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| cutout at highway speed dies at stops https://slantsix.org/forum/viewtopic.php?t=57758 |
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| Author: | mgtumwater25 [ Tue May 26, 2015 9:10 am ] |
| Post subject: | cutout at highway speed dies at stops |
Hey my names mike and I'm new to this forum. I recently bought an 85 dodge shortbed with a lean burn slant six. Right away I got on pulling the engine and re-gasketing and replacing the oil pump. The engine came with a new starter, water pump , alternator and a reman. Holley 1945 . So the problems I am having ( and I feel they are all related ) is 1. The truck dies at stops upon harder braking, 2. Between 2nd and 3rd shift ( automatic) it stumbles and almost dies out ( with moderate gas) 3. At 55 mph with moderate acceleration it dies the same as between 2nd and 3rd. So far I have regasketing the carb ( the floats seemed plenty high) and fixed the accelerator pump , I have also swapped over to a chrystler electronic ignition with vacume advance and installed an electric fuel pump...I'm lost any ideas are appreciated |
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| Author: | coconuteater64 [ Tue May 26, 2015 9:53 am ] |
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First of all, welcome! You have pretty much same truck as one of mine, except for the transmission. Did you rebuild the 1945, or just change gaskets? I rebuilt mine twice, boiling it out each time, only to discover the throttle shaft was worn out and leaking air. I tossed it in favor of a 1920 I got from another member here. Second question, why the electric fuel pump? Sometimes those can cause problems all on their own due to electrical fluctuations or too much pressure lifting the needle off the seat. |
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| Author: | SlantSixDan [ Tue May 26, 2015 10:23 am ] |
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"Remanufactured" carburetors tend to be junk that just won't run right no matter what you do. A good new carb will be harder to find, but worth hunting down. You may want to consider going to a 2bbl carb and intake for better overall driveability. Also, yeah, electric fuel pump will tend to cause more problems than it solves. |
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| Author: | mgtumwater25 [ Tue May 26, 2015 11:56 am ] |
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When I tore the motor down the cam lobe that runs the fuel pump was pretty heavily worn , all the other lobes were wore but not like this and I'm doing this on a budget. As for the carb it was remanufactured 2 years ago and the only thing I saw wrong was the accelerater pump was sticking in its sleeve.i completely disassembled minus pulling jets and idle screws and soaked it in carb clean blew it out with an air compressor an checked the floats and reassembled...a new carb isn't really an option but I guess I could find a junkyard 1920 or carter. I've also had people tell me it could be my torque converter, thoughts on this? |
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| Author: | coconuteater64 [ Tue May 26, 2015 12:14 pm ] |
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I am wary of reman carbs for the same reason Dan is - they tend to be junk. I've had one actually catch fire the first time it was cranked after installation! They didn't have the right float installed. I've had two that were good, but they were from actual carburetor shops and cost way more than what you would pay at Napa or Auto Stoned. I bought a brand new Holley when I got the chance. It was a great choice. One thing I would suggest is to look for a vacuum leak. |
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| Author: | mgtumwater25 [ Tue May 26, 2015 1:39 pm ] |
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OK I'll keep that in mind before I ever buy a reman carb, I've only ever bought new.i have checked for vacume leaks as well,sprayed the intake and carb down with carb clean while at idle and noticed no change in idle speed , also hooked a vacume gauge up ,it stays steady around 15 inches vac pressure and drops to 0 as revved ..I am not completely against buying a new carb but before dropping that kinda cash ide like to isolate the problem and be sure |
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| Author: | coconuteater64 [ Tue May 26, 2015 2:39 pm ] |
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I don't know what the regular vacuum reading should be- that's what a good shop manual is for- but that seems kinda low. My old D100 idles at 22" and even the worn out sludge monster farm truck has 19" at idle, warmed up. What concerns me is the cam. You said it was worn so much the fuel pump eccentric was gone. That concerns me a bit. As for new carbs, they're getting hard to find, at least the 1 bbl kind. On my D100 I used a really nice refurbished Motorcraft 2bbl from a mom & pop carb shop on a modified super six intake. But you need something as a daily driver from what I gather, so that's probably not the route you would go. <a target="_blank" href="http://imageshack.com/f/8q65ec7rnj"><img src="http://imagizer.imageshack.us/v2/280x200q90/314/65ec7rn.jpg" border="0"></a> How's your ignition timing? |
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| Author: | mgtumwater25 [ Tue May 26, 2015 4:42 pm ] |
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Yea I kinda like the little one barrel , great on gas, yes the cam was pretty worn but I don't think that would cause any of my problems, other then the cutout and dieing at stops the motor runs pretty damn good. As far as ignition timing it seems to run best around 12 btdc and when I plug the vacume advance in it runs around 24 btdc. I wasn't to sure what to set it at after swapping to electronic ignition but that's where I put it by ear, it was pinging a lot at 5 btdc and on the hood it sais to put it at 16 |
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| Author: | mgtumwater25 [ Tue May 26, 2015 5:27 pm ] |
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Also the fuel pump eccentric wasn't gone, and the motor was still running and driving ,I only replaced the fuel pump with an electric because It was dieing , that was my first guess.then I put an electronic ignition in it because the lean burn distributor was full of rust and I read the computers are junk |
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| Author: | coconuteater64 [ Tue May 26, 2015 6:53 pm ] |
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OK, I misunderstood what you said about the camshaft. Anyway, Lean Burn isn't necessarily bad when it works, but they existed in the harsh underhood environment and quickly failed. They also took the blame for bad driveability when actually poor maintenance was to blame. Having said that, once the capacitors dried out or corrosion took root they were basically irreparable. Here's what I did with mine: <img src="http://imagizer.imageshack.us/v2/280x200q90/133/stuffoffd100xo0.jpg" border="0"> I kept the air cleaner and tossed the rest. I tried selling it, and even giving it away, but nobody wanted the stuff. the carb was worn out (bad throttle shafts). I suggest starting with simple things first. Check the basics like plug wires, plugs, distributor cap, rotor, and check the timing again. Don't just give them a look, bust out a voltohm meter and really check them. Check your coil. Even take a look at your ignition switch; I had a pickup that dies going uphill and it turned out the weight of the keychain was just enough to make the contacts inside the switch move a tiny bit. It was just like shutting the truck off. Drove me crazy trying to track that down. Once you've eliminated everything electrical, then it's likely a fuel problem. |
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| Author: | mgtumwater25 [ Tue May 26, 2015 7:01 pm ] |
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Yea I replaced everything on the truck now pretty much, wires plugs ,coil, carb cleaned and gaskets, oil pump, water pump and went completely threw the underhood wiring when I put in the ignition , :/... But I actually have had problems with the ignition switch! Sometimes the windshield wipers won't work and I have to hold the key forward about an eighth inch to get them to come on...I replaced the lock itself cuz the switch looked new but perhaps I will give that a shot then like you said I may have to kick a couple hundred out for a new carb ... I am also curious what other members are running for timing when switching over from lean burn, should it stay at 16 btcd as base timing with vacume advance in hooked? Or should it be 16 btdc with vacume hooked up? |
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| Author: | coconuteater64 [ Tue May 26, 2015 7:15 pm ] |
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Quote: I replaced the lock itself cuz the switch looked new
The lock is separate from the switch, as you probably already know. I'd check the switch itself electrically with a good voltohm meter and wiggle it around a bit to check continuity. Like I said, mine only moved ever so slightly, but this was enough to break the electrical connection by moving the switch to the sweet spot between "run" and "start". I checked this because it was the only thing I hadn't checked yet and sure enough, a new switch cured the uphill blues. After 6 years it hasn't done it again.
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| Author: | cpslntdchrg [ Wed May 27, 2015 9:11 am ] |
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I do not have a lean burn system, but 16 deg BTDC looks like a lot. I know the lean burn had ways to take advantage of that advance, but you replaced it with the Chrysler EI, which has different settings. 0 BTDC (from the service manual) to 10 BTCD with no vacuum connected (as the service manual tuning workflow states) is what I've used, settled on 6. Did you change the distributor? Springs and vacuum (or lack of) settings are different in the lean burn than in the standard EI systems The carb also was different. Is the carb you have the original? or the one that came with the truck when you bought it? You might have been given an already reman carb, so it might be damaged/doomed already, even if you changed gaskets and serviced it. If you buy a Factory Service Manual for your truck's year you can check if it has all equipment (and not a Haynes please, follow SlantSixDan reccomendations on that matter). Are you using the proper vacuum port for the advance? The Frequently Asked Questions thread in the Engine Folder has links to service manuals and videos for the 1945, so you can check what is missing in your carb. It would be a good idea installing a pre lean-burn 1945 or a 1920, with a same-era distributor. I was expecting reduced pinging as you decrease degrees BTDC, as the spark comes later, and there is less burning time before the expansion cicle, and the exhaust valves open. The engine will get lazier too. It baffles me you got more pinging. I hope coconuteater64 and others with experience in lean burn delete can give you a hand. By the way, did you remove the catalytic converter? Before it melts or keep plugging the exhaust? |
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| Author: | mgtumwater25 [ Tue Jun 02, 2015 5:51 am ] |
| Post subject: | |
So just an update , I figured it out , my float were 3/32 of an inch to high in my holley 1945...even when I set them level with the carb bowl while upside down the fuel tang wouldn't let any fuel into the carb . . Anyways I ended up setting it just a little below level and it has been running great for 3 days now 30 miles each way to and from work . Now I guess a cam is next on my list of purchases seeing as I can't get over 15 inches of vacume :/ |
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| Author: | mgtumwater25 [ Tue Jun 02, 2015 5:51 am ] |
| Post subject: | |
Thanks for all the replies! |
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