non-starting 993 issue: Help!
Thread Starter
Track Day
Joined: Jun 2016
Posts: 16
Likes: 0
non-cranking 993 issue: Help!
Was advised to post over here about a problem I'm having with my 993. Here's the original thread link:
https://rennlist.com/forums/911-foru...l#post13712275
"Need some help diagnosing my 97 993. Here is what I can tell you:
Pulled the car out of the garage last week. Had the boot/doors open for a bit, nothing crazy long. Went to start it to take it out for the night and nothing. Lights come on, radio comes on, alarm arms/disarms but it doesn't crank, nada. We pushed it back in the garage and I did the following:
-Tried the other set of keys/fob. nope.
-replaced the DME relay. nope.
-pulled the battery and put it on the tender for a couple days. nope.
The only thing I can think of, based on some texting with the previous owner and my local guru, is that the ECU/M is not reading the immobilizer correctly and it's keeping the car "locked down". Can anyone help shed some light on what might be going on? I really REALLY don't want to spend north of $500 having the box flashed if I don't have to.
Thanks,
Joe"
https://rennlist.com/forums/911-foru...l#post13712275
"Need some help diagnosing my 97 993. Here is what I can tell you:
Pulled the car out of the garage last week. Had the boot/doors open for a bit, nothing crazy long. Went to start it to take it out for the night and nothing. Lights come on, radio comes on, alarm arms/disarms but it doesn't crank, nada. We pushed it back in the garage and I did the following:
-Tried the other set of keys/fob. nope.
-replaced the DME relay. nope.
-pulled the battery and put it on the tender for a couple days. nope.
The only thing I can think of, based on some texting with the previous owner and my local guru, is that the ECU/M is not reading the immobilizer correctly and it's keeping the car "locked down". Can anyone help shed some light on what might be going on? I really REALLY don't want to spend north of $500 having the box flashed if I don't have to.
Thanks,
Joe"
Last edited by Synthsis; Nov 7, 2016 at 10:28 PM.
Rennlist Member
Joined: Oct 2006
Posts: 8,366
Likes: 1,205
From: Vista CA
very near the DME relay is a "start relay"
If you do not have start voltage present at the starter motor, try replacing the "start relay".
It is the same as 3 or 4 others in the tray, so you can just swap them around.
good luck.
If you do not have start voltage present at the starter motor, try replacing the "start relay".
It is the same as 3 or 4 others in the tray, so you can just swap them around.
good luck.
Drifting
Joined: May 2006
Posts: 3,074
Likes: 205
From: Paris
more details better
what is the history of works on car? did it have immobilizer problems?
what other problems and what was fixed,
how many miles and what type of 993 is it?
did you lock it with immobilizer after no start?
are you sure the battery is good?
thanks
what is the history of works on car? did it have immobilizer problems?
what other problems and what was fixed,
how many miles and what type of 993 is it?
did you lock it with immobilizer after no start?
are you sure the battery is good?
thanks
Thread Starter
Track Day
Joined: Jun 2016
Posts: 16
Likes: 0
There's a decent service history on the car but nothing electrical related. The one thing that I would have to do when starting the car is arm then disarm the car before it would start.
128k on the clock, standard N/A 97 993
The fob will still arm/disarm the car even though it won't start. Battery is still reading above 12V, so that's decent.
128k on the clock, standard N/A 97 993
The fob will still arm/disarm the car even though it won't start. Battery is still reading above 12V, so that's decent.
Drifting
Joined: May 2006
Posts: 3,074
Likes: 205
From: Paris
do you hear anything with key on position 3 ? clicking in engine, fuel pump whine ?
do the dash lights fade a tad when you turn key to start position number 3 ?
what i mean by pos. 3 is :
position 1, key in
position 2 , dash lights
position 3 , cranks
do the dash lights fade a tad when you turn key to start position number 3 ?
what i mean by pos. 3 is :
position 1, key in
position 2 , dash lights
position 3 , cranks
Instructor
Joined: Apr 2010
Posts: 249
Likes: 10
From: Everett, WA
Does your car have a clutch interlock switch? My '96 doesn't but I think they might have added that starting in with the '97 models (at least it is in the wiring diagrams for the '97-98 models). That might be faulty and preventing the starter relay from energizing.
GC
GC
Trending Topics
Racer
Joined: Apr 2015
Posts: 477
Likes: 3
From: Central, NJ
I would start with the basics....how old is the battery. What is the voltage?
You need over 12.4 to start it. Do you have a multi-meter? Does your battery have water or AGM. If water did you check to see if the cells are low on water?
You can pick up a cheap battery tester load for just over $20 bucks and good to have around.
You need over 12.4 to start it. Do you have a multi-meter? Does your battery have water or AGM. If water did you check to see if the cells are low on water?
You can pick up a cheap battery tester load for just over $20 bucks and good to have around.
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
Drifting
Joined: Mar 2006
Posts: 2,432
Likes: 36
From: Hannover
https://rennlist.com/forums/993-foru...metimes-2.html
You should get some electrical drawings for your model to help the process.
RL Technical Advisor
Joined: May 2001
Posts: 11,870
Likes: 75
From: Portland Oregon
The VERY first thing to do here is check the no-load battery voltage and make sure its 12.66 VDC. Anything less is below 100% charge and an old battery may be sufficiently sulfated so that it won't start the engine. I've seen this far too many times to recount.
Check the date code on that battery to make sure its less than 5 years old. Anything beyond that is on borrowed time and may not work, even if charged.
If all that checks out OK, clean the battery terminals, clamps and ALL grounds so they are bright, shiny & clean.
Check the date code on that battery to make sure its less than 5 years old. Anything beyond that is on borrowed time and may not work, even if charged.
If all that checks out OK, clean the battery terminals, clamps and ALL grounds so they are bright, shiny & clean.
Rennlist Member
Joined: Jun 2008
Posts: 4,114
Likes: 583
From: Winston-Salem, NC
I concur with GC96. Suggest you by-pass the clutch safety microswitch at the base of the clutch pedal assembly. If, after you do by-pass it and the car starts, there's your culprit.
Race Car
Joined: May 2003
Posts: 4,248
Likes: 103
From: SoCal
the start relay and the immobilizer. This should allow the engine to crank.
The next step would be the typical troubleshooting of a no-start situation
described here under "No-Start";
http://www.systemsc.com/diagnostic.htm
Addict
Rennlist Member
Rennlist Member
Joined: Apr 2007
Posts: 1,210
Likes: 2
From: Los Angeles
I have/had a similar symptom—it was/is my ignition switch. Every once in a while something doesn't connect. I try 15 -20 times, taking the key in an out every two or three times and jiggle it a bit then, boom it starts, then it doesn't happen for another 6–8 months. Then it will happen 2 times in 3 days then nothing for a year. It has been like this for 4 years, I really should get it replaced, but it is so infrequent I haven bothered.
It drove my mechanic crazy though because it happened when he was trying to program a couple of remotes for me.
It drove my mechanic crazy though because it happened when he was trying to program a couple of remotes for me.
Thread Starter
Track Day
Joined: Jun 2016
Posts: 16
Likes: 0
Jumping the start relay (R61) pins 87 & 30 eliminates the clutch switch,
the start relay and the immobilizer. This should allow the engine to crank.
The next step would be the typical troubleshooting of a no-start situation
described here under "No-Start";
http://www.systemsc.com/diagnostic.htm
the start relay and the immobilizer. This should allow the engine to crank.
The next step would be the typical troubleshooting of a no-start situation
described here under "No-Start";
http://www.systemsc.com/diagnostic.htm
Can you elaborate on this? I might have time tomorrow night to dig into the car and this is the first thing I'm going to do. Being a small business owner is an 8 day a week job, lol, but I think I've carved out a little time tomorrow after work.
