Injector Questions - Page 2 - Rennlist - Porsche Discussion Forums

Notices
964 Forum
Sponsored By:
Sponsored By:

Injector Questions

 
Old 03-25-2012, 10:56 AM
  #16  
Goughary
Super User
 
Goughary's Avatar
 
Join Date: Oct 2010
Location: fairfield, CT
Posts: 3,589
Default

Fwiw - I sent mine off to Witch hunter last fall. cleaned flowed new seals and tested for not much money at all...it's worth it just since it's likely that will solved any issues, and then you'd know if you had to bite the bullet and buy new...Mine were pretty bad and they came back next to new.
Goughary is offline  
Old 03-26-2012, 03:20 PM
  #17  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: San Jose, CA
Posts: 17,024
Default

They were all cleaned and refurbed 6 years ago when I rebuilt the engine.

The advice given here gives me hope, especially the corrosion, because that will certainly be an intermittent problem. Thanks a lot guys, I'll check back with you after I take a look at all 6.
sundog is offline  
Old 03-26-2012, 08:16 PM
  #18  
Indycam
Super User
 
Join Date: Sep 2004
Location: not in HRM
Posts: 5,061
Default

The test stand they were tested on doesn't get cooking hot like a cylinder head .
I'm not saying the injector is bad because it got hot hot , but who knows .
Indycam is offline  
Old 03-27-2012, 02:06 PM
  #19  
frankvan
User
 
frankvan's Avatar
 
Join Date: Jan 2005
Location: St. Albert, Alberta, Canada
Posts: 696
Default

To me it sounds like excellent reasoning to upgrade to higher flow injectors and a full on motec.
frankvan is offline  
Old 07-26-2012, 04:42 PM
  #20  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: San Jose, CA
Posts: 17,024
Default

Altight, after replacing 2 of the injectors that the scantool said were the culprit, the symptoms still appear. It seems pretty random. Sometimes when the engine is cold it will happen, and sometimes when hot.

Although when hot I need to shut off and restart as many as 20 times before the CEL goes off, and the injector is not "stuck" open.

Does anybody know where the signals for the 6 injectors originates? And also, where does the signal to the CEL/scantool get the injector number that has "failed". Is it a resistance thing that determines when the scantool thinks it has failed? A counter of the number of times it triggers?

I've bought 4 used injectors, and will replace the remaining injectors to see if that solves the problem, but I'm thinking it is electrical. I don't know what other components are associated with the injector signal.

Any help would really be appreciated.
sundog is offline  
Old 07-26-2012, 09:01 PM
  #21  
dutchcrunch
Addict
Rennlist Member
 
Join Date: Dec 2002
Location: indianapolis
Posts: 1,043
Default diagnostics

i think you should switch sides with injectors to see if it follows as suggested. if it does not follow to other side it could be the connection at the ecu, the wiring or the ecu, i belive its your ecu, seems its fine for a while and acts up. code reading helps but its not always pin point acuuracy, just lets you know whats going on. thats where the real trouble shooting starts.
dutchcrunch is offline  
Old 07-26-2012, 09:03 PM
  #22  
dutchcrunch
Addict
Rennlist Member
 
Join Date: Dec 2002
Location: indianapolis
Posts: 1,043
Default

dont introduce used parts because you will never know if there good or bad, use what you have and do the swaps, its cheaper and faster to diagnose the problem. believe you me a bad ecu will not always flag itself. and that injecter control in the ecu is constantly working so it does and can wear out over time.
dutchcrunch is offline  
Old 11-19-2012, 10:12 PM
  #23  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: San Jose, CA
Posts: 17,024
Default Update on the saga.

2 weeks ago I replaced the injectors, and they seemed to work OK. Car was running strong, and no CEL. So I was planning on going to Laguna Seca this week for 2 days of DE/TT.

When I tried to start the car this morning the battery was completely dead, so I charged it for half an hour, and the car started, but the CEL and white smoke was back. Tried to restart a few times, but the light wouldn't go out.

So I got to thinking, this Battery has been a problem for a while, doesn't hold a charge, and doesn't even seem to charge while driving (apparently). I went and got a new DieHard at Sears today, put it in, and the car started right away with no CEL, or smoke. Started it a few times and it is all good. Unfortunately, I won't be able to make Laguna, too much prep that I would've done today.

Does anybody know if a low battery, or bad battery, would cause the DME to give bad signals (full on) to an injector? Or did I really not fix the problem yet.
sundog is offline  
Old 11-20-2012, 06:00 PM
  #24  
Jacke2c
Formerly turbotwoshoes
Rennlist Member
 
Jacke2c's Avatar
 
Join Date: Mar 2010
Location: Russellville, Arkansas
Posts: 723
Default Similar issues....

I have been following your threads. I suspect you have a drain somewhere...but more importantly right now, I strongly suspect a bad/corroded/loose ground. Mine gave similar symptoms and I spent about 3 hours cleaning grounds everywhere. It looks like you had your engine out. Did all the grounds get put back?
Jacke2c is offline  
Old 11-20-2012, 07:10 PM
  #25  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: San Jose, CA
Posts: 17,024
Default

Originally Posted by turbotwoshoes View Post
I have been following your threads. I suspect you have a drain somewhere...but more importantly right now, I strongly suspect a bad/corroded/loose ground. Mine gave similar symptoms and I spent about 3 hours cleaning grounds everywhere. It looks like you had your engine out. Did all the grounds get put back?
The engine was out about 5 years ago. And everyting was OK until last year.

How many grounds are there? Direct Battery, Starter? Anything near the DME?
sundog is offline  
Old 12-08-2012, 11:45 AM
  #26  
kos11-12
Addict
Rennlist Member
 
kos11-12's Avatar
 
Join Date: Jan 2007
Location: London UK & Paris FR
Posts: 1,481
Default

Hi guys,

Sorry I am bringing up this thread again...
Sundog is your issue resolved....?
It did it happened to me today, after driving for about 20 miles to see a friend and on my way back , but then near home it was back to normal,
It also happened to me a few moths ago....we replaced the crank sensor and it was find until today, it's maddness to sort out those issues..to much electronics and to old ....or tho my ECU & injectors are from 07...And a brand new fuel filter
I also suspect a bad connection to my DME ....
kos11-12 is offline  
Old 12-09-2012, 04:46 PM
  #27  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: San Jose, CA
Posts: 17,024
Default

Originally Posted by kos11-12 View Post
Hi guys,

Sorry I am bringing up this thread again...
Sundog is your issue resolved....?
It did it happened to me today, after driving for about 20 miles to see a friend and on my way back , but then near home it was back to normal,
It also happened to me a few moths ago....we replaced the crank sensor and it was find until today, it's maddness to sort out those issues..to much electronics and to old ....or tho my ECU & injectors are from 07...And a brand new fuel filter
I also suspect a bad connection to my DME ....
The symptoms for me are the rough running and white smoke out the tail pipe. If you had this, and drove it at all, I would recommend an oil change before driving again. The reason is that fuel gets past the rings and into the case.

I think that I solved my problem, or at least know what is causing it. I replaced the battery, and it worked just fine. But my battery seems to drain, even when driving, so it may be an issue with the alternator.

How does one test the alternator?
sundog is offline  
Old 12-09-2012, 06:59 PM
  #28  
kos11-12
Addict
Rennlist Member
 
kos11-12's Avatar
 
Join Date: Jan 2007
Location: London UK & Paris FR
Posts: 1,481
Default

Hi
Yes I drove it for about 20 miles, but then the issue cleared and was back to normal when arrived home, I suspected thought a dirt got i to one of injectors,
so you re saying petrol is gone throught the cylinder and mixed with the oil ...?!

I have a small Odyssey battery with cut off to save the battery when the car is not driven for a long time, I have checked the charging system by wiring the voltmeter to battery and checked the charge at 3000 RPM with light and AC on and it was reading find just under 14 volts, but I heard it's not accurate, apparently the alternator charge should be checked at the alternator ...
I also have strange stalling issue, the car stop running at low speed it basicly shut itself , it only hapens sometime, it could run find for a couple of months, I always restart it by unplugging the - & + of the battery and unplugging the DME, not in any special order, it's really weird ...I suspect a bad connection to the DME.....wonder if it's related to the injector issue stuck open....!?
kos11-12 is offline  
Old 12-09-2012, 07:04 PM
  #29  
kos11-12
Addict
Rennlist Member
 
kos11-12's Avatar
 
Join Date: Jan 2007
Location: London UK & Paris FR
Posts: 1,481
Default

Maybe bad fuel, the fuel in Europe is unstable and off after a few months , not good for a car that it's not driven often, I now refuel only for the journey I need to do...
kos11-12 is offline  
Old 04-09-2013, 03:36 PM
  #30  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: San Jose, CA
Posts: 17,024
Default

Well, the problem is still there. Although we seem to have narrowed it down to the number 2 injector. Changed the injector, and it still is an issue. New Battery, and even when fully charged, it will happen randomly, Injector number 2 stuck open, and CEL. Usually if I remove the connector, and reconnect or move the wire around it seems to go away, until some random start down the road.

Alternator seems to be a little low, 13.4-13.5 V when running. But we don't think that would cause the issue with a single injector. And the draw seems to be upwards of 400mA sometimes. And if I remove the plug for the injector, it goes down to 100 mA.

So, we think that it is a harness issue, does anybody know where the injector wires go, working back from the injector, because it looks like harness short at this time.
sundog is offline  

Thread Tools
Search this Thread
Quick Reply: Injector Questions


Contact Us About Us Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: