68 Died help diagnosis

My son's 68 289 just stopped working.

History: Parked it Last night, this morning would not turn over, ran battery dead.

Put fresh battery on the Car and now it turns over....but will not start?

Fuel pressure is 5 PSI.

Compression is > 100 on at least 7 of the 8 cylinders. (we tested them individually and I'm not certain we did not miss one.)

Bright spark, from plug laying on the fender

Plugs look bright white and bone dry.

I can see the accelerator pump putting enough gas into the intake to make a puddle in the intake manifold. (looking in the carb with the throttle open, plugs still dry. (Yet all plugs still dry?)

Starting fluid has no effect.

Timing on #1 cylinder checks out with timing light.

Oil is fine, no strange colors or scents.

Strange Symptoms.... With engine turning over I can plug the exhaust with my hands and I get no or very little pressure.

I can put my hands over the Carb and It does not seem to ":Suck" very hard.

Son says Gas milage was really bad last few days?

Any Ideas? I would have guessed broken CAM etc... but all the cylinders compression checked out.

Things to try On Thursday:

Vacume Gage (Forgot this one until I sat down to type this.)

Remove Valve cover and verify every thing is moving as it should.

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nospam
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that's kinda low, and i wouldn't be surprised if that's the problem. I'm not certain what the lowest compression is that a v8 will still run on, but my 302 took its final dump in a similar manner when the compression was in this range, and i couldn't restart the thing either. Went for a rebuilt at that point and had no more problems, obviously

Reply to
vince garcia

More information....

Took the Rocker covers off, all 8 valves on that side look to move apropriatly.

Hooked up a vacume gage, With the throttle clocsed and the engine cranking at a good speed I Got almost no reading on the vacume gage.

More info on the compression... Every cylinder we tested was in the 115 to 120 range. All significantly > 100. I'm not 100 certain we did not miss one

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nospam

How are the points?

Reply to
Mike Lapke

Hmmm... not sure if cranking rpm is enough to register any kind of useable reading on a vacuum gauge anyway. I would think that an extremely low vacuum reading while cranking would be normal. If the compression pressure is ok, then the vacuum should ultimately be ok too, so I don't think I'd worry about it. If you have decent compression and fuel (which you have), then it must be some ignition related thing. I know you mentioned that you have a bright spark. Is it indeed "bright"? Because I've seen cases where a spark was present, but was weak, and the engine would not start for anything. Need a GOOD spark. The new battery was a good idea. I'd look over the whole ignition system, points, coil, etc... maybe even throw in a set of new plugs, cheap enough. Double-check the ignition timing. I know you tried starter fluid with no success, but what is the status of the fuel in the tank? I'ts hard to understand that you are not even getting a mere "cough" from the engine when you have compression, fuel, spark and timing. Even if the valve timing or ignition timing was out a bit, the engine would still fire, at least a little. Something in this list must still be out of wack. Best of luck and let us know how it goes.

Reply to
jack0554

I used to have a '67 Galaxie 500 with a 289. At about 199,000 miles or so (original engine and transmission) I snapped a rocker stud. When I first got the car at 189,500 miles it took 100+ MPH runs to the shore great and occasional high RPM acceleration, but I guess it finally gave out. I don't blame the thing as about half the valve tips were worn at an angle, putting sideways stress on the rocker shafts and valves.

In any case, I got a new set of 289 closed chamber heads for my '68 Galaxie

500s 302 and then put my '68s open chamber heads on the 289. With the open chamber heads the 289 compression was 100 PSI on the dot across 6 cylinders, and the two cylinders that were giving me trouble on the '68 read low. Compression on the '68 went up to ~165 PSI in 6 cylinders and the two trouble cylinders were a bit low. After a 5 minute test drive and a little spinning of the tires I promptly killed what was left of the rings in those two cylinders. Car smoked a lot out the valve covers and dipstick as I tried to get it home and finally died, never to restart, presumably from a vacuum leak or maybe more cylinders giving out. I'm about ready to get a new shortblock and put my new heads, intake and carb on that.

Anyway, I drove the '67 like that for a good 3,000 miles with no trouble other than blowing oil from badly worn valve guides and burnt valves and poor gas mileage (11-12 MPG highway) from being very low on compression in two cylinders. It ran pretty good though. At first I was barely able to get up to 83 MPH on the highway but after 100+ miles like that I realized my coolant was low and the engine was just overheating out the wazoo. Filled up the coolant system and it would make it up to just over 100 MPH. With the original closed chamber flat rocker/slotted pushrod hole heads I was able to get up to just shy of 120 MPH.

So to surmise, yes a Ford V8 can run just fine on 100 PSI compression... On

6 cylinders no less. Furthermore, if such a wounded beast of a tiny little 289 can haul a 2 ton Galaxie to over 100 MPH it ought to do just fine in a small car like a Mustang. These are durable engines when taken care of properly... My '68 was not (damned uncle drove it into the ground for 7 years before I saved it), and therefore needs a new engine at half the mileage my '67 had on it. Nonetheless, these old Fords are simple and reliable cars.

The biggest problem I've had with my Galaxies is points (particularly on long highway trips), so I always kept a spare set of points with me, among other parts and all my tools in the trunk (part of my prepared for the apocalypse kit, lol). As Mike suggested, check the points. Either file them and re-gap or better yet, spend a few bucks and get a new point set and condenser (even if you've done it recently). Once you get it running again buy a Pertronix kit... I know I'm getting one when I get my Gal back together.

Cory

Reply to
Cory Dunkle

I had a similar problem with a 1972 Mustang. Ended up being the ignition coil. It would spark when I tested it, but evidently not strong enough to jump the gap under cylinder pressure.

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News at Mediacom

It was a combination of three things.

1)Carb base gasket was completly shot, naking big vacume leak. (Also found cracked vaccume hose to PVC valve.)

2)Had flooded engine washing oil out of rings. Oiled all cylinders and did compression before and after. Compression improved significantly. (Also learned that I have three weak cylinders, this motor is not long for this world. Anyone reccomend a goood Rebuild source Near San Diego or LA?)

3)Weak ignition coil.

We fixed all three tonight and now it starts and runs well..

We have been rebuilding this car for several years as a Father Son project, everything has been replaced but the Motor. It's now time to do the motor.

(17 yr old son want s to hop it up, father thiks he drives it too hard already...)

Reply to
nospam

It sounds as though you've checked all of the basics. Now it's probably time to take it to a professional and let him work some magic. Pay him/her well.

Regards,

-JD

--------------------------------- JD's Locally-Famous Mustang Page: http:/207.13.104.8/users/jdadams---------------------------------

Reply to
JD Adams

Today while rooting thorugh old papers and receipts I found on the back of the receipt the numbers from the compression test on my '68 after installing the new heads. The passenger side bank were all 175 PSI, except #4 which was

180 PSI. My two bad cylinders #5 and #6 were 135 PSI and 60 PSI respectively, and 7-8 were about 165 PSI. When I get my new shortblock (next week if all goes as planned) that should give me a bit over 180 PSI I'd imagine. I hope that's not too much pressure for a daily driver on pump gas. Should be fine on a fresh shortblock I'd imagine. Worst case scenario I suppose would be that I get a bigger cam to bleed off a little pressure.

Cory

Reply to
Cory Dunkle

That should probably be ok, but I wouldn't want to go any higher than that for safe pump gas operation. You will probably need to run 93 octane... but that's good... you will make good power. 170 - 180 psi sounds optimum.

Yes. But if you go with a "bigger" cam, make sure you get one that has a later intake valve closing event. Also, do not "advance" the cam at all... keep it straight up, or if anything, retard it a tad. Ultimately, you want the intake valve closing event to be as late as possible... within reason (to reduce cylinder pressure). This is the only thing that will effectively reduce pressure and detonation tendencies. Some people think that more overlap is what you need, but overlap itself does not bleed off pressure, and has much less effect on reducing detonation. You could even use your existing cam, but just retard it by 4 or 6 degrees. This would reduce your cranking compression pressure by about... maybe 5 psi.... maybe not enough to make a drastic difference, but if you are right on the line, retarding the cam is one relatively easy and free way of aiding the problem a bit.

Here's an article having to do with camshaft / compression ratio / cylinder pressure relationships... it's based on Pontiac V8 engines, but the theory should apply:

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Reply to
Speedy

Sounds good. I actually have 94 octane available here if I need it, but I'd rather not do that as it's about 15-20 cents more than 93, and only available at a handful of stations. That and it would stink when I drive up in New England as they seem to only have 91 octane up there.

Thanks for the information, I thought all I would need is a bit more overlap to bleed off pressure. Very informative site too. It would seem from that information that I'm right around the boarderline of acceptable pump gas compression. But as you said, that's a good thing if I take advantage of it and get it set up properly. My Galaxie is a heavy car at 3,600 lbs, probably just shy of 2 tons with myself, gas, and the stuff I normally carry with me in the car. If I can get more power out of the small engine going into it then that's great.

One other option I had was to buy a 289 short block. The 289 should have low enough compression pressure to run on 87 octane. My old '67 Galaxie with 289 had closed chamber heads and ran on 87 octane. As a plus the 289 would rev easier, but I think I'd do better with the extra cubes and higher compression in a heavy car. It would be nice to run on 87 again, but I don't mind paying for 93 for the extra performance. I don't drive a whole lot anymore (only 100-200 miles/week) so it's not like it would be killing me as in when I was putting 500+ miles/week on the Gal. That's expensive at $40 a fill up. So anyway, it seems to be a reasonably safe gamble to get the 302 short block and top it with these closed chamber heads. If it pings it shouldn't be too hard to correct.

Cory

Reply to
Cory Dunkle

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Overlap itself will not reduce cranking cylinder pressure at all. Moving the intake valve closing event later in the cycle is the only thing that will reduce cranking cylinder pressure. Greater overlap WILL however reduce peak combustion pressure by diluting the combustible mixture with exhaust, and thus will help to reduce detonation too, but has a much less effect per degree of change in terms of reducing detonation, than reducing compression pressure. What may be confusing is that most cams with a "later" intake valve closing event will most often inherently have greater duration and thus inherently more overlap... generally. But the main point here is to realize that if you happen to have a relatively small cam with an early intake valve closing event (and minimal overlap), and then if that cam happens to be advanced a good deal, you may be able to reduce detonation a decent amount by simply retarding that cam. No need to go out and get a "big overlap" cam. I've seen some aftermarket cams that come with a ground-in advance of 5 degrees, and then I've seen people take these very cams and advance them another 6 degrees (usually because they do not know any better or because they did not take the time to degree in the cam and actually measure what they were doing)... and maybe on a small engine with low compression this is fine, but if you are dealing with a higher compression engine that has detonation tendancies, this would be a mistake. Another note... take two cams with the same intake and exhaust duration.... but let's say one has a tight lobe centerline, and the other has a wider lobe centerline. The tight lobe center cam will have more overlap and an earlier intake valve closing. The wide lobe center cam will have less overlap and a later intake closing. The wide lobe center cam is the one you want... at least for a street engine that is on the borderline of detonation due to relatively high compression. For a daily driver, you certainly do not want too much overlap anyway, because that will hurt economy, raise emissions, and give the engine generally poor manners at low rpm (low vacuum, etc). Of course all this info is very general.

Reply to
Speedy
2)Had flooded engine washing oil out of rings. Oiled all cylinders and did compression before and after. Compression improved significantly. (Also learned that I have three weak cylinders, this motor is not long for this world. Anyone reccomend a goood Rebuild source Near San Diego or LA?)

Try ' Don and Harold's ' and ask for Ken or Don.They are located in the north part of Long Beach at 500 E Wardlow,just off the 405 fwy.They did some good work on my 351w,and they have several mustangs in there at any given time.I'm not 100% sure if they do rebuilds there,but if not they would certainly be able to recommend someone. The phone number is 562 426 7321

Andrew

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me

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smoke

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