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Re: Need advice, plugs fouled, backfiring thru carb
[Re: RMCHRGR]
#1595139
03/29/14 12:24 PM
03/29/14 12:24 PM
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Joined: Aug 2004
Posts: 9,654
Southern by Choice
Shoozy
I have a foot fetish
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I have a foot fetish
Joined: Aug 2004
Posts: 9,654
Southern by Choice
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I believe Bob was referring to the distributor harness, not the plug wires
Old, tired, and sometimes broke down. Me, not my car...
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: RMCHRGR]
#1595140
03/29/14 12:25 PM
03/29/14 12:25 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Quote:
Check the MSD distributer wires,may be backwards. 
Had Firecore wires on at first. HEI style wires no way to reverse them. Put some old Taylor wires back on with the OE cap, same results.
He is referring to the pick up wires at the dist
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: MR_P_BODY]
#1595141
03/29/14 01:10 PM
03/29/14 01:10 PM
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Joined: Sep 2007
Posts: 1,890
Spahn Ranch
RMCHRGR
OP
top fuel
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OP
top fuel
Joined: Sep 2007
Posts: 1,890
Spahn Ranch
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Just to be clear, the car will run and actually seems to run OK, just intermittently. I believe the hard starting issue is what's causing the plug fouling.
Maybe I'm incorrect but I am not overly concerned about mechanical problems like a bad valve. When it does run, I don't really hear much in the way of any ticks or a miss or anything like that. The valves probably need to be lashed but I'd rather get it running consistently before I do that. Still could be hanging up but I've seen cars run sort of OK where a valve isn't even touching the seat.
I could be wrong but I would think that from the fact that it is capable of running that the pickup wires are correct. I also double and triple checked the coil wires from the MSD according to their wiring diagram - orange to +, black to ground. If I take the coil wire off the cap and crank it to fill the bowls or something, I get a good, blue spark.
The main issue I am having is getting it started consistently, having it stay running and not foul plugs.
I'm in NY, it's still pretty cold out, I'm thinking this may have something to do with it but not too much. Regardless, it's still way too rich to the point of plug fouling. I believe the carb is spitting because it's flooded, not backfiring because of timing.
I would like to switch out the carb for a known good one, I might try to make that happen. I don't have another one that would work at the moment, only a TQ and no adapter.
Float level seems correct. According to Quick Fuel who makes the Proform carbs, fuel should be halfway up the sight glass @ 6.5 psi. That's what I got. Have the pink pump cam on #2 to delay the shot a little. Power valve is a 4.5. Only in front, blocked in back. The throttle blades are closed to where the transfer slot is a little square. They're the same front and back.
I went to the parts store and got another set of plugs (#6) but I went hotter to an RC12YC. Gonna gap them to .050". Battery is charged up. Temp is about 50 degrees and drizzling rain.
Sorry for the long response. Thanks for the replies.
'71 Duster
'17 Ram 1500
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: DodgeCharger]
#1595143
03/29/14 02:50 PM
03/29/14 02:50 PM
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Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
RobX4406
I Live Here
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I Live Here
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
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557 and only able to run 18* of initial, that really weak. It's only got 170 cranking pressure. Not earth shattering
I'd take a jumper cable, hook it to the neg battery and straight to the engine block. See if it starts easier. If so you found a grounding issue.
If it's not some crazy compression, doesn't appear to be, that should be above 20* timing and easily spin over.
Lots fo times those bigger cams never give you a really clean idle profile, but, you can get it better than fouling plugs. I have a 340 with stock compression and a 508 camshaft with it locked out at 36*. Starts fine even when warm out here in the desert.
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: RobX4406]
#1595144
03/29/14 08:07 PM
03/29/14 08:07 PM
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Joined: Sep 2007
Posts: 1,890
Spahn Ranch
RMCHRGR
OP
top fuel
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OP
top fuel
Joined: Sep 2007
Posts: 1,890
Spahn Ranch
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OK, got it running pretty well. I was even able to hot start it without too much trouble. It was running long enough that eventually I ran out of gas.
Once I got it running, initial timing was 26 degrees. Plate in the distributor is 13 so x 2 = 26. I remember now when I got it a few years ago I checked the timing and being surprised where it was at. Looked like almost 30 on the OE damper. Makes sense now.
As stated, I went to a hotter plug and it seemed to help a little. They were still getting a little carboned while fiddling with the idle but nowhere near as bad. I checked them at one point, no carbon at all. At least it was running and I was able to restart it.
A/F ratio was between 12.5-13 at idle. Seems like the A/F ratio is really sensitive to the idle mixture screws/throttle blades. Seems like a 1/4 turn can move the meter almost one point either way. With no load seems like the best throttle response is around 12.5. I'd like it to be leaner but I have not actually driven it yet.
Thanks for all the suggestions and tips. Took some doing to get to this basic point but I've learned some things for sure. I admit, I'm kind of a rookie at tuning. I was a tech for a while but I never dealt with carbs or distributors when I was working. I know it ain't rocket science but it can get confusing when you're chasing multiple issues.
Probably be back asking about bogs and hesitations soon.
'71 Duster
'17 Ram 1500
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: RMCHRGR]
#1595145
03/29/14 09:22 PM
03/29/14 09:22 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
OK, got it running pretty well. I was even able to hot start it without too much trouble. It was running long enough that eventually I ran out of gas.
Once I got it running, initial timing was 26 degrees. Plate in the distributor is 13 so x 2 = 26. I remember now when I got it a few years ago I checked the timing and being surprised where it was at. Looked like almost 30 on the OE damper. Makes sense now.
As stated, I went to a hotter plug and it seemed to help a little. They were still getting a little carboned while fiddling with the idle but nowhere near as bad. I checked them at one point, no carbon at all. At least it was running and I was able to restart it.
A/F ratio was between 12.5-13 at idle. Seems like the A/F ratio is really sensitive to the idle mixture screws/throttle blades. Seems like a 1/4 turn can move the meter almost one point either way. With no load seems like the best throttle response is around 12.5. I'd like it to be leaner but I have not actually driven it yet.
Thanks for all the suggestions and tips. Took some doing to get to this basic point but I've learned some things for sure. I admit, I'm kind of a rookie at tuning. I was a tech for a while but I never dealt with carbs or distributors when I was working. I know it ain't rocket science but it can get confusing when you're chasing multiple issues.
Probably be back asking about bogs and hesitations soon.
Cool.. your getting there... I never worry about the
AFR at idle... I set it so it idles the best it can
and set the WOT to the best MPH... I only use my AFR
to set the cruise... but once I get all the points
dialed in(idle, wot and cruise) I take a reading so
I can get back to it fairly easy.... and yes the mixture
screws can be touchy with how much you move them..
what I do is once its warmed up.. slowly turn in
one at a time till the rpm starts to drop then back
them out 1/4 turn... go around the carb a couple of
time to get it right... you might be lowering the
curb idle(the idle screw) during this process but
do it all a few times and it'll come right in... but
the base timing is what you have to set FIRST.. thats
a MUST
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: RMCHRGR]
#1595147
04/02/14 04:30 PM
04/02/14 04:30 PM
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Joined: Jul 2003
Posts: 12,129
Cleveland
sunroofgtx
I Live Here
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I Live Here
Joined: Jul 2003
Posts: 12,129
Cleveland
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Crazy question, but what kind of fuel are you running?
Join the quickest team in motorsports. Team FireCore. CustomWiresets.com
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: B G Racing]
#1595150
04/03/14 12:02 AM
04/03/14 12:02 AM
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Joined: Sep 2007
Posts: 1,890
Spahn Ranch
RMCHRGR
OP
top fuel
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OP
top fuel
Joined: Sep 2007
Posts: 1,890
Spahn Ranch
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Man, I tried to reply like three times here and I keep losing my text.  Anyway, the car is running. I took it out for a ride today for the first time in over a year. Seems to run OK, gets up and goes. Surprised myself! Fuel is a mix of pump 93/Cam 2 100 unleaded. It will run on 93 but I can get the Cam 2 at the pump down the road from my house so I try to keep at least 5 gallons of it in there. Plugs are at .050" cause I thought it would help to promote more spark energy. Dunno, I guess I could try .035" on my next set of plugs. Almost everything I've read over the years about plug gaps says .045-.060" is what you want. I think advancing the timing and going to a hotter plug is really what helped. When I did the compression test, I thought I might have a roasted valve in the #5 cylinder but I'm not really sure. I don't have a leak down tester. (on my list) Could be bad but seems to run OK anyway. I changed the oil which I think helped with compression. The old oil was thin and black. I'll probably be rebuilding this engine sooner than later. Thanks again for the tips, this has been helpful.
'71 Duster
'17 Ram 1500
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: B G Racing]
#1595151
04/21/14 04:56 PM
04/21/14 04:56 PM
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Joined: Sep 2007
Posts: 1,890
Spahn Ranch
RMCHRGR
OP
top fuel
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OP
top fuel
Joined: Sep 2007
Posts: 1,890
Spahn Ranch
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Quote:
Check the MSD distributer wires,may be backwards.
This was my problem.
I'll admit, I have been messing with this hard starting issue for the better part of two months and it was driving me nucking futs.
Even though the car would run, it was very hard to start in all situations and no adjustments were having any effect - timing or carb. It would eventually fire after multiple attempts though it never stayed running without holding the throttle open. Once it got warmed up it would stay running which is part of why this was confusing.
I figured I needed to try something different. Something was telling me it had to be ignition/timing related since the plugs were still black no matter what I did to the carb.
I read back through the thread here to see if I missed something. I read BG's reply and started looking into the issue some more. Turns out it is a somewhat common problem with magnetic pickup (Mopar) distributors. You kind of really have to read through some of the replies on the MSD forums and decide for yourself to switch the wires.
The thing is, the MSD instructions don't really make any mention of this particular issue and I wired it like they said. I kept re-checking believing it to be correct and since it kind of ran, there was no real reason to think I had it wired wrong. Plus, I did all the MSD troubleshooting procedures with no apparent issues.
So just for kicks, this AM I went out and switched the wires. Two pumps on the throttle, turned the key and the car fired instantly and easily and stayed running. I was relieved but completely annoyed at the same time.
Need to start from scratch on tuning now but at least its starting and running right now so I have a proper baseline. Live and learn I guess. Thanks again for all the replies.
'71 Duster
'17 Ram 1500
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: RMCHRGR]
#1595152
04/21/14 07:18 PM
04/21/14 07:18 PM
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Joined: Feb 2005
Posts: 5,221
Branson, Mo.
joedust451
super gas
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super gas
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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Quote:
Quote:
Check the MSD distributer wires,may be backwards.
This was my problem.
I'll admit, I have been messing with this hard starting issue for the better part of two months and it was driving me nucking futs.
Even though the car would run, it was very hard to start in all situations and no adjustments were having any effect - timing or carb. It would eventually fire after multiple attempts though it never stayed running without holding the throttle open. Once it got warmed up it would stay running which is part of why this was confusing.
I figured I needed to try something different. Something was telling me it had to be ignition/timing related since the plugs were still black no matter what I did to the carb.
I read back through the thread here to see if I missed something. I read BG's reply and started looking into the issue some more. Turns out it is a somewhat common problem with magnetic pickup (Mopar) distributors. You kind of really have to read through some of the replies on the MSD forums and decide for yourself to switch the wires.
The thing is, the MSD instructions don't really make any mention of this particular issue and I wired it like they said. I kept re-checking believing it to be correct and since it kind of ran, there was no real reason to think I had it wired wrong. Plus, I did all the MSD troubleshooting procedures with no apparent issues.
So just for kicks, this AM I went out and switched the wires. Two pumps on the throttle, turned the key and the car fired instantly and easily and stayed running. I was relieved but completely annoyed at the same time.
Need to start from scratch on tuning now but at least its starting and running right now so I have a proper baseline. Live and learn I guess. Thanks again for all the replies.
Glad to hear you fixed it, I had this happen once, The problem i found is some pick-up coils have different color wires, this can get confusing.
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: RMCHRGR]
#1595154
04/21/14 11:25 PM
04/21/14 11:25 PM
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Joined: Aug 2003
Posts: 43,129
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,129
Bend,OR USA
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Quote:
Quote:
Glad to hear you fixed it, I had this happen once, The problem i found is some pick-up coils have different color wires, this can get confusing.
The pickup wires on the unit I have are gray with black tracer and black. I used the connector and harness from an old MP chrome box.
From what I read, the polarity might have more to do with the terminals on the connector as opposed to the colors of the wires. Kind of makes sense since I never would have thought the lighter wire would be on the negative side.
The black wire on the Mopar electronic distributors is the negative side of the mag. pickup regardless of the other colored wire . I use to run my pump gas Duster between 14.5 and 15.3 at idle AFR on non ethanol Oregon 91 octane pump swill, I ended up leaning the part throttle fuel AFR down to that also It really made the car easier to drive than when it was between 12.2 to 13.3 AFR    It kept the spark plugs a lot cleaner also
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Need advice, plugs fouled, backfiring thru carb
[Re: RMCHRGR]
#1595157
04/23/14 04:40 PM
04/23/14 04:40 PM
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Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
B G Racing
master
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master
Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
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Quote:
Quote:
Sometimes is the simplest things that can reek havoc on an ignition system.
Yep. That would be me.
Thanks for chiming in though, would never have even thought to switch those wires for any reason. I'll be honest, I had no idea what you were even referring to until I went back and read up on it.
My post was clarified by a few other members,the condition you discribed brought to mind the first thing was distributer wires were crossed.This is a common error.That should have been the first and simplest check and remedy.We have seen this time and time again,people spend a lot of time and dollars chasing in many directions for this very issue.We had a lot of racers haul cars long distances and we have checked and corrected this in just a few minutes usually before they even unload the car from the trailer.The first indication is when someone is using MSD boxes with mopar or other brand distributers and splice the connectors in line.
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