Motor Backfires Thru Exhaust When Trying To Start

[patrickt]

Originally Posted by Jim Coleman

Packtrickt,

I have to get the motor back together first, the water pump, alternator and oil pan are off the car no oil or coolant in the motor.

This will take a couple of days.

Thanks,

Jim

That's fine. I would feel better if you repeated all the steps of finding TDC, rotating the engine around until it is about 20 degrees BTDC, and then move your wires around the cap until the #1 wire is over the rotor. Make sure you have the right firing order, and don't get clockwise and counter-clockwise confused. Triple check all of that and I bet the car fires up and idles on all eight cylinders. Maybe.

[patrickt]

Have we made any progress on this little task?

[Jim Coleman]

patrickt,

It's hard to work with the back issues.

The MRI says I have multiple spinal disc bulges and a tail bone problem as well - instead of just an L-3 problem. Next step is referral to a neurosurgeon.

I got the oil pan back on with a new one piece gasket, but am having some seepage.

I've tried reinstalling the electric water pump three times using several types of gaskets and even the "right stuff" gasket maker and it still leaks. Ordered a new electric water pump today, that should take care of the leaks. The pump should be here in 3 days.

After the new water pump is installed I'll get back to the timing issues.

Thanks,

Jim

[blykins]

DO NOT HAVE SURGERY!

Go see your family doctor and get a referral to a physical therapist. Trust me!

[Jim Coleman]

My wife agrees with you. My health care is with the VA, and I will ask my primary care Doctor to refer me to therapy.

Thanks,

Jim

[blykins]

Jim, see if you can find one that specializes in spine care. Better yet, find one that is familiar with the McKenzie method.

I had 12 sessions of physical therapy to deal with my 1/2" herniation on L5S1. I did about 140 exercises (press ups) per day.

I also had my PCP prescribe an oral steroid pack. That will help reduce the inflammation so the exercises can be more effective.

[bobcowan]

Originally Posted by blykins

DO NOT HAVE SURGERY!

Go see your family doctor and get a referral to a physical therapist. Trust me!

This might be incorrect advice. Disc bulging does not mean you need surgery. In fact, 50% of people with bulging discs do not have back pain.

However, sometimes surgery and sharp objects are the correct answer. And there are more surgical options than discectomy and fusion.

A visit with PT is always a good idea. I'm surprised you have not done that yet. People who do PT prior to surgery have a better outcome.

An EMG might be a good idea. Depending on symptoms and what the MRI shows.

I think a consult with a neurosurgeon is also a good idea. Not to get surgery, but to talk about surgery. What are your options? What are the potential benefits? What are the potential risks? Once you are well informed, then you can make an intelligent decision.

You should also consider a consult with pain management. You want a procedurist, and not a pill pusher. They have some excellent tools that might be helpful for you.

Keep in mind that we cannot eliminate or cure chronic low back pain. We don't know how. Our goal becomes control, and function despite pain. A lot of people don't like it or believe it when I say that.

[Jim Coleman]

Thanks, Bob

Good information.


Jim

[Jim Coleman]

Here's the latest update:

I found and bought a harmonic balancer cover that supposedly has the correct TDC markings, it's supposed to correct slippage in the balancer as it is installed using the keyway as a line up. The water pump came today as well.

Unfortunately, night before last I got up at 3:00 AM to get some Sprite from the fridge, and tripped and fell on my tail bone, may have cracked or bruised some ribs as well. They ran a battery of X rays today, and it will be Monday before the results are in.

The pain will have to subside before I'll be able to work on the car.

Thanks,

Jim

[Jim Coleman]

The results of the X Rays show that I don't have any cracked or broken ribs or spinal injury from the fall. The ribs are still sore, but they will heal. The Doctor will be sending me to pain management soon for steroid treatment.

I installed the new water pump today, and after it was installed found a small plug in the installation bolt sack. Figured out that the purpose of the plug was to seal an unused bolt hole in the passenger side cylinder head. I'll bet that's where the water leak was coming from on the old water pump! So, I'll have to take it back off -- install the plug and use new gaskets. That problem should be solved.

Thanks,

Jim

[Jim Coleman]

IT STARTED !!!!

Problem must've been the balancer has slipped. With the cover and the correct markings on it, I was able to set it up exactly as instructed. I also had one wire crossed. I only let it run long enough to make sure it had good oil pressure and shut it off. (The water pump leak is also fixed).

Now, can someone tell me the correct break in procedure so I don't wipe out the cam ? I used Royal Purple break in oil.

Thanks !

Jim

[Gaz64]

Jim,

Any flat tappet camshaft run-in involves immediate startup, no mucking around to fire up etc.

Timing light to be fitted, and timing to be verified at around 30 degrees by a second person at startup. Lock distributor.

So the engine needs to start first go, and run at 2000 rpm plus, oil pressure verified and checked during the procedure.

Run engine at 2000 - 2500 varied in this speed range, do not idle, do not blip the throttle. Engine needs to run for 15 - 20 minutes.

Monitor engine oil pressure, engine coolant temp, and engine sound.

Timing can then be checked at 2500, and then at final hot idle speed.

Gary

[patrickt]

Well that's good news. I take it you don't have a solid flat tappet in there.

[Gaz64]

Originally Posted by patrickt

Well that's good news. I take it you don't have a solid flat tappet in there.

I think Jim needs to VERIFY what camshaft he does have.

In post No.1, he says solid lift (lifter) cam.

Now is that a solid flat tappet, or solid roller?

Gary

[patrickt]

OK, you know the SFTs can be kind of finicky on break in.

[Jim Coleman]

The camshaft is a GM 30-30 solid lift cam from the 70's. Sorry for the confusion.

Thanks,

Jim

[Gaz64]

Here's an article on the 30-30 cams:

https://www.enginelabs.com/engine-te...lock-camshaft/

Gary

[Jim Coleman]

Gary,

Bought an non digital timing light so I can set the timing correctly. After readjusting the valves using the TDC reading on the new cover, I think they are right. Motor started, and I ran it for about 10 minutes -- then it hit 200 degrees and I shut it down. When I shut it down it backfired once really loud. I assume it was too lean. Hopefully I didn't kill it! Could you give me the complete timing procedure again so I can now get it set right rather than trying to set it "by ear" ?

Thanks again,

Jim

[Gaz64]

Where did you set the timing at idle?

Gary

[Jim Coleman]

Gary,

Don't remember exactly; think I got it started at 30 degrees before TDC. Didn't have a timing light.

When I first started it, it was running terribly -- I had set the valves using the harmonic balancer TDC markings, which was off. I readjusted the valves using the TDC markings on the new balancer cover and it fired up and ran much better. Then, I tried moving the distributor and listening to the motor as it was warming up. After 10 minutes, it hit 200 degrees which scared me, and I shut it down. That's when the loud bang happened thru the exhaust and I haven't tried to restart it. Thought I'd try to start it tomorrow and see what happens.

It's 2:30 AM here and I have to get some sleep so I won't be able to answer you until tomorrow.

Thanks,

Jim