620 1974 L18 Crank Bolt LOOSE & Fan/Pulley Bolts not clamping tightly

[Stoffregen Motorsports]

Heavy water could have gotten into your ignition system causing resistance, but not enough to kill the engine. In other words, leaning into the throttle may be the only time you may have noticed the issue.

 

The coil on my Land Rover has a crack in the tip, and a zip tie holding the coil wire boot tight to the tip. A couple years ago, while crossing a stream so deep that it was running over my feet inside the cab, water got into the crack in the coil and almost killed the motor, right in the middle of the deep stream. After it dried off, the problem went away, unless I leaned into the throttle. I couldn't figre out what the problem was until I remembered the cracked coil. The symptoms were near identical to what you described.

[Cardinal Grammeter]

18 minutes ago, Stoffregen Motorsports said:

Heavy water could have gotten into your ignition system causing resistance, but not enough to kill the engine. In other words, leaning into the throttle may be the only time you may have noticed the issue.

 

The coil on my Land Rover has a crack in the tip, and a zip tie holding the coil wire boot tight to the tip. A couple years ago, while crossing a stream so deep that it was running over my feet inside the cab, water got into the crack in the coil and almost killed the motor, right in the middle of the deep stream. After it dried off, the problem went away, unless I leaned into the throttle. I couldn't figre out what the problem was until I remembered the cracked coil. The symptoms were near identical to what you described.

 

I never changed the plug wires, points, cond, cap, etc. when I bot truck about 10 years ago.  I have put plugs in it and the wires seemed flexible still.  BUT I don't have the late model 620 inner fender aprons that "seal" it off down to the frame and over the upper control arms.  So running 60 mph over standing water on the turnpike surely was misting the engine.  I know distributors sure don't like water.

 

I'm keeping my fingers crossed that now, the mysterious onset of a massive primary lean condition and popping if too much throttle, and seeming bad accel pump when pressing throttle, has totally disappeared.  NO "accel pump" behavior, no lean, full power now, able to lug in 4th up hills, etc. etc.  

 

I don't know how cater could have "solved" the carb problem but the torrential rain turnpike driving is the only possible explanation - doing the engine front repairs don't come close to the carb.  HOWEVER, the engine was missing and stumbling in a completely different way when I got off the pike at the toll both - perhaps these misfires coughed through the carb and blew the the "clog" out.  I don't think anything more than mist could have made it into the air cleaner and don't think that moisture could have cleaned out some secondary air bleed (but a clogged air bleed would richen mixture which is the opposite of what carb was doing. 

 

...something in the transfer slots would make more sense given the flat spot while throttle applied - in fact the flat spot was so bad at at low rpm, if it intentionally moved throttle too much, then engine would completely "flame out' for at least a second.  But this would not explain the general lean condition in the primary section including a significant reduction in power - I would have to use a lower gear going up all my familiar hills.

[banzai510(hainz)]

One time with my L motor it snowed a few days and then warmed up really fast.

Next day I had a hard time starting. lots of popping ect. I lifted the dist cap and the condensation of obvious!!!!!! dried it out and was good to go.

 

popping can be a not good grounded condesor if one still uses Point ignition, and then the last is bushing wear on distributor causing point bounce.

Edited May 7, 2022 by banzai510(hainz)

[datzenmike]

 

Get a Nitrile glove. Poke holes in the finger tips. SMALL holes. Pull nipples off plug wires and push through holes in finger tips. Put nipples back on and fit to top of distributor cap. Roll glove up like condom and roll down over the distributor cap and on down over distributor body. If finger tips don't tightly grip the wires and seal out moisture, use the other glove and make holes smaller. That's why you get two. With this it's impossible for water to get into the distributor. 

[Cardinal Grammeter]

Awesome distributor "boot" - it's almost like something Datsun would actually have done(!)

 

I don't know WTF happened to the carb.  But the past 2 times, dirt was definitely what caused the problem.  So this previous (3rd time) problems was probably dirt too.  Now I have the alcohol resistant Tomco kit, but I'm hesitant to disturb the carb if it is working correctly.

 

This last time, I really bent up the fast idle cam link so I was all the way up on the cam when the choke was closed (OE setting is at the "next to top" position.   The Lean and Flat Spot problem was in winter and there wasn't enough choke, but there wasn't a pulloff  either - so i figured if I replaced the pulloff, I could run a lot more choke and it wouldn't load up the engine.

 

I'm leaving carb alone - have to do brakes next.  No fun with torn rotator cuff  (Argh)

[datzenmike]

First year I used a latex and it barely lasted the winter. Latex and petroleum don't mix. Nitrile is chemical resistant. I grabbed them from the Dr.'s office when they weren't looking.

[Stoffregen Motorsports]

You could just pull the glove out of your ass after you leave the Dr's office.

[620slodat]

18 hours ago, datzenmike said:

 

Get a Nitrile glove. Poke holes in the finger tips. SMALL holes. Pull nipples off plug wires and push through holes in finger tips. Put nipples back on and fit to top of distributor cap. Roll glove up like condom and roll down over the distributor cap and on down over distributor body. If finger tips don't tightly grip the wires and seal out moisture, use the other glove and make holes smaller. That's why you get two. With this it's impossible for water to get into the distributor. 

 The first time I saw this used was at a 4X4 event. A lot of mud and water was present, and the vehicle was an early Scout with a 4 cyl. The wires going through the fingertips were sealed with silicone sealer. It definitely kept the water and mud out.

 

Don

[banzai510(hainz)]

Dirt in carb?

I run the stock filter in it orginal location then put another in line. so more or less 2 fuel filters as the 521 is notorious for having a dirty tank. Water/dirt goes by the fuel fill clamp and cause rust in tank an

[Cardinal Grammeter]

2 hours ago, banzai510(hainz) said:

Dirt in carb?

I run the stock filter in it orginal location then put another in line. so more or less 2 fuel filters as the 521 is notorious for having a dirty tank. Water/dirt goes by the fuel fill clamp and cause rust in tank an

 

I have the stock 90* clear bowl fuel filter in the fender bracket plus the ultra fine mesh screen in the carb fuel fitting and TWICE I removed huge debris:  a black gasket material like "toothpic" shard right in the primary main jet and a big, black, "boulder" clump from the air bleed over the primary emulsion tube.  These were HUGE and would have been 100% stopped by the filters.   UNLESS microscopic bits of rubber fuel line passes through the filters, then deposits as sediment in low flow velocity areas in fuel passages, and then breaks off like a "blood clot" and does the damage - but I just can't believe that theory.

 

This 3rd time, I never found debris, but when I cleaned the carb, it did improve but was still bad.  Than after that torrential rain storm driving on turnpike, the carb suddenly started working properly.  I guess there was debris somewhere that I didn't get to.  Perhaps the idle mixture screw or transfer slot which I don't think I checked.

I have a decision to make, my choke pulloff is dead and dare I touch the carb???  LOL

[Stoffregen Motorsports]

I forget, in your other thread about the choke, did you say if you had replaced all the rubber hoses? If rubber is present, and you have not replaces the hoses, this sounds like a good place to start.

[Cardinal Grammeter]

I definitely want to do the two in the engine compartment, but there is one on the top of the tank that will be difficult.

 

NOTE:  Weren't there issues with "alcohol resistant hose" that actually wasn't?  Or, if true, has that been sorted?

At least alcohol doesn't eat through steel, eh?  LOL

[Stoffregen Motorsports]

You need to make sure you get hose with the correct SAE rating for the modern fuels. Most auto parts store guys aren't even aware of the ratings and just sell you what they carry. If you ask for a specific SAE number hose, they might be able to help you find it. Or...just order a roll from Summit Racing, or just about any other online source.

 

The SAE rating can vary from state to state, based on the mix of fuel. If you want to educate yourself on the requirements, do a google search for SAE rated gasoline hose, or check this article out - https://www.fleetmaintenance.com/equipment/powertrain/article/12044377/modern-fuels-require-modern-fuel-hose

 

or here - https://www.sae.org/standards/content/j30_202205

 

EDIT - that first article is from 2015, and there is a new SAE rating since then.

Edited May 9, 2022 by Stoffregen Motorsports

[Cardinal Grammeter]

RE:  Loose Crank Bolt :  Lugging:  I'm sure my constant lugging the engine at low speed does not help - I will shift into 4th so the engine rpm drops back to idle, and then lug it out.  The engine has so much grunt off idle, I like to drive it that way.  Lots of times my truck sounds like a Model T when I drive by someone in town.  However I don't drive the engine constantly around idle while lugging.  I'll lug it down only if I have enough torque to accelerate.

 

NOTE:  Heard story many decades ago drivers of tri-axle dump trucks in a quarry were lugging their engines pulling out and going up a grade coming out of the pit.  The problem was they were breaking driveshafts or u-joints (or maybe both).  So the trucking company made their drivers stop.   Or Else!

 

So lugging is not good for 

Edited May 13, 2022 by Cardinal Grammeter

[datzenmike]

Yeah, avoid lugging. It's very bad to severely load the bearings when the oil pressure is also not at it's maximum. The engine is also not as efficient. I avoid RPMs below 2K if the gas pedal is going down and down and not accelerating or just barely holding an even speed say on an incline. If lugging when accelerating you are just holding everyone else behind you to your speed. There is nothing to be gained lugging an engine.   

[Cardinal Grammeter]

I know lugging isn't good, but around town, I keep rpm below 2000 rpm (maybe even lower).  

 

There is an rpm below which the engine will start rocking in the mounts - this should NEVER be done and I don't do it, BUT I get as close to that as I can as long as I can't feel the engine "chugging".

 

I'm glad I put the Red Loctite on the snout and bolt.

 

The "problem" is the engine has so much off idle torque I take advantage of it - and marvel at it too - this little 1.8 has lots of grunt.  Once I get into 4th, I rarely get out of it.

 

I think the 1.5" exhaust has a lot to do with off idle torque.  Also that exhaust pipe mini-merge collector was not a miter cut so it has a "nozzle" at the ends of the 2 tubes where they were flatted into "D" shapes.  So there is a exhaust reflection at that point and also a restriction - the restriction making exhaust effectively a little smaller than 1.5 inches.  But I have no idea other than big exhaust kills low end torque.