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dan macmillan
Samba Member
Joined: October 19, 2003
Posts: 3110
Location: Northern Ontario, Canada
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 Posted: Wed Jun 17, 2009 3:25 pm Post subject: Bus dies intermittently |
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Thought I would throw this one out there to see if anyone has experienced it.
78 2.0l hydraulic with factory fuel inj.
Engine is mechanically sound.
valves adjusted
new fuel pump, tank drained and cleaned
new fuel filter
fuel pressure good
injectors flow tested
new points, gapped and dwell set to specs
new ign coil
new plugs
new cap
new rotor
new wires
new double relay
new ign switch
airfow meter checked electrically, wiper tracks good
all electrical terminals new
all grounds 100% clean and tight
ground inside dist good
wiggle/tug tested the harnesses
The only things I have not changed are the condenser and temp sensor 2.
Now for the problem
Starts and idles perfectly.
Usually it runs 100%, idles, accelerates and maitains highway speeds up to 70mph. Have not gone faster.
The problem I am having occurs mainly just after a cold start [sits for a few hours, so not necessarily a cold engine, Ambient tems hi 70's to mid 80's.] if I do not let it warm up. If I start the engine and take off right away, after about 5 minutes of driving when accelerating the engine dies. Absolutely nothing on the throttle. It usually restarts on it's own before it would coast to a stop.
The problem is totally intermittent and random.
As a result I have not had enough time to isolate the problem as it self corrects before I can stop the vehicle. I do know that I have power to the coil when this happens.
Any thoughts??
Anyone have a similar problem?
Thanks
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Licensed Automotive Service Technician
Licensed Truck and Coach Technician
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CFC/HCFC/HFC A/C handling and installation license
Alignment specialist
66 Modified Manx,68 Kyote,74 Thing,74 Beetle, 76 Transporter,75 self made Double Cab,65 Meyers Manx,78Westy,68 Ghia, 79 Bradley GT2
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Wild Bill
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Joined: January 02, 2006
Posts: 1013
Location: Pepsi-Cola, Fl
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| Posted: Wed Jun 17, 2009 4:35 pm Post subject: |
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That is just about a new system!
Change out the t2 and condenser to complete the "New" parts in the system.
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"Life in the Fast Lane ?....What the Hell does that feel Like?"
"Wild" Bill Tucker
Pensacola, Fl
1978 Champagne Edition (High Top Camper Converstion.) 2.0L FI
1969 Squareback 2.0L
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SGKent 
Samba Member
Joined: October 30, 2007
Posts: 41031
Location: Citrus Heights CA (Near Sacramento)
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| Posted: Wed Jun 17, 2009 4:49 pm Post subject: |
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if that doesn't get it, see if someone will lend you an ecu for the same year to isolate that as not being the cause. Also - ignition switches can be faulty sometimes. You might rig a test light to the + side of the coil, fuel pump etc so you can see if it is losing power momentarially. Just run some speaker wire soldered to a small bulb and taped. If it goes out at the same time the engine dies that will show you it is an electrical problem. Also fuel pumps can be intermittent sometimes.
My heart goes out for you because these are very hard things to find.
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Randy in Maine
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Joined: August 03, 2003
Posts: 34890
Location: The Beach
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| Posted: Wed Jun 17, 2009 5:35 pm Post subject: |
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| Just out of curiosity, does your AAR have an internal resistance of about 30 ohms? |
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Wild Bill
Samba Member
Joined: January 02, 2006
Posts: 1013
Location: Pepsi-Cola, Fl
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| Posted: Wed Jun 17, 2009 6:07 pm Post subject: |
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Come to think of it I did have a similar event happen to me . The condenser (brand New) had broken free from it's metal bracket. The cheap ass weld was weak. This caused the power to the ecu that controls the firing of the injectors to work intermittent as the condenser would come in contact with the bottom of the dizzy and ground then move and unground.
Double check that condenser and or replace it.
_________________
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Life in the Fast Lane ?....What the Hell does that feel Like?"
"Wild" Bill Tucker
Pensacola, Fl
1978 Champagne Edition (High Top Camper Converstion.) 2.0L FI
1969 Squareback 2.0L
www.rareairvw.com |
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dan macmillan
Samba Member
Joined: October 19, 2003
Posts: 3110
Location: Northern Ontario, Canada
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| Posted: Wed Jun 17, 2009 6:09 pm Post subject: |
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| SGKent wrote: |
if that doesn't get it, see if someone will lend you an ecu for the same year to isolate that as not being the cause. Also - ignition switches can be faulty sometimes. You might rig a test light to the + side of the coil, fuel pump etc so you can see if it is losing power momentarially. Just run some speaker wire soldered to a small bulb and taped. If it goes out at the same time the engine dies that will show you it is an electrical problem. Also fuel pumps can be intermittent sometimes.
My heart goes out for you because these are very hard things to find. |
Been there done that. That is how I know the coil gets power all the time.
I know it is not fuel as it shuts down instantly and restarts instantly. I killed the pump at idle and 2000rpm and it slowly dies as the pressure drops. Spark and or injection will kill it instantly.
| Quote: |
| Just out of curiosity, does your AAR have an internal resistance of about 30 ohms? |
AAR is irrelavent as it is not an idle issue. I have a couple of t4s that the AAR is dead. I have just set the idle to specs warm. Those I have to warm up for about a minute in the colder months.
It did however stumble 2 times at idle, enough to stall the engine. Instantly restarted. The problem does seem to be ign or inj related. I will be trying a temp sensor 2 in the morning I am also going to swap distributors with a know good pointless dist, pertronix, as I do not have a new condenser and the closest one is 500km away. If that does not do it I will change out the ECM. The biggest headace is the fact that it does not do it all the time.
I know that a disconnected Temp Sens 2 will drive the fuel extremely rich. Will a shorted one lean it out enough to kill the engine?
_________________
Licensed Automotive Service Technician
Licensed Truck and Coach Technician
Licensed Heavy Duty Equipment Technician
CFC/HCFC/HFC A/C handling and installation license
Alignment specialist
66 Modified Manx,68 Kyote,74 Thing,74 Beetle, 76 Transporter,75 self made Double Cab,65 Meyers Manx,78Westy,68 Ghia, 79 Bradley GT2
Current projects:
Built for others:69 Manx Clone |
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onion456
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Joined: September 09, 2006
Posts: 674
Location: Houston, TX
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| Posted: Wed Jun 17, 2009 7:01 pm Post subject: |
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x2 ignition switch! happened to me. try jiggling the key. fiddle with the electrical connector at the switch. when it dies next, and youre still coasting, move the key and see if it finds power again.
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'76 Sage Green Westy 2.0 FI
'76 Creamsicle 7-passenger 2.0 CS FI
'85 Tan Westy |
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dan macmillan
Samba Member
Joined: October 19, 2003
Posts: 3110
Location: Northern Ontario, Canada
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| Posted: Thu Jun 18, 2009 3:53 am Post subject: |
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| onion456 wrote: |
| x2 ignition switch! happened to me. try jiggling the key. fiddle with the electrical connector at the switch. when it dies next, and youre still coasting, move the key and see if it finds power again. |
I have already done that many times. Also when it is running normally I have wiggled and tugged on the entire harness from the column to the injectors with no change in rpm, besides monitoring voltage at the coil using a test light shows no power loss from ign switch to coil at any time.
Thanks for the suggestion.
_________________
Licensed Automotive Service Technician
Licensed Truck and Coach Technician
Licensed Heavy Duty Equipment Technician
CFC/HCFC/HFC A/C handling and installation license
Alignment specialist
66 Modified Manx,68 Kyote,74 Thing,74 Beetle, 76 Transporter,75 self made Double Cab,65 Meyers Manx,78Westy,68 Ghia, 79 Bradley GT2
Current projects:
Built for others:69 Manx Clone |
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vw72hippy
Samba Member
Joined: January 08, 2005
Posts: 176
Location: ohio
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| Posted: Thu Jun 18, 2009 5:27 am Post subject: |
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| this is why i like carbs. |
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XXX/Rx/RnR
Samba Member
Joined: March 01, 2008
Posts: 405
Location: valley of the sun
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| Posted: Thu Jun 18, 2009 6:51 am Post subject: |
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| Shorted ignition switch or loose ground. Defective ignition wire. High voltage leak (check for carbon tracks). If condenser was breaking down after getting hot would not restart or would continue to miss. Try the other distributor. Dielectric inspection of the coil case, rotor, condenser and block. Good luck with this one. |
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dacanepa
Samba Member
Joined: October 03, 2009
Posts: 1
Location: Sacramento
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| Posted: Sat Mar 27, 2010 4:00 pm Post subject: |
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| I am having an issue that when my 78 runs for a good while and is fully warmed up it will die.When trying to restart It doesn't even fire at all.I have to wait for it to cool a bit before it will restart. |
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bsairhead
Samba Member
Joined: October 08, 2008
Posts: 3578
Location: viroqua wi.
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| Posted: Sat Mar 27, 2010 4:34 pm Post subject: |
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| Check your rotor for cracks between the center and tip |
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busdaddy
Samba Member
Joined: February 12, 2004
Posts: 51144
Location: Surrey B.C. Canada, but thinking of Ukraine
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| Posted: Sat Mar 27, 2010 5:20 pm Post subject: |
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Try another coil just for fun.
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SGKent
Samba Member
Joined: October 30, 2007
Posts: 41031
Location: Citrus Heights CA (Near Sacramento)
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| Posted: Sat Mar 27, 2010 5:54 pm Post subject: |
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does it die on its own or just not start? Does it turn over when it is hot?
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