Doesn't start when engine warm

[MG88]

Recently I stepped out of my '00 boxster for a couple of minutes after driving 15 miles or so and found that I couldn't start the car again. Engine turns over nicely but no start :huh: . After a while though the car started normally. Since then this happened a number of times and usually after the engine cools down somewhat it will start again.

Checked fault codes with Durametric SW and found P1818 and P1823 codes. Couldn't find these in my Boxster service manual but luckily they are here in the P-codes section. I also tried to reset ECU by disconnecting battery (-), that seamed to have worked the first time, but then it wouldn't help anymore afterwards. (not sure if that was coincidence)

So now I'm stuck, not sure if these codes are related to the problem - anybody has an idea?

[rockymount1]

The Codes would indicate

P1818 Pressure regulator 2

P1823 Pressure regulator 3

which are the fuel injector pressure regulators.

I don't know whether the fault is that they aren't working or that they sense an under or over pressure condition. Someone else should be able to help.

Recently I stepped out of my '00 boxster for a couple of minutes after driving 15 miles or so and found that I couldn't start the car again. Engine turns over nicely but no start :huh: . After a while though the car started normally. Since then this happened a number of times and usually after the engine cools down somewhat it will start again.

Checked fault codes with Durametric SW and found P1818 and P1823 codes. Couldn't find these in my Boxster service manual but luckily they are here in the P-codes section. I also tried to reset ECU by disconnecting battery (-), that seamed to have worked the first time, but then it wouldn't help anymore afterwards. (not sure if that was coincidence)

So now I'm stuck, not sure if these codes are related to the problem - anybody has an idea?

[Loren]

P1818 Pressure regulator 2

Possible fault cause:

- Short circuit to B+/ground/mutual short circuit or open circuit

- Pressure regulator is faulty

- Tiptronic control module is faulty

P1823 Pressure regulator 3

Possible fault cause:

- Short circuit to B+/ground/mutual short circuit or open circuit

- Pressure regulator faulty

- Tiptronic control module is faulty

[MG88]

Thanks Loren and Rockymount1, I've read the service manual a little more today and found that these regulators are within the tiptronic tranny on the hydrolic control module - oops - so getting them out will be interesting.

I checked Pins 52 vs 1,4,5,29 for continuity and short to B+ on TCM connector but they seem to be fine, all around 8.5 ohm. Now that was with cold engine, I check again tomorrow after driving around for a while. Since I don't have a spare TCM I'm not sure how to verify if that's the problem - any ideas?

But I'm still wondering if the "no start" with warm engine is caused by problems with the pressure control solenoids - now the service manual "thinks" that a fault here would cause a "reduced driving program" - that doesn't sound like it would cause start up problems - then again my understanding here is quite limited :).

[MG88]

So I had some time and played around with it again. I found that the engine actually stopped if it was warm enough ~220F per instrument cluster. Once the engine stopped I got P1571 Immobilizer and then also P1790 on a later try.

Anyhow I thought maybe DME or Tiptronic module are getting to hot, they were actually cooking but maybe that's normal? I cleared all codes with Durametric SW and problem was gone <_< B) . Don't know why and what but the car starts normally now when warm and I let it run for 1h and no unexpected shutdowns.

Now symptoms are gone, rootcause is unknown and I'll be driving with my laptop in case I have to reset codes again.

[niceguy]

Hi MG88, Loren and rockymount1,

After reading this post, I find what a co-incident that the symptoms are exactly the same on my 2002 2.7 Tip. So, if I am patient enough to wait for a few mintues, the car would start and run perfectly normal without any power loss. In addition, I do notice while I was standing around the car in an enclosed garage after a drive, the car did switch on its engine fans for a brief 30 secs or so to cool itself even after the engine was switched off. This does not happen tho if I switch the engine off in open air.

I am just wondering what will be my best fix without a Durametric SW? Yet, I do have a ODBII to USB cable that I used to work on my Subaru WRX with OpenECU SW. Can I make use of this cable and possibly get a suitable SW anywhere?

Is there a fix before something really big could happen to my tranny?

Thanks for your time in advance

So I had some time and played around with it again. I found that the engine actually stopped if it was warm enough ~220F per instrument cluster. Once the engine stopped I got P1571 Immobilizer and then also P1790 on a later try.

Anyhow I thought maybe DME or Tiptronic module are getting to hot, they were actually cooking but maybe that's normal? I cleared all codes with Durametric SW and problem was gone <_< B) . Don't know why and what but the car starts normally now when warm and I let it run for 1h and no unexpected shutdowns.

Now symptoms are gone, rootcause is unknown and I'll be driving with my laptop in case I have to reset codes again.

Edited October 2, 2008 by niceguy

[MG88]

Hi niceguy

not sure if your problem is similar to what I had. In regards to the fans they might be on even after the engines is off if the engine compartment or cooling water is hot enough. As I remember there is one engine compartment fan and 2 fans in the front to cool the water.

As it turns out my problem was due to a faulty RPM sensor. It was just coincidence that the car would work after resetting the codes, it started stalling after another hour or so of driving. I gave up and brought it in for repair.

Marvin at the Rennshop helped me out, he did an excellent diagnostics job :D .

Hi MG88, Loren and rockymount1,

After reading this post, I find what a co-incident that the symptoms are exactly the same on my 2002 2.7 Tip. So, if I am patient enough to wait for a few mintues, the car would start and run perfectly normal without any power loss. In addition, I do notice while I was standing around the car in an enclosed garage after a drive, the car did switch on its engine fans for a brief 30 secs or so to cool itself even after the engine was switched off. This does not happen tho if I switch the engine off in open air.

I am just wondering what will be my best fix without a Durametric SW? Yet, I do have a ODBII to USB cable that I used to work on my Subaru WRX with OpenECU SW. Can I make use of this cable and possibly get a suitable SW anywhere?

Is there a fix before something really big could happen to my tranny?

Thanks for your time in advance

So I had some time and played around with it again. I found that the engine actually stopped if it was warm enough ~220F per instrument cluster. Once the engine stopped I got P1571 Immobilizer and then also P1790 on a later try.

Anyhow I thought maybe DME or Tiptronic module are getting to hot, they were actually cooking but maybe that's normal? I cleared all codes with Durametric SW and problem was gone <_< B) . Don't know why and what but the car starts normally now when warm and I let it run for 1h and no unexpected shutdowns.

Now symptoms are gone, rootcause is unknown and I'll be driving with my laptop in case I have to reset codes again.

[Loren]

The radiator fans do not run when the engine is off.

[niceguy]

The radiator fans do not run when the engine is off.

Hi MG88 and Loren,

Thanks for the replies.

However, I heard the fan(s) near the intake just behind the passenger's door ran for a brief minute or so. That was when I had the key removed from the car, door closed but car still unlocked.

Well, the problem seems to have gone now and only comes back if i park in an enclosed underground carpark with very poor ventilation. Otherwise, there is usually absolutely no problem with the car.

On the other hand, how may I test if the car is producing all the power it should? I tested the 0-60mph using an accelerometer and the average is around 7.2 secs. What is the avg of 0-60 and 0-400m on a 2003 2.7 Boxster?

Thank you very much again for your help.

Guy

[Loren]

The radiator fans do not run when the engine is off.

Hi MG88 and Loren,

Thanks for the replies.

However, I heard the fan(s) near the intake just behind the passenger's door ran for a brief minute or so. That was when I had the key removed from the car, door closed but car still unlocked.

Well, the problem seems to have gone now and only comes back if i park in an enclosed underground carpark with very poor ventilation. Otherwise, there is usually absolutely no problem with the car.

On the other hand, how may I test if the car is producing all the power it should? I tested the 0-60mph using an accelerometer and the average is around 7.2 secs. What is the avg of 0-60 and 0-400m on a 2003 2.7 Boxster?

Thank you very much again for your help.

Guy

From the service manual...

"Switch-on conditions for engine compartment fan (this fan pulls air into the engine compartment) The engine compartment fan is switched on when the engine compartment temperature is > 176 degrees F or the coolant temperature is > 216 degrees F.

After-running of engine compartment fan

If the ignition is switched off and the engine compartment temperature is more than 140 degrees F, the DME control module remains in readiness for another 20 minutes. During this time, the engine compartment temperature is retrieved every 10 seconds. If the engine compartment temperature is > 185 degrees F , the engine compartment fan is switched on for 20 seconds. If the engine compartment temperature is still > 185 degrees F after this time, the fan remains on for a further 30 seconds."

You might check to see if your engine compartment temperature sensor has come out of it's holder and is laying on the engine.

Here are some pics (in the post) from a Carrera that had that problem (Boxster is the same as I recall).

http://www.renntech.org/forums/index.php?s...ost&p=35812

[niceguy]

The radiator fans do not run when the engine is off.

Hi MG88 and Loren,

Thanks for the replies.

However, I heard the fan(s) near the intake just behind the passenger's door ran for a brief minute or so. That was when I had the key removed from the car, door closed but car still unlocked.

Well, the problem seems to have gone now and only comes back if i park in an enclosed underground carpark with very poor ventilation. Otherwise, there is usually absolutely no problem with the car.

On the other hand, how may I test if the car is producing all the power it should? I tested the 0-60mph using an accelerometer and the average is around 7.2 secs. What is the avg of 0-60 and 0-400m on a 2003 2.7 Boxster?

Thank you very much again for your help.

Guy

From the service manual...

"Switch-on conditions for engine compartment fan (this fan pulls air into the engine compartment) The engine compartment fan is switched on when the engine compartment temperature is > 176 degrees F or the coolant temperature is > 216 degrees F.

After-running of engine compartment fan

If the ignition is switched off and the engine compartment temperature is more than 140 degrees F, the DME control module remains in readiness for another 20 minutes. During this time, the engine compartment temperature is retrieved every 10 seconds. If the engine compartment temperature is > 185 degrees F , the engine compartment fan is switched on for 20 seconds. If the engine compartment temperature is still > 185 degrees F after this time, the fan remains on for a further 30 seconds."

You might check to see if your engine compartment temperature sensor has come out of it's holder and is laying on the engine.

Here are some pics (in the post) from a Carrera that had that problem (Boxster is the same as I recall).

http://www.renntech.org/forums/index.php?s...ost&p=35812

Hi Loren,

Thank you for getting back to me so quickly and your help is purely accurate and informative.

I am definitely goinig to get my hands dirty this weekend to see if the engine compartment temp sensor has come out of it's holder. Will be posting back to share the result.

Change of topic, the convertible roof has become noiser over time giving me those high pitched "ekk" "ikk" "erk" sounds. However, there is absolutely no noise when the roof is down. Therefore, I suspect most of the noise is coming from the roof frabic, above the engine cover, near where the rear window sits. Could it be the roof rack hitting the roof frabic that is cause the low but annoying noise?

Many thanks again

Guy