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Discussion Starter #1
So, in an effort to enjoy my 66 this summer. I opted to give the ole 289 a shot at getting it running before pulling the motor and putting my 331 roller I built and 4r70w swap in. (That plus I really need to get the controller and would like to switch to fuel injection)

Previously was a 2bl car, that I've never had on the road. Bought it as a project, but it did run. And ran okay, it did idle fine and would rev alright. I wouldn't say it ran great, as I had a few carb/fuel issues previously. But, I drove it to the paint shop, and it hesitated and fell on her face when trying to give her gas. When I took to the paint shop, there were some troubles between nasty fuel, clogged carb, and other bs while it was there. But, it was driven back from the paint shop to my house. (Mind you the shop is about 3 blocks away).

Since I got it back, drained all the fuel out which was skunked. I put on a new fuel pump. Purged the lines. New fuel sender. had the distributor recurved. New PCV valve and hoses. New Spark Plugs

So, I tossed on a used Weiland intake (pre stealth) and a used (rebuilt) Edelbrock 500cfm carb. Started up but idled horribly. It seemed that I was getting a vac leak around the intake and carb base. Chopping it up to be probably not the best idea to throw a used intake on there. I bough a street warrior weiland the other day. Added a carb spacer to ensure good carb seal.

It will start fine with just the twist of the key. Timing set at 12degrees (vac advance removed). For about 60 seconds it's nice and smooth, but once it warms up and the choke opens the idle is all over the place from 775rpm to 1050rpm. vaccuum is sweeping along with the idle everywhere, and dipping very low. I've attempted to adjust the idle speed, the idle mixture screws, the timing. Nothing is giving me any sort of smooth or consistent idle, except for running the idle at like 1200rpm. I've checked everywhere for vac leaks, and I'm getting no reaction spraying carb cleaner anywhere. Adjusting the idle mixture screws doesn't really do anything seeing the idle is all over the place. I can fully tighten one side with no reaction. Move it out one turn, and tighten the other side, no reaction really. Fuel pressure is good at the carb at approx 5 psi. Dies immediately as soon as you put it in drive or reverse. And the exhaust is popping a bit here and there. Cap has some carbon soot at each terminal inside. Firing order is correct for the 289.

I don't want to chalk this up as a carb issue, but wanted to see if anyone thinks there might be something bigger here? I'm a dummy when it comes to carbs for the most part, as I've spent most of my life tinkering with fuel injection and fox bodies. Be honest, hold no punches. Should I continue to fight the 289 or pull it and move towards the 331 i have? Is this something simple? Can it just be the carb needs a proper rebuild? Am i a dummy? I don't want to just keep throwing money at it.

 

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Discussion Starter #3
I'd start my diagnosis looking for vacuum leaks attributed to poorly sealing gaskets.
I looked, I'm not see any at all. Used Felpro 1250 (i think that's the part number). Used guide studs to set. Black RTV bead on front and rear. I'm getting no reaction with spraying carb cleaner around the intake/carb base/vac lines. I'll give it another go here again.
 

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Discussion Starter #4
I should mention, if you pull the PCV valve hose from the carb while it's running, It dies immediately. Don't know if that matters or not.
 

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Discussion Starter #6
I'm getting a slight reaction when spraying the car cleaner on the back side of the carb to intake surface.

Originally when I put on the used intake, before I bought the spacer, the carb rocked a little on the intake. Could the carb base be warped?
 

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Discussion Starter #7
Also, when tightening the drivers side idle mixture screw the car will die.

No reaction on the passenger side idle mixture screw.
 

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Does it have a C4 trans? Maybe the diaphragm inside the vacuum modulator is ruptured and that's where the vacuum leak is. Remove any and all vaccum hoses from the carb and manifold and then see how it runs.
If an idle mixture screw has no effect when turning it then internal passages inside the carb are clogged.
 

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Discussion Starter #10
Does it have a C4 trans? Maybe the diaphragm inside the vacuum modulator is ruptured and that's where the vacuum leak is. Remove any and all vaccum hoses from the carb and manifold and then see how it runs.
If an idle mixture screw has no effect when turning it then internal passages inside the carb are clogged.
Yes C4. Vac modulator is disconnected as that is where my vacuum gauge is connected.

Side note- it's only popping from the passenger side bank. For what it's worth all header tubes are temping around 285-350 degrees when it's running EXCEPT cylinder 1&2. Cylinder 1&2 are running around 180-200.
 

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Discussion Starter #12
All this screams of a vacuum leak. Dollars to doughnuts it is indeed between the carburetor and the intake. Yeah, check the intake for flatness.
Klutch, do you think the vac leak can cause the exhaust popping? I know the new intake is flat. The carb i have concern about though.
 

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If its consistent popping in the exhaust at idle that sounds like its just one cylinder and the vacuum gauge needle is swinging you could have an "exhaust" valve problem. An intake valve would pop out of the intake. How fast and how far is the needle swinging? Could be a burned exhaust valve, broken valve spring, sticking valve. An ignition or fuel problem does not change the sealing ability of the cylinder. It will effect the needle differently than an actual cylinder sealing problem. If there are no fuel or ignition problems and all cylinders are sealing equally the needle is steady. If one is not sealing every time it is that cylinder's turn to draw a vacuum it doesn't and that causes a momentary drop in vacuum and the needle drops.

Do a compression test. If you find a bad cylinder remove the valve cover and inspect the springs for a broken one. Then get the cylinder on TDC. Remove the spark plug and stick a rubber tipped air nozzle against the hole and see if you can here air coming out of the exhaust pipe. Takes two people. Air out the exhaust is a burned exhaust valve. Air out of the carb I a burned intake valve. Air out of the oil filler cap is bad rings or a hole in a piston.

Very good Holley vacuum gauge diagnosing video. Unfortunately it stops before showing you all the different readings.



748156
 

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Discussion Starter #14
If its consistent popping in the exhaust at idle that sounds like its just one cylinder and the vacuum gauge needle is swinging you could have an "exhaust" valve problem. An intake valve would pop out of the intake. How fast and how far is the needle swinging? Could be a burned exhaust valve, broken valve spring, sticking valve. An ignition or fuel problem does not change the sealing ability of the cylinder. It will effect the needle differently than an actual cylinder sealing problem. If there are no fuel or ignition problems and all cylinders are sealing equally the needle is steady. If one is not sealing every time it is that cylinder's turn to draw a vacuum it doesn't and that causes a momentary drop in vacuum and the needle drops.

Do a compression test. If you find a bad cylinder remove the valve cover and inspect the springs for a broken one. Then get the cylinder on TDC. Remove the spark plug and stick a rubber tipped air nozzle against the hole and see if you can here air coming out of the exhaust pipe. Takes two people. Air out the exhaust is a burned exhaust valve. Air out of the carb I a burned intake valve. Air out of the oil filler cap is bad rings or a hole in a piston.

Very good Holley vacuum gauge diagnosing video. Unfortunately it stops before showing you all the different readings.



View attachment 748156
I posted two videos, one showing the vac gauge as soon as I start the car and then after it warmed up a bit, and also another video of the exhaust popping. The vac gauge is all over the board after the choke opens up. But based on this chart, it would indicate Leaky Head Gasket. Awesome chart and video, I just wish the video would finish and not stop at #6.
 

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Those compression readings don't really point out a single bad cylinder do they? They are all a little low. When you do a compresion check you remove all the plugs so the starter can spin the engine fast. You also hold the throttle open so the air can get into the cylinders. Squirt some oil in a cylinder and see if the compression comes up. That would mean the rings are not sealing good.

Try removing the spark plug wires on that side and then just set them back on the plugs. With the best insulated pliers you can find remove one wire at a time and see how that effects each cylinder. It will have a large effect on a good cylinder and little or no effect on a bad one.

You can do a leak down check on each cylinder. That is one tool I still don't have. We had one built into the old Sun scope at work.
 

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Discussion Starter #18
Well, leakdown is showing 100% for all of 1-4 with each piston at tdc. Either I've got a horrible leakdown tester or This bank of cylinders is completely shot.
 

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That is with the cylinders each on top dead center. You might get a little leakage on the rings on a worn-out engine but there should be none coming out the exhaust if the exhaust valve is closed. Loosen the rocker arms on that one cylinder and see if the you still here the leak at the exhaust. If you do that was the popping noise in your exhaust.

I'd tell you to go to work and start saving some money for that new engine but you can't.

I once had a compression problem on a 289 when I was 16. I use to shift on this 150K mile motor when the valves floated. The engine and broke off an exhaust valve and there was a cloud of white so thick I could not see anything in the rearview mirror. In my later years I would have said this engine fails "the dipstick text". If you can remove the spark plug and check the oil level through the hole using the dipstick it fails the dipstick test.

748185


I ended up building this 289 with 351W heads, GT-40 sodium filled valves. GT-40 Lemans cam, Cobra intake. gear drive Hipo manifolds. Mallory dual point distributor Holley 650 double pumper. I drove it for a few years and then traded it for a real 1966 Austin Mini Cooper S which I should have kept. The guy took my fake '65 GT-350 vintage road racing and about a year later he called up pissed off. Because he had pulled a valve through the aluminum retainer during a race. He chewed me out for using them. I didn't build the heads, they came off the neighbor's 12-second drag Mustang after he rolled it. I was 16, how was I suppose to know you didn't run aluminum retainers on the street?

That was 1977 and I could get just about get any Hipo Ford part at the dealer. The guy that sold me the heads was the parts counter man so I got a good discount. Actually he use to bring the parts home and I paid him there. Now that I think about it he was probably stealing them and pocketing my money. I didn't keep those exhaust manifolds very long, I stuck headers on there.

That was back in the stone age. No aftermarket heads. roller cams or roller rockers. You can see the poly locks for adjusting the solid lifters. That was trick stuff back then.

748186
 

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Discussion Starter #20
Ahhh, love stories of disaster.

Cant start building? Lol, it's almost done. Kinda have to know when it's time to move on. I gave the 289 a valiant effort but had already started the 331 build a while back.

So, I switched gears today towards that for the time being. Just gonna have to cut my losses and offer the 289 to someone that's looking for a steal and an original motor.
748191

88 roller block, bored 30 over, decked to 8.195. DSS fx flat top pistons cut for trick flow heads, lunati roller, trick flow fast as cast 170s. Weiland stealth. I just need a front cover, pushrod, a converter for the 4r70w, mount for trans, and shorter driveshaft. Then to decide on air/fuel delivery. I really wanted to go Holley sniper efi, that's what I was mentioning about funds.
 
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