Im almost at the point of getting a honda!

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JR

JR

Pissed off senior member.
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Lets just say that there is a 360 out there that was rebuilt about 7000 miles ago. It ran great, idled great, no problems at all...until one day it started to run like crap. When you first start the motor in the morning it fires right away, warms up to 180* you bump the throttle to drop the idle and away you go. About 10 min. later it starts to run rough, theres a low miss through the exhaust, you have to power brake it to keep it from dieing.
Back in the driveway you put it in park and it smoothes out, you give it some gas and right off idle it starts to sputter and backfires out the exhaust with a loud crack, unhook the vacume advance, give it the same amount of gas and nothing. It reves fine until about 2500 rpm then it starts to cut out and sputter, rev it higher and it smoothes out but there is still a little sputtering.
if you do a quick rev from idle to say 2500 rpm as soon as it drops back down to idle it runs rough, slowly bring up the idle and its rough all the way. Shut off the car and start it again and it will idle fine. With the idle adjustment screw 1 1/2 turns in like usual there is now 5lbs of vacume comming out of the pass side port on the eddy carb (2 diferent carbs, one was brand new). If you cover the carb with your hands the idle drops and the car will die.

Now lets say that the fuel system from the tank to the carb is fine, the charging system is fine, the ignition system from the pluggs to the box is all fine and all the wireing under hood is fine as well. There is no oil in the water or water in the oil, the temp stays right were it should be and the oil pressure is great.

You have tried

2 different carbs (one was freash out of the box)
4 distributers
2 sets of new plugs
new wires
2 caps
2 rotors
2 ign. boxes
new fuel pump and filter
new ballast
new voltage reg
new alt.
new intake gaskets (cam looked fine when intake was off)
new carb base gaskets
doucheing the hell out of everything with carb cleaner, propaine, and wd40 looking for vacume leaks and found nothing.
there is no water in the gas.


What would your guess be? Internally what could cause a motor with all new gutts do this? Vacume leak, where?
 
only thing i can say about honda....first i have one, second i have never had a problem, well now it sputters but cause i dont wanna spend money on tune up, all money going to cuda, and it gets 25mpg with bad driving....its nice and reliable, and only cost me $50 woooo :toothy7:
 
Have you tried Holy Water, Satan begone!

I have no idea but I bet your tired of chasing this problem around, that sucks, good luck to you. Hope you get it figured out.
 
Hell, at this point I would welcome satan into my car! :twisted: Maybe he would chase off whatever is screwing with it!
 
what about your gas tank, is it old or new, did you shake up some crap from the bottom of it?
 
Its old but there is no junk comming out. I have pumped about 5 gallons out total just to check for anything.


On a side note. sdolsay, what mounting brackets did you use to mount the TA tips on your car, the stock AAR or TA ones? I have a set of TA tips that we are going to put on my girlfriends 72 scamp.
 
The tips were already on the car when I bought it, I can look under it and check if you want me to, I didn't know there was a diff, now you have me curious, I'll have to look into this :)
 
If you could can you take a pic of where their mounted? I found some of the TA/AAR hangers on ebay for 10 bucks each I just don't know if they will work on an A-body.
 
Wow, seems you have swapped everything but the motor itself to try to rectify the problem......buy a honda :lol: :lol: (joking)..I know you stated your fuel lines are fine, however did you pull out your fuel sock in the tank? Just another idea!
 
I haven't taken it as far as to drop the tank or pull the sending unit (the last thing I need is a gas leak to go along with everything else) I cranked the motor over several times with the fuel line into a jar and it pumped out normal and clean. if **** comes to shove I may pull the sending unit just to check everything.
I keep thinking back to how it backfires and sputters when I hook up the vacume advance so that is kinda steering me away from the fuel. At this point I am just tired of thinking about it and Im going to goto bed and drive my girlfriends 93 Mazda to work....again....for the 3rd week....I still hate cars. disgust :banghead: :sad8: :sleepy1:
 
Must be frustrating I am sure. I will check with my old man for you when I see him. H has been an old school mechanic and is usually pretty good at these riddles.
 
Sounds to me like your cam timing is retarded. Check the specs on your cam card and degree the cam. While you're at it, change the chain and gears if you haven't already. You'd be amazed how many "rebuilds" reuse the old chain and gears. Just my $.02. Hope this helps.
 
i would check the wiring where it comes through the bulkhead. corosion in the connections gave me the same troubles on a 71 duster
 
I'm guessing you mean 5 inches of vacuum? What's your vacuum reading right off the intake manifold? If it's 5 inches, it's way, way low unless you have a monster cam.

It's so freakin' hard to diagnose a problem over the net. When I was a professional mechanic, I would use all of my senses to track down a problem. What does it SOUND like, does it SMELL rich, where do I FEEL the vibration, what does the exhaust LOOK like. It really is a ***** doing it this way. To bad you don't live closer.

Good luck and let us know if you come across any more information that might help us help you.
 
360scamp,

Here is a pic of the TA tip mount, not pretty, but it works for now :)

BTW it looks like me and por15 is gonna have a date under my car this summer, man thats gonna be a ***** to prep :)

PipesSmall.jpg
 
Don't despair you will get it tracked down. If in doubt take it to a good mechanic who you can really trust. Nothing wrong with giving in and sending it to a professional.
 
I switched to a clear glass fuel filter and I've never looked back, I like being able to see what's going into my motor.

Your car sounds EXACTLY like my 273 I had last year. Exact same problems. It drove me crazy. I changed the points. Changed to electronic ignition. Changed the carb. Changed the timing chain. Changed the intake manifold. Eventually I changed the motor! :)

Actually, I finally came to believe I must have a head gasket problem and pulled the heads off. While off I decided to take them in to be checked and the machine shop said they were toast. My cam was worn too and there were just too many strikes against the old 273 so I took it to the dump and threw it over the wall into the scrap metal pile....damn that felt good! I installed a 318 I got for free and except for a bit of a timing thing it's running great and I can't believe I didn't put this sucker in 5 years ago!

I know this doesn't help, but you're not alone.
 
After reading you list of things you have changed and it sounds like it runs fine when it's cool and gets worse when it warms up... try a new coil.


Chuck
 
Just to rule out the tank and lines, you could get a small gas can and hook it up straight to the carb since you said it does it in neutral. If it starts to run better, there you go, if not, at least you know your entire fuel system is OK. Easier then pulling the tank.
 
I had almost the same problem on my 74 duster right after I bought it.
The to things I found was : 1.the rocker arms and shafts where shot and the the cam was going flat on three lobes. 2. A broken wire in the harness going to the distributor right at the connector.
Hopes this helps
OG
 
If it starts fine and runs properly for 10 minutes before showing signs of problems, I agree with opinions above to check or switch out coil, check pickup/sock in fuel tank, and check all related wiring and connections, especially in the bulkhead area. I would check these relatively easy items before going deeper. Mike
 
The wires at the bulkhead are in good condition on bolth sides. I cleanned the terminals and replaced any wires that were brittle or cracked with ones from a spare harness. The coil is an accell super coil I have also tried an MSD blaster 2 coil and had the same problems.

The chain (double roller) was brand new and the cam is a delta cams regrind with new hyd. lifters. Its pretty much a 340 cam that is set at 4* advanced on the keyway. It has run great for about 7000 miles daily driving until now.

A friend of mine suggested a blown head gasket maybe between the cylinders due to no water in the oil or oil in the water.
 
I had a similar problem in a pickup, it was exactly as you described it. Take your gas cap off and drive around to see if the problem re-occurs, if it does not, then you have a clogged vent tube, when the cap is on and engine running it is causing a vaccum in the tank that builds up and fights the fuel pums for the gas. The best think about this fix is that its free if it is your problem. Possibility two, the pickup in the tank is clogged with junk.

Check out what the tank in my 68 looked like.

100_0162.jpg


100_0161.jpg


What it is supposed to look like:
100_0434.jpg


Here is where the vent tube is:
100_0437.jpg
 
Pull the valve covers & watch the rocker arms when running to see if they are fully opening the valves.

Did you check the timing chain marks? This probably isn't the problem though since you said it runs fine when cold.

When you install the intake make sure you put a little silicone around the intake ports.

Also, like others have said check all the engine wiring. I would just replace it if it's original since Evans Wiring has them for around $100 new.

Good Luck
 
There is no vent tube off the filler on my 73, I rewired the entire engine harness and I have pulled the valvecovers and everything is working like it should all the rockers were going up and down all the way and getting oil.
The headgasket is about the only thing that I can think of. But I dont wanna do it damn it!!!
 
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