 '70 D-jet runs terrible cold, great when warm,, Please share your wisdom |
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| Porsche Rescue |
 Sep 9 2008, 03:45 PM
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Saving and Enjoying Old Porsches  Group: Members Posts: 2,978 Joined: 31-December 02 From: Bend, Oregon Member No.: 64 Region Association: None  |
Car starts when cold (not quickly, but it does start, air temp. 80 degrees), then it is a bitch to keep it going. Once on the road and warmed up it performs beautifully.
I have checked the Aux. Air Valve and it is sucking when cold, plugged when hot. I replaced the head temp sensor even though the old one tested OK. The new one helped a little, but not near enough. I have studied Brad Anders' site and can't come up with any other ideas of what to check. I have to believe the ignition system is fine because it runs so well when warm. I have checked timing and dwell and they are on spec. Any suggestions out there? |
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| Porsche Rescue |
Sep 9 2008, 08:40 PM
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#2
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Saving and Enjoying Old Porsches Group: Members Posts: 2,978 Joined: 31-December 02 From: Bend, Oregon Member No.: 64 Region Association: None |
I will do some ECU checking on Thursday. No time to play tomorrow.
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| Porsche Rescue |
Sep 19 2008, 03:08 PM
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#3
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Saving and Enjoying Old Porsches Group: Members Posts: 2,978 Joined: 31-December 02 From: Bend, Oregon Member No.: 64 Region Association: None |
Took a week, but finally made time to do some more checking.
Removed the ECU plug and did all the Brad Anders resistance checks and everything meets his specs. My ECU is the correct 015 unit for a '70. I replaced the head temp sensor (probably unnecessary). Both old and new are the correct Bosch 012 unit. I have a back-up ECU (037) but I think it requires a different temp sensor and the '73 resistor. My next step is to try a resistor as suggested above. Here's where my ignorance of things electronic really shows. Asked the guy at Radio Shack for a 1/4 or 1/2 watt 270 ohm ballast resistor. All he had was 220 ohms or 330 ohms. Opted for the 220. Word "ballast" is nowhere to be seen. After investing all of 99 cents for 5, I am thinking I don't have the right component. Before wiring one into the sensor line, thought I should check. So, do I have a resistor that might help? And is 220 too far away from 270 ohms?  |
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Posts in this topic
Porsche Rescue '70 D-jet runs terrible cold, great when warm, Sep 9 2008, 03:45 PM
Bartlett 914 Make sure you have the correct CHT and the Correct... Sep 9 2008, 04:36 PM r_towle you could add the 270 Ohm resistor to your CHT lin... Sep 9 2008, 04:54 PM Porsche Rescue Thanks Mark and Rich. Anders mentions the resistor... Sep 9 2008, 06:12 PM r_towle the spare ECU is a 2.0 liter ecu, but from what I ... Sep 9 2008, 07:01 PM
orange914
the spare ECU is a 2.0 liter ecu, but from what I... Sep 9 2008, 08:22 PM Rand Tweaking with resistors is cool and all, but it... Sep 19 2008, 03:32 PM Porsche Rescue My instinct is the same as yours, something else m... Sep 19 2008, 03:57 PM Rav914 CSV? Sep 19 2008, 04:07 PM Porsche Rescue As I understand, CSV only injects at low temp (50 ... Sep 19 2008, 04:12 PM mattillac bad MPS? sticky decel. valve? the AAR might work o... Sep 19 2008, 04:39 PM Rand CSV isn't kicking in at his ambient temps. Dec... Sep 19 2008, 04:48 PM toon1 Does the car back fire on accel before it's wa... Sep 19 2008, 05:40 PM mattillac could this be a bad TPS or need TPS adustment? ano... Sep 19 2008, 07:09 PM Rav914 Didn't know that about the CSV. Subscribed. ... Sep 19 2008, 11:06 PM toon1
could this be a bad TPS or need TPS adustment? an... Sep 20 2008, 12:32 AM Porsche Rescue All who offered help last fall, please see my post... Feb 7 2009, 02:43 PM orange914
All who offered help last fall, please see my pos... Feb 7 2009, 03:32 PM r_towle I will run down the issues that it could be.
The ... Feb 7 2009, 04:05 PM r_towle TPS pic at Idle with flapper closed on throttle bo... Feb 7 2009, 04:08 PM r_towle One more thing
Fuel pressure and new fuel filter.... Feb 7 2009, 04:11 PM Porsche Rescue It pains me to write this..........and Rich Towle,... May 30 2009, 05:54 PM Bleyseng I don't know, its just that if the valves are ... May 31 2009, 09:14 AM |
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