Stumped.......

Rick C · Post by **Rick C** » Thu Mar 18, 2010 9:10 am

Put the M37 away for the winter.....drove it in garage and took batteries out. Put the batteries back in today and tried to start. Nothing showing on gauges when I turn ignition switch on and when I hit starter pedal I get a spark at the pos terminal where the battery jumper goes. Batteries are back where they came from ......what changed over the winter??????
Rick

Carter · Post by **Carter** » Thu Mar 18, 2010 9:49 am

Clean the battery terminals and cable ends thoroughly, corrosion of these will produce the problems you describe.

Montanaorbust · Post by **Montanaorbust** » Thu Mar 18, 2010 10:05 am

Rick.. I am sure you hooked your batteries back up correctly, but i would go back and check again....

Josh · Post by **Josh** » Thu Mar 18, 2010 2:04 pm

put a multi-meter across them separately, and then in series to see what you are getting voltage wise. Check both at the terminal stud itself, and at the cable lug.

m37jarhead · Post by **m37jarhead** » Thu Mar 18, 2010 2:52 pm

While you're at it, check the contact points on top of the starter.
Four screws lets you remove the unit on top of the starter and then you
can r&r the unit. Mine had a similar problem years ago. It sure looked
ugly in there. I cleaned up all the corrosion and the starter spun like new.

hbb · Post by **hbb** » Thu Mar 18, 2010 4:13 pm

The most important thing to do is load test the battery’s are in good shape and they have not sulfated in the cells over the winter with the long time of no charge going back into them and if they serviceable to check the water level. When you load test the battery it should not go below 10.5 volts under load and recover back to 12.5 volts min. but at least put a charger on, but take the battery’s out and out of the series.
hb

Rick C · Post by **Rick C** » Thu Mar 18, 2010 7:39 pm

Ok, got it going. 2 issues. Cracked clamp on the negative terminal so there was a gap (hence the sparking) and a worn wire where the wire from the harness crosed over the switch on top of starter. All fixed and she lives. Now I can work on the high speed hesitation issues.....
Gotta love old trucks
Thanks all
Rick

hbb · Post by **hbb** » Fri Mar 19, 2010 8:21 am

Rick;
Go to the thread that I had posted about the not wanting to go over 40 mph and coughing sputtering, I had ended up with a whole rats nest before I reached the end of it but you most likely have a fuel flow or pressure related concern with high speed hesitation. Maybe even blockage in the carb but first check you fuel pressure at the carburetor inlet, it should be no lower than the 4psi range.

hb

cuz · Post by **cuz** » Fri Mar 19, 2010 11:38 am

Are you experiencing a hesitation at high speed when you attempt to accelerate?

Or are you reaching a certain speed and can go no further?

Makes a big difference in where to start looking.

Rick C · Post by **Rick C** » Fri Mar 19, 2010 3:52 pm

It acts funny at the top of the RPM range in 2 - 4 gears. When in 4th and hitting just over 35 is won't go any faster and sounds odd..hard to explain... It actually gets better if I pull a hill.... I put a Carb from midwest on and teh only other thing I want to do is have the fuel pump rebuilt. Already checked the in tank filter and it looks good.....
Rick

cuz · Post by **cuz** » Fri Mar 19, 2010 8:37 pm

Is the loss of high end power new this spring?

Rick C · Post by **Rick C** » Sat Mar 20, 2010 6:19 am

No, it was dogging me last year too. Started after I changed the oil last year. Seemed to get worse after the new carb was added......

cuz · Post by **cuz** » Sat Mar 20, 2010 7:03 am

Have you run a vacuum test and compression testyet? If so what were you readings?

Rick C · Post by **Rick C** » Sat Mar 20, 2010 3:07 pm

The compression test wasn't so hot...all around 100. Been like that since I got it in 1996 though....

cuz · Post by **cuz** » Sat Mar 20, 2010 9:32 pm

The vacuum test can tell a great deal.