metalmonkey47 Posted March 30, 2012 Report Share Posted March 30, 2012 (edited) This is NOT my truck (obviously) but I'm trying to help diagnose a funny noise. Sounds like a dying squirrel under the hood. We searched all over for vacuum leaks but weren't able to locate any. The truck runs fantastic, makes plenty of power, and doesn't even hesitate to leave you behind. (Ignore the backfire in the vid. That was prior to a timing adjustment) The truck is L18 w/ Weber and a shortie header. We were able to narrow down using a medical grade stethoscope that the sound is coming from the secondary barrel on the driver side under the idle jet. http://www.youtube.com/watch?v=MDUYCXgigyw Edited March 30, 2012 by metalmonkey47 Quote Link to comment
banzai510(hainz) Posted March 30, 2012 Report Share Posted March 30, 2012 carb adapter tight Whats that canister on the intake? Maybe a diaprham in that has a hole and is making the whistle. make sure the 2nd barrel is fully closed. at idle the 2nd barrel should be fulley closed. Sometimes the spring that keeps the 2nd barrel falls off but this wiyuld cause idle proplems. If you think its the 2nd barrel open the aircleaner and get motor running and open the 2nd barrel by passing the 1st barrel to keep it running. see what it does. Isolate the proplem from there. Quote Link to comment
datzenmike Posted March 30, 2012 Report Share Posted March 30, 2012 PCV valve hose is off. That's the air being sucked in. Quote Link to comment
datsunaholic Posted March 30, 2012 Report Share Posted March 30, 2012 Some Webers have a BIG vacuum port on the back, on the secondary barrel. I had the cap blow off mine and then came the high-pitched squeal of air being sucked in. Fortunately I found the cap in the parking garage the next day. Then I fixed the backfiring problem (which was a loose tach lead grounding out the ignition against the brake pedal). Quote Link to comment
TENDRIL Posted March 31, 2012 Report Share Posted March 31, 2012 when i replaced my mounting gasket on my webby i didn't tighten 1 corner nut and it squealed just like that but, did you just replace anything on the carb where you had to take it off the mani? Quote Link to comment
metalmonkey47 Posted March 31, 2012 Author Report Share Posted March 31, 2012 Thanks for the suggestions guys. I'm gonna do some looking over it soon and post back. Gonna look into all of that for sure and get back to you, since I don't know much about it as of right now! Quote Link to comment
metalmonkey47 Posted May 10, 2012 Author Report Share Posted May 10, 2012 So here we go... truck no longer runs. He was on the way back home with it and it stopped running. We've verified spark and fuel. When it runs, it runs like shit an backfires out the carb like mad. We have seen 3 foot fireballs out of the carb. The squealing got louder, but is probably unrelated. We tore the Weber apart and didn't find anything out of the norm to cause the squealing. According to him, when he got out and checked the truck, the distributor was loose. We played with timing a bit but it still doesn't run. I personally think the the distributor when it was loose lifted up enough for the shaft to skip a tooth or two on the distributor and leave timing WAY retarded. We played with it last week, but I haven't had a chance to get back out there and help him. Thoughts? Quote Link to comment
izzo Posted May 10, 2012 Report Share Posted May 10, 2012 that spindle shouldn't skip a tooth, unless the oil pump was off. IIRC there just isn't enough room for it to move up far enough to do that. But its been a year or two since I've tossed an L together..... Quote Link to comment
banzai510(hainz) Posted May 10, 2012 Report Share Posted May 10, 2012 Distributors on L motors cant skip a tooth.its a slot. How about pull the distribtor and see if it spins ok Quote Link to comment
metalmonkey47 Posted May 10, 2012 Author Report Share Posted May 10, 2012 that spindle shouldn't skip a tooth, unless the oil pump was off. IIRC there just isn't enough room for it to move up far enough to do that. But its been a year or two since I've tossed an L together..... Distributors on L motors cant skip a tooth.its a slot. How about pull the distribtor and see if it spins ok OOPS I'm still thinking A-Series! The bolt was long gone when he got back to it so It could have easily lifted up enough for it to spin 180 degrees on the slot, leaving the timing WAY off. I need to get back over there and do some more looking at it. Quote Link to comment
metalmonkey47 Posted May 14, 2012 Author Report Share Posted May 14, 2012 Still looking. Ignition timing is out the door here. We've tested the distributor by swapping a new one since it was available and we've gotten no change. I'm thinking cam timing is the next possibility. Slack on the timing chain allowing it to skip a tooth? I don't have much experience here, so anymore advice is appreciated. What can I do to check this? I'm valvetrain ignorant and I know nothing about 'timing marks' and all that good stuff. Quote Link to comment
Laecaon Posted May 14, 2012 Report Share Posted May 14, 2012 Pull the valve cover off. Turn motor til crank is at TDC, and cam lobes of cylinder 1 are just about at 10&2. Look at the timing marks at the cam sprocket to the cam retaining plate. Crank at TDC Cam at TDC roughly Timing marks Backfiring and afterfiring is quite odd and I would say there is some wonky ignition stuff, my did this when the condenser went out. Fuel or mechanical timing should be consistently either back or after fire, not both. Quote Link to comment
banzai510(hainz) Posted May 14, 2012 Report Share Posted May 14, 2012 Persoanlly if this was working and then the squealling started, I highly dought a cam timming movement change. Quote Link to comment
metalmonkey47 Posted May 20, 2012 Author Report Share Posted May 20, 2012 Cam timing probably wasn't it. I looked at it today, and he has NO spark now. He's replaced the dizzy and coil under warranty. He has 12V @ ignition, and at dizzy (points dizzy) + has about 8V iIRC. No spark from coil though. We removed the condenser just on a whim to see if it was possibly a DOA part. No change. Quote Link to comment
datzenmike Posted May 20, 2012 Report Share Posted May 20, 2012 OOPS I'm still thinking A-Series! The bolt was long gone when he got back to it so It could have easily lifted up enough for it to spin 180 degrees on the slot, leaving the timing WAY off. I need to get back over there and do some more looking at it. Again the dizzy can only fit the spindle in one position. It can't fit 180 on it. If you look the slot is off center to prevent this. :) Cam timing probably wasn't it. I looked at it today, and he has NO spark now. He's replaced the dizzy and coil under warranty. He has 12V @ ignition, and at dizzy (points dizzy) + has about 8V iIRC. No spark from coil though. We removed the condenser just on a whim to see if it was possibly a DOA part. No change. Crank over with the cap off. The points MUST close and MUST open for the coil to work. If you have dual points and one set doesn't open, it wont fire. If there is a bare wire touching the dizzy body, it won't fire. Quote Link to comment
ggzilla Posted May 20, 2012 Report Share Posted May 20, 2012 well at least it is just a spark problem. Those are elementary. The squealing is an unusual problem. Wonder what that will turn out to be? Quote Link to comment
metalmonkey47 Posted May 20, 2012 Author Report Share Posted May 20, 2012 Dang mike, that's great about the dizzy. I've never had to look that far into it on an L series to worry about it. I'll look at the points next time I'm in his direction. The squealing is odd, because I've had the carb apart down to every last piece and didn't see anything unusual. When it ran, it had no symptoms of a vacuum leak, and we didn't find any when we were looking with carb cleaner. Quote Link to comment
banzai510(hainz) Posted May 20, 2012 Report Share Posted May 20, 2012 Get a test light from Distributor tab to the +side battery. turn motor over and light should switch ON/OFF if good. If light ON all the time its grounding out. If Off all the time its not groundeing out. Once I went to Pertronix I never had this proplem ever again. Points I would have proplems like this only when I swapped out the points. So usually operator induced error. worn wire. Quote Link to comment
metalmonkey47 Posted June 1, 2012 Author Report Share Posted June 1, 2012 The truck runs! Thank god. Turns out the points were garbage. AC Cardone reman distributors are garbage. New points and it runs. As far as the squealing, he found a leak around a shaft or something? Not too clear about that, but it's good now. Quote Link to comment
ggzilla Posted June 1, 2012 Report Share Posted June 1, 2012 Someone bought a re-manufactured distributor ... and did not choose electronic ignition? Glad to hear the problems have been solved. Happy driving! Quote Link to comment
metalmonkey47 Posted June 1, 2012 Author Report Share Posted June 1, 2012 Someone bought a re-manufactured distributor ... and did not choose electronic ignition? Glad to hear the problems have been solved. Happy driving! Yeah... at the time he wasn't aware of the simplicity of the swap. He's going for a matchbox soon. As am I. I've got the remote igniter dizzy on my L20 with the matchbox module. Quote Link to comment
Laecaon Posted June 1, 2012 Report Share Posted June 1, 2012 Remote igniter has better bearings. Quote Link to comment
DAT510 Posted June 1, 2012 Report Share Posted June 1, 2012 The squealing might be the adapters.. Run your fingers along it with it running for a change of tone or it stopping.. Mine sounded like it was coming from the water Pump or similar to the sound when a alternator goes out... Mu squealing. And from the adapters that vibrated loose (like everything else in my engine bay!! ) Quote Link to comment
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