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The Road Runner runs and drives! BUT..need help.Update!

Posted By: ONEBADBIRD

The Road Runner runs and drives! BUT..need help.Update! - 09/07/12 09:43 PM

Well the 69 Road Runner is on the road! but...., about 20 minutes into the ride it starts to run rougher and rougher until it dies completely. What I have is a 440 block rebuilt with stock iron heads rebuilt, stock intake, 750 Holley double pumper carb (mech. secondaries), Mopar electronic ignition(all new components), 727 trans rebuilt(with new converter), power disc brake upgrade (front only). So the car has had the timing set and the carb idle adjusted and runs great off the start idles good, runs good under the load of the trans, but after about 20 minute ride or so it starts to run rougher and rougher until it just stalls out completely. It has 195 thermostat and runs cool while driving around 190/195. It has a new sending unit (5/16) in the gas tank, new gas, new rubber lines, new fuel filter. Now to me it just seems related that when everything under the hood warms up it starts acting up. Checked vacuum lines but will re-check again. What do you make of this situation? Have you experienced this similiar behavior with your ride? What should I check next? Thanks, Jay
Posted By: Andrewh

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 09:51 PM

you didn't say, can you restart immediatly?
if not, how long till you can?
once you can does it run fine?

when it is dead, did you check for spark, fuel?
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 10:02 PM

It can be re-started but runs rough still at idle and when put into gear it dies. It has good fuel pressure took everything apart and cranked it over and was pumping good past the filter too, Now I thought the problem yesterday was the vacuum line going from the carb to the brake booster. Found out that this morning it was darn near falling off the brake booster side...so I hooked another hose up and away we went, ran fine stopped for gas (3rd time now for gas at different gas stations). Went about 3 miles then things started acting up running rougher while in gear got her home then she die in the drive. It has good oil pressure too averages about 40 psi give or take depend on the throttle.
Posted By: mikemee1331

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 10:07 PM

sounds to me as if either your coil or your ECU is getting hot. you are running a ballast correct? orange box?
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 10:44 PM

I am running an orange box, Yes, and the ballast resistor 4 pin one that goes with my electronic ignition harness upgrade.
Posted By: meepmeep70

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 10:48 PM

i'm guessing ECU,had a new one crap out on me,at the same time i was trying installing my 6pak,how aggreivating,pertronix now good luck

Attached picture 7369130-drivenperfect.jpg
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 10:52 PM

My orange box is against the firewall along with the ballast resistor and the coil is mounted on top of the intake as stock. I have an (Accel coil yellow super stock) are they junk too? It seems to me the heat is affecting something? I have heard some people running the chrome box but why? It runs great to start but starts running like the timing is off? Is there any way to test any of these mentioned components? Thanks, Jay
Posted By: meepmeep70

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 10:57 PM

not sure how you will test,my car ran great,sputtered and died after 15 min.,cool for a few minutes fire right up,ran great again for 15min,ECU was getting hot(mounted on firewall as well).if it was me i would buy a new one and install,should be able to grab one for 25.00 at autozone or the likes

Attached picture 7369143-rrwowrain.jpg
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 10:59 PM

Thanks for the info everyone so far! Jay
Posted By: Dan Halen

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 10:59 PM

Just went through this with a friends car. When the car stalls

see if you can hold your hand on the carb without burning it. He

added a heat shield under the carb and now it runs great.
Posted By: mikemee1331

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 11:43 PM

Quote:

not sure how you will test,my car ran great,sputtered and died after 15 min.,cool for a few minutes fire right up,ran great again for 15min,ECU was getting hot(mounted on firewall as well).if it was me i would buy a new one and install,should be able to grab one for 25.00 at autozone or the likes

this would be my suggestion. what ohm is the ballast you are using, and no that coil is not junk.
Posted By: RapidRobert

Re: The Road Runner runs and drives! BUT.......need help. - 09/07/12 11:58 PM

Quote:

.if it was me i would buy a new one and install,should be able to grab one for 25.00 at autozone or the likes

this would be my suggestion.

X3. Less likely would be the coil or the pickup (check the gap though). Unrelated to your issue you mentioned a 4 terminal ballast, clarify that if you would
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/08/12 02:23 AM

Well I picked up a new ECU at the local auto parts store and it seems so far to do the trick! Thank you for the advice everyone! As far as the 4 post ballast I'll have to take a pic of it. What I did was pick up new wiring from M&H and the ballast required 2 male prongs on one side and 2 on the other. From reading other post on the net, Since I am using the 4 prong ECU I do not need the use of the 4 prong ballast? I'm learning as I go! The motor is staying running as it should so far so good. Now I need to fix the dash lights, valve cover leaks , exhaust leaks, adjust trans and carb linkage etc..... The joys of the old car I love it though. I'll have to post some pics of her out of the garage after 8 years! Until my next question Thanks again. Jay
Posted By: RapidRobert

Re: The Road Runner runs and drives! BUT.......need help. - 09/08/12 02:37 AM

Quote:

Well I picked up a new ECU at the local auto parts store and it seems so far to do the trick!

Success . I didn't think the 4 terminal ballast harness was used in '69. I'm assuming the 4 terminal ballast will plug in to the harness (has 2 double ends) only 1 way so that you are on the lowest ohm half of the ballast. As you researched the other side of the ballast is not used on a 4 pin ECU.
Posted By: mikemee1331

Re: The Road Runner runs and drives! BUT.......need help. - 09/08/12 11:58 AM

Quote:

Quote:

Well I picked up a new ECU at the local auto parts store and it seems so far to do the trick!

Success . I didn't think the 4 terminal ballast harness was used in '69. I'm assuming the 4 terminal ballast will plug in to the harness (has 2 double ends) only 1 way so that you are on the lowest ohm half of the ballast. As you researched the other side of the ballast is not used on a 4 pin ECU.

you sir are correct. 69 should be a 2 pin. but, don't we all tend to use what we got and make it work? that's half the fun!
Posted By: meepmeep70

Re: The Road Runner runs and drives! BUT.......need help. - 09/08/12 06:50 PM

Well I picked up a new ECU at the local auto parts store and it seems so far to do the trick!.
great,next trip to the store buy a spare,because you will be happy it is in the trunk,even if never needed
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 04:07 PM

Well the car is up to its old tricks again! Took it out last night about 20 to 30 minutes and it slowly started to go down hill with starting to stumble and chugging. I could hear it coming on so I headed for home and as I turned the corner it died out let it sit for 30 seconds and fire it up chirped the tires a few time to keep it running and pulled into the drive in which it died again. Sounds to me like it could be a fuel delivery problem maybe?
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 04:14 PM

It also seems that even when running good when first taken out it runs like an old dog. It just seem like it is not winding up with all of it's potential. So now thinking probably vacuum, or fuel. Assuming it was vacuum related I would think it would stall and stumble from the start not 20 to 30 minutes later? Just thinking out loud. Thanks for any input, Jay
Posted By: mikemee1331

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 04:30 PM

Quote:

Well the car is up to its old tricks again! Took it out last night about 20 to 30 minutes and it slowly started to go down hill with starting to stumble and chugging. I could hear it coming on so I headed for home and as I turned the corner it died out let it sit for 30 seconds and fire it up chirped the tires a few time to keep it running and pulled into the drive in which it died again. Sounds to me like it could be a fuel delivery problem maybe?

this is more consistent with a gradual buildup of heat in the electricial components than it is with a fuel issue. that leads me back to the 4 pin ballast when 1969 only has 2. how old is that coil? and once again, what ohm is that ballast? do you know why your wiring has been changed to a 4 pin??
Posted By: Dougsmopars

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 04:34 PM

I use the chrome box in both of mine. Used them for years in other cars. Never had any trouble with chrome box. Lots of people have problems with orange box.
Posted By: mikemee1331

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 04:59 PM

Quote:

Quote:

Well the car is up to its old tricks again! Took it out last night about 20 to 30 minutes and it slowly started to go down hill with starting to stumble and chugging. I could hear it coming on so I headed for home and as I turned the corner it died out let it sit for 30 seconds and fire it up chirped the tires a few time to keep it running and pulled into the drive in which it died again. Sounds to me like it could be a fuel delivery problem maybe?

this is more consistent with a gradual buildup of heat in the electricial components than it is with a fuel issue. that leads me back to the 4 pin ballast when 1969 only has 2. how old is that coil? and once again, what ohm is that ballast? do you know why your wiring has been changed to a 4 pin??

answered my own question after i re-read your post. your new harness came with a 4 pin. ok then, most likely the 5th pin on your ecu is not being used and you don't need a 4 pin ballast. i reading around on the coil you are using it seems it requires a 1.2ohm ballast. what are you using? i'm guessing a .5 ohm?
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 08:36 PM

SO... upon more inspection I found the wires going to the alternator (running a dual field alternator) that are black and violet that go to the battery side of the alternator that gets clapped down with a nut was just flopping around on there!!! Could this have been part or all of the problem? Its beeen tightened down now!
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 08:48 PM

Here is a pic of some of electrical set up.

Attached picture 7371751-IMG01557-20120909-1531.jpg
Posted By: mikemee1331

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 09:05 PM

no, that doesn't help. here is a diagram of how your ballast should be wired - http://www.allpar.com/fix/electronic-ignition.html - i'm guessing you have it reversed and the coil is overheating.
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 09:17 PM

I will check out that web site. Thanks for your help Mike!
Posted By: SomeCarGuy

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 09:30 PM

You have a bad ground for the ECU. This is consistant with causing your problem. The more heat that builds, the worse it makes the ground. The reason so many people have "bad" ECU boxes is because they establish a new good ground by R&R the box. You were good for a short time until the ground corroded again.

I would run a ground wire from the mounting screw to the battery and be done with it.
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 09:39 PM

You are thinking the wiring on the ballast is reversed? I am just learning this but I thought the ballast could be connected either side with the connections? What exactly is reversed the connections on the coil itself.
Posted By: mikemee1331

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 09:45 PM

Quote:

You are thinking the wiring on the ballast is reversed? I am just learning this but I thought the ballast could be connected either side with the connections? What exactly is reversed the connections on the coil itself.

since i don't know the ohm readings on the ballast you have installed i am going by supplied information on what your ballast 'might' be. one side is 1.2 ohm and the other is .5 ohms. the 1.2 side should be routed to your coil and the .5 side to the box. also, above your post, SomeCarGuy has a very good point. make sure your ecu has a good ground. although a bad ground would just cause the motor to not run. a flaky one would drive you nuts with a work/no-work situation.
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 09:50 PM

From the ECU to the coil is wired correctly. The only wire that is in the harness to the ECU but not being used is (green with a red tracer) still running to the ballast not sure why or where it goes from there must be wrapped up in the wiring harness somewhere?

I can try running a ground wire from the mounting screw on the ECU directly to the battery.
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 09:53 PM

I will check ballast for ohm's Thanks for hanging with me as I try to figure this out!
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 09:55 PM

Whats the smallest wire size would you recocmend should I run from ECU for a ground.
Posted By: mikemee1331

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 10:06 PM

since you don't need a pin 3 on your ECU why not just eliminate it? go to the parts store get a single sided ballast 1.2-1.5 ohm. follow the diagram.
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 10:14 PM

I see now where one side is reading a high ohm reading than the other so, I need to flip them around to be on the correct side for the correct ohms going to the coil.
Posted By: mikemee1331

Re: The Road Runner runs and drives! BUT.......need help. - 09/09/12 10:45 PM

assuming you have them reversed then yes, just flip the top to the bottom. as to the ground, it's just a ground. use what you have laying around. just make sure you have BARE metal to BARE metal.
Posted By: DartGTX

Re: The Road Runner runs and drives! BUT.......need help. - 09/10/12 12:01 AM

Common problem with restored cars and/or new paint. Did you remove the paint behind both the ignition box and the voltage regulator? Bare metal contact provides ground and heat dissipation for both electronic components.
Good luck!

Attached picture 7372048-1970_plymouth_gtx_yellow_black_car_postcard-p239566851075389526qibm_400.jpg
Posted By: ONEBADBIRD

Re: The Road Runner runs and drives! BUT.......need help. - 09/10/12 01:02 AM

Yes, I am doing that behind all my mounts for my electrical connections. Thanks!
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