not runing up over 40 mph and then not starting

[hbb]

I am working on a 62 m37 with oem ignition system 24 volt, and I have seemed to have opened Pandora’s box .I first performed general maintenance on it, lubed, Replaced exhaust system, adjusted brakes and several other odds and ends, when I drained the oil I had about 3.5galans of gas in the oil coming through the fuel pump and the pump was leaking externally also, I replaced the pump with remand pump from finally was able to road test it and when I would get to about 38-40 mph it started bucking like I might have been on the revlimiter .before this repair the vehicle would run 50 mph easily and faster if pushed .
The next day after the road test it would not start, crank no fire. I found one of the fittings at the distributor to be plugged, removed that distributer and installed another distributer that I had, it fired right up smoothed out and ran great in the shop took it out on the road and the same thing 40 mph max, back in shop checked fuel pressure reads 5psi but I did not run it down the road with the pressure gauge on it, then I broke the exhaust pipe loose from the first joint to eliminate possible exhaust blockage, replaced the fuel filter and then back into the distributer and checking I have 3 coils with 3 different ohm reading and I am not sure what the resistance value should be. This has been a week long grind for such a simple system it is sure kicking my butt any suggestions or should I just scuttle the thing! It is a great vehicle other than that one of the best driving ones that I have been in and it is real pretty ( oh yes it is not my vehicle I am helping a friend out) . I have 24 volts at the coil installed and when cranking it will drop per manual instructions.
hb

[cuz]

hb,

before this repair the vehicle would run 50 mph easily and faster if pushed .

With that said the problem came with your repair activities.

Since you didn't detail all the repairs it would be a shot in the dark to make any guesses here.

performed general maintenance

several other odds and ends

You will have to back track each repair and service you performed to see which may be the culprit.

I found one of the fittings at the distributor to be plugged

If this is one of the two vent fittings and you have a warm climate the coil could have become overheated.

Those coils have about three different manufacturers and each have their own specs. The Auto-lite coil used in the 4007 distributor primary resistance should be 6.2 to 6.5 ohms and secondary resistance between 10,000 and 11,000 ohms. You should check the readings with the coil cold and then again with it warm (use a heat gun). Current draw is 3.7 to 3.9 amps @ 24 volts.

[WarrenD]

I think I'd look at the re-manned fuel pump. It might not be working up to max capability. It would seem that something you did is responsible, not likely the exhaust, since, as said above, it was working well before. I'd go for the fuel pump. (I've bought many re-manned parts that were less than functional!)

[hbb]

I apologize for the hit and miss on the events and repairs, let me back track. All was well after the maintenance was finished. It would run right up to 50-55 mph no problem, then I found the fuel pump leaking into the crank case, I replaced the fuel pump with a rebuilt pump and that is when I was not able to get much past 40 mph and it would start bucking/surging started and I was suspect of the pump and ran a fuel pressure test in the shop (at idle and at 2500 rpm) with a reading of 5+ psi.
I then back tracked and checked timing, plugs for fouling and the gaps set at .030, point gap at .020, I then checked voltage at the distributor lead with 24 volts, then checked coil and had 24 volts the road tested again with the same results, not finding anything else with another road test same with the same results. That night I was rechecking suspect fuel pressure and the engine died with 5 psi on the gage, then would crank and not fire I the checked for spark and had no spark ,at that time I had fuel so then with the coil whore stories I stared with checking the coil cooling lines and found a plugged fitting, thinking I cooked a coil I installed a known good distributor and the engine started and ran great in the shop but on the road test I had the same bucking/surging at 38-40 mph, the next morning the engine would crank but not fire, I again checked fuel pressure it was good then checked for spark and no spark but I had good voltages, I charged the batteries thinking I might have too much voltage drop at crank, once batteries were charged I had good voltages good fuel pressure, engine cranks and has good crank speed but no spark.
I do suspect the fuel pump as being my surging issue at speed and I have a replacement coming but the ignition is what is killing me.

[cuz]

For the loss of spark issue:

Are you by chance installing 12 volt coils in a 24 volt truck? They make very identical looking 12 volt coils for that distributor. Are you getting good grounds on the distributor? Do you still get an arc at the points when you leave the switch on and open and close them manually?

What were the resistance readings you got on the coils?

Have you double checked the Douglas connector at the distributor for internal shorting? This is especially suspect when the wiring is old and you just disturbed it.

For the limited high end speed and roughness issue:

Have you done a flow quantity check on the pump?
Have you physically opened the carb and confirmed the fuel level in it?
Have you checked fuel pressure and flow at the inlet fitting on the carb instead of the pump outlet?

[hbb]

Thanks for the reply! CUZ
The coils are all marked 24 volt, the fuel pressure is being read at the carb inlet, and yes I forgot to mention that I removed the carb and checked it for contamination in side keeping the fuel inside and to check the fuel height in the float bowl, and I did replace the inline fuel filter. If I could just get it back running my next step was to install a longer hose on the fuel pressure gage and check fuel pressure at road speed under a load
I have a clean base at the distributor good grounding.
I am just hoping for the right mojo from one of you that have gone through the agony of this simple system, back in the day we had oscilloscopes that you took the hunt and peck out of the but I will beat this beast, I have another loner distributor to install and also a new fuel pump coming to eliminate the possible fuel concerns that started this mess. It has to be something like I cannot find my glasses that I have in my hand just right there in plain sight.

[MSeriesRebuild]

Did debris from the bad fuel pump diaphragm clog passages in the carb? Are you using original equipment reman pumps or some replacement type? Are they being rebuilt using parts compatible with today's gasoline? NOS rebuild kits are a NO NO.

No doubt distributor issues are at hand with the no fire situation, but the bucking issue, I would believe to be fuel related.

Another issue you should check out for sure, how much damage was done to the bottom end of the engine from running it with gas diluted oil in the crankcase? This very issue has killed many a bearing and cylinder wall to the point of no return other than rebuild. Are you positive you are dealing with a gas only issue as the reason for the rise in oil level? The same thing will take place if coolant finds its way into the pan via a cracked block. Either are rather typical issues with this engine.

Feel free to call me at the shop tomorrow, we'll discuss farther distributor issues, etc, if you can't get it figured out, 704-474-4683.

[hbb]

Thanks for the reply Charles;
Yes I did go into the carb inspecting for debris, the gentleman that owns the vehicle had purchased the rebuilt pump from vintage power wagons! But as anything there could be an internal concern with the pump and I agree with that! I have been trying to make a rose out of spare used parts with the ignition and will be getting new points, condenser and coil although I think the coil may be alright. the points and condenser are questionable I remade new internal leads and striped the insulation from the filter and recovered it with heat shrink tubing and rechecked the continuity of all the primary leads and secondary wires and the battery’s are charging. I should have in hand new parts by Thursday, replacement fuel pump and distributor internal parts.
There was not any water in the oil when it was drained, first the oil come out then the gas finished drained into a very clean pan dumped the mixture into a can and inspected for signs of bearing material and there were not any notable signs of bearing damage. I have done a compression test all cylinders are within 5 psi of each other at 104-109 psi and think this would come up a little if I could get it running again. I have also done a leak down and I have less than 6% leak down across the board. When the engine was running with fresh oil after the fuel pump exchange it had no audible wear sounds squeals or knocks.
hb

[cuz]

You mention an inline filter. I see two more possibilities. A loose fuel line before the pump sucking air or a damaged or corroded line sucking are between the pump and the pickup in the tank.

The tank filter may still be installed and been ignored and may be getting seriously clogged up. This would show up as you try to maintain a sustained run at power which may finally suck enough tank crud to limit the already slim flow.

Have you inspected the tank and the in tank filter?

[Cal_Gary]

I'll ask this because I've done this-is the in-line fuel filter pointed in the right direction? That'll starve it for fuel if it is backward....
Gary

[hbb]

Thanks Cuz, Charles,Warren and Cal:
The filter is point the right direction for flow and I will be checking the in tank filter tomorrow! But I did get it running again with a loner distributor that had new points and condenser the coil check out at 6.2 ohms, but I still have a fuel starvation concern. The new fuel pump is not here yet and like I had mentioned I will be checking the tank filter hopefully is should be on the end of the night mare of what can go wrong will go wrong! I will post what happens next and thank everyone that has responded to this .Charles gave me a lot of info today by phone it’s great to have this kind of feedback.
hb

[hbb]

Ok, I have checked and removed the in tank filter and also rechecked to make total sure that the fuel fitlllller is installed correctly. I also found a fuel pressure gauge the is more sensitive to the lower pressures and after running it again with the new gauge and filter removed from the pickup in the tank I have a reading of 3.5 psi ! Below specs . still waiting for the new pump to arrive.
With now figuring out the distributor concerns and get a new pump in it SHOULD BE BUSTIN BUGS IN NO TIME! Thanks again for everyone’s help
hb

[hbb]

I have finally beaten down the beast and made it purr like a kitten! What it finally took to get fire was a coil new set of points, condenser (several attempts with donor distributors) and I was finally able to get spark. Three fuel pumps later with enough fuel pressure to get a min of 4.psi. The one I finally used is from Midwest it is a civilian style and it will run 4.5-5.3 psi. great that problem solved but still falling on it’s nose ,I removed the carb and completely disassembled it and found the main jet way to fat secondary circuit had crap in it also primary jet had some blockage and float was set to low but was still not getting the right amount of fuel in the carb! Out of a pile of parts carbs I found a needle that was .030 shorter and problem completely solved. Starts, idles, runs down the road at 52 mph, starts hot and cold .it took three weeks of messing around with old used parts while waiting for new to arrive but without the donor I would be still fooling with it. Just goes to show you that new and rebuilt parts are not always going to work the way they should, and if you don’t know ask for help and read you manuals. Again I want to thank all of the input that was sent my way on this one. Not one bit of advice was ignored!
hb
But oh yes now I have to repair the right front fender that I scratched.