Cut-off, Black Smoke
10-07-2002, 09:11 AM
#17
Burning Brakes
Join Date: Jun 2001
Location: Stockholm, Sweden
Posts: 1,232
Likes: 0
Received 0 Likes
on
0 Posts
Greg, did you read my post on your thread at the 964 forum.
It could be a problem with the cold start regulator. It has a bimetallic strip that heats up by electricity. It could be a short in the wiring on that strip. The whole thing is heat sensitive, so when you redline your car the engine might get hot enough for the bimetallic strip to open (or close, don't remeber which) up the regulator.
It is really easy to check, let the engine get warm, if you have a fast idle just pinch the hose connected to the intercoolers right side. If the idle goes down, you most probably have a faulty cold start regulator.
Check and report back.
Mark, it is the "FM CL - 007P" you can by it from Forge directly, they also have a US reseller, search this forum for "CBV" and you will find the name of the dealer.
I am really happy with my Forge CBV, it keeps the boost up between shifts. According to my stock boost gauge I keep 0.7 bar boost if I do a fast shift between 3rd and 4th gear at 6.000 rpm.
It could be a problem with the cold start regulator. It has a bimetallic strip that heats up by electricity. It could be a short in the wiring on that strip. The whole thing is heat sensitive, so when you redline your car the engine might get hot enough for the bimetallic strip to open (or close, don't remeber which) up the regulator.
It is really easy to check, let the engine get warm, if you have a fast idle just pinch the hose connected to the intercoolers right side. If the idle goes down, you most probably have a faulty cold start regulator.
Check and report back.
Mark, it is the "FM CL - 007P" you can by it from Forge directly, they also have a US reseller, search this forum for "CBV" and you will find the name of the dealer.
I am really happy with my Forge CBV, it keeps the boost up between shifts. According to my stock boost gauge I keep 0.7 bar boost if I do a fast shift between 3rd and 4th gear at 6.000 rpm.
10-08-2002, 02:39 PM
#18
Racer
Join Date: Jan 2002
Location: UK
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
Hi Staffan.
I will check and report back..
PS The only thing that worries me slightly is that I had put the car on charge just before this problem first started. It is the same charger as I have used many times before, and because it has a "safe" charging option you can connect it to the battery whilst the battery is still in the car and connected. I have done this many times before. The only thing I did differently this time is that for various reasons the charger was left connected for several days. I can't see how this could have caused the problem I am now having - if there was a problem with the charger I would expect it to have happened on any of the other occasions I have used it. I can't see what difference it makes leaving it on charge for so long - especially since the charger automatically goes into maintenance mode to keep the battery topped up. So it's probably just a coincidence - but I get nervous about coincidences..!
Greg
I will check and report back..
PS The only thing that worries me slightly is that I had put the car on charge just before this problem first started. It is the same charger as I have used many times before, and because it has a "safe" charging option you can connect it to the battery whilst the battery is still in the car and connected. I have done this many times before. The only thing I did differently this time is that for various reasons the charger was left connected for several days. I can't see how this could have caused the problem I am now having - if there was a problem with the charger I would expect it to have happened on any of the other occasions I have used it. I can't see what difference it makes leaving it on charge for so long - especially since the charger automatically goes into maintenance mode to keep the battery topped up. So it's probably just a coincidence - but I get nervous about coincidences..!
Greg
10-08-2002, 11:00 PM
#19
Instructor
Join Date: Jun 2001
Posts: 183
Likes: 0
Received 0 Likes
on
0 Posts
Mark, it is the "FM CL - 007P" you can by it from Forge directly, they also have a US reseller, search this forum for "CBV" and you will find the name of the dealer.
I am really happy with my Forge CBV, it keeps the boost up between shifts. According to my stock boost gauge I keep 0.7 bar boost if I do a fast shift between 3rd and 4th gear at 6.000 rpm.[/QB][/QUOTE]
Thanks!
I am really happy with my Forge CBV, it keeps the boost up between shifts. According to my stock boost gauge I keep 0.7 bar boost if I do a fast shift between 3rd and 4th gear at 6.000 rpm.[/QB][/QUOTE]
Thanks!
10-12-2002, 09:52 AM
#20
Racer
Join Date: Jan 2002
Location: UK
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
Staffan -
I did the check you suggested. Here's what happened:
1. I start the car, and it begins idling at 1,500 and rises steadily to 3,000 revs!
2. After a few minutes the revs have dropped slightly, but are still far too high. I wait a few more minutes.
3. By now it's probably been running for around 10 minutes, so I go out to try the hose test, and the instant I open the engine compartment, the revs rise. (Sudden inrush of colder air..??)
4. I try pinching the hose, and as soon as I pinch it shut the revs drop. Let go and they rise again. Pinch it and the revs drop again.
So - does this mean it's the cold start regulator? If so, is this difficult or expensive to fix?
[PS later during the day I went for a drive; revs stayed high for 10 minutes. Tried a bit of full boost to see if that would help - it didn't. But as soon as I hit the rev limiter the problem seemed to go away again. Coincidence? Or does it mean something?]
Thanks
I did the check you suggested. Here's what happened:
1. I start the car, and it begins idling at 1,500 and rises steadily to 3,000 revs!
2. After a few minutes the revs have dropped slightly, but are still far too high. I wait a few more minutes.
3. By now it's probably been running for around 10 minutes, so I go out to try the hose test, and the instant I open the engine compartment, the revs rise. (Sudden inrush of colder air..??)
4. I try pinching the hose, and as soon as I pinch it shut the revs drop. Let go and they rise again. Pinch it and the revs drop again.
So - does this mean it's the cold start regulator? If so, is this difficult or expensive to fix?
[PS later during the day I went for a drive; revs stayed high for 10 minutes. Tried a bit of full boost to see if that would help - it didn't. But as soon as I hit the rev limiter the problem seemed to go away again. Coincidence? Or does it mean something?]
Thanks
10-12-2002, 01:20 PM
#21
Addict
Rennlist Member
RIP
Rennlist Member
RIP
Join Date: Feb 2002
Location: London
Posts: 802
Likes: 0
Received 0 Likes
on
0 Posts
Gregg, my car is at G-force at the moment having some mods done. They informed me that my cold start regulator was shagged (cause of my very rich fuelling). They quoted £600 for a new item and £200 for a reconditioned one.
10-12-2002, 07:56 PM
#23
Burning Brakes
Join Date: Jun 2001
Location: Stockholm, Sweden
Posts: 1,232
Likes: 0
Received 0 Likes
on
0 Posts
Greg, I really think we are getting closer.
The cold start regulator (CSR) is the prime suspect at this stage.
Either the CSR is gone or it isn't getting any electricity. I am pretty sure that the CSR is gone, but you might want to check a few other things.
A new one is about $100-150 USD, you could order it from your Porsche och Bosch dealer, the Bosch part number is on the back (I think).
I suspect that James is refering to the warm-up regulator, but I am not sure. The cold start regulator is not very complicated.
You find the CSR by following the hose attached on the intercoolers right hand side. It's a shiny thing, you can't miss it. It's a 5 minute thing to get it out, undo 2 bolts and two hoses (if I remember correctly).
If you decide to do some more testing you could:
1. Make sure the electric plug on the CSR is making good contact (clean it, spray it etc.)
2. Measure the resistance in the CSR, you need of course to disconnect the electric plug to do that
3. Make sure the CSR is getting electricy by measuring if there is any voltage in the plug. I think the engine needs to be running to do this.
If you decide to check 2 and 3, then report the numbers and I will check on my car, no problem.
If it's a short in the wiring, which I suspect, I heard that the relays for the fuel pumps might get damaged. This is just a reminder if you replace the part and still have this problem.
That's all I can think of right now, personally I would replace the part and cross my fingers since it's a common problem, and I like to gamble :-)
Staffan
The cold start regulator (CSR) is the prime suspect at this stage.
Either the CSR is gone or it isn't getting any electricity. I am pretty sure that the CSR is gone, but you might want to check a few other things.
A new one is about $100-150 USD, you could order it from your Porsche och Bosch dealer, the Bosch part number is on the back (I think).
I suspect that James is refering to the warm-up regulator, but I am not sure. The cold start regulator is not very complicated.
You find the CSR by following the hose attached on the intercoolers right hand side. It's a shiny thing, you can't miss it. It's a 5 minute thing to get it out, undo 2 bolts and two hoses (if I remember correctly).
If you decide to do some more testing you could:
1. Make sure the electric plug on the CSR is making good contact (clean it, spray it etc.)
2. Measure the resistance in the CSR, you need of course to disconnect the electric plug to do that
3. Make sure the CSR is getting electricy by measuring if there is any voltage in the plug. I think the engine needs to be running to do this.
If you decide to check 2 and 3, then report the numbers and I will check on my car, no problem.
If it's a short in the wiring, which I suspect, I heard that the relays for the fuel pumps might get damaged. This is just a reminder if you replace the part and still have this problem.
That's all I can think of right now, personally I would replace the part and cross my fingers since it's a common problem, and I like to gamble :-)
Staffan
10-12-2002, 08:26 PM
#24
Burning Brakes
Join Date: Jun 2001
Location: Stockholm, Sweden
Posts: 1,232
Likes: 0
Received 0 Likes
on
0 Posts
Another test you could do is to get the thing out, power it up with 12V, the valve should close after a while. If it doesn't you know for sure the part is gone.
Staffan
Staffan
10-13-2002, 08:09 AM
#26
Burning Brakes
Join Date: Jun 2001
Location: Stockholm, Sweden
Posts: 1,232
Likes: 0
Received 0 Likes
on
0 Posts
Greg, if you decide to test this part by powering with 12V, don't use the battery, use your charger, if it's a short (which I suspect) it would do bad things to your battery.
We should call this thing Auxiliary Air Valve, so it's not confused with anything else. It's also called Auxiliary Air Regulator and Slide Valve.
For future reference you could check this thing mechanically (bimetallic strip and return spring) by putting it in the freezer (in a plastic bag) after a while the valve should open up. When put in the owen (warning, never done this myself) the valve should close fully.
We should call this thing Auxiliary Air Valve, so it's not confused with anything else. It's also called Auxiliary Air Regulator and Slide Valve.
For future reference you could check this thing mechanically (bimetallic strip and return spring) by putting it in the freezer (in a plastic bag) after a while the valve should open up. When put in the owen (warning, never done this myself) the valve should close fully.
10-13-2002, 01:27 PM
#27
Racer
Join Date: Jan 2002
Location: UK
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
Hi Staffan.
I didn't try it yet because (a) it's raining and (b) it didn't look like a 5-minute job to me. It looks like you need to remove the intercooler to get to the valve - and I seem to remember reading something about how it's very difficult to put the intercooler back on properly and get it correctly aligned unless you know what you're doing and there's more than one person helping.
Maybe I'll have a go later... then again my local mechanic said he'd take a quick look on Tuesday so maybe I'll wait for him...
I didn't try it yet because (a) it's raining and (b) it didn't look like a 5-minute job to me. It looks like you need to remove the intercooler to get to the valve - and I seem to remember reading something about how it's very difficult to put the intercooler back on properly and get it correctly aligned unless you know what you're doing and there's more than one person helping.
Maybe I'll have a go later... then again my local mechanic said he'd take a quick look on Tuesday so maybe I'll wait for him...
10-15-2002, 04:24 AM
#29
Racer
Join Date: Jan 2002
Location: UK
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
Staffan -
I have a question. If it's the cold start regulator (or whatever the name is) - how can it increase the idle revs up to 3,000 rpm? What I mean is - surely no matter how cold the engine is, the cold start system was not designed to increase the idling speed above 1,500 revs or thereabouts?
I have a question. If it's the cold start regulator (or whatever the name is) - how can it increase the idle revs up to 3,000 rpm? What I mean is - surely no matter how cold the engine is, the cold start system was not designed to increase the idling speed above 1,500 revs or thereabouts?
10-15-2002, 11:27 AM
#30
Burning Brakes
Join Date: Jun 2001
Location: Stockholm, Sweden
Posts: 1,232
Likes: 0
Received 0 Likes
on
0 Posts
The AAV is very simple, it doesn't know how many rpm your engine is doing. My AAV had a broken return spring, the valve was half open at all times, that made my car run an idle of about 2.000 rpm (if I remeber correctly).
The AAV has a valve, it should be open when the engine is cold, it should be closed when the engine is warm.
You pinched the hose feeding the AAV with air, the idle went down. If the AAV would have worked, your idle would have stayed the same since the valve would have been closed (see the picture a couple of posts ago).
So, your valve is (partly) open when the engine is warm. The idle goes down when you redline your car. The idle goes up when the engine compartement is opened.
To me that's an indication of that the AAV is mechanically working, so you don't need to test it by putting in the freezer and owen to check if the valve is open or closing as it should. So the return spring and the bimettalic strip should be okey.
So, it seems like the bimettalic strip doesn't get heated up by the wiring around it. So either the wiring doesn't get any electricity or is broke someway or the other (probably a short).
By doing the tests described above you will find out where the problem is. Start by feeding the AAV with 12 V, if the valve doesn't close you need to by a new AAV. If this test close the valve you need to find out why it doesn't get any electricity.
Could there be another reason for your high idle, for sure, but we have really good reasons for suspecting a problem related to the AAV.
Staffan
The AAV has a valve, it should be open when the engine is cold, it should be closed when the engine is warm.
You pinched the hose feeding the AAV with air, the idle went down. If the AAV would have worked, your idle would have stayed the same since the valve would have been closed (see the picture a couple of posts ago).
So, your valve is (partly) open when the engine is warm. The idle goes down when you redline your car. The idle goes up when the engine compartement is opened.
To me that's an indication of that the AAV is mechanically working, so you don't need to test it by putting in the freezer and owen to check if the valve is open or closing as it should. So the return spring and the bimettalic strip should be okey.
So, it seems like the bimettalic strip doesn't get heated up by the wiring around it. So either the wiring doesn't get any electricity or is broke someway or the other (probably a short).
By doing the tests described above you will find out where the problem is. Start by feeding the AAV with 12 V, if the valve doesn't close you need to by a new AAV. If this test close the valve you need to find out why it doesn't get any electricity.
Could there be another reason for your high idle, for sure, but we have really good reasons for suspecting a problem related to the AAV.
Staffan