Odd Symptoms Recently.... UPDATE - Page 2

rawky · 11-07-2009, 10:50 AM

I haven't worked on the hatch recently. But are you saying the electrical wires may have got nipped somewhere? Where do they generally snag exactly?

BTW do I need a Temp II as above?

jcorenman · 11-07-2009, 11:22 AM

Quote:

Originally Posted by rawky

BTW do I need a Temp II as above?

What was the temperature? At 0C the resistance should be 4.4-6.8K ohms, lower at warmer temps and higher at colder temps.

Be sure that you are reading from each terminal to ground, not across the two terminals-- there are two separate thermistors. 10K sounds too high by 2x but it would be very odd for both thermistors to be bad.

This test is described on pg. D.24-14 of the WSM (section 24/28) below. It is worth doing this check from the LH connector as described-- be sure to disconnect the battery ground-strap when disconnecting the LH as there is live 12V on that connector.

t2.png

Cheers, Jim

rawky · 11-07-2009, 11:31 AM

It was 8-10C when I did it, and yes I did it from each individual post to a good ground. It was consistent when I took it all of and started again to be sure....

Ok, I will also try it at the LH plug. How do I tell which is the LH and which is the EZK?

jcorenman · 11-07-2009, 12:37 PM

Quote:

Originally Posted by rawky

It was 8-10C when I did it, and yes I did it from each individual post to a good ground. It was consistent when I took it all of and started again to be sure....

Then they are both 2x too high, which would cause the LH to think it was much colder than it actually is, which would cause too much fuel at startup. But it would be very odd to have both sensors off that far. Check it at the LH to be sure...

Quote:

Originally Posted by rawky

Ok, I will also try it at the LH plug. How do I tell which is the LH and which is the EZK?

The larger box. The smaller metalized molded-plastic box is the the EZK, the larger sheet-metal box is the LH.

There are also a bunch of basic resistance and voltage checks in the WSM (the Temp-II page above is a part of that).
If you don't have a copy of the WSM see the current WSM thread (<==linky).

Cheers, Jim

rawky · 11-08-2009, 01:55 PM

Right, LH results

This time the car said 5C temperature, which makes me doubt my gauging of the previous temperature, but anyway here are the results.

5C

4.4kΩ 4.42kΩ

So is this the problem? This problem seems intermittent because the car started fine today, but it only happens sometimes now! 2 times out of the five times I tried to start it in the morning last week... Why would the car have these symptoms only intermittently? Should I just fit a new one and eliminate the Temp II from the list of what it could be? What's the part no.?

Rawky

John Speake · 11-08-2009, 02:08 PM

Those readings are corect at the temp you note. Inspect the temp 2 harness connector carefully, make sure the sockets are clear of gunk. The heat can make stuff melt down into them from the wires.

Then peel back the rubber boot and check there are no bare wires.

Some people change temp 2 sensors as preventitive maintainance. They cost about 25 GBP.

rawky · 11-08-2009, 02:12 PM

Is that 25 GBP price from Porsche themselves? What was the part number, do you know?

I'll inspect the harness, but when I was taking the readings part of the rubber boot higher up the wire split, and I could see the two wires inside (intact from what I could see). Could this be allowing things to play with the connections? What would you suggest to cover the hole? Heatshrink maybe? I'll be sure give it all a good clean regardless.

Cheers
rawky

NB - I presume those Temp II readings are deemed ok?

John Speake · 11-08-2009, 02:19 PM

That's what I charge. P/N is 928 606 126 00. Don't you have a copy of PET ?

rawky · 11-08-2009, 02:57 PM

Ok, would it be ok to give you a ring during this week to get a new Temp II? When's best time to call?

What is PET? I haven't come across that before John... Is it something to look up part numbers with I presume?

Rawky

John Speake · 11-08-2009, 03:08 PM

Anytime within reason.

PET is the Porsche Parts System You can download from here:

http://www.porsche.com/all/media/pdf...82_KATALOG.pdf

rawky · 11-08-2009, 03:18 PM

Ok, will do. Thanks John!

rawky · 11-11-2009, 03:20 PM

UPDATE

Had a good talk with John Speake the other day, and we got talking about me renting his diagnostic tester to see whats what. Which is very kind of you John!
Just in case this makes a difference, the car starts perfectly and completely normally if I keep my foot to the floor. What does this tell us?

Also, when I take my foot off the pedal for the first 20 minutes of driving, the instant mpg reading doesnt go straight to 90MPG like it normally does.
Anything to read from this?

Rawky

Andrew Olson · 11-11-2009, 04:57 PM

Your throttle position switch might be bad.

Next time the car is cold, before you start it, open the hood and manually rotate the throttle quadrant (like you're trying to rev it). Slowly let it rotate back to it's resting position. You should hear a click. This is the micro switch inside the throttle position switch.

If you do not hear a click, check to see if there is slack in the throttle cable (the one to the gas pedal). If it is taught, you might try adjusting the throttle cable at the fire wall. If there is slack... you probably need to replace the throttle position switch. Unfortunately, it's deep under the intake and will require you to remove the intake.

Good luck.

rawky · 11-11-2009, 05:01 PM

Would that be causing over rich running and make it harder to start? When I try and start it, its like a flooded engine that wants to fire and just can't. When my foot is on the floor it starts fine.
Would that make this the cause of all of this? Do they go bad overnight like this?

What gets me is it's intermittent!

If I can get the diagnostic kit on it, it will be sorted what it is. I'll either rent John's or go to my local Porsche dealer and have them do it....

Rawky

Mrmerlin · 11-11-2009, 05:52 PM

have you inspected the dampers and FPR for internal leaks ? remove the vacuum hose and sniff it if it smells like fuel then you have an internal leak this will cause the car to have extra fuel.
Have you ever replaced the fuel injectors?? or had them cleaned

11-08-2009, 02:08 PM	#21
John Speake Addict Rennlist Member Rennlist Site Sponsor Join Date: Feb 2002 Location: Cambridge England Posts: 3,912	Those readings are corect at the temp you note. Inspect the temp 2 harness connector carefully, make sure the sockets are clear of gunk. The heat can make stuff melt down into them from the wires. Then peel back the rubber boot and check there are no bare wires. Some people change temp 2 sensors as preventitive maintainance. They cost about 25 GBP. __________________ John '86 Euro S2 SharkTuned LH & EZ-F www.jdsporsche.com Home of the SharkTuner Rebuilt LH, EZK ECUs & MAFs available from agents worldwide Diagnostic testers for all models of Porsche 1987 >

11-08-2009, 02:19 PM	#23
John Speake Addict Rennlist Member Rennlist Site Sponsor Join Date: Feb 2002 Location: Cambridge England Posts: 3,912	That's what I charge. P/N is 928 606 126 00. Don't you have a copy of PET ? __________________ John '86 Euro S2 SharkTuned LH & EZ-F www.jdsporsche.com Home of the SharkTuner Rebuilt LH, EZK ECUs & MAFs available from agents worldwide Diagnostic testers for all models of Porsche 1987 >

11-08-2009, 03:08 PM	#25
John Speake Addict Rennlist Member Rennlist Site Sponsor Join Date: Feb 2002 Location: Cambridge England Posts: 3,912	Anytime within reason. PET is the Porsche Parts System You can download from here: http://www.porsche.com/all/media/pdf...82_KATALOG.pdf __________________ John '86 Euro S2 SharkTuned LH & EZ-F www.jdsporsche.com Home of the SharkTuner Rebuilt LH, EZK ECUs & MAFs available from agents worldwide Diagnostic testers for all models of Porsche 1987 >

11-11-2009, 04:57 PM	#28
Andrew Olson Supercharged Rennlist Member Join Date: May 2002 Location: M-F Ohio. S-S Michigan. Sucks, but I'm gettin' paid! Posts: 12,747	Your throttle position switch might be bad. Next time the car is cold, before you start it, open the hood and manually rotate the throttle quadrant (like you're trying to rev it). Slowly let it rotate back to it's resting position. You should hear a click. This is the micro switch inside the throttle position switch. If you do not hear a click, check to see if there is slack in the throttle cable (the one to the gas pedal). If it is taught, you might try adjusting the throttle cable at the fire wall. If there is slack... you probably need to replace the throttle position switch. Unfortunately, it's deep under the intake and will require you to remove the intake. Good luck. __________________ AO

11-11-2009, 05:52 PM	#30
Mrmerlin Addict Rennlist Member Join Date: May 2004 Location: Aurora Colorado Posts: 6,841	have you inspected the dampers and FPR for internal leaks ? remove the vacuum hose and sniff it if it smells like fuel then you have an internal leak this will cause the car to have extra fuel. Have you ever replaced the fuel injectors?? or had them cleaned __________________ 1988 S4 Elfenbein Perlglanz with a full Pearl Gray leather interior, Auto 1986.5 Meteor Metallic/ tan-brown, Auto

11-07-2009, 10:50 AM	#16
rawky User Join Date: Aug 2008 Location: Newcastle, UK Posts: 263	I haven't worked on the hatch recently. But are you saying the electrical wires may have got nipped somewhere? Where do they generally snag exactly? BTW do I need a Temp II as above?

11-07-2009, 11:31 AM	#18
rawky User Join Date: Aug 2008 Location: Newcastle, UK Posts: 263	It was 8-10C when I did it, and yes I did it from each individual post to a good ground. It was consistent when I took it all of and started again to be sure.... Ok, I will also try it at the LH plug. How do I tell which is the LH and which is the EZK?

11-08-2009, 01:55 PM	#20
rawky User Join Date: Aug 2008 Location: Newcastle, UK Posts: 263	Right, LH results This time the car said 5C temperature, which makes me doubt my gauging of the previous temperature, but anyway here are the results. 5C 4.4kΩ 4.42kΩ So is this the problem? This problem seems intermittent because the car started fine today, but it only happens sometimes now! 2 times out of the five times I tried to start it in the morning last week... Why would the car have these symptoms only intermittently? Should I just fit a new one and eliminate the Temp II from the list of what it could be? What's the part no.? Rawky

11-08-2009, 02:12 PM	#22
rawky User Join Date: Aug 2008 Location: Newcastle, UK Posts: 263	Is that 25 GBP price from Porsche themselves? What was the part number, do you know? I'll inspect the harness, but when I was taking the readings part of the rubber boot higher up the wire split, and I could see the two wires inside (intact from what I could see). Could this be allowing things to play with the connections? What would you suggest to cover the hole? Heatshrink maybe? I'll be sure give it all a good clean regardless. Cheers rawky NB - I presume those Temp II readings are deemed ok?

11-08-2009, 02:57 PM	#24
rawky User Join Date: Aug 2008 Location: Newcastle, UK Posts: 263	Ok, would it be ok to give you a ring during this week to get a new Temp II? When's best time to call? What is PET? I haven't come across that before John... Is it something to look up part numbers with I presume? Rawky

11-08-2009, 03:18 PM	#26
rawky User Join Date: Aug 2008 Location: Newcastle, UK Posts: 263	Ok, will do. Thanks John!

11-11-2009, 03:20 PM	#27
rawky User Join Date: Aug 2008 Location: Newcastle, UK Posts: 263	UPDATE Had a good talk with John Speake the other day, and we got talking about me renting his diagnostic tester to see whats what. Which is very kind of you John! Just in case this makes a difference, the car starts perfectly and completely normally if I keep my foot to the floor. What does this tell us? Also, when I take my foot off the pedal for the first 20 minutes of driving, the instant mpg reading doesnt go straight to 90MPG like it normally does. Anything to read from this? Rawky

11-11-2009, 05:01 PM	#29
rawky User Join Date: Aug 2008 Location: Newcastle, UK Posts: 263	Would that be causing over rich running and make it harder to start? When I try and start it, its like a flooded engine that wants to fire and just can't. When my foot is on the floor it starts fine. Would that make this the cause of all of this? Do they go bad overnight like this? What gets me is it's intermittent! If I can get the diagnostic kit on it, it will be sorted what it is. I'll either rent John's or go to my local Porsche dealer and have them do it.... Rawky