So- I got this car a few years ago as a project. I ended up letting my brother use it for driving to school and work, and then just started to rebuild it, now that i've gotten it back. Now it’s running rough and I’m at a loss as to why… About the Car… 1972.5 (late model production, half breed between 72 and 73) 302, - Runs Rough, eats up about a ½ quart a month. AT 3-speed on the column. - Rebuilt the tranny (had it done by Proffessional) but now it shifts hard- could it be linkage? Replaced new u-joint because tranny was shifting hard. I put new front shocks in and air adjustable shocks in the back. & New brakes all around Installed Aftermarket (Chrome Fram) Air filter & housing (took off orrigional and disconnected vacume hose. NOTE: My brother did this, so I am unaware what hose he closed off and if he did it properly) I noticed that I had a cap with a hose on my valve cover on the right hand side, and a PCV valve with no hose on the left valve cover. A race car driver told me I needed to have a vacume hose going from my PCV valve to my carb (one day when it started to run rough) So he hooked it up for me but it didn’t make a difference. Earlier I had replaced the PCV valve, so it should be working fine, with little or no residue. Took the points out and put in Electronic Ignition – Later the coil went bad so I replaced it with one I bought for my VW Bug (Bosch) Also replaced the ignition Switch itself (it was sticking) Changed Spark Plugs because it was idleing rough. – Found there to be oil around the MIDDLE of the plug, not on either end. Replaced Valve Cover Gaskets, plugs and wires and didn’t have a problem after that. (Still eats up oil) Changed the wheel bearings out – MY GOD never seen a bearing be eaten away like that! I also put on an old flowmaster 40 series, still in excellent condition it’s just the discontinued style. Would that mess with my compression? I’ve changed out the belts and tightened them down, I heard it could be timing, but my distributor cap locks in place, and I haven’t adjusted it since I got the car, even when I switched over to electronic. And I put a new Optimum battery in it. Questions: -Why would it run rough like this? I have pulled one wire at a time trying to find the misfire (which cylinder) but I can’t distinguish, I also had others listen but it doesn’t make too much of a difference except when I pull half of them. (one at a time of course) It shakes pretty bad. – Would it matter if I threw a 4cyl coil in for an 8 cyl? -Where could I find a diagram, or what is the proper set up for the vacume on this car? -I checked the plugs again and they were VERY clean no corrosion, no oil leaks, ect. -It did get hot on me last week, but I’m pretty sure it was running rough before it got overheated. (I also took the thermostat out for this summer) -My carb is also sticking a little, could the air/fuel mix cause it to run bad? I have adjusted it a little aand wether I go lean or rich it still runs rough. PLEASE HELP! I love this car but it’s driving me to my witts end!
CometKate, You have to adjust your timing after you install the new ignition system. Put a 180F thermostat back in. It sounds like you might have a vacuum leak - hose fell off or didn't get reconnected when you changed air cleaners? A cylinder leak-down test will tell you if there are internal problems and what they are. You need a coil that matches the ignition system you are using. When adjusting a carb start by setting both screws (idle mixture) to 1 1/2 turns out. The easiest way to do this is to turn them gently all the way in with the engine off and then turn each one out exactly 1 1/2 turns. Then start the engine and set the idle speed with the idle stop screw. Set the timing, and then hook up a tach or vacuum gauge and adjust the mixture to the highest reading and then 1/4 turn out. Re-adjust the idle speed and repeat the mixture adjustment - make sure that you turn both screw the same amount. How old are your plug wires? Old wires can cause missing too.
definitly check and set the timing. there is bolt at the base of it that you loosen to be able to twist the housing to adjust timeing. the cap has noting to do with adjusting timeing. what carb is on the car? what weight oil are you useing? the cap in the valve cover with a hose on it, where does that hose go? the 4 cylinder coil doesnt mater. coils are not cylinder count specific. defintly get rid of the air shocks. if you dont want to buy new shocks then just let the air out and leave it the air lines disconected. the shifting on the c4 can be soffened up by either adjusting the vac. modulator or replacing it. paul s will be able to give you beter guideance on what to do with the vac modulator.
How will they hurt my car? I run them a little lower than most people like, (I'm not jacking the a$$ end up or lowering it) I'm just running them at the stock height.
I'll def. put the 180F thermostat back in. There was a hose going to the stock air cleaner (which I still have) but the aftermarket has no vacume attachments, so I had someone attach a new hose from the PCV over to the carb? There is a hose hanging off the carb with a screw cap on it should it be hooked up too? How do you do a cylinder leak down test? Bought the coil yesterday for my car, but I haven't put it in yet, Great advice on the carb, will definately do that, and I did just replace the wires probably 6 months ago at the longest. Checked them each with a replacement wire, no change. Thanks for the help! I'll do all this and msg you guys back on Mon!
I'll def. put the 180F thermostat back in. There was a hose going to the stock air cleaner (which I still have) but the aftermarket has no vacume attachments, so I had someone attach a new hose from the PCV over to the carb? There is a hose hanging off the carb with a screw cap on it should it be hooked up too? How do you do a cylinder leak down test? Bought the coil yesterday for my car, but I haven't put it in yet, Great advice on the carb, will definately do that, and I did just replace the wires probably 6 months ago at the longest. Checked them each with a replacement wire, no change. Thanks for the help! I'll do all this and msg you guys back
Yeah, I've went through a couple filters before I realized it's from my old rusty tank. Fixed that though. thanks
-check and set the timing. I'm afraid I might f*&% it up, how do I know if I'm adjusting it correctly? Will it sound better or worse? It has the stock 2 barrel on it, and it's looking rough, the choke plate sometimes doesn't open all the way but even if I hold it open it doesn't really run better. I have the electronic choke hooked up, and it seems to stick sporatically. I'm using 10W -30 and almost always valvoline, (if not then I spring for redline or royal purple) The cap on the valve cover with the hose is the oil cap. Why are the air shocks bad? What will happen? the shifting on the c4 can be soffened up by either adjusting the vac. modulator or replacing it. paul s will be able to give you beter guideance on what to do with the vac modulator.[/QUOTE]- I would love to hear more about this, please continue! Great! Thanks a ton guys!
to check and set the timing you need a timeing light. its pretty easy to do. hook up timing light per the instructions for the light. usually a clamp to positive side of the battery and another to the negitive side of the battery. then another clamp on the #1 cylinder spark plug wire. the #1 cylinder is the front cylinder on the passenger side. with the motor off look at the balancer. its behind the bottom pully. some where around it are the timing marks they are usually really hard to see. there should be a 10atc, 0, 10 btc, ect... there will be lines for every degree or 2 degrees. you can take some sand paper and clean this area up and use some white out, touch up paint or nail polish and paint the numubers and lines so they will be easy to read. the important ones to paint are 0 and 10 btc (btc= before top dead center). now on the timing cover usually towards the passenger side towards the top is the pointer. it helps to clean it off and put paint on its point. there should be a vac. line going to the distributor. take it off the distrubtor and plug it with somthing. a golf tee works well. now start the motor and point the timing light at the pointer on the front of the motor. you should see the timing marks you painted. stock timeing is usally at the 6 to 8 btc marks. you can usually get more power and economy out of the motor by moving it up to 10 to 14 degrees. you adjust it by loosening the distrubtor hold down at the base of the distrubtor just enough to where you can turn the whole distrubtor. if it hasnt been done in along time it might be hard to turn. once you get it set. tighten the hold down and recheck the timing to make sure it didnt shift when tightening. turn off the motor, hook up the vac. line, and disconect the timing light. take som pics that show where the vac lines are and arnt. we can tell you if they are right or not. check in the transmission section for how to adjust the vac modulator or pm pauls.
the shock mounts are know to tear out of the floor of the trunk from the extra load that air shocks with air in them put on the mounts.
Great, thanks for the awesome instruction on doing the timing, def first thing I'll check when I get home. I appreciate it, I'll have to take some pics and post back up for sure, that would be amazing if you guys could help out on that. (Vacume) And that's crazy about the air shocks, never heard of that before. Def. don't want that to happen. It does ride and handle so much smoother though lol
Shakin/misfire So I worked on the car the other day, took the hose off of the PCV valve and capped the vacume to the carb. Also took off the vacume canister and capped too. I used some starter fluid to check for vac leaks- none, I adjusted idle - no difference with misfire except idled faster or slower took wires off on by one, some cylinders were apparently making it idle worse, and some weren't. (about half) I marked the ones that I thought were bad, replace some wires, to check wires. Ran the same. I pulled wires one by one again, and some made it run worse, and some made it run the same, but they weren't the same as I marked the first time. The motor is sporatically misfiring. I put a 67 VW coil in, (after my last one started going out) as an emergency fix. Could it be that this coil is just wrong for my car, and the petronix electronic ignition system that was put in? Also, in the last few months on my way home, there were 2 different time where were it was REALLY hot and my temp gauge came on for like a min, and I let the car cool until it was off, and continued driving, would this make it misfire? (I took out thermostat at beginning of summer)
did you check the timing yet? you really need to do a compression test. you can get a compression tester at any auto parts store. they have instructions with them. also pick up a remote starter buton when you get the tester. it will make doing the test alot easyer. have you pulled your spark plugs? pull them take pics of them and post them. they can tell us alot. keep them orientated to what cylinder they come out of. what brand and type of spark plug are you using?
