Rough running Fairlane

My Fairlane wagon is running rough. It starts fine, but when you rapidly apply the gas (put your foot in it), it sputters and sometimes dies but most times will get running if I smoothly and slowly apply the gas.

To recap, it's a 302 with a C4. Last year I put an external trans cooler, new aluminum radiator, new water pump, complete new exhaust system (from manifolds to exhaust tips), new timing chain and gears.

This year, I've put on a new carb (2 barrel), new fuel pump and replaced the fuel filter several times. I replaced the coil and checked the points and plugs. Still runs rough.

I purchased a package HEI ignition from Summit, made by Mallory - new distributor, coil, CD controller, Accel plugs and new wires. I took it to my local hot rod shop for installation. They replaced the ignition system and it still runs rough. Symptoms are more pronounced now.

Shop then removed intake manifold and confirmed the camshaft was OK - it was. They also checked pressure on each cylinder and all were down about 10% so good enough for now.

Anyone have ideas about where to look next? I'm about ready to get a new crate engine....that Coyote engine and a 6 speed would really improve things....

Thanks for your help, jrwscout

 

The hot rod shop wasn't able to tell that it was running rough and or they weren't able to fix it?
Have you checked for vacuum leaks at all? Exhaust leaks? Is the carb tuned right? Just because it is new doesn't mean it was tuned. Sorry if you tried all of this.

 

The shop was able to tell that it was running rough but hasn't been able to fix it. They have done all the work starting with the HEI ignition replacement up to now. They did the compression test and checked the cam for flat spots. The car still isn't fixed and is still at the shop.

I will follow up with the shop on vacuum leak check. We have checked for exhaust leaks. Carb tuning - I didn't change any of the settings out of the box. it starts right up but after about 2,000 rpm things get ugly - stalls, coughs, etc. at about 5,000 rpm there's a slight backfire that you can feel as a hesitation.

Thanks for the tips and suggestions!

 

First thing is that the carb needs to be set up. Out of the box they will run, period. The aid/fuel mixture is off for sure, and the accelerator pump is likely needing adjustment as well. The other thing is, what brand of carb is it? Is it jetted correctly for the engine? It sounds like the jets or metering rods may be the incorrect ones for that carb on that engine.

 

X2 on the carb setup and accelerator pump adjustment.
You can't just stick a carb on and expect it to work right out of the box.
It can take some fiddling.

 

It could be something like a float level adjustment too.

 

Thanks for the suggestions - the carb is a replacement I ordered from O'Reilly's. It's a replacement for the stock 2 barrel - remanufactured original. The shop is closed over the weekend so I can't get to the car. The car ran the same way before and after the carb change. I wanted to put an Edelbrock carb on it but to do that I have to change the intake manifold.

 

I'm gonna say you've a real bad timing chain - did the shop check that?

 

Haven't checked the timing chain, but it was replaced last year (less than 500 miles ago).

Anybody hear that Mallory distributors are problematic?

 

Wow, a lot of responses I didn't realize that many had come in. All good advice here.

1) Check the carb! You say the problem was there before you replaced the carb. This only means that your old carb may not have been tuned. New carbs are not set up for your engine. They are set up to start almost any car and it is up to you from there.
a) Edelbrock carbs I hear are great out of the box. They probably have an adapter so that you don't need to change your intake, but this is just speculation because I don't know everything about your situation.
b) The carb you bought was from O'Reilley's. I don't know how great they are at producing good re-manufactured carbs, but I would suggest googling your carb and O'Reilley and see if you come up with any common problems.

2) You received new exhaust, complete. There may be a leak, something to check out. Leaks in the exhaust can make things funky.

3) Vacuum leak, I know you said you would look into it, but double check and make sure you don't have any open (unused vacuum ports) on your carb. If you happen to have an open port, grab an assortment pack of those rubber vacuum port caps at O'Reilley's. Plug up any open vacuum ports.

4) You asked if the distributor could be the problem. Yes, does it have vacuum advance? Are there weights and spring kits available for it? Again I would google the distributor and see if there are common problems with it.

5) You replaced the timing chain and gears. Did you check the cam while you had all of that off? Any possible bad lifters? Does it make weird noises at 2k RPM or just stall and stutter?

Just some notes: Go with the easiest checks first. Vacuum leaks, carb adjustment. Look up youtube adjusting carb (put in your carb). It is good to see someone adjust the carb.
Even if you replace something, this is not guaranteed to fix the problem even if it is the problem area.
If you take off a valve cover does it look clean inside? Does it look like oil is getting everywhere? Valves can stick and cause weird problems.

Depending on your cam I would not be revving it up to 5k RPM for testing. I would stick to normal driving RPM's for testing. If something is wrong revving it high may cause other problems.

Even if you get that new crate engine you need to learn to adjust a carb properly. It is something that you get with practice and you have a ton of people here who would love to help you out. Lastly, I don't know the situation of the shop that you have your car at, but I would be a little wary of anyone working on my car who could not give me an answer to a problem like this within a week.

Sorry for the long post but I wanted to blab a little about cars today. Others will chime in and let you know whether this is stuff you should check or other things to check. It would be easier if you had the car with you too. Good luck.

 

The Ford 2bbl carb is a good one. It is basically the same one as I have on Nora still. I've had a few of them. LOL I've also had a couple of 302s backed by C-4 transmissions with that same carb. First, I wouldn't be over concerned about an exhaust leak. That 302 is not really particular about back pressure. In fact, a good 2 1/4 inch dual exhaust with an H cross over will free up about 20 horse and about 4 mpg. Been there, done that.

You do need to tune the carb, starting with the idle mixture screws. I've seen some WACKY tuning done on these carbs including one that was operating as a small 1 bbl, because the one side was almost completely closed, and the other so open the metering rod was loose. It still ran, but not like it should have. You start by turning the passenger side adjustment screw in until the idle slows, then back it out until the idle is as high at it goes. There is about 1/16th of a turn leeway. Then you do the driver's side screw the same way. Go back and forth between the two until the idle is smooth and as fast as possible. You will likely have to lower the idle adjustment as you do this to stay in the idle circuit.

To check for a vacuum leak, the easy way is to use an unlit propane torch, turned low, and run it around the base of the carb and along all the vacuum lines. If the idle picks up, there's a leak. Check the vacuum regulator that leads to the distributor. It can fall apart and leak, whether or not it shows. I think there are still some in the Ford parts warehouse. There were a couple of years ago, anyway.

One other thing to check. Make sure the spark plug wires are in the correct order. The older 302x like yours have an 'eccentric' firing order, to say the least, and the engine will idle just fine with the numbers 2 and 3 and/or 6 and 7 wires mixed up (ask me how I know). You just won't have proper power. Check, also, that the wires are not touching. That can cause no end of problems. On these engines especially, wire looms are your friend. If the wires are older, wait until after dark, mix some dish detergent and water in a spray bottle. Start the car and spray the wires. If they are failing, you'll have a lovely light show under your hood.

What kind of plugs are you using? These old Fords do best with el cheapskate Champion plugs, but set the gap for 50 thou. make sure the coil is good, too. I always use the Accel coil, but you have to clip the horseshoe. Make sure you don't mix the polarity. It will run with the polarity reversed, but not give as good a spark as it should.

One more thing to make sure of on these old Fords. There are 2 filters in the PCV system. The normal foam one in the breather housing that everyone knows about. The second is in the oil filler cap, and nobody ever seems to check or replace them. Your local parts store may well have the new filler cap in stock. They are about $8.00. I just replaced the one on Nora when I bought her. The first time I had to add oil I noticed the weight of the cap, looked in, and sure enough, plugged right up. That can cause all sorts of problems.

You are right about the Edelbrock carb. You do need to do the intake as well. I use the Performer series, as they work really well, and are tuned for low end torque. The 1401 carb body is fantastic, but talk to the Edelbrock tech support people about how you use the car. They will tell you which metering rods and jets to use. Both can be changed easily with the carb off the car, but without opening the carb. Great performance, and increased fuel economy, so eventually changing them does pay for itself. Again, been there, done that.

Hope some of this helps.

 

Mike I am so glad a Ford person was able to chime in. Glad to hear your input, I love learning specifics about certain engines. It is amazing how much they differ between engines.

 

Thanks everyone for the input - I am developing a plan of attack for tomorrow morning to meet with the shop and confirm the items you've all addressed. I'll keep you posted - thanks again for the suggestions and troubleshooting ideas!

 

MrMister: I love these old Fords, and won't drive anything but. To my mind, nothing beats them for torque or fuel economy, and with the right parts, tuning them is a snap. The one ting I did forget to mention before is that the Windsor engines need a touch of knock under load. The are spec'ed for 12 degrees BTDC. I normally run about 15 on engines without a knock sensor, since that is where the knock sensor seems to make them run anyway. It doesn't seem to hurt longevity, since I know of one 91 Crown nearing the million mile mark and we've had several of them go in excess of 500,000 miles with no issues at all. Too little timing and they get sluggish and will misfire.

 

Doesn't Pontiac beat out Ford in Torque? I know it beats Chevy.