440 Rough Running-A bit at least

Posted By: toyotajeep

440 Rough Running-A bit at least - 05/13/11 02:31 AM

I have been driving my 440 Dart Sport for 10 miles at a stretch or so. Engine is used but no smoke or low op with new gaskets and a .450-.455 cam, SD intake, and an Eddy 600 (just a carb to get the car going carb-runs perfect on my other rigs).

The car has a bit of a rough running condition out on the road at cruise. Kind of a light bucking or backfire here or there at speed. If you rev it at idle it doesn't clear out quite as smoothly either as it should. Just kind of hick ups and pops mildly here and there but will pull RPM.

Timing is this: It has about 36 degrees at 2300 RPM with the vacuum advance plugged. I set this with a dial back light. I had to go over 20 degrees initial to get that though. It starts ok and pulls 17 +/- inches at 800 RPM idle. Runs good down low.

The wires and new, plugs are new, I switched cap and rotor etc. with another set off of the shelf.

The car acts the same at cruise no matter where the timing is set at within reason. The car is driveable as is, but it drives me nuts with the mild issue.....

Is there a chance that the control box, coil etc. could be part of this?

The ballast resister is stock 1974. The control box is stock. The car sat for 20 years so who knows what is what there.

The coil is an Accel Yellow coil that is round, I believe it was from a points application, not sure that it matters.

Thoughts or ideas? I should say that I drove it very briefly last summer and it was the same.

Carb? Ignition?

Thank you, ROB

Posted By: 6bblFLASH

Re: 440 Rough Running-A bit at least - 05/13/11 02:46 AM

Re-check the plug wires/firing order. I`ve done that more than once

Also kinda sounds like a fouled or cracked plug.

Posted By: RapidRobert

Re: 440 Rough Running-A bit at least - 05/13/11 02:50 AM

Quote:

It has about 36 degrees at 2300 RPM with the vacuum advance plugged. I had to go over 20 degrees initial to get that though.

Thoughts or ideas?

The dist slots are only giving you 7.5 in the dist 36-21=15 divided by 2=7.5??. Real quick might plug in the vac adv & see if it gets better/worse/same

Posted By: rbkt65

Re: 440 Rough Running-A bit at least - 05/13/11 04:29 AM

son had same thing on warmed over 360 in truck and we fianlly found out that w/stock ign box aftermarket coil is a no-no-try stock coil and see if it help-also better carry an extra box just in case

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/13/11 05:48 AM

I was thinking about this for awhile tonight. For all of its faults, the car has always had a similar issue to this, or it has never left. The very first day I drove it it felt the same.

That was another engine etc. What ever it is has been wrong with the car from day one when I first started the car.

I have noted your statement regarding the coil. I have a fair pile of spare ECU's and coils etc. and I will try and replace one tomorrow.

And Robert, I am sure there is some distributor work to do. It have a few parts ones etc. to mess with along with different degree advance plates etc.

Whatever is causing this, it is does not appear to be fuel related since I have had three different carbs, and two engines.

Keep in mind, this is a project car that does not get driven. I think I have 20 miles max on the car. I am finally closing the deal and getting it done.

ROB

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/13/11 03:29 PM

I pulled the coil off. It is the Mopar one that Accel makes for Mopars and ends in M, or at least the PN says so.

So far here is what I have done, all with parts on hand.

1. Different coil wire
2. Different coil
3. Different coil polarity
4. Different ignition control box

No differece, car runs the same. I am going to go through the firing order again, and then start checking wires with my DVOM.

It is a bit like a bad plug wire..

More later.

ROB

I'm thinking I wil

Posted By: imfixinmopars426

Re: 440 Rough Running-A bit at least - 05/13/11 03:58 PM

first...check the compression on all cyl's..i hate to say,but sounds like a valve leak.

Posted By: cjs69mope

Re: 440 Rough Running-A bit at least - 05/13/11 04:56 PM

I have been chasing the same problem on my stroked 440 for 3 summers.
i have finnaly determined the the the problem was the carb .
it was to lean in the transisiton circuit of the carb .
This is where you run most of the time when crusing, changing main jets only masked the problem and makes the engine run to rich.
For you you may want to look into a couple of theads , Tunning with an o2sensor . and Demon carb ?'s . There is good info about tunning the idle feed restrictions to get the car to cruse at the proper a/f ratio required by the engine . every motor needs its own a/f number keep that in mind . hope this helps you . CJ

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/13/11 06:43 PM

Ok. Also, I discovered that the advance plate (or whatever the proper term is) is "mushy feeling" for lack of a better word, it is loose.

I am looking into that here in about an hour.

ROB

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/14/11 03:14 AM

OK. I fiddled with it some more and test drove it again.

The "rough" running is definitely RPM related. It somewhat bucks and so forth at certain speeds. I don't have a tach in the car right now, but it is in second at about 25 MPH or about 55 MPH in 3rd.

Currently my total timing is 36 degrees advance, with the VA plugged and at about 2500 RPM as measured with an underhood tach.

I have done the following, more as learning thing than anything, today:

Different ECU
Different coil
Checked plug wires - all within spec
Checked firing order 3 x's
New cap and rotor
Different pick-up in distributor
Etc. I think you get the point.

Same thing. I can advance / retard timing. It runs a bit different, but it still has the same basic running situation as before.

I am looking closely at the carb. I haven't touched it. It runs so well at idle you over look things. I have never ran it at all on the road, only on this car. The rest of the time it is a low RPM plow truck carb.

At WOT it is smooth and pulls pretty good, but at any constant RPM in the normal driving range it isn't happy.

As some have said, it may be a lean thing. It is an Eddy 600 on a 440 and I live at 4500 ' elevation. Sounds like there could be some lean going on.

Without starting the usual carb fight, I do have a 3310 that I have ran on other rigs. I may throw that on. Not much more to do electrically right now.

One member mentioned doing a compression check. I need to do that as well next week.

Thoughts on the situation being more fuel related? I have a new tank and new fuel pump etc.

Thank you for your help. I will get it going.....

ROB

Posted By: RapidRobert

Re: 440 Rough Running-A bit at least - 05/14/11 04:03 AM

Quote:

At WOT it is smooth and pulls pretty good. it may be a lean thing. It is an Eddy 600 on a 440 and I live at 4500 ' elevation. Sounds like there could be some lean going on.

Thoughts on the situation being more fuel related?

Block the metering rod pistons up & (re)try it

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/14/11 04:35 AM

I just came across a calibration kit for a 1406 on my shelf. If I could, I would like to keep the carb that is on it and put some miles on the car first before I start up grading it etc. If I give up a few HP so be it for now.

I will have to read up on this carb this weekend since I haven't had to tune this type of carb before.

So, you think I may be experiencing a lean surge type condition?

ROB

Posted By: RapidRobert

Re: 440 Rough Running-A bit at least - 05/14/11 04:43 AM

I have a 1406 on a 318 & it's lean on the main metering and the choke comes off WAY too fast and the choke pulloff (internal piston) is not functioning. Ain't dug into it yet (waiting for Santa to give me a LM-1) ex for richening up the rods/jets & when it's warmed up past the choke stage it's OK. Yeah I'd block them up for a 15 min test or toss in rods w the thinnest "cruise" step

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/14/11 01:28 PM

I read the Edelbrock manual that came with my parts. I have three sets of most everything so I should be good.

Set the float height
Install different rods / jets or some combo
Repeat until I get what I want

I can see that a AF guage would be handy.

It looks pretty straight forward. I want to put some miles on the car, and then go chasing performance. There are enough other things to work out first though.

Posted By: RapidRobert

Re: 440 Rough Running-A bit at least - 05/14/11 01:34 PM

Quote:

Set the float height
Install different rods. I want to put some miles on the car,

On a level surface start car for 10 seconds then pull rods & carb top & fuel level should b at the notch on the float baffles on each side (iirc the dry setting is 7/16"), reinstall top & perfect time to use the richest "cruise" rods in the kit which ain't even close to being too rich & you'll b up and running in minutes

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/14/11 01:48 PM

I will post up on Monday with my findings. The car is at work right now which is 20 miles away.

My students and I did learn the inside of the distributor pretty well, and I think any advance work shouldn't be too hard now due to the quality time spent inside of there.

I will confess that as a 4x4 guy if it runs decent it is ok and you leave it alone. Approaching this as a performance car is totally different. OK isn't enough.

They give you a matrix with different percentages to change the settings. Should I go clear to the Rich settings and then see what that does?

I would say that I am feeding close to 100 more cubes than the carb is designed for so I think it would work.

Posted By: RapidRobert

Re: 440 Rough Running-A bit at least - 05/14/11 02:07 PM

Quote:

Should I go clear to the Rich settings and then see what that does?

yes, check the float level & right now dont even bother w the charts/formulas, just toss in the richest rods in the box, the "cruise" step which is not the end tip but the next "step" up from there & from my exp w the 1406 you'll have a smile on your face. This'll give you some driveability & let you get some happier miles then later you can work on the dist as sumpin dont sound kosher w it & it needs to be dialed in b 4 the carb then come back to the carb but for now I'd simply richen the carb. Might even put in at least .095" (or bigger) jets in & need just the right width screwdriver shank so you dont scrape the sides going to the jets plus the right length and width blade & push down fairly hard straight down on the jets to break em loose & not gouge them as mine at least were in there solid then put the new ones in MODERATELY snug but not tight. Not being patronizing, just wanting to share my exp w my 1406 EDIT meant .098" or bigger

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/14/11 02:35 PM

Not worried about patronizing. I do gear work, rebuilt my own 727, paint cars, do body swaps (4x4 thing) etc.

What I have never done is really get a car dialed in. I am finding now that I have officially crested 40 years old that I don't want to drive something that does not run well. I won't drive it / ride it / use it unless I have to.

Posted By: Dodgem

Re: 440 Rough Running-A bit at least - 05/14/11 03:01 PM

Check the distributor for bushing wear. if it is wobbling back and forth sometimes the problem.
says .006 replace think that is from center so .012 back and forth total it is toast. I've seen them with .050 total and yes they ran like crap!

Posted By: imfixinmopars426

Re: 440 Rough Running-A bit at least - 05/14/11 03:07 PM

Quote:

I would say that I am feeding close to 100 more cubes than the carb is designed for so I think it would work.

i ran a 1405 on a 440/.484 cam challenger w/air+3.91.street car,drove all the time and went on trips too.car ran 13.65's all day,and im a freak about drivability. i jetted/needled+spring kitted the carb,and it was great! decent fuel mileage,great low rpm-5500 power also. your carb will work fine if jetted,and if any issues are repaired...so ck the comp yet? yep it sounds like lean cond? my supercoupe was doing that crap,at cruise,and i jetted the 1406 around to take care of most of it,but she has 128k,and is tired. so keep us posted,good luck,mike

Posted By: RemCharger

Re: 440 Rough Running-A bit at least - 05/14/11 05:32 PM

Quote:

Without starting the usual carb fight, I do have a 3310 that I have ran on other rigs. I may throw that on.

Thank you for your help. I will get it going.....

ROB

Posted By: Jeremiah

Re: 440 Rough Running-A bit at least - 05/15/11 04:37 AM

Quote:

Quote:

Without starting the usual carb fight, I do have a 3310 that I have ran on other rigs. I may throw that on.

Thank you for your help. I will get it going.....

ROB

^100

Posted By: Swiss_Robert

Re: 440 Rough Running-A bit at least - 05/15/11 10:51 AM

When you're going to check everything - check the spark plugs again.

I've had some similar problems with new plugs - one of them was somehow "bad". If you still have the old ones, give it a try and put them back.

Just to make sure...

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/16/11 08:39 PM

Ok Update time.

I jetted the carb richer, and followed the eddy manual to a T. It is better, but not done I now have a bit of a bog, but some of the irritation is gone.

Here is what I have noticed so far:

If I am accelerating, even gently, it is fine with no hesitation. If I cruise gently it does its bucking thing.

Some good news is that the distributor has well in excess of .025 play at the top. Which is twice what it should be.....so the poster above is on the right track I hope.

So back to the distributor. No worries, the kids and I like this stuff

And I will pull the plugs too.

I should have an update this evening with the findings.

FWIW- timing is 22 BTDC at idle, 35 at 2500 RPM both with the vacuum advance plugged.

I'll be back.

ROB

Posted By: Dodgem

Re: 440 Rough Running-A bit at least - 05/16/11 09:02 PM

You can replace the top bushing well a machine shop can it's 1/2 oilite bushing!
A new MP dizzy is probably best!

Posted By: RapidRobert

Re: 440 Rough Running-A bit at least - 05/16/11 09:08 PM

plug the vac adv in for a quick test & see if it affects it (the bucking)

Posted By: 1968RR

Re: 440 Rough Running-A bit at least - 05/16/11 09:10 PM

Quote:

Ok Update time.

I jetted the carb richer, and followed the eddy manual to a T. It is better, but not done I now have a bit of a bog, but some of the irritation is gone.

Here is what I have noticed so far:

If I am accelerating, even gently, it is fine with no hesitation. If I cruise gently it does its bucking thing.

Some good news is that the distributor has well in excess of .025 play at the top. Which is twice what it should be.....so the poster above is on the right track I hope.

So back to the distributor. No worries, the kids and I like this stuff

And I will pull the plugs too.

I should have an update this evening with the findings.

FWIW- timing is 22 BTDC at idle, 35 at 2500 RPM both with the vacuum advance plugged.

I'll be back.

ROB

You may want to adjust your timing curve. At idle, 22 degrees seems like a bit much for your combo. Get a kit and open up the distributor. Try to get a curve that gets rid of the bog (maybe 15 degrees at idle and 35 all-in).
Also, using the 10% ethanol gasoline can cause a bog if your carb was originally tuned for pure gasoline.
Good luck.

Posted By: Challenger 1

Re: 440 Rough Running-A bit at least - 05/16/11 09:45 PM

Quote:

They give you a matrix with different percentages to change the settings. Should I go clear to the Rich settings and then see what that does?

I would say that I am feeding close to 100 more cubes than the carb is designed for so I think it would work.

Yes I agree with you, that 1405 is gonna be lean on a 440. I think it will run fine on a 440 but it is gonna need smaller rods and bigger jet's. for sure, imo. I have run the 1405 for 20 years now all around the US. From Pikes peak to Key west. I have tuned that carb a lot. There's nothing wrong with them. Jet it up and I'm sure it will help.

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/16/11 10:56 PM

I haven't driven it yet but we found the distributor was way out of whack. I now have 18 degrees initial, with 35 at 2500 RPM, vacuum advance off.

Also, the reluctor gap is much tighter and my timing is not bouncing all over the place.

I'll report back after the test drive.

Rob

Posted By: Dodgem

Re: 440 Rough Running-A bit at least - 05/16/11 11:14 PM

Yea I usually only run .004 reluctor gap just so it don't hit.

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/17/11 02:39 AM

OK.

Update time. Runs even better. I put some smaller diameter metering rods in it since lunch and it is snappier, and the bog seems to be gone.

I ran it without the vacuum advance hooked up. Still has a slight (very slight now) miss going on. It is so minor that I may be getting it confused with some other things. Hooked it back up, it is basically the same.

I should note that it has 3" exhaust with those cheap Flowmaster knock offs that Summit carries. So anything that is slightly off is amplified by the exhaust. Although it is really not that loud.

One thing I really noticed is that it is quite sensitive to timing. 32 total at 2500 is not enough, and 38-39 is too much. No more bouncing around on the timing with the distributor fixed.

I pulled some plugs (4 of them) they were all a light grey. They are Autolite 85's.

I am going to do some driveline work tomorrow, and plug wire clean up and rerouting etc. and check the plug gaps etc. and then take it for a real spin.

I know to some people it may seem like I have fiddled with this forever, but it is learning time. I have spent essentially zero $ on all of this and have made a lot of progress. Much of it is due to the help of this board for which I am much obliged. It has been somewhat fun too, the kids like it.

And yes, I will be adding a real carb in the next few weeks. This carb is just temporary for now to get the car going. My 3310 needs some very serious TLC, so I will likely run one of my Thermoquads next.

Quick question, what do you gap your plugs to? .035 or more?

More information to follow tomorrow most likely.

Posted By: RapidRobert

Re: 440 Rough Running-A bit at least - 05/17/11 02:45 AM

Quote:

I know to some people it may seem like I have fiddled with this forever, but it is learning time. what do you gap your plugs to? .035 or more?

You're fine bro. Start w 35 & can exp w 30 and 40 maybe even more.

Posted By: Dodgem

Re: 440 Rough Running-A bit at least - 05/17/11 03:25 AM

Posted By: Challenger 1

Re: 440 Rough Running-A bit at least - 05/17/11 03:29 AM

Posted By: Jeremiah

Re: 440 Rough Running-A bit at least - 05/17/11 06:17 AM

Quote:

My 3310 needs some very serious TLC, so I will likely run one of my Thermoquads next.

What does the 3310 need?

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/17/11 01:26 PM

I thought about this since you asked. It leaks a bit here and there. I think most of it is the front bowl fitting.

But it never has idled at all hardly. No adjustment etc. is fixing that. But.........when I was installing it on my good running 460 the other day I noticed that it was rocking when bolting it down. I think the base plate is warped. I never really thought to check that.....but if it was, it would make sense.

I seems to run decently outside of idle. I also picked up another parts carb that is the same model last fall. I'll get them together and see what I can come up with.

The car is fast (to me, rookie 440 guy) , in a mild DD type of way. I will say though, that I am sure I am leaving alot of HP on the table.

Today is driveline work and some wiring clean-up day. I have several of my students that are really into this thing. One of my freshmen can take the distributor apart and put it together on his own and do a good job of it. He has a lot of promise....

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 05/27/11 03:36 PM

Update time.

I took the car home from the shop and got busy with other stuff around my house etc.

I ended up putting the small Eddy that was on the 440 back on my F..d 460. Guess what, it runs the same on that engine. Crisp, clean down low..........and a higher rpm miss type of a sound, just like my car.

So, I am going through my 750 this weekend. I have new gaskets and a complete unmolested parts 750 that is the same PN.

We'll see what results I get from the Holley.

Just an update. More to come.

ROB

Posted By: toyotajeep

Re: 440 Rough Running-A bit at least - 06/03/11 05:38 AM

OK. I know a few of you (including myself) hate it when there is a post and no update. So here we go........

I took two 3310-2 750's to work. One I had gone through last year and used the blue gaskets. For whatever reason it never would idle right etc. I personally think it had been messed with by a PO at some point. Leaked etc. I was not a fan of it.

So I took my other carb that I really don't think anyone had ever been inside of and combined them. Cleaned everything out etc.

Results:

Runs real nice. Good even vacuum around 16 Inches. Nice secondaries. No leaks and so forth.

There is still a very slight issue at a constant speed, but it is nothing like before. It could be the 3" exhaust with dumps etc.

Power is mucho better. I would say the engine is happier acting and whatever HP I picked up, it was worth it.......It feels like a 440 in an A body.

I should be driving it to work soon, and I will give an update after I get some miles on it next week.

*One EZ Question- I have 70 jets in it, and the other had 72's, is there likely much to be gained by switching right now?

Thanks for the advice.

ROB