Hi everyone,
my name is Jonas, I am currently doing an internship for six months in Michigan - Oakland. I fulfilled my dream and bought myself a V8 car. I ended up buying a 1976 Gran Torino with a 400 cui engine in it .

it stood for a very long time so i expected it to improve in power after some driving. It did improve but not enough. I don't think it have the power it should have.

First thing i noticed it backfires when i fully step on it on a red light. So i have to get it rolling a bit before i can step on the gas completely.
Also sometimes it starts not very good if the engine is on usage temperature. It starts up good cold.

I have made some photos of the engine sticker and engine bay, can you tell me what i can exactly read out of it? I already know that there are different egr / smog versions and that after a certain year the 400 have a retarded camshaft due to the emission regulations?

since I am in Michigan, and i am planning to get some carb / intake upgrade after a few paychecks I think i will get rid of the egr stuff and see if it runs better. Since the carb is set up to lean for the egr stuff can i adjust this?

Any Suggestions what i should check for the low power and the backfire on the red light?





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Cheers
Jonas

 

Welcome to FTE!

Congrats on getting your car.

Just my opinion but the first thing would be to go after the backfire. Check the wires and distributor cap to make sure you are not getting a scattered spark due to a crack or other short circuit type situations.

While you have the distributor cap off, rotate the engine until the rotor moves. Then reverse the rotation and note how far the crank moves before the rotor moves. Over 10 degrees, you should consider replacing the timing chain. The new timing set will set cam timing back to "straight up" instead of retarded. That is one step, and don't expect miracles when you do it.

I would also suggest a compression test. If you have a leaking or burned valve, you can get a backfire out of that, in addition to a miss in your engine. (you don't mention one, so good if you don't have one)

Now, don't be upset, but your vehicle came into being at about the lowest point in US automotive history. The power killers in your motor are low compression, and the cam. The external smog stuff like the egr are not responsible for the low power. Removing the egr can open a can of worms including (worse) detonation.

My opinion on the 400 is to go all the way for a fix. Pistons with decent compression, and a decent cam. Intake manifold, maybe headers depending on what you want.

Otherwise, fix the backfire and run it.

Good luck with it.

 

Amen! I agree with everything said, with one exception - the compression test. Instead, I would go with a leak-down test.

My experience with compression tests is that they don't always give a good picture of what is happening. I had an 82 F150 w/a 351W that shook badly at idle, but a compression test said all was well. However, a leak-down test showed that three cylinders had leaking valves - and they were adjacent in the firing order.

 

Quick question: removed dist cap and plugs. How should i turn the engine? Its okay if its in park gear right?

 

Turn the engine with a breaker bar and socket on the harmonic balancer' bolt. IIRC, that's a 15/16" bolt head. You have to do it that way to be able to move it slowly enough to find the end of the slack in each direction.

 

Got it. Crankshaft moves around 5° before distributor moves. Sounds good?

Sorry for bad spelling and grammar. I am writing with my smartphone

 

Your turned it both ways and only got 5 degrees?

 

Distributor looks good. Like replaced. Vac advance moves freely. Plug cables were in the right order. Can anybody tell me why there is an oil puddle right infront of the carb?

Spark plugs and a photo of the hot air tube i try to get a replacement for.

 

 

That's probably not oil but the remains of gas that leaked out of the carb.

But, again, is the 5 degrees the slop from going fully from one direction to another?

 

Yes 5 degrees. Measured the distance on the belt. And measured the diamater of the crankshaft wheel.( Distance on the belt / pi * diamater crankshaft wheel)* 360°

So it needed to turn it 5° to get movement on the distributor in both directions. Measured

 

Well done! Sounds like something I would have done. But, you did use 3.14159 - right?

So, it seems like your timing chain has been replaced. Too little wear for the original. And the plugs look good so the air/fuel ratio is good.

 

Checket the numbers again. 5.054° with german accuracy ;-). Car says 80k miles on the tachometer. But my vin number saiys it should have a 335 in it. I should ask the seller again if there was a engine replacement. Car is 1 owner.

I will try to get a loan compression tester at orileys along with new spark plugs and the hot air tube. Anything else i should check before?

Btw this is my working space and my very limited tools.

 

Checked my pcv valve. Moves freely, but i am able to blow a liitle bit air through it in the direction where it should close? Or is this supposed to be so? Should i replace it?
Heres a picture of the rubber sealing and the inside. If the rubber sealing leaks, could it affect engine power?

 

Nice car. Should be in a movie.

I'd replace the PCV valve and the gasket.

And, for what it could ultimately be, go to Dimora's Build on the 335 Series forum. He put a potent 400 in his LTD.