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Acceleration Junkie
 
Join Date: Aug 2007
Location: Laguna Beach, CA
Posts: 263
Garage
Quote:
Originally Posted by x98boardwell View Post
As usual, a ton of knowledge and great advice packed into one paragraph. You are welcome to come to Fresno and drive my car anytime if you miss it too much. Or heck, why not an automatic?

Be well,
Bryan
Thanks Bryan.
Wish I truly had a ton of knowledge. I know about the TTS because I started with a bare bones 930 engine without wires. Good news is I got the engine to run and the alternator to charge. Overboost switch? What overboost switch? Life on the edge. . .
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Chris Toy
356-930 Gone
Old 09-25-2009, 08:19 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #21 (permalink)
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Join Date: Jul 2009
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356-930 ,

My mechanic & I are debating because I told him that the TTS when the engine is hot the TTS does not turn on the CSV.But my mechanic objected because how come when the CSV is connected and he tries to the start the engine when the car has been shut down 30 mins after is having difficulty starting but when he disconnects the CSV the car starts immediately.He had ruled out fuel issues because when the CSV is connected and repeated crankings are done he could smell raw fuel in the exhaust. He is thinking more that the car might have a weak spark when the engine is hot because when the car is flooded because of repeated crankings the car refuses to start. The mechanic said that the CSV might be spraying fuel even when the car is hot thereby flooding it.The car simply refuses to start when its flooded.But when the CSV is immedately disconnected the car will sputter probably bec. of the flooding then it will settle to a nice idle.Do you have a wiring diagram of the TTS how its connected to the CSV or better yet a site were I can download the wiring diagram of the 89 930,so we can end my debate w/ my mechanic or at least we can diagnose & correct if theres a wrong connection.The forum has been very helpful and I hope somebody in the future will benefit from this discussion.

thanks in advace,

TDH 888
Old 09-26-2009, 06:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #22 (permalink)
one of the great unwashed
 
patkeefe's Avatar
 
Join Date: Apr 2004
Location: Ringwood, NJ
Posts: 2,851
If the symptoms are what you say they are, then the CIS system is wired incorrectly. Alas, I do not have wiring diagram for your MY.

If your CIS is wired correctly, you will not allow fuel pumps to run with the throttle plate closed, so you cannot possibly flood the engine with fuel. Although all of my experience is with SC n/a CIS modded for turbo use, all CIS is principally the same. Do a search for spark conditions by Early_S_Man (Warren was the king of electronic ignition diagnostics). Also, find the CIS Primer by Jim Williams, which will give you a good understanding of CIS.

I also maintain you cannot possibly troubleshoot CIS without a CIS pressure gauge, period.

Oh, and check for unmetered air entering the system.
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Patrick E. Keefe
78 SC
01 Boxster

Last edited by patkeefe; 09-26-2009 at 06:43 PM.. Reason: forgot something
Old 09-26-2009, 06:38 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #23 (permalink)
Acceleration Junkie
 
Join Date: Aug 2007
Location: Laguna Beach, CA
Posts: 263
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Quote:
Originally Posted by TDH888 View Post
356-930 ,

My mechanic & I are debating because I told him that the TTS when the engine is hot the TTS does not turn on the CSV.But my mechanic objected because how come when the CSV is connected and he tries to the start the engine when the car has been shut down 30 mins after is having difficulty starting but when he disconnects the CSV the car starts immediately.He had ruled out fuel issues because when the CSV is connected and repeated crankings are done he could smell raw fuel in the exhaust. He is thinking more that the car might have a weak spark when the engine is hot because when the car is flooded because of repeated crankings the car refuses to start. The mechanic said that the CSV might be spraying fuel even when the car is hot thereby flooding it.The car simply refuses to start when its flooded.But when the CSV is immedately disconnected the car will sputter probably bec. of the flooding then it will settle to a nice idle.Do you have a wiring diagram of the TTS how its connected to the CSV or better yet a site were I can download the wiring diagram of the 89 930,so we can end my debate w/ my mechanic or at least we can diagnose & correct if theres a wrong connection.The forum has been very helpful and I hope somebody in the future will benefit from this discussion.

thanks in advace,

TDH 888
"My mechanic & I are debating because I told him that the TTS when the engine is hot the TTS does not turn on the CSV." True, provided the TTS is working right.
". . . how come when the CSV is connected and he tries to the start the engine when the car has been shut down 30 mins after is having difficulty starting but when he disconnects the CSV the car starts immediately." Because the CSV is getting turned on when the engine is hot and it's not supposed to get turned on.
"The car simply refuses to start when its flooded. But when the CSV is immediately disconnected the car will sputter probably bec. of the flooding then it will settle to a nice idle." Remove extra fuel source (via CSV) engine starts. Sure sign of excess fuel.

The CSV is not supposed to be spraying fuel when the engine is hot. (Smelling raw fuel, unplugging it, getting the engine to start without it plugged in is a sure sign the CSV is adding fuel when it should not).
If the CSV is spraying fuel when attempting to start the engine when it is hot, either the TTS is bad or the lead from the TTS to the CSV (or the CSV itself) is shorted to ground. Again, the CSV is supposed to add fuel only when the engine is cold.
I don't have a wiring diagram but here's how it works. You can trouble shoot with a volt meter. There is an auxiliary terminal on the starter motor that gets 12V applied to it only when the starter motor is engaged. The "hot side" of the TTS and one side of the CSV are tied to this terminal/to each other, i.e. they are common. The second terminal of the TTS is grounded (when cold) and is wired to the second terminal of the CSV. When the starter motor's auxiliary 12V terminal gets turned on, (during cranking only) the CSV flows fuel as long as the TTS’s ground lug remains grounded, 10-seconds or less when cold. The lug should not be at ground when the engine is hot. It should not be at ground after extended period of cranking.
Make sure that 12V is Not present on the TTS or the CSV when the ignition is “on.” The TTS should see 12V only when cranking.
Now, disclaimer. This is how a ’79 930 CIS fuel/start system works. Perhaps as Pat Keefe notes, your model/year could be different?
You must be getting fuel pressure of some measure or no fuel smell when hot.
And do get a CIS fuel control pressure gage set. No more guessing at some of these fueling problems.
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Chris Toy
356-930 Gone
Old 09-26-2009, 09:29 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #24 (permalink)
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Posts: 130
Quote:
Originally Posted by 356-930 View Post
"My mechanic & I are debating because I told him that the TTS when the engine is hot the TTS does not turn on the CSV." True, provided the TTS is working right.
". . . how come when the CSV is connected and he tries to the start the engine when the car has been shut down 30 mins after is having difficulty starting but when he disconnects the CSV the car starts immediately." Because the CSV is getting turned on when the engine is hot and it's not supposed to get turned on.
"The car simply refuses to start when its flooded. But when the CSV is immediately disconnected the car will sputter probably bec. of the flooding then it will settle to a nice idle." Remove extra fuel source (via CSV) engine starts. Sure sign of excess fuel.

The CSV is not supposed to be spraying fuel when the engine is hot. (Smelling raw fuel, unplugging it, getting the engine to start without it plugged in is a sure sign the CSV is adding fuel when it should not).
If the CSV is spraying fuel when attempting to start the engine when it is hot, either the TTS is bad or the lead from the TTS to the CSV (or the CSV itself) is shorted to ground. Again, the CSV is supposed to add fuel only when the engine is cold.
I don't have a wiring diagram but here's how it works. You can trouble shoot with a volt meter. There is an auxiliary terminal on the starter motor that gets 12V applied to it only when the starter motor is engaged. The "hot side" of the TTS and one side of the CSV are tied to this terminal/to each other, i.e. they are common. The second terminal of the TTS is grounded (when cold) and is wired to the second terminal of the CSV. When the starter motor's auxiliary 12V terminal gets turned on, (during cranking only) the CSV flows fuel as long as the TTS’s ground lug remains grounded, 10-seconds or less when cold. The lug should not be at ground when the engine is hot. It should not be at ground after extended period of cranking.
Make sure that 12V is Not present on the TTS or the CSV when the ignition is “on.” The TTS should see 12V only when cranking.
Now, disclaimer. This is how a ’79 930 CIS fuel/start system works. Perhaps as Pat Keefe notes, your model/year could be different?
You must be getting fuel pressure of some measure or no fuel smell when hot.
And do get a CIS fuel control pressure gage set. No more guessing at some of these fueling problems.
Thanks Patrick & Chris will suggest this to my mechanic.
Old 09-27-2009, 06:47 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #25 (permalink)
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Join Date: Jul 2009
Posts: 130
Vapor lock problem solved

To all who responded and gave advices to this thread ,

Thank you very much. The mechanic & I were able to solve the vapor lock problem. We replaced the fuel accumulator and ignition coil w/c I got from pelican parts and the problem solved .Starts everytime hot or cold. The fuel accumulator I ordered is part no.911 110 197 01 instead of 911 110 197 02. The 01's physical dimensions is markedly smaller than the 02's.The reason I ordered the 01's instead of the 02's is because of the price difference. My mechanic was able to install it w/out any difficulty including the clamps but w/ some minor repositoning of the fuel hoses.I tested the car the whole day and the car starts everytime (15, 30 mins, sometimes 1-2 hour intervals). I will take the car for a 15 mins drive in the super hi way tomorrow mid day (when the weather here in our country is at its hottest) for further testing.Has anybody tried using the 01's instead of the correct for my model year (1989) 02's?

thanks again for your help,

tdh888
Old 10-26-2009, 06:19 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #26 (permalink)
 
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