Overfueling when warm

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jmstu76
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Overfueling when warm

Post by jmstu76 » Fri Oct 23, 2015 8:30 am

Hey Guys and Gals,
'76 stock 2.0L bus with L-Jet Injection, hydraulic lifters. Bus is timed correctly and hasn't given any problems in quite some time. Maintained often. Yesterday morning it fired up fine, just a crank or two, never a foot on the gas pedal. idles without a foot on the gas pedal. AAR works and idles down when warm. Drove 30 miles to work no problem. Was in the office for an hour and was given an assignment so out to the bus. Cranks and it tried to catch then nothing. just cranks and cranks, Had someone run the starter with my hand on the fuel pump and it kicked on. Used a spark plug wire and plug and verified spark. Could smell fuel. Checked double relay connections and FI connections. Checked grounds under the intake plenum and connections at the coil. For giggles unplugged the white FI wire from the coil. She cranked for a bit and then slowly caught and coughed. Enough for me to plug the white signal wire back to the coil and manually work the throttle valve and she was back to running.

fast forward to this morning. fired the bus up at 6:45am to take the boy to the bus stop. fired right off. Next set of kids go to the bus stop at 8am. Tried to fire and then nothing, just crank. drive way slopes down so I rolled the bus, popped the clutch and it chugged a bit and fired up.

SOOOO. long story short. On warm start up the last two days I am having a severe enough over fueling to flood or wet the plugs to the point of no fire.

I have tried cranking with the accelerator all the way down and no change.

Thoughts of possible problem areas - Cold Start injector over injecting fuel. Temp II sensor faulty. Thermo Time switch issue?

help please,
James
1976 2.0L FI with Hydraulic lifters

Edmond, OK
(405) 623-2191

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SlowLane
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Re: Overfueling when warm

Post by SlowLane » Fri Oct 23, 2015 10:13 am

At first blush your symptoms seem to indicate a Thermo-Time Switch which isn't opening its contacts when warm.

Quick check: before next trying to fire up your warm engine, pull the electrical connector off of the cold start valve. Try to start the warm engine with the CSV electrically disconnected. If it fires up normally, the TTS is suspect. If it still floods, then suspect a leaky CSV. Either result should lead to further investigation in the appropriate area.

Then again, swapping out the TSII may result in its oft-reported talismanic effect.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Randy in Maine
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Re: Overfueling when warm

Post by Randy in Maine » Fri Oct 23, 2015 11:03 am

Points or pertronics?
79 VW Bus

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jmstu76
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Re: Overfueling when warm

Post by jmstu76 » Fri Oct 23, 2015 12:05 pm

SlowLane wrote:At first blush your symptoms seem to indicate a Thermo-Time Switch which isn't opening its contacts when warm.

Quick check: before next trying to fire up your warm engine, pull the electrical connector off of the cold start valve. Try to start the warm engine with the CSV electrically disconnected. If it fires up normally, the TTS is suspect. If it still floods, then suspect a leaky CSV. Either result should lead to further investigation in the appropriate area.

Then again, swapping out the TSII may result in its oft-reported talismanic effect.
WIll do and will report.
James
1976 2.0L FI with Hydraulic lifters

Edmond, OK
(405) 623-2191

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jmstu76
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Re: Overfueling when warm

Post by jmstu76 » Fri Oct 23, 2015 12:06 pm

Randy in Maine wrote:Points or pertronics?
Comufire
James
1976 2.0L FI with Hydraulic lifters

Edmond, OK
(405) 623-2191

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Amskeptic
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Re: Overfueling when warm

Post by Amskeptic » Fri Oct 23, 2015 7:01 pm

SlowLane wrote:If it still floods, then suspect a leaky CSV. Either result should lead to further investigation in the appropriate area.

Then again, swapping out the TSII may result in its oft-reported talismanic effect.
A physically leaky CSV would also give acrid eye-watering sooty exhaust at all times.

TS-II sensor resistance would be interesting. Start by checking to see that it is firmly seated. Then read cold ohms (2,500 ohms @ 68*, slightly more when colder, dropping off as it gets warmer) Check wiring for any broken insulation, shorts, etc.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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jmstu76
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Re: Overfueling when warm

Post by jmstu76 » Sat Oct 24, 2015 9:33 pm

Amskeptic wrote:
SlowLane wrote:If it still floods, then suspect a leaky CSV. Either result should lead to further investigation in the appropriate area.

Then again, swapping out the TSII may result in its oft-reported talismanic effect.
A physically leaky CSV would also give acrid eye-watering sooty exhaust at all times.

TS-II sensor resistance would be interesting. Start by checking to see that it is firmly seated. Then read cold ohms (2,500 ohms @ 68*, slightly more when colder, dropping off as it gets warmer) Check wiring for any broken insulation, shorts, etc.
Colin
Check for broken insulation on the engine wiring harness or around the TEMP II, CSV and/or the thermotime switch?
James
1976 2.0L FI with Hydraulic lifters

Edmond, OK
(405) 623-2191

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jmstu76
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Re: Overfueling when warm

Post by jmstu76 » Sat Oct 24, 2015 9:36 pm

This morning when cold it fired right off and idled wonderfully. Drove wonderfully. It did start sometimes when warm without an issue, and then it didn't. I unplugged the CSV and and it chugged back to life, then ran fine.

My question is this. Just because I unplugged the CSV doesn't necessarily make it bad correct? It could still be a bad Thermo time switch or possibly something else.

Does anyone have information on how long a CSV should fire when cold and how long if at all it should fire when warm?

With a helper and a test light, It would be nice to physically see what that lil sucker is doing while trying to start.
James
1976 2.0L FI with Hydraulic lifters

Edmond, OK
(405) 623-2191

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Randy in Maine
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Re: Overfueling when warm

Post by Randy in Maine » Sun Oct 25, 2015 5:25 am

The CSV only gives you about an 8 second ride when cold. There should be nothing when the TTS is warm.

About the same as riding a bull at the rodeo.
79 VW Bus

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Randy in Maine
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Re: Overfueling when warm

Post by Randy in Maine » Sun Oct 25, 2015 5:58 am

If it were me, I think I would want to do a little elimination of possibles.

When it won't start, stick on your dwell meter to the coil and see if you get a signal. With a points replacement module it won't be a real signal (like a dwell angle of 47º) but it will give you something as opposed to no signal. You can test it in your driveway when cold so you will have a reference.

Usually a points replacement module either works or it doesn't. Here is the test. http://www.ttalk.info/Tech/PerNegGndTest.htm
They hate "dirty voltage" though. If you think yours may be the problem, just swap in your spare set of points and condenser and re-time the engine and see if that fixes the problem. A dying coil can also do that although I have never had one go bad. I always use the Bosch blue ones.

My buddy down the street was using 40 year old points as opposed to new ones ("new ones are not as good" he kept saying) and had the same no start situation until he changed them and it was likely a condenser that did not want to condense anymore.

Using your volt ohm meter (for both continuity and for resistance) test the engine wiring harness where the CSV, TTS, AAR, and TSII plug in and also at the ECU "big plug. Not only should you clean all of the connections as you do this but also examine to ensure one of the "pins" at the "big plug/ECU have not been "pushed in".

Make 100% sure that the electrical connections are indeed going to the right component also. Somebody will be along in a minute to confirm but I THINK it is CSV= blue, TTS = brown, and AAR =black. You would not be the first person to have ever have mixed them up.

More important that the initial TTSII reading is the fact that the resistance should change smoothly as the engine warms up in your driveway with your ohm meter plugged into the wiring harness where the TTS plugs into the engine wiring harness connection.

Report back your findings.
79 VW Bus

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Amskeptic
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Re: Overfueling when warm

Post by Amskeptic » Sun Oct 25, 2015 9:23 am

jmstu76 wrote:This morning when cold it fired right off and idled wonderfully. Drove wonderfully. It did start sometimes when warm without an issue, and then it didn't. I unplugged the CSV and and it chugged back to life, then ran fine.

My question is this. Just because I unplugged the CSV doesn't necessarily make it bad correct? It could still be a bad Thermo time switch or possibly something else.

Does anyone have information on how long a CSV should fire when cold and how long if at all it should fire when warm?

With a helper and a test light, It would be nice to physically see what that lil sucker is doing while trying to start.
If you have a leaky CSV, you would *expect* a champion cold start, because that is when the CSV is supposed to work.
"and then it didn't" you wrote. Does that mean it did not start when warm? And then it did "chug back to life" when you unplugged the cold start valve?

Be specific here, jmstu76 . . . .

NOW THEN, record into your memory the following:

The cold start valve is only given voltage when key is in "start" position. That only gives the *opportunity* for cold start operation.
The actual cold start activation rests solely with the thermo-time switch, it provides the needed ground.
It grounds for 11 seconds in subzero temperatures, and it grounds for barely a half second at 60*.

Once the engine is running, the cold start valve/thermo-time switch are dormant.
The only way the cold start valve could be a problem on a running engine is if it has a physical leak.
If the thermo-time switch is grounded permanently by some internal failure, it may give you difficult starts when the engine is warm, and you'd clean that right up just by unplugging it.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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jmstu76
Getting Hooked!
Location: Edmond, Oklahoma
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Re: Overfueling when warm

Post by jmstu76 » Sun Oct 25, 2015 7:32 pm

Amskeptic wrote:
jmstu76 wrote:This morning when cold it fired right off and idled wonderfully. Drove wonderfully. It did start sometimes when warm without an issue, and then it didn't. I unplugged the CSV and and it chugged back to life, then ran fine.

My question is this. Just because I unplugged the CSV doesn't necessarily make it bad correct? It could still be a bad Thermo time switch or possibly something else.

Does anyone have information on how long a CSV should fire when cold and how long if at all it should fire when warm?

With a helper and a test light, It would be nice to physically see what that lil sucker is doing while trying to start.
If you have a leaky CSV, you would *expect* a champion cold start, because that is when the CSV is supposed to work.
"and then it didn't" you wrote. Does that mean it did not start when warm? And then it did "chug back to life" when you unplugged the cold start valve?

Be specific here, jmstu76 . . . .

NOW THEN, record into your memory the following:

The cold start valve is only given voltage when key is in "start" position. That only gives the *opportunity* for cold start operation.
The actual cold start activation rests solely with the thermo-time switch, it provides the needed ground.
It grounds for 11 seconds in subzero temperatures, and it grounds for barely a half second at 60*.

Once the engine is running, the cold start valve/thermo-time switch are dormant.
The only way the cold start valve could be a problem on a running engine is if it has a physical leak.
If the thermo-time switch is grounded permanently by some internal failure, it may give you difficult starts when the engine is warm, and you'd clean that right up just by unplugging it.
Colin
I apologize for not being clear. When I said "and then it didn't" I should have typed that it did not start at all when warm. Again today it fired up perfectly when cold. Upon arrival at the house, I backed it up onto my ramps to adjust the clutch and shut it off. I immediately tried to fire it back up just to see if it would and it did not start. I unplugged the CSV and ran the starter and it caught and coughed and chugged until I gave it enough gas to clear itself out.

I have other used Thermotime switches and I believe I have a new one. I do believe that switch is buried under the plenum though.
James
1976 2.0L FI with Hydraulic lifters

Edmond, OK
(405) 623-2191

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Amskeptic
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Re: Overfueling when warm

Post by Amskeptic » Mon Oct 26, 2015 5:51 am

jmstu76 wrote: it did not start at all when warm.
today it fired up perfectly when cold.
unplugged the CSV and it caught
Thermotime switch.
Yes. I believe so. Do not be put off by all the whine babies who mewl piteously that they cannot reach the thing. You need two ratchets, two extensions, two 13mm sockets (or a 1/2" socket as the other). Merely remove the correct case through bolt and nut, and it will slip out easily enough. It has a brown plug. Make sure the brown plug is the plug you have. I have seen engines where the black AAR plug was in its stead. Know what the symptoms were? Yeah. That ^
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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