401 wont crank

[guffey24]

Alright guys, I am not sure where to go with this

before I rule out the obvious

I will start here

I have fuel, carb probally needs a rebuild after sitting for a while

I have spark

I started retracing my steps when I was rebuilding the motor to figure out If I had done anything odd or missed a step

I built this using a great book/soft copy of

BJ Builds An AMC

well I get into the section where it starts talking about installing Cam/Timing gears/Drive gear

I did everything by the book so I thought

I didnt retard or advance the timing so I set the lower gear on the zero mark

this is the step that I got ahead of myself, I honestly didnt pay attention to this. I slid the chain, and gears on as a complete unit

[next step says engage the chain while trying to line up the timing gear marks. The mark on the lower gear should be closet to the mark on the upper gear. Then slide the gear on the cam snout. Look at the gear alignment closely. Make sure the marks are in a straight line with the cam and crank. If it's off, then remove the cam gear, skip the chain a tooth and re-install it. One tooth off is bad news!]

Did I screw myself or what?

[1980_Cj7]

So you don't know if the timing marks on the timing gears were lined up or not?

Man, I am so glad I invested in the cam degreeing kit and took the time to use it. After what happened with our engine on the first rebuild, it was well worth the peace of mind knowing the timing was right, especially when you think of the damage that can result from it being wrong.

I hope yours is just off enuff that it won't start and didn't do any damage. I'd pull the timing cover and check the timing gears.

Another easy thing to check is if you may just be 180 degees off on the distributor. Is it popping or trying to start or trying to do anything?

[tufcj]

Sorry to say that the marks aren't lined up when the chain/gears come out of the box. If the marks aren't aligned properly, then the cam timing is off and it will never start.

Best bet is to pull the timing cover and verify that the marks are aligned. Too much cranking isn't good for a new cam. If you've cranked it a lot, you should probably pull the lifters and re-coat the lobes and bottoms of the lifters with assembly lube.

Bob
tufcj

[guffey24]

I thought that it might be 180 out also, but when I found top dead center to number 1 the first time it was 180 out

reason I know this is because when trying to crank it it was pouring gas out of the manifolds when the exhaust valves were open

that would make it out 180 right?

It has yet to crank and run so maybe no damage was done, cross my fingers

looks like the timing cover is coming back off this weekend

[hotratz]

Umm, do you really mean to say it does crank but will not fire?

[guffey24]

exactly

[1980_Cj7]

looks like the timing cover is coming back off this weekend

The weekend! C'mon, don't tell us you're gonna keep us in suspense that long. Open that baby up and find out what's going on.

[guffey24]

yeah I am healing right now, last sat the t-19 came off the tranny jack onto my fingers

tried to catch it, still trying to figure out why I thought I could catch a 200lb transmission falling about 2 ft

they basically had to sew this one 8) back on the left hand, it blew out on both sides just like a tractor trailer tire on the interstate, crushed it nicely

[mika01]

:shocked!: DAM! that must have been painful. Hope your on smoething, for the pain I mean

[tufcj]

I know that pain.

I smashed/blew out the pinkie on my right hand stacking rocks for a friend in Moab. Took about 4 hours to get from where we were to the emergency room (and I had to drive/shift my Jeep). Doctor at the hospital couldn't believe the bone wasn't broken, given the amount of damage.

It's been over 3 years, and I still have serious scarring, and quite a loss of motion in that finger.

I feel for you.

Bob
tufcj

[Goose]

:shock: OWWWW Frickin Owww!!

Why is it that our body's otherwise finely tuned survival instinct do that..I have done similar stupid things.. :roll:

isnt it nice that your nervous system has that built in delay..you know to give you time to see what you just did and to fully realize just how friggin bad it is going to hurt in a second.. :mrgreen:

[guffey24]

Alright guys, I stripped the whole front part of the motor and guess what I found

my timing gears where not even close to being lined up, I am talking 5 to 6 chain links off from lining up

It aint no wonder I couldnt get it to fire

I havent put anything back on yet except for the timing cover, is there anything else I should check, or do you guys think I should be okay for now

[1980_Cj7]

Somehow I missed your most recent post until now, and I've been anxious to hear how you are making out. I hate to say it, or even think it, but I'd be worried if you bent any valves. Which direction was it off, advanced or retarded?

This cam stuff still confuses me, but if I'm picturing it correctly, if you were retarded (well, you know what I mean, not you, but your cam), you stand a better chance of not having messed up your valves. If you were off in the advanced direction though, and had the intake valve open too far at TDC, you might be in trouble.

Some of the more experienced guys in here can chime in and agree or correct me though.

The other thing I wondering is how you'd tell if you did any valve damage short of pulling the heads off. A leak test? A compression test?

After having just gone thru an year long nightmare myself, I sincerely wish you luck and send up a prayer for you. Keep us posted.

[guffey24]

She runs :!:

everything seems to be good

I will keep you posted

[Mudrat]

yeah I am healing right now, last sat the t-19 came off the tranny jack onto my fingers

tried to catch it, still trying to figure out why I thought I could catch a 200lb transmission falling about 2 ft
I feel your pain brother - I had a T-5 with the Dana 300 on it try and fall on me and ripped my shoulder muscles Feb 2006 :roll: Shoulder still bothers me :smile:

[guffey24]

I have an issue that is concerning me reguarding the oil pressure

I have only cranked the Jeep twice, as I want to make sure everything is okay

here is a little build info

I installed a new oil pump, with the rebuild, I used the old sending unit, I packed the new oil pump gears with vasoline as described in BJ builds an AMC. I am using 15w40 Shell rotella and 1 bottle of Lucas oil treatment for cam break in

My oil pressure gauge has buried both times I cranked it

over 100 psi

what could the trouble be

bad sending unit?
faulty aftermarket electric gauge?

should I run a mechanical oil gauge?

Or should I look for something internal, I hope not

[1980_Cj7]

You gotta get your terminology straight with this "crank" thing. Again, crank means turning the crankshaft by means of the starter. Running the engine means having it actually start and continue to run on it's own power (gas).

What spring did you use in the oil pump? Fuzz can tell you a lot more detail on this, but there is a heavier spring you can use to increase the oil pressure. I believe Fuzz even blew some oil filters apart, but I'll let him elaborate.

[guffey24]

it started and ran on it's own

sorry about that George

the oil pressure thing is really bothering me, I used a red supposedly HD spring

[BREK]

My amx would do the same thing after I installed the red heavy spring & was using 10w40 castrol. Now I have the stock spring, bulltear nickel cover & pump gears (hrc cut), and I am using brad penn grade 1 10w30 oil and I see no higher than 70 when cold 65 when warm with an autometer pro-comp mechanical gauge.

[Mudrat]

Had a similar issue, but 0 oil press. Scared the crap outta me!!! I put in a mechanical (plumbing) and the same set up Brek has witht he red spring and I'm just a little less, 60-65 cold idle and 45-50 warm.

[AMX69PHATTY]

If the Oil Pressure Relief Plunger is too tight in the bore and sticks it will cause high oil pressure. Sounds like the relief isn't relieving for some reason. If the plunger is stuck it can be a bear to get out of the bore on the filter adapter.

[Mudrat]

AMX ... me? Wasn't a problem getting out. The problem was finding the spring on the other side of the shop. :shock:

My problem was a bad "new" sensor - took it back and got my $$ back when I bought the mech guages :t:

Note to self ... put a rag over the cap when you unscrew the damned thing next time !! :?

[guffey24]

If the Oil Pressure Relief Plunger is too tight in the bore and sticks it will cause high oil pressure. Sounds like the relief isn't relieving for some reason. If the plunger is stuck it can be a bear to get out of the bore on the filter adapter.

The oil pressure relief plunger will not move at all, it is stuck

give me some ideas on how to get this thing out :-|

I thought about taking a tap or a long easy out and trying to get it out, but that would be a stretch

any ideas

[guffey24]

alright guys got it unstuck and cleaned it up real good

the releif valve and the cavity it sits in

put everything back together and it did not change anything

I am thinking that the red HD spring might be the problem

I am also going to change to a mechanical oil pressure gauge

which will get rid of another thing that it could be

the sending unit

[jeepsr4ever]

I doubt your actually reading 100psi. If it was 100psi your filter would be bloated. Check to see if it had bloated on you. The plunger goes in nipple end first then the spring goes into the plunger and then the nut. Are you sure you installed the plunger correctly?

[guffey24]

yeah I installed it correctly both times

it is dripping oil out of the oil filter, and around the oil pump housing gasket, I havent looked at the filter to see if it is bloated

when I pulled the plug the spring came out and the plunger didnt, it was stuck

I got it out cleaned it up, and reinstalled it

put oil in it and the gauge went right back to 100 psi where the gauge ends

0-100 psi

[jeepsr4ever]

Red springs are rated at 70psi not 100psi

[AMX69PHATTY]

Sounds like the Relief Plunger is stuck again.
When I measured a new one from a Sealed Power Kit it was
.0001 to .0003 bigger O.D. than the stock one out of a '76 304.
Doesn't sound like much, but it don't take much.
The new one caused me same problem and ballooned a filter.

MC, would you happen to know the Plunger Dia. Spec & Tolerance ?

[jeepsr4ever]

Plungers should not be larger than .561. The hole it goes into is actually a precision bore that should be held pretty close to .5625 or 9/16". We ream the 626 and the 534 oiling plate holes out to .563 when they are being made here in house. I am suspecting you may be bypassing your filter. Whats the scoup on your oil filter adaptor?...is it new or used and what is the date code on it. Pre 1988 means oil filter bypass...1988-1991 means no oil filter bypass. Some 1987's had it either way. Maybe you forgot to put your bypass back in if was dis-assembled.

[guffey24]

the 401 came from a 78 Waggy

the oil pump housing still has some of the AMC factory paint, so it is used

the oil relief housing points downwards towards the oil pan

the oil filter angles back towards the frame rail, and the oil sending unit mounts right above the oil filter in the block with an adapter into the block

looks identical to the setup that came on the 304 that was stock

it has a little circle on the outside of the housing with 3 numbers in it

dont know the order, but the numbers are 2,7,4

it is pushing oil out of the oil pump gasket, and also dripping out of the screw that holds the spring and the plunger in place

any other ideas?

what should be my next step?

[82Waggy]

I had a brand new one that was stuck due to casting debris and machining flash.

Make sure the plunger drops all the way in so that the point on the end touches the far wall, and that it is free to move easily back and forth without the spring. If it won't bottom and fall out freely without the spring you need to ream out the plunger cavity to the proper diameter and get rid of all the garbage.

[guffey24]

I had a brand new one that was stuck due to casting debris and machining flash.

Make sure the plunger drops all the way in so that the point on the end touches the far wall, and that it is free to move easily back and forth without the spring. If it won't bottom and fall out freely without the spring you need to ream out the plunger cavity to the proper diameter and get rid of all the garbage.

so what you are saying is that the plunger should slide in and out easy, I get that part

If I am under my Jeep and slide the plunger up in the hole it should freely fall back out?

If that is the case, the plunger I have fits real tight and will not come out on it's own, when I push it up in there, with or without the spring it stays and does not come out on it's own

[1980_Cj7]

I'd work the bore a little, real slow and by hand, with some real fine emory paper on an appropriately sized drill bit. Go slow and do lots of test fitting. Check and make sure the plunger is smooth too.

[82Waggy]

I had a brand new one that was stuck due to casting debris and machining flash.

Make sure the plunger drops all the way in so that the point on the end touches the far wall, and that it is free to move easily back and forth without the spring. If it won't bottom and fall out freely without the spring you need to ream out the plunger cavity to the proper diameter and get rid of all the garbage.

so what you are saying is that the plunger should slide in and out easy, I get that part

If I am under my Jeep and slide the plunger up in the hole it should freely fall back out?

If that is the case, the plunger I have fits real tight and will not come out on it's own, when I push it up in there, with or without the spring it stays and does not come out on it's own

You need to pull the filter adapter off the timing cover to be able to see what I am talking about and to clean it up properly. I assumed you already had it off. If you have never done this, get a copy of the TSM before you attempt it as the pump gears will come out too and you will need to remove and replace the old gasket properly.

If you try to machine/clean the filter adapter while it is on the vehicle the chances are you will release all kinds of chunk into the engine that may tear things up.

[jeepsr4ever]

Your probly much better off getting a new updated oil filter adaptor than trying to deal with a bad/grooved one. I am sure we can find a *Flat one. :wink:

[guffey24]

Your probly much better off getting a new updated oil filter adaptor than trying to deal with a bad/grooved one. I am sure we can find a *Flat one. :wink:

I will take mine off again, and see what it looks like, and I am guessing that this is the one I would need to replace it with

http://www.bulltear.com/catalog/product_info.php?cPath=21_35&products_id=135

[jeepsr4ever]

Yes that is the replacement

[guffey24]

alright guys I got everything fixed for now, took the oil filter adapter off and cleaned the whole thing real good, installed a new gasket

also installed a mechanical oil pressure gauge

I am in Fuzz's good range now

70 psi cold and 25-30 PSI when it warms up

thanks for all the help

[mika01]

Plungers should not be larger than .561. The hole it goes into is actually a precision bore that should be held pretty close to .5625 or 9/16". We ream the 626 and the 534 oiling plate holes out to .563 when they are being made here in house. I am suspecting you may be bypassing your filter. Whats the scoup on your oil filter adaptor?...is it new or used and what is the date code on it. Pre 1988 means oil filter bypass...1988-1991 means no oil filter bypass. Some 1987's had it either way. Maybe you forgot to put your bypass back in if was dis-assembled.

Wow this was quite a revelation for me. I just fired up my 401 which had a 75 timing cover with oil filter adapter and was getting about 12 psi cold. Once I read this I scavenged an oil filter adapter from a 89 and voila 50 psi cold! :!:
Thanks for info MC never would have guessed it! :t:

[Holeshot]

I also have seen a bunch of stuck plungers.