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smitch
Samba Member
Joined: April 21, 2004
Posts: 45
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 Posted: Tue Aug 01, 2006 2:14 pm Post subject: engine difficult to start when hot |
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Calling all wierd engine problem gurus. Anyone know what might be the cause of this ? Starts first turn when cold (even after sitting for 2 years !) but after a run it's hard as hell to get started again. Turns over fine on the starter hot and cold. Oil temp gauge reads 190-215 with 40psi oil pressure (20 at idle) I've done very little running so far so I've maybe only started 3 or 4 times when hot, many more OK from cold. Set up is I think a fairly standard mid 70's 1600 TP with 34 PICT carb, electronic ignition on a VW vacuum advance dizzy. 12v alternator in a 64 split. The only thing I've done recently is replace the FACET electric pump with a standard mechanical one and new fuel hoses and gag the auto choke fully open as per John Muir recommend. Can't remember if I ever started it hot with the electric pump fitted, only ran a few times and that was two years ago.
Any ideas ?
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TinCanFab
Samba Member
Joined: April 04, 2006
Posts: 2743
Location: Waterford, California
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| Posted: Tue Aug 01, 2006 2:51 pm Post subject: |
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| try replacing the electronic ignition with points and condensor temporarily. i've had similiar problems and that solved it. |
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Wayland
Samba Member
Joined: December 29, 2005
Posts: 498
Location: Lasqueti Island B.C.
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| Posted: Tue Aug 01, 2006 3:50 pm Post subject: |
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| Try depressing the gas pedal all the way before cranking. Hot soaking (carb pecolating fuel out into the throat) is a very common Vw problem, especially in hot weather. |
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iamdonquixote
Samba Member
Joined: January 28, 2003
Posts: 2041
Location: M*ssholia
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| Posted: Tue Aug 01, 2006 4:22 pm Post subject: |
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| are you using the round brazilian fuel pump? If so the fuel pressure is set too high, for many units out of the box. Fuel pressure should be less than 4psi for sure. High fuel pressure will overfilll the float and cause hard starting that will require the pedal to be completely depressed. You can adjust fuel pressure by adding gaskets. Do a search for fuel pressure. |
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P-Dub
Samba Member
Joined: October 17, 2002
Posts: 1064
Location: Oh, hi!
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| Posted: Tue Aug 01, 2006 4:29 pm Post subject: |
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| Wayland wrote: |
| Try depressing the gas pedal all the way before cranking. Hot soaking (carb pecolating fuel out into the throat) is a very common Vw problem, especially in hot weather. |
I agree with Wayland. I've had this issue with all single carb VW's I've ever owned. |
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Clara 
Samba Member
Joined: June 14, 2003
Posts: 12400
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| Posted: Tue Aug 01, 2006 7:11 pm Post subject: |
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| P-Dub wrote: |
| Wayland wrote: |
| Try depressing the gas pedal all the way before cranking. Hot soaking (carb pecolating fuel out into the throat) is a very common Vw problem, especially in hot weather. |
I agree with Wayland. I've had this issue with all single carb VW's I've ever owned. |
funny, my single carb VWs seem to prefer than I press the gas pedal halfway down as the starter is turning.
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Ragtop
Samba Member
Joined: November 23, 2003
Posts: 615
Location: Rio Rancho New Mexico
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| Posted: Tue Aug 01, 2006 9:06 pm Post subject: |
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| Try adjusting your valves. Tight valves (open) when hot will lower the compression making it hard to start. |
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slow36hp
scott wimberley
Joined: August 09, 2004
Posts: 3113
Location: mukilteo washington
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smitch
Samba Member
Joined: April 21, 2004
Posts: 45
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| Posted: Wed Aug 02, 2006 12:26 pm Post subject: |
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| slow36hp wrote: |
| by hard to start is the starter struggling or is it lack of firing |
lack of firing, starter churns it over fine until the battery begins to loose it. Although I've only triedstarting it hot a couple of time, I was aware of having to press the pedal some. thanks for all your help guys, I'll try some more operating combinations. Don't think the new pump is a Brazil item, I'll check the box it came in. Thanks.
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slow36hp
scott wimberley
Joined: August 09, 2004
Posts: 3113
Location: mukilteo washington
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[email protected]
Samba Member
Joined: September 22, 2002
Posts: 1243
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| Posted: Wed Aug 02, 2006 5:58 pm Post subject: |
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| I have the same problem and I installed a brazilion pump. I just floods it self if left for more than a few min. after 15 it starts right up. In going to try a og fule pump soon to see if this cures it. |
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ratpanel61
Samba Member
Joined: November 04, 2003
Posts: 345
Location: Va Beach, VA
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| Posted: Wed Aug 02, 2006 6:19 pm Post subject: |
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This sounds a lot like what I have going on...2027cc, dual 40mm webers, and electric fuel pump. It starts and runs fine the first time, every time; but when I shut it off, the starter turns fine but it takes a little while to fire again. I was thinking (on mine at least) that maybe I need a fuel pressure regulator to make sure that it's only at the required 3-4psi (it's a Facet pump).
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Friedpotatoes
Addicted4life
Joined: April 04, 2003
Posts: 1215
Location: Fresno California
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| Posted: Thu Aug 03, 2006 3:44 pm Post subject: |
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insted of holding full open i do more of half throttle....works for me
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Humby
Samba Member
Joined: December 28, 2004
Posts: 6
Location: Belgium (Boom)
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| Posted: Fri Aug 04, 2006 3:14 pm Post subject: |
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I have just the same problem...
Cold cranking is perfect, but hot is always a problem.
I think it has something to do with the starter and bad earth connections. Because every time I try to start the hot motor, the earth cable of the battery becomes very, very hot!
Sometimes the starter doesn't turn at all. Just a small "click". It is surely not the battery (it s a new one, bigger, with higher current) and also not the starter (it s the third one that I try)...
It looks like all the current flows to the starter and nothing to the ignition...
When the bus is "push started" (sorry, I don't know the exact word for it) it runs after 2 meters also in very hot conditions... Very, very strange, but I'm sick of it!
Aircooled greetz,
Humby  |
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Yellowbeard
Samba Member
Joined: March 07, 2006
Posts: 2288
Location: At large again...
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| Posted: Fri Aug 04, 2006 4:59 pm Post subject: |
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| Humby wrote: |
I have just the same problem...
Cold cranking is perfect, but hot is always a problem.
I think it has something to do with the starter and bad earth connections. Because every time I try to start the hot motor, the earth cable of the battery becomes very, very hot!
Sometimes the starter doesn't turn at all. Just a small "click". It is surely not the battery (it s a new one, bigger, with higher current) and also not the starter (it s the third one that I try)...
It looks like all the current flows to the starter and nothing to the ignition...
When the bus is "push started" (sorry, I don't know the exact word for it) it runs after 2 meters also in very hot conditions... Very, very strange, but I'm sick of it!
Aircooled greetz,
Humby |
Humby,
Sounds like you need a hard start relay. Cip1 sells 'em. I used an old Ford relay on an early beetle with the same problem. Worked like a charm...
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| Lohe wrote: |
Thanks. Thread went from me not being able to understand what Ipis was saying because English is obviously not his first language to me not being able to understand it because English is my first language  |
Fuel pumps galore:
http://www.thesamba.com/vw/classifieds/detail.php?id=845378 |
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Humby
Samba Member
Joined: December 28, 2004
Posts: 6
Location: Belgium (Boom)
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| Posted: Sat Aug 05, 2006 2:59 am Post subject: |
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| don3751 wrote: |
Humby,
Sounds like you need a hard start relay. Cip1 sells 'em. I used an old Ford relay on an early beetle with the same problem. Worked like a charm... |
Can you give me some extra info about it plz?
Aircooled greetz,
Humby |
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Humby
Samba Member
Joined: December 28, 2004
Posts: 6
Location: Belgium (Boom)
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| Posted: Sat Aug 05, 2006 4:25 am Post subject: |
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I just did a "search" and the world of VW starters is now open for me.
Thanx for the advice!
Aircooled greetz,
Humby |
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Eric&Barb
Samba Member
Joined: September 19, 2004
Posts: 24759
Location: Olympia Wash Rinse & Repeat
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| Posted: Sat Aug 05, 2006 7:25 am Post subject: |
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Hi Volks,
The hot start relay is a bandaid. Better to fix the real problem in the wiring and thusly have a better electrical system overall for brighter lights and faster wipers.
Check voltage from the regulator at about 2,000 RPM or higher. We have seen NOS regulators that have put out 6 volts (for 12 volt system output should be 14 volts) instead of 7 volts. Then check voltage at battery posts, and with that figure check voltage thoughout the wiring system looking for any voltage drop.
Take apart each connection in the wiring to clean, dielectric grease and retighten. Do not forget there are two grounding cables!
Soldering together the fuse box clips in each slot is a must. Check out the headlight switch rebuild in the type2.com library.
If all your electrical system is working properly it could be the one or both of the starter bushings are worn.
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VWBobby
Samba Member
Joined: April 21, 2004
Posts: 1537
Location: Central Oregon Coast
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| Posted: Sat Aug 05, 2006 9:03 am Post subject: |
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1st problem is definitely vapor lock (fuel boiling out of the carb and flooding the engine when hot) OR a bad electronic module...
If you have a clear plastic filter installed in the fuel line near the carb, see if you can spot tiny bubbles boiling inside it when the engine is hot. That's what causes vapor lock and you have to hold the throttle 1/2-full open to get it started again. Try moving the metal fuel line away from the heads/exhaust.
If you check the spark when the engine is hot and turns out it is weak, swap it out with points/condensor.
Clean all your grounds, including the ground strap on the trans. You can actually burn out a solenoid by having a bad ground. It makes the positive wire and solenoid contacts get hot. A bad starter bushing can do the same thing also... |
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Clara
Samba Member
Joined: June 14, 2003
Posts: 12400
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| Posted: Sat Aug 05, 2006 9:24 am Post subject: |
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Sometime sthe hot start issue is a sign the starter is going...you may just need a new starter.
But clean up the battery connections and ground first...that can help, and won't hurt. Use dielectric grease to keep corrosion out of the connections. Is your ground cable frayed?
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