicles Porsche Helped Engineer that Aren't Porsches
Verdad Gallardo
9 Features and Characteristics That Only Porsche People Understand
Verdad Gallardo
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way
Joe Kucinski
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)
Verdad Gallardo
Three Wheelin'
Joined: Dec 2002
Posts: 1,825
Likes: 3
From: St Louis, Missouri, USA
Maybe you can guess and jump to the right fix but that almost never works for me. Heck if I swapped in a DME/KLR with my luck - it would get damaged too, then I'ld really be pissed....
Do you know you have spark? (simple ignition spark tester - $8 seen at HF). Do you know you have fuel pressure? (a little bit special fuel gauge - $30). Do you know you have injector pulses? (noid light - $15 any autozone, napa etc)....Bruce
Do you know you have spark? (simple ignition spark tester - $8 seen at HF). Do you know you have fuel pressure? (a little bit special fuel gauge - $30). Do you know you have injector pulses? (noid light - $15 any autozone, napa etc)....Bruce
Racer
Joined: Dec 2008
Posts: 426
Likes: 17
From: Kingston, Ontario, Canada
You mentioned that with the key in the on position you can hear the injectors and smell fuel. From what I've read, the fuel pump doesn't start pumping until it sees a signal from the crank sensor. Which means you have to be turning motor over. If you are pumping fuel just when the key is in the on position then perhaps it is a bad DME relay or fuse box.
Try hooking up a gauge to your fuel rail and check the pressure there. Fuel damper could also be faulty.
Try hooking up a gauge to your fuel rail and check the pressure there. Fuel damper could also be faulty.
Proprietoristicly Refined
Rennlist Member
Rennlist Member
Joined: Oct 2001
Posts: 1,816
Likes: 5
From: ~Carefree Highway~
When I replaced my AOS seals and stuff, I left the AFM plug off. The car will not start with this plug off.
If your car was running perfect clean the AFM connection and move the inside door to make sure it is not binding.
And since I do not see the obvious question asked---When you turn the key to crank ---do you see the tach bounce 1/16th of an inch?
Just another idea.
John
If your car was running perfect clean the AFM connection and move the inside door to make sure it is not binding.
And since I do not see the obvious question asked---When you turn the key to crank ---do you see the tach bounce 1/16th of an inch?
Just another idea.
John
Burning Brakes
Joined: Nov 2007
Posts: 1,242
Likes: 3
From: West Chester, PA / Morristown, NJ
Gotta start with the basics man...
Does the tach even bounce when trying to start?
Also, have a fire extinguisher handy. Why are you smelling fuel with key on! Fuel pump shouldn't even be running. Can you hear it run with just the key on?
Does the tach even bounce when trying to start?
Also, have a fire extinguisher handy. Why are you smelling fuel with key on! Fuel pump shouldn't even be running. Can you hear it run with just the key on?