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Problems with my 88 3.2

The other day I started it up, drove about a mile to get gas, after fueling it wouldn't start. Replaced the DME relay the next day, thought I fixed the problem. Today started the car, drove about a mile to home depot, picked up what I needed, once again, the car won't start. I am going to let the car sit for a couple hours and try starting it. Please Help. Thanks Greg
Old 01-10-2008, 03:20 PM
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Check your CHT and/or O2 sensor. Maybe your CHT sensor is failing once it heats up?

The CHT sensor on these cars can create all sorts of drivability issues, especially the single wire CHT sensors.
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Last edited by WydRyd; 01-10-2008 at 08:26 PM..
Old 01-10-2008, 07:06 PM
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3.2 problems

Thanks Merv, fortunatly I have a 2 wire sensor, going to take a hard look at both 02 sensor and CHT sensor. Thanks Greg
Old 01-10-2008, 08:49 PM
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I am pretty sure that the o2 doesnt get factored into the mix untill running temp. The CHT is defenatly somthing that I would look at.
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Old 01-10-2008, 08:58 PM
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3.2 problems

Not sure yet, but I think the problem may have taken out the new DME relay I just put in, maybe a ground problem??
Old 01-10-2008, 09:05 PM
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latest test 3.2 problems

checking grounds, with DME relay plugged in I am showing a ground at 85b, but when I crank engine I am showing OL, should be showing a ground when cranking. Furthermore I was incorrect, my CHT sensor is only a single wire not 2 wire, I looked at the connector and saw 2 wires, only 1 going to sensor. Question is what would cause 85b, on DME relay to loose ground when I crank the motor?
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Quote:
Originally Posted by 930gt-40r View Post
I am pretty sure that the o2 doesnt get factored into the mix untill running temp. The CHT is defenatly somthing that I would look at.
The O2 sensor does have an integrated heating element to bring it up to operating temps quicker for DME input.

Also, the O2 sensor is only really effective at idle and part throttle. At WOT, the DME ignores the input.

Having a dud O2 sensor doesn't really cause the issue you are experiencing Greg. I've run without an O2 sensor for many years and I have no issues whatsoever.

The CHt sensor on the other hand is an integral part of the EFI system. If that goes bad, and they usually do, it can cause all sorts of intermittent issues. Disconnect it from the harness and your car will never start. I would put my money on the CHT sensor going bad as it warms up.

It's a wise idea to remove the old single wire unit and fit a more updated 2 wire sensor. Be warned, it's a pain in the @ss to get to, but well worth the peace of mind of running a new 2 wire unit.
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Old 01-13-2008, 04:00 PM
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Well I replaced the CHT sensor with a new 2 wire one, adjusted speed and ref. sensor, both are new, replaced DME sensor, won't start, no spark to plugs, I might be looking at a DME rebuild. Checked all ground wires, What have I missed, fuel pump is working. Thanks for all the input so far guys, pulling my hair out on this one
Old 01-13-2008, 05:06 PM
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Are you talking about the CDI box in the engine compartment or the "DME" box under the driver's seat? The car will run with out the "DME" box (our cars don't have a DME really).
Old 01-13-2008, 05:27 PM
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I have a 930 Turbo and just got this 88 carrera cab. with a 3.2 in it. If it was my 3.3 I wouldn't have a problem finding the problem, the 3.2 is different though.
Old 01-13-2008, 05:33 PM
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WOW, never heard of complete DME failure in these Carrera's. This would probably be my first

What about swapping out the ignition coil? It's unlikely though, as they typically just fail completely, not intermittently when warm like you describe. Worth a try though and certainly much cheaper than a DME!

Do you know anyone with a Carrera ? Maybe swap out your DME with theirs to rule it out?
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Old 01-13-2008, 05:45 PM
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I will run a test on the coil just to be sure, you never know. There is a Carrera in town and I do know the owner if I can find him, not too many Porsches here in St. George Utah. I have heard of the ground welds in the DME comming loose, will have to send it in to have checked if the coil is O.K., I am just running out of places to look and things to try, you know.
Old 01-13-2008, 08:31 PM
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Coil checked out O.K.. After cranking the motor and no start, I get a high piched beep from the engine compartment, sometimes 3 beeps, anybody know what that is?
Old 01-13-2008, 09:34 PM
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Just read the Title... Sorry about that.
Old 01-14-2008, 06:29 PM
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no problem Rocket, should probably have my head checked for owning 2 Porsches. Ha`Ha, I love them, untill they quit running. Tried another DME, still
no start. So put the car on my auto hauler and took it to my mechanic. Thanks everybody for all your input.
Old 01-16-2008, 10:48 PM
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