Distributor problems
04-12-2008, 07:31 AM
#1
Guest
Posts: n/a
Distributor problems
Hi,
I've got strange problems with my engine.
It's a stock 318 in a 1976 W200.
After it behaved very strange with the stock setup (2bbl Carter BBD, I never trusted it) I decided to start building new stuff on it.
So I got a nice weiand intake and a 600 holley 4010. Also I changed from mech. to elect. fuel pump (holley). The carb is renewed.
The engine refuses to run and if it sometimes does it won't last very long and it backfires like hell.
Strange thing: I'm 100% shure, that we put everything together properly, adjusted 1st cyl. to TDC and put in Distributor correctly, but when we check later we have a 180 degree twisted rotor.
We experienced this silly game now several times.
Everything in terms of ignition is new: rotor, cap, ballast resistor, ecu (orange box), wires and plugs.
What makes the distributor shaft turning 180 degrees????
My last idea: there must be something wrong with the gear drive, turning the distributor.
When I get it right there's a shaft coming up from oil pump to a gear, driven by the gear of the camshaft. Are there any bearings which could wear?
People suggested a broken camshaft, but then the engine won' turn the distributor at all, right?
Anybody out there who got a similar problem?
Thanks,
cheers
JUS
I've got strange problems with my engine.
It's a stock 318 in a 1976 W200.
After it behaved very strange with the stock setup (2bbl Carter BBD, I never trusted it) I decided to start building new stuff on it.
So I got a nice weiand intake and a 600 holley 4010. Also I changed from mech. to elect. fuel pump (holley). The carb is renewed.
The engine refuses to run and if it sometimes does it won't last very long and it backfires like hell.
Strange thing: I'm 100% shure, that we put everything together properly, adjusted 1st cyl. to TDC and put in Distributor correctly, but when we check later we have a 180 degree twisted rotor.
We experienced this silly game now several times.
Everything in terms of ignition is new: rotor, cap, ballast resistor, ecu (orange box), wires and plugs.
What makes the distributor shaft turning 180 degrees????
My last idea: there must be something wrong with the gear drive, turning the distributor.
When I get it right there's a shaft coming up from oil pump to a gear, driven by the gear of the camshaft. Are there any bearings which could wear?
People suggested a broken camshaft, but then the engine won' turn the distributor at all, right?
Anybody out there who got a similar problem?
Thanks,
cheers
JUS
04-12-2008, 09:06 AM
#2
First, with all the carb/ intake work, do I understand that you are using the same distributor that you had previously?
Attempting to put this politely, which is difficult for me!! I believe you have an incorrect understanding of 180. It may simply be that the distributor is in fact 180 out, or just out of time.
There is the possibility that your engine has the horrid fiber cam drive sprocket, and if there's "some miles" on the engine, the chain could be/ could have slipped
You can get an idea of this by simply turning the engine with a socket on the balancer bolt. Turn CW and CCW a few degrees and you'll "feel" the slack in the chain. More than a few degrees is suspect. I'd say on a fiber sprocket, 10 degrees is VERY suspicious.
Here's how I set timing.
First, unles I'm sure--because of an engine's history, that the timing marks are correct, I always check them with a positive stop made from an old plug. If you are sure the factory (balancer) mark is correct, I'll skip that for now.
Second, if the valve covers are on, simply remove no 1 plug, and bump the engine over with a remote switch, until AS THE MARK approaches TDC, your finger will be "blown" out of the plug hole. This is the correct stroke. Now just bring the mark carefully to say, 5-10 BTC, and pop the dist. in. Of course it can only go in two ways, so wherever you "want" no1 wire to be is where you put it.
Now, you can ALSO set the timing very close in many cases. Pull the coil wire from the dist cap, and hook to a short test gap, old plug, or even a neon test lamp. Rotate the dist. purposly retard (CW) and with the key on, experiment rotating the dist. past the firing point going CW. At some point you should be able to get a spark, and by experimentation, should be able to slow down your rotation, and after a few tries, get the spark right on. This is where you snug the dist. enough that it stays put, and the engine should start right up and run.
Last, of course, you get your timing light and really set the timing.
Attempting to put this politely, which is difficult for me!! I believe you have an incorrect understanding of 180. It may simply be that the distributor is in fact 180 out, or just out of time.
There is the possibility that your engine has the horrid fiber cam drive sprocket, and if there's "some miles" on the engine, the chain could be/ could have slipped
You can get an idea of this by simply turning the engine with a socket on the balancer bolt. Turn CW and CCW a few degrees and you'll "feel" the slack in the chain. More than a few degrees is suspect. I'd say on a fiber sprocket, 10 degrees is VERY suspicious.
Here's how I set timing.
First, unles I'm sure--because of an engine's history, that the timing marks are correct, I always check them with a positive stop made from an old plug. If you are sure the factory (balancer) mark is correct, I'll skip that for now.
Second, if the valve covers are on, simply remove no 1 plug, and bump the engine over with a remote switch, until AS THE MARK approaches TDC, your finger will be "blown" out of the plug hole. This is the correct stroke. Now just bring the mark carefully to say, 5-10 BTC, and pop the dist. in. Of course it can only go in two ways, so wherever you "want" no1 wire to be is where you put it.
Now, you can ALSO set the timing very close in many cases. Pull the coil wire from the dist cap, and hook to a short test gap, old plug, or even a neon test lamp. Rotate the dist. purposly retard (CW) and with the key on, experiment rotating the dist. past the firing point going CW. At some point you should be able to get a spark, and by experimentation, should be able to slow down your rotation, and after a few tries, get the spark right on. This is where you snug the dist. enough that it stays put, and the engine should start right up and run.
Last, of course, you get your timing light and really set the timing.
Last edited by 440roadrunner; 04-12-2008 at 09:22 AM.
04-12-2008, 10:39 AM
#3
Guest
Posts: n/a
Before I started replacing carb and stuff the car got kind of "slower", means first it was possible to go 50 miles, later it just went 20 miles per hour. Trying to go faster felt like engine is loosing power.
Attempting to put this politely, which is difficult for me!! I believe you have an incorrect understanding of 180. It may simply be that the distributor is in fact 180 out, or just out of time.
I mean my wire of 1st cylinder ir pointing to the front and that's where I want my rotor pointing towards when 1st cylinder is on TDC. We checked all this many times - valve cover removed, both valves of 1st cylinder closed.
180 degrees wrong means should point forward, but points backwards. Easy.
There is the possibility that your engine has the horrid fiber cam drive sprocket, and if there's "some miles" on the engine, the chain could be/ could have slipped
You can get an idea of this by simply turning the engine with a socket on the balancer bolt. Turn CW and CCW a few degrees and you'll "feel" the slack in the chain. More than a few degrees is suspect. I'd say on a fiber sprocket, 10 degrees is VERY suspicious.
You can get an idea of this by simply turning the engine with a socket on the balancer bolt. Turn CW and CCW a few degrees and you'll "feel" the slack in the chain. More than a few degrees is suspect. I'd say on a fiber sprocket, 10 degrees is VERY suspicious.
Here's how I set timing.
First, unles I'm sure--because of an engine's history, that the timing marks are correct, I always check them with a positive stop made from an old plug. If you are sure the factory (balancer) mark is correct, I'll skip that for now.
Second, if the valve covers are on, simply remove no 1 plug, and bump the engine over with a remote switch, until AS THE MARK approaches TDC, your finger will be "blown" out of the plug hole. This is the correct stroke. Now just bring the mark carefully to say, 5-10 BTC, and pop the dist. in. Of course it can only go in two ways, so wherever you "want" no1 wire to be is where you put it.
Now, you can ALSO set the timing very close in many cases. Pull the coil wire from the dist cap, and hook to a short test gap, old plug, or even a neon test lamp. Rotate the dist. purposly retard (CW) and with the key on, experiment rotating the dist. past the firing point going CW. At some point you should be able to get a spark, and by experimentation, should be able to slow down your rotation, and after a few tries, get the spark right on. This is where you snug the dist. enough that it stays put, and the engine should start right up and run.
Last, of course, you get your timing light and really set the timing.
First, unles I'm sure--because of an engine's history, that the timing marks are correct, I always check them with a positive stop made from an old plug. If you are sure the factory (balancer) mark is correct, I'll skip that for now.
Second, if the valve covers are on, simply remove no 1 plug, and bump the engine over with a remote switch, until AS THE MARK approaches TDC, your finger will be "blown" out of the plug hole. This is the correct stroke. Now just bring the mark carefully to say, 5-10 BTC, and pop the dist. in. Of course it can only go in two ways, so wherever you "want" no1 wire to be is where you put it.
Now, you can ALSO set the timing very close in many cases. Pull the coil wire from the dist cap, and hook to a short test gap, old plug, or even a neon test lamp. Rotate the dist. purposly retard (CW) and with the key on, experiment rotating the dist. past the firing point going CW. At some point you should be able to get a spark, and by experimentation, should be able to slow down your rotation, and after a few tries, get the spark right on. This is where you snug the dist. enough that it stays put, and the engine should start right up and run.
Last, of course, you get your timing light and really set the timing.
My question was, if someone had this kind of problem of a "self misadjusting" Distributor shaft.
cheers
JUS
04-12-2008, 03:15 PM
#4
Ok, I'm just trying to make sure "we understand" each other. So you DO understand, do you not--that every other time the TDC marks come up, that the dist. will be 180 'off'?
By observing the no1 valves, that should alleviate the problem of whether the dist. is initially installed 180 "out." I usually just stuff my finger in no1--much easier than pulling the cover.
Now I HAVE seen the "top hat" mechanism of a GM contact point type V8 dist come loose from the shaft. I have never personally seen this problem on a Chrysler, but it should not be all that difficult to see. Simply clamp the bottom of the dist. shaft, and try to turn the top with some force, maybe, with a rag around the rotor mount and a pair of pliers. The bottom where the advance weight mechanism would have to be broken loose, and I suppose it could happen.
This should not be hard to run down---it only takes a few minutes to pull the plate out of the dist. and examine the weights and so on.
I cannot IMAGINE a situation where the cam would be broken in such a way that this would happen. I would think that simply cranking the engine with at least one valve cover off would instantly tell you this.
By observing the no1 valves, that should alleviate the problem of whether the dist. is initially installed 180 "out." I usually just stuff my finger in no1--much easier than pulling the cover.
Now I HAVE seen the "top hat" mechanism of a GM contact point type V8 dist come loose from the shaft. I have never personally seen this problem on a Chrysler, but it should not be all that difficult to see. Simply clamp the bottom of the dist. shaft, and try to turn the top with some force, maybe, with a rag around the rotor mount and a pair of pliers. The bottom where the advance weight mechanism would have to be broken loose, and I suppose it could happen.
This should not be hard to run down---it only takes a few minutes to pull the plate out of the dist. and examine the weights and so on.
I cannot IMAGINE a situation where the cam would be broken in such a way that this would happen. I would think that simply cranking the engine with at least one valve cover off would instantly tell you this.
04-14-2008, 09:59 AM
#5
Guest
Posts: n/a
Ok, I'm just trying to make sure "we understand" each other. So you DO understand, do you not--that every other time the TDC marks come up, that the dist. will be 180 'off'?
By observing the no1 valves, that should alleviate the problem of whether the dist. is initially installed 180 "out." I usually just stuff my finger in no1--much easier than pulling the cover.
Now I HAVE seen the "top hat" mechanism of a GM contact point type V8 dist come loose from the shaft. I have never personally seen this problem on a Chrysler, but it should not be all that difficult to see. Simply clamp the bottom of the dist. shaft, and try to turn the top with some force, maybe, with a rag around the rotor mount and a pair of pliers. The bottom where the advance weight mechanism would have to be broken loose, and I suppose it could happen.
This should not be hard to run down---it only takes a few minutes to pull the plate out of the dist. and examine the weights and so on.
I cannot IMAGINE a situation where the cam would be broken in such a way that this would happen. I would think that simply cranking the engine with at least one valve cover off would instantly tell you this.
By observing the no1 valves, that should alleviate the problem of whether the dist. is initially installed 180 "out." I usually just stuff my finger in no1--much easier than pulling the cover.
Now I HAVE seen the "top hat" mechanism of a GM contact point type V8 dist come loose from the shaft. I have never personally seen this problem on a Chrysler, but it should not be all that difficult to see. Simply clamp the bottom of the dist. shaft, and try to turn the top with some force, maybe, with a rag around the rotor mount and a pair of pliers. The bottom where the advance weight mechanism would have to be broken loose, and I suppose it could happen.
This should not be hard to run down---it only takes a few minutes to pull the plate out of the dist. and examine the weights and so on.
I cannot IMAGINE a situation where the cam would be broken in such a way that this would happen. I would think that simply cranking the engine with at least one valve cover off would instantly tell you this.
We found the problem, it was the shaft of the distributor which was not properly sittin' in its counterpart, the sprocket of the oil-pump-drive.
See the pictures, the one with the signs of wear of just 2mm (0.07 inch) was the one jumping around.
The comparison with another distributor shows, that this should be around 5mm (0.2 inch).
But now the engine runs great in idle, revs up without load (tranny in "N" or "P"), keeps on running puttin' in gear, but as soon as the throttle is touched it dies.
It's a weiand intake and 600cfm holley 4010, renewed, everything checked, power valve OK, accel pump working (squirting gasoline).
Any ideas?
cheers
JUS
04-15-2008, 05:08 PM
#6
I don't remember, anymore, but in the back of my mind it seems to me that some distributors, like for instance SB and maybe B (383) distributor shafts are very similar, but slightly different. You didn't somehow get some used mismatched parts? Quickest way to tell a B engine dist. from a SB is that the advance goes the opposite direction.
It APPEARS from some stuff that I've read, that the old "poly" (early) 318 dist's are different from the newer LA engines
Could it also be---that either the bottom of the drive gear (thrust face) is worn, that the thrust face for the bushing is worn, allowing the gear to sink too far?
Good to hear you are on the right track
It APPEARS from some stuff that I've read, that the old "poly" (early) 318 dist's are different from the newer LA engines
Could it also be---that either the bottom of the drive gear (thrust face) is worn, that the thrust face for the bushing is worn, allowing the gear to sink too far?
Good to hear you are on the right track
04-15-2008, 05:11 PM
#7
OK, Thanks!
We found the problem, it was the shaft of the distributor which was not properly sittin' in its counterpart, the sprocket of the oil-pump-drive.
See the pictures, the one with the signs of wear of just 2mm (0.07 inch) was the one jumping around.
The comparison with another distributor shows, that this should be around 5mm (0.2 inch).
But now the engine runs great in idle, revs up without load (tranny in "N" or "P"), keeps on running puttin' in gear, but as soon as the throttle is touched it dies.
It's a weiand intake and 600cfm holley 4010, renewed, everything checked, power valve OK, accel pump working (squirting gasoline).
Any ideas?
cheers
JUS
We found the problem, it was the shaft of the distributor which was not properly sittin' in its counterpart, the sprocket of the oil-pump-drive.
See the pictures, the one with the signs of wear of just 2mm (0.07 inch) was the one jumping around.
The comparison with another distributor shows, that this should be around 5mm (0.2 inch).
But now the engine runs great in idle, revs up without load (tranny in "N" or "P"), keeps on running puttin' in gear, but as soon as the throttle is touched it dies.
It's a weiand intake and 600cfm holley 4010, renewed, everything checked, power valve OK, accel pump working (squirting gasoline).
Any ideas?
cheers
JUS
So you're saying that now there's a second problem? The engine is nice and responsive in neutral? Can you tell that the mechanical advance is working OK? Where is the timing? hmmmmmmmmmmmmmmm
04-16-2008, 03:55 AM
#8
Guest
Posts: n/a
Now we solved this problem as well.
It was not ignition any more, it was misconfiguration of the holley carb.
We tried instead of the 4010 (square bore) a 4011 (spread bore) and there's no bog any more when accelerating.
Seems to work better with the small primaries on the weiand #8007, which has the mounts for the spread bore anyway.
Now I'll do finetuning of the carb.
Thanks, cheers
JUS
It was not ignition any more, it was misconfiguration of the holley carb.
We tried instead of the 4010 (square bore) a 4011 (spread bore) and there's no bog any more when accelerating.
Seems to work better with the small primaries on the weiand #8007, which has the mounts for the spread bore anyway.
Now I'll do finetuning of the carb.
Thanks, cheers
JUS
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