Help getting 200 to idle

[Anonymous]

I have a 65 stang with a 200 inline in it. The car idles alright when sitting in park or neutral, but when put in gear it can barely stay running. I can hear a slight miss in the engine in park, but I swear it's going to throw something when put in gear.

Here is the laundry list of items I have changed out so far. I'm looking for some help in diagnosing this issue.

Head was rebuilt about 2 years ago.
New rocker assemby from fordsix
rebuilt carb, original style, installed about 4 years ago.
New plugs/wires

About 10 years ago, my dad had the old 3 speed manual swapped out with a C4. The car has never idled well, before the conversion or after.

My thought is the ignition or carberation is to blame. Since I replaced the carburator, I hate to go back there, but you know how poor rebuilds can be. I was thinking my next step would be replacing the points with a pertronix, but after reading the forum, I think I may try to do the DSII conversion.

Any suggestions would be appreciated.

 

[fordconvert]

Make sure the basics are coverd and working. Check your advavce in the dizzy. If you have the Load O make sure you have a SCV carb and it is hooked in the right spot. Timing and idle speed/mixtures work together and when you set them you have to go back and fourth till things get close. Get a timing light and a dwell/tach meter and make sure everything is set and working properly. With a timing light you should be able to get an idea if the advance is at least close. Simple things like point gap/dwell can cause all sort of strange things with the spark. Also make sure your rotor is tight, I have seen many fords where the little clip underneath is broken or missing so the rotor wabbles all over the place. Teflon thread tape on the shaft works to snug them up if needed.

 

[addo]

Are you setting the idle speed in D, with headlights, wipers and blower fan on full?

 

[ludwig]

Ditto to what Addo said. I would suggest the Pertronix just cuz. It is about $80 and you get a stronger spark with that. If you are definitely going the DS2 route, now might be the time.

You may also have a vacuum leak here or there. The main thing is to set the idle in DRIVE. I get it to about 750 RPM and that works real well for me. Revs a little higher, like 1100 in PARK.

 

[Anonymous]

I have not been setting the idle speed in drive with all the accessories running. Will definitely try that. 1100 sounds a little high, but if that is the norm, then I won't feel so bad with a fast idle in park.

I have also wondered if a vacuum leak might be causing part of the problem. The hose going to the transmission makes a tight loop to get to the modulator on the back side. Just to confirm that wasn't causing the problem, I plugged the vacuum hose and received the same results. The only other vacuum is between the distributor and carb.

To be honest, it is a two person job setting the timing and idle speed, especially if it needs to be in gear. My dad's been helping with it and we have been setting it by touch feel, but seem to get same results wether we advance or retard it. I will definitely get a timing light on it. I am also suspecting points as part of the problem, which I want to get rid of. I want to make this car my daily driver, so which is better, Pertronix or DS2? Also, how can I tell the SCV carb and correct hookup point for the vacuum?

 

[random hero]

my 72 maverick had the same problem, replace the cap rotor, plugs and wires(points and condenser if you feel the need). but before you go and buy this, pull the distributor cap and look at the tip of the rotor for corrosion, that was my problematic point, my cap wasn't helping either. i would replace everything i said, just to be safe...gl with it

 

[addo]

As a first mod to the ignition, I'd urge installing the GM module and a suitable coil. Your points can work with it, and the immediate benefit is better sparking. It's described on the "gofastforless" website.

Set your idle speed either to factory spec, or the lowest you can get smoothly - but base timing has to be correct for this to work well. Should gain some RPM shifting out of D, but not masses.

 

[ludwig]

You can do it yourself if you can promote a couple of chuncks of concrete rubble (not cinder blocks) or some 4x4 blocks. Chock the front wheels, let the car roll forward slightly and set the parking brake. Then you can set the idle without the thing running away. You shouldn't have to rev it any until the idle is in spec and you put it back in park. From how you describe the problem, you shouldn't have to worry about it moving in drive at this point.

 

[CZLN6]

Howdy back Water Boy and All:

First, before you change anything else, set the initial advance with a timing light. The stock specs calls for 12 degrees of initial advance. Next set the low speed idle air screw to the highest vacuum/or idle speed. Turn it back in until the idle just begins to drop and leave it there. AKT you can use up to 5 degrees of additional inital advance for extra performance and economy, but listen carefully for pinging. If you get any move the initial setting back 2 degrees at a time until ping disappears. Advancing the initial will cause your idle speed to go up. Be sure to reset after timing adjustments.

Do all idle tests as Lugwig and others have described.

If that doesn't smooth out your in-gear idle, next check the carb and distributor for any sign of vacuum leaks. If you have a vacuum guage a vacuum leak will show up as an unsteady needle. Places to look/listen are; carb to manifold, choke vacuum pull-off, SCV, hose to distributor vacum cannister, and a broken diaphram inside the canister.

If you find any leaks, fix and retune as in the 1st paragraph.

If this doesn't solve your idle problem, check under the distributor cap for corrosion. Clean or replace as needed, Check the point condition and gap. Specs call for a gap of .024" to .026". Time and wear of the point rubbing block on the distributor cam will cause the points to close down in time. This will be most noticeable at the lowest rpms.

After you've covered this much let us know what you've found. AKT a 4 year old 1100 carb is no longer new. A good cleaning by spraying carb cleaner inside and out and running a can of fuel system cleaner through the tank will help the engine run cleaner.

A change to a Petronix Ignitor or to a later electronic distributor is a good idea, but I'd solve your current tuning problem 1st before you add new challenges. AKT if you change to any distributor other than your stock Load-a-Matic you will need to change to a non-SCV carb for the carb and distributor to be compatible.

Adios, David

 

[Anonymous]

Sounds like first thing I'll do is dig out the timing light. I hope to get over and work on it Wed night. It's at my parents house about 45 min away, so I want to get the dang thing drivable so I can work on it at my house.

I may have some further questions about the vacuum lines. I can only think of the manifold to trans, dist to carb, and then the choke heater tube (which I wasn't sure if that held vacuum). If so, I think that line is pretty loose.

Thanks everyone for the suggestions, I'll let you know how it goes.

BTW, has anyone done the upgrade to DS2 from Pertronix that would want to sell their old unit (just the Pertronix, not the entire distributor)?

 

[mceachrw]

i have a ds2 setup on the way that will replace a pertronix 1. i'll probably make the swap next weekend. i would sell you just the pertronix if you don't find one by then.

 

[CZLN6]

Howdy Back:

To clarify- The Choke on an 1100 uses vacuum while the choke is closed, in cold start mode. The vacuum draws air through the tube in the exhaust manifold and into the black disk on the side of the choke. The hot air being drawn in heats the bimetal coiled spring inside the disk causing it to expand and open the choke. This could only cause a vacuum leak when the engine is cold, unless there are problems on the inside of the choke.

Adios, David

 

[pedal2themetal45]

Did you try setting the idle while it was in gear?? In gear the idle should be about 600 to 650 rpm....
with motor at running temp.
Set park Brake
start car
put in Drive
set idle to 600 - 650 rpm..
Tim

 

[fb71]

you said its never idled well, but you never said how it runs. Is it lazy (lacks power), or does it run fine off-idle, just idle crappy? Did you check your cam lift while you were changing the rockers? Wiped (flattened) cam lobes can cause poor idle with a load, smooth idle with no load, and lack of power on accel....

 

[Anonymous]

mceachrw, I'm definitely interested in the Pertronix you have, send me an email of how much you want for it. raberkstresser@comcast.net

fb71, I didn't check anything on the cam when I did the head and rocker swap out. I assume I would need to pull the cam to look at it? This car is 300K+ car. My great uncle did little to it other than change a timing chain I think at one point (darn car is a lemon) . So it's very possible the cam is worn out.

 

[pedal2themetal45]

Head and rocker swap :
are the rockers adjustable and if yes are they adjusted properly??
Tim

 

[fb71]

fb71, I didn't check anything on the cam when I did the head and rocker swap out. I assume I would need to pull the cam to look at it? This car is 300K+ car. My great uncle did little to it other than change a timing chain I think at one point (darn car is a lemon) . So it's very possible the cam is worn out.

that would be the best way. But if you have a dial indicator and a degree wheel, you can do it by pulling just the valve cover and rocker ass'y. You'll need a 10" extention for the dial indicator tip. place the tip on the top of the lifter. Now, you can just check total lobe lift here, by rotating thr crank and measuring how far the indicator travels, or, you can get fancy and add the degree wheel to the equation, and check lift vs. crank/cam position.

 

[Bort62]

I am going to jump in here and say that an extremely flattend camshaft is a very uncommon occurance.

Especially in more than one or two places.

I would exhaust all other posibilities before getting too excited about this one.

 

[fb71]

I agree that's its not common. However, in high mileage engines, its been my experience that all the lobes seem to wear relatively uniformly. And I have pulled countless cams from 260s, 289s and 302s where all lobes had bearly any profile remaining. I just thought a quick check of lobe lift would rule out that factor, and allow him to concentrate on other issues. To many times I've seen folks throw all kinds of external parts at driveability problems, only to come uo empty-handed. They neglect to remember that under the carb and dizzy or efi and edis, is still 'suck-squish-bang-blow'. If those basic components aren't in good shape, the rest of it is pointless. That's all I was recommending.

 

[Bort62]

Absolutely, and the cam I pulled out of my old 305 firebird had some pretty flat lobes on one or two.

It's just not the first thing to check. It's more of an "if all else fails" sort of thing.