Cold start issue?

[flatsixjunky]

Here it goes. I've owned the car for a little over one year. Last year (October) I did a complete tune up, magnecor wires, plugs, filters, BP oil. So far the car has ran impeccable. I've put 3500 miles since the tune up and I'm going for a new oil change in the next few weeks. Yesterday and for the first time the car cranked a little lazy (around 28C = 82.4 outside temp). On my second try it started. The car idled fine for a few minutes and I turned it off. When I tried again (still somewhat cold) it started but it was kind a lazy again, didn't took as long as the first try but longer than what I've been used to so far. I took it then for a spirited drive on a small highway near my place on which the speed limit is 110km/h = 68m/h. I stopped on my way home to pick something up. The warm up start was fine, although it took a little longer than it used to (again). When I came back home I tested the battery, it read 13.5. Today I did not start the car, but the battery read 13.25.

I did a search on "Cold start issues" and I ran into this thread:

1987 911 Carrera 3.2 cold start blues...help!

This thread led me to this tech article and other another thread:

http://www.pelicanparts.com/techarticles/911_cyl_head_temp_sensor/911_cyl_head_temp_sensor.htm

Head Temperature Sensor Replacement


Well, if it is the CHT, I already found out how to change it, but I would like to be sure. It seems that the battery is charging fine, which means that the Alt is charging the battery. BTW battery is an interstate. What are your opinions?

The only thing different that has happened to the car lately was that about a week and a half ago inadvertedly I poured like 15Euros of Gas (@ 1.25 Euros/liter = 12 liters) which is 10% ethanol. As soon as I realized this I stopped pouring payed and drove to another place where I finished filling it up with what they call here 98ron gas. For like two days after that the car, at start up, a little more white smoke came out of my muffler and the smell was different. It continued to start fine up until yesterday.

Could it be an injector problem because of the ethanol?

Remember guy's I'm new to all this and so far I've done my best to take care of everything myself, I would like to continue and learn more.

Thanks for helping.

Orlando

[flatsixjunky]

I took the car today for a spin, again it took longer to start. Once it starts the car runs just like before but it takes longer cranking. Is this sign of something starting to go bad? Could it be anyone of my two suspects? Anybody out there?

[kidrock]

This sounds like one of those problems that's gonna take some serious diagnosis, unfortunately. FWIW, I don't believe the presence of ethanol in your gas is your problem.

I didn't read the threads you provided, but I'm assuming they led you on a track to believe that it may possibly be the CHT sensor. If you have a Bentley, it provides the specs for that sensor.

Your problem could be a number of things, either in the fuel or charging system. My suggestion is to isolate the problem as easily and as quickly as possible. Start with the fuel system. Next time she doesn't start, disconnect one of the hoses to your ICV and spray some carb cleaner into it. Put it together quickly and temporarily and start the motor. If it starts immediately then dies, you will have a fuel starvation issue. If it doesn't start, it could be any of the 3.2 sensors, or the coil / wires / plugs / rotor / cap...maybe even bad grounds.

I remember reading a post recently where a subscriber had a similar issue, and found some really dirty fuse contacts under the trunk. Another possibility.

And FYI, the CHT sensor is easy to replace...except screwing the new one in without the special P tool. It can be done with needlenose, but a bit of a PITA.

Good luck, and keep us posted.

[flatsixjunky]

Hello Kidrock,

Thanks for giving me some of your time. Today I cleaned battery poles and ground, the battery + was a little loose. The car started again with no issues. I'm starting to think this was actually what was happening.

Anyway I have another question, please take a look at the pic.



How can I tell if I have a single wire CHT sender or a double wire?

I've read that the single wire is prone to failure. Do I have to disconnect it in order to tell or can you or anyone familiar with these can tell me from the pic. If I have a single wire I intend to do the upgrade immediately.

Another thing, I recently bought a new DME relay, so today I decided to switch to the new one and keep the old one as a spare. Please see pic.



This thing is 21 yrs old, 04/07/88. I hope the new one is at least half as good, I would be very happy if it lasts 10 yrs.

Also since I have a new voltmeter and the Bentley, I'm going to start testing around components, I'm a strong believer in better safe than sorry.

Anyway thanks a lot.

Orlando

[kidrock]

Orlando,

great to hear that she's starting correctly again (knock on wood). Hopefully, you've solved the problem by tightening up your battery cables. The best fix is the one that costs no $$$.

It appears you have the original DME relay...over 20 years old. That's awesome, a true sign of Porsche quality. Keep it as a spare. It's a possibility that your old relay may have played a part in your starting issues.

You don't need to take anything apart to check your CHT. Jack up the right rear of your car and remove the wheel (make sure you put jackstands under the car, don't depend on the jack itself to maintain the weight of the car). The CHT sensor is located underneath the car at cylinder #3 (driver's side, front of motor). IIRC, the sensor will probably have either a clear, or black wire protector. Gently pull the protector back to reveal if you have a 1 or 2-wire sensor.

Not difficult to replace; just a bit of a PITA to get to.

P.S.---just for good measure, clean and tighten that darn ground strap under the car at the tranny. Also, clean those ground wire connectors at intake runner #1 on your motor...your 3.2 will thank you for it.

[flatsixjunky]

Hello kidrock and thanks for the help,

great to hear that she's starting correctly again

from kr

Well she's not, today it was the same thing again. It almost did not start, very lazy cranking. I took it for a spin and as usual, after the car warms up it's starts right off. It's only in the mornings when the engine has been sitting overnight.

I thought this was my problem.



I took it off and I grind it with a Dremel tool, on the pole clamp and on the ground end to rid it off any rust or build up. That was yesterday and today like I said it was no better. Anyway I already bought a new ground cable.

On another subject, this is why I bought the Dremel tool, this thing has been making me sick for a year now.



This is how it looks now.



Is there anything I should apply to it before giving it a coat of black paint?

Look at the job this rusted clamp was doing on my battery corner. You can also see the shiny inside of the negative clamp



Is there anything to clean this other than water with baking soda?

Thanks for the help.

O-

[flatsixjunky]

Hello,

Well my car did not stat today. I knew this was about to happen. I went to buy a present for my youngest daughter, she'll be 1 yr old next week. At the house the car started, although lazy, like before. After buying her presents the car did not start and the car was warm at the time. The battery read 13.35, I'm keeping the volt meter in the car now. First it turned a couple of times without starting, with less power at each turn. The second try it only turned once. I waited 10 minutes and tried again, same result. Some guy help me jump start the car, it started at first turn, immediately, as if the starter is not getting enough power. I believe this has to be electrical, the car runs perfectly once started, I truly don't think it's fuel related. I'm going to have the battery checked tomorrow.

Thanks,

O-

[rcaradimos]

I think the new battery will fix you right up. Under 60$ @ your local autozone / walmart or whatever big box store you have in France.

[flatsixjunky]

Today the car did not start again, now it only starts if you jump it. I took readings of the battery while the car was idling, and it read 14.5 @ 880, 14.75 @ 2K and 14.8 @ 3K. I read this thread:

Real time - battery just exploded

John Cramer gives very good advice there. After reading it I can imagine my VR is toast. I can't use the car now, I'll risk killing alternator or the Motronic.

I tested it a second time, this time it read 14.4 @ idle, 14.5 @ 2K and 14.6 @ 3K, I also tested it @ 1500 with headlights, interior lights and radio on, it read 14.4. Am I safe to assume that the culprit is the VR and that my Alt is still undamaged?

Thanks,

O-

[flatsixjunky]

Hello,

I just finished pulling my alternator, 2.5hrs.





Changing the VR should be easy now but I need someone to confirm or not a question on my previous post.

Am I safe to assume that the culprit is the VR and that my Alt is still undamaged?

from myself

Thanks,

O-

[Wayne 962]

I think you're on the wrong track. Just because the battery has a high voltage doesn't mean it's still good. The battery has to be able to output some serious cranking amps in order to turn the engine over. I'm pretty sure that your battery is worn out - just replace it and you should be fine.

-Wayne

[flatsixjunky]

Hello,

Thank you Wayne. How about the 14.5 V and up readings? The Bentley states that a "reading over 14.2 most likely indicates a faulty VR" I get over 14.2 even with all electrical on? I read the same thing from John Cramer's on this thread.

http://forums.pelicanparts.com/showt...=484983&page=2

I know I should have taken the battery for a test, but since I was getting those volt readings (I thought I wasn't supposed to be getting such high numbers 14.6V) I really thought my problem was the V.R.

Thank you for your time Wayne.

O-

[scarceller]

Take the battery to a good auto parts store that has a battery bench tester. With a bench tester they can test cold crank output amps as well as a slew of other tests.

Also, clean the ground terminal on cyl #1 intake runner - this is the main ground for all the DME sensors and the DME. While at it check the drive train ground strap at the front of the transmission clean it's contact points. These 2 ground points can cause DME issues and they are easy enough to clean up.

Best of luck.

[scarceller]

One more small test next time you go to start the car cold:
Before you try to start the car jumper 12V to the fuel pump fuse in the front trunk fuse block you can even simply jumper power to the pump fuse from the fuse right next to it (the one closer to the front). Let the pump run for 10-15seconds then try starting and see if this helped.

These cars do not start the pump till cranking starts and this means voltage and current are under lots of stress because you have the starter cranking while the pump is trying to pressurize the fuel system. Running the pump before hand get fuel pressure well established before cranking begins. A weak pump or battery will certainly compromise the ability to establish fuel pressure at startup.

[flatsixjunky]

Hello,

Well, I had my batt and alt bench tested, guess what, rcaradimos and Wayne, you guy's were right, the alt is fine and the batt needs replacement. The testing was done at a Bosch service center. The guy who tested the alt told me that getting 14.4-14.6 at the batt it's pretty normal for these alt's. I then reread what the bentley say's "A reading MUCH HIGHER THAN 14.2..." I guess much higher would mean 15 and up. So I bought a new battery but I have yet to install it because , well, since I had already separated the fan and fan housing I decided to give it a polish. This is how it looks now.



I've been reading the polish fan threads and for the life of me with just a Dremel you can't get those mirror look finish. I know this is a dumb question but who exactly does bead blasting? Where does someone get's that done? I'm going to get 1200 sand paper and give that a try. The fan and the interior of the housing are not that hard because they're smooth surfaces but how do you guy's do the outside of the fan housing?

Thanks for looking,

O-

[scarceller]

The polished fan won't last long because it's magnesium and over time it simply dulls, folks have polished then clear powder coated that helps but still they tend to dull. IMHO you are not going to get that thing to stay polished over time.

[flatsixjunky]

Hello,

Scarceller, thank you for the advice you've given me, I will be changing battery ground, tranny ground strap and I will be checking the ground terminal on cyl #1 intake runner.

About the fan and housing, I know it wont last forever but I would not mind doing it once every 1.5 to two years to keep my engine looking sharp.

About bead blasting, who do I go to if I wanted that done?

Thanks,

O-

[kidrock]

a high-quality auto paint shop will usually have some type of media-blasting equipment.

IMHO, you don't need to bead-blast it. I recently used "Brasso", some rags, and lots of elbow grease to polish my fan and housing. It took about 2 hours, cost next to nothing, and looks great.

I personally wouldn't recommend using a Dremel, Scotch-brite or sandpaper...but that doesn't mean plenty of other guys haven't used them before.

[flatsixjunky]

Hello kidrock,

I won't bead blast this, I'd rather buy new parts with the money. I wish i had "Brasso" here, I remember using that to shine belt buckles when I was a child. I will try to find something similar. I'm not happy with the results, before it was uniformly dirty, now it's not uniformly shiny.

Thanks anyway,

O-