Camper Special - won't idle when cold (video)

MadMax78

78 2.0l fuel injected, Mallory ignition, Webcam camshaft, solid lifters

I have made a little video of my starting problems. When the bus is cold it starts like this and I can only keep it running by working the throttle. After about 1 or 2 minutes it will idle just fine.

This is a rebuilt engine, pretty much everything is new except the EFI components. Before installing I tested both the auxilary air regulator and the thermo time switch ok. Only thing I didn't test is the cold start valve. The AAR adjustment was set to full open when cold, maybe this is a problem... I also checked the vacuum lines by spraying some starting gas on them, no leaks found.

I guess it would be weird if the CSV is causing this since it should stop after a couple of seconds if it was. Other option would be that the CSV never stops injecting fuel...

Maybe it's something totally different, I hope you can give me some pointers by watching the video. The engine has about 150 miles on it now and this problem started at the fourth startup, first three startups were just fine. Quite odd...

Startup when cold, engine stalls after a while, restarts, kept the rpm's a little higher on the next run.

Link

Thanks in advance for any help
_________________
1978 T2b ASI Riviera Plan I // Camper Special with MegaSquirt Injection & Ignition // 091 with 5.14 R/P and Peloquins LSD
Powered by Just Kampers, German Supply , Busted Bus, Aircooled Technology & DIYAutoTune
2008: Amsterdam - Beijing - Olympics -- 17.500km
2010: Amsterdam - Cape Town - FIFA World Cup -- 26.000km
2014: New York - Rio de Janeiro - FIFA World Cup -- 27.000km
http://www.oranjetrophy.nl
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Camper Special Club Member

MadMax78 · Posted: Thu Apr 24, 2008 5:15 am Post subject:

Anyone?
_________________
1978 T2b ASI Riviera Plan I // Camper Special with MegaSquirt Injection & Ignition // 091 with 5.14 R/P and Peloquins LSD
Powered by Just Kampers, German Supply , Busted Bus, Aircooled Technology & DIYAutoTune
2008: Amsterdam - Beijing - Olympics -- 17.500km
2010: Amsterdam - Cape Town - FIFA World Cup -- 26.000km
2014: New York - Rio de Janeiro - FIFA World Cup -- 27.000km
http://www.oranjetrophy.nl
******************************************
Camper Special Club Member

fukengruvenoval · Posted: Thu Apr 24, 2008 5:27 am Post subject:

My suggestion would still be vacuum leak... Is the crankcase breather hose hooked up? Is the brake booster hose connected? Is the brake booster leaking? Did you block off the EGR connection? Is that leaking? Is your throttle body tight agains the manifold? These are all areas I still had leaks, despite being very careful when installing my FI. It seems to me the system is losing air somewhere after the AFM, preventing a proper idle.

Having the AAR wide open is good. That should give you a nice, fast idle at start up.

What is your timing set at? The engine seems to be struggling, I wonder if the timing is too retarded?

Perhaps you can post a picture of the engine, up close, in case there is anything obvious missing...
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Check out my video series at www.youtube.com/midnightoilgarage

MadMax78 · Posted: Thu Apr 24, 2008 5:43 am Post subject:

Crankcase breather is hooked up, brake booster is connected, didn't test the connection for leaks though. Booster could be leaking, but unlikely since it works fine and didn't cause problems on the old engine. I made a blockoff plate for the EGR system and used a new gasket for a good seal. Throttle body also has a new rubber seal and should be tight.

Timing is set to 28 deg. BTDC @ 3500 rpm.

I don't have a "top view" picture of the engine installed. I installed all the hoses per Ratwell's vacuum article, so all should be in place. I did make one modification to the system though...
Since the Mallory does not need vacuum advance I connected the throttle body's vacuum connection to the air box vacuum connection directly, without the T that would normally go to the dizzy. Could this be a problem?
_________________
1978 T2b ASI Riviera Plan I // Camper Special with MegaSquirt Injection & Ignition // 091 with 5.14 R/P and Peloquins LSD
Powered by Just Kampers, German Supply , Busted Bus, Aircooled Technology & DIYAutoTune
2008: Amsterdam - Beijing - Olympics -- 17.500km
2010: Amsterdam - Cape Town - FIFA World Cup -- 26.000km
2014: New York - Rio de Janeiro - FIFA World Cup -- 27.000km
http://www.oranjetrophy.nl
******************************************
Camper Special Club Member

fukengruvenoval · Posted: Thu Apr 24, 2008 5:47 am Post subject:

All I can suggest is you check everything again, very carefully. There are an amazing number of connections that need to be tight and not leaking to get a smooth engine. Are the connections to the S-boot tight? Have you checked the S-boot for cracks?

Are your intake runners torqued to the heads properly?

Eliminating the "T" for the vacuum advance shouldn't be a problem.
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Check out my video series at www.youtube.com/midnightoilgarage

MadMax78 · Posted: Thu Apr 24, 2008 6:08 am Post subject:

Intake runners are torqued to spec. The S boot could be a problem, I had 3 boots and picked the best one. It didn't show cracks when bending it back and forth a little. I didn't do a leak test on it though.

I'll bury my head in the engine bay for a while and go over all these connections again and see if I can find anything.

Thanks for the pointers!

Oh, btw, the engine makes a kind of hissing sound which you can clearly hear before it stalls at around 26 sec. Is this a normal sound?
_________________
1978 T2b ASI Riviera Plan I // Camper Special with MegaSquirt Injection & Ignition // 091 with 5.14 R/P and Peloquins LSD
Powered by Just Kampers, German Supply , Busted Bus, Aircooled Technology & DIYAutoTune
2008: Amsterdam - Beijing - Olympics -- 17.500km
2010: Amsterdam - Cape Town - FIFA World Cup -- 26.000km
2014: New York - Rio de Janeiro - FIFA World Cup -- 27.000km
http://www.oranjetrophy.nl
******************************************
Camper Special Club Member

barryben · Posted: Thu Apr 24, 2008 6:27 am Post subject:

that looks and sounds exactly like the problem I had with a split AAR L boot. AAR itself was fine, just the boot was split at the end where it connects to the AAR and wouldn't hold a vacuum. After 3-4 minutes or so (when the AAR closes off) the engine would run much better.

Now replaced boot (German Supply) - all is well Cool

RE: the hissing sound - I think someone's mentioned that before on here, it sounds like it's the air being dispersed through the plenum, nothing to worry about.
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1978 2.0i kombi from Sweden

germansupplyscott · Posted: Thu Apr 24, 2008 7:45 am Post subject:

i don't think it is a leak. tight engine maybe and to me it sounds like it could be running rich at idle but it cleans up off idle. i have had injected engines that needed a small hole in the throttle plate to idle well. some original plates had holes in them, i've swapped out a holed plate and solved this in the past.
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SL

[email protected] · Posted: Thu Apr 24, 2008 8:22 am Post subject:

Bursch · Posted: Thu Apr 24, 2008 10:20 am Post subject:

Jake Raby · Posted: Thu Apr 24, 2008 11:16 am Post subject:

Why is this not posted on my support forums?? Use the tools we give you, or lose them!

That said, I question fuel pressure stability (which must be verified) as well as the fact that your T/B may not have the hole in the butterfly and the idle speed screw can't move enough air for the better breathing engine to idle...
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

MadMax78 · Posted: Thu Apr 24, 2008 3:46 pm Post subject:

Randy in Maine · Posted: Thu Apr 24, 2008 4:10 pm Post subject:

And your vacuum supply is set up pretty much like this?

Image may have been reduced in size. Click image to view fullscreen.

regis101 · Posted: Thu Apr 24, 2008 5:00 pm Post subject:

Make sure the coil is wired correctly or change it for a known good one.
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Peace, Regis

MadMax78 · Posted: Fri Apr 25, 2008 2:05 am Post subject:

Just went to my local garage to get some CO readings. Appeared that the engine was running far too rich. Getting up to about 7% CO. At cold start this would probably be around 10% and this may have been the cause of the starting issues.

I richened the AFM a couple of days ago because the engine was a little hot. Had to reset the AFM to where it came from and also move the wiper arm a little leaner. Values now are:

@930 RPM
1,58% CO, AFR 1,26

@2000 RPM
2,00% CO, AFR 0,98

@3500 RPM
2,9% CO, AFR 0,93

The engine now is running quite hot, CHT goes up to 390 at 55 mph... with an ambient temperature of only 65 F. Jake, could the engine be relatively hot because it isn't broken in yet?

I'll start it up in a couple of hours and see if it will start better now.
_________________
1978 T2b ASI Riviera Plan I // Camper Special with MegaSquirt Injection & Ignition // 091 with 5.14 R/P and Peloquins LSD
Powered by Just Kampers, German Supply , Busted Bus, Aircooled Technology & DIYAutoTune
2008: Amsterdam - Beijing - Olympics -- 17.500km
2010: Amsterdam - Cape Town - FIFA World Cup -- 26.000km
2014: New York - Rio de Janeiro - FIFA World Cup -- 27.000km
http://www.oranjetrophy.nl
******************************************
Camper Special Club Member

Jake Raby · Posted: Fri Apr 25, 2008 6:59 am Post subject:

mycoleptodiscus · Posted: Fri Apr 25, 2008 10:52 am Post subject: Problem

Valve adjustments? Valves too tight? I put in the cromoly pushrods and swivel foot adjusters and set up everything perfectly. It idled for shit cold with the "zero lash" Jake spec's. I set it to 0.006" (factory) and it was much better. Also keep in mind that after starting a few times, parts can seat themselves a bit so, again, your valve adjustments could be off.
_________________
1978 VW Westfalia
Blueprinted & Balanced 2.0l FI
Automatic Transmission
104,400 miles

Jake Raby · Posted: Fri Apr 25, 2008 10:59 am Post subject:

All that lash is killing your valve train at temperature, lash beats valve seats to death and KILLS chamber filling and delays valve timing events- the engine is hot a lot longer than it is cold!

I have never experienced more stable idle speeds with more/ less valve lash.
the most I ever run with Manton pushrods for lash is a tight .002
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

Randy in Maine · Posted: Fri Apr 25, 2008 11:13 am Post subject:

If you think the AAR is the problem, see what happens if you by pass the whole thing with some duct tape at the air plenum and a cork in the S boot.

If it runs well when warm, you know the problem is in the AAR.

Internal resistance in the AARheating element should be 30 ohms between the terminals and it derives its power from the starter terminal #30 (I think but double check that). Some of them have a screw to adjust how far the little round door opens.

Bursch · Posted: Fri Apr 25, 2008 4:33 pm Post subject:


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Camper Special - won't idle when cold (video)
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