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Just bought 84' nissan 720


hellcatfa

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Hello. I would like to thank the users of this forum for the information I found here.

 

My truck is a 1984 Nissan 720. I bought it with a bad headgasket, and slight knock. The head gasket was blown between 3 and 4, but still made it onto the trailer.

 

I proceded to replace the headgasket. Had I actually read the manual I woulden't have had to remove the timing cover to reinstall the tensoner.

I learned the hard way.

 

According to the haynes manual install oil pump at tdc with the dimple alligned with the oil hole on the shaft.

 

Didnt start. well from eyeballing the rotor location it was firing 3 instead of 1.

 

Yesterday I went through it all over again except I removed the oil pump and installed the shaft so that it would be firing one at tdc.

It started but It was super retarted, and bareley ran.

 

Has anyone run into this problem?

 

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Thanks for the picture. I just tried this and it runs all crappy.

 

I'm worried that I skipped a tooth on the crankshaft. I let the chain fall but it didnt seem like it skipped

 

I turned the engine over by hand and no binds. I dont hear any valves hitting when it tries to run.

Whats the best way to tell if i skipped a tooth?  Can I tell by looking at the camshaft when at tdc?

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First, off, what do you mean "it's not idling"?  Does it stall?  Is it just really rough?

 

Also, white smoke?  Have you checked for oil+coolant?  Also, you should pull the plugs and see what they look like.  Keep in mind that there may be 2 plugs per cylinder (intake side and exhaust side).  I dunno which models do or don't have 8 plugs, but my '85 Z24 does.

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Sounds to me like you blew the head gasket again, the white smoke pouring out the tailpipe is the water/antifreeze steaming ... see if your exhaust smells like antifreeze... That'll also explain why it won't idle or idles really rough and stalls.

Another thing it could be if it's a Z24 is that the blocks are prone to cracking at the head bolt holes and a crack in the wrong place could let the coolant enter the cylinders once the engine warms up, sometimes it'll do it with a cold engine but either way, it's definitely something to check for when you remove the head again. The cracks can usually be welded shut and the block deck milled flat again but you'll need to find someone who's confident welding the cast iron or be ready to replace the block.

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If you can see your breath on the mornings you start your truck then it's just normal condensation. All vehicles do it.

 

Can't see this leaking so soon after a gasket replacement unless something is severely wrong. A fresh gasket will seal just about anything and blow later.,

 

Did you check the head for being level? It's the most common cause of gasket failure.

Did you remove the intake from the head?

Did you clean the head and the block surfaces absolutely clean? This is critical to good sealing?

Did you torque the head bolts in the proper sequence?... basicaly tightening from the center out to both ends of the head?

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I may have found the problem but its not set in stone. I havent been able to look at the truck in a few days.

 

The master cylinder blew just overnight. I had no pedal. I believe that brake fluid was sucked through the power booster and into the intake.

However I havent been able to prove this theory yet. I discovered moisture of some kind in the vacuum line from the power booster.

This was a few days ago and I havent touched the truck since.

 

Also the smoke had an odd smell. Unlike that of coolant or oil.

 

I will find some time in the next few days to look into this further.

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  • 1 month later...

Been a while since I posted. My truck is now legal and on the road.

 

I would like to thank the users of this forum for all of the information I was able to acquire off this site.

 

I rebuilt my master cylinder and turned the check valve upright. No more brake fluid smoke.

 

Just put added fluid in the rearend. It was about half a quart low. 

 

I believe I may have a cold solder inside of the fuel pump relay because the truck died on acceleration, and would not run good for about 15 min.

Since that occurred I havent had a problem since. I have a jumper ready in case it happens again.

 

I just got my Idle about right but I think It could be lower.

 

In the next few days I would like to fix my camber it is real bad negtive on the drivers side.

What is the best way to go about doing this? I read something about only needing washers is this true?

 

Well heres what yall have been waiting for.720001_zps10fb2adb.jpg720003_zps28f4d202.jpg720002_zpsc83cdd97.jpg720006_zpsa8712d9b.jpg

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Where on the upper control arm are these washers? I have not yet figured this out.

This is an upper control arm on a 720, there is a shim near that green brake line that has been cut.

DSCN2103.JPG

See how it bolts on in back of the shock tower.

DSCN2101.JPG

See how this upper control arm has no washers to remove.

DSCN2102.JPG

I would have to be there to figure out what your issue is without photos, if you truck has been lowered, you cannot fix it without modifications.

 

OK, see how 2 nuts were put between the back of the shock tower and the upper control arm spindle, this is on a highly modified frontend that was lowered a lot, consider them nuts washers, as that is where washers would be if you have any.

DSCN2105.JPG

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Thanks for the pictures. That is a big help.

Tomorrow I will see what can be done about my camber.

 

Also can anyone tell me about the clutch switch, fuel cutoff? The clutch interlock doesnt work, and the switch is present.

I read about a fuel cutoff on deacceleration using the clutch switch,neutral switch. Curiously I reached down and pressed the switch with the truck in neutral and it died.

Also dies in gear when the switch is hit. The clutch arm is missing something that depresses the switch so it isn't pressed while driving.

Is this part of the fuel cutoff system?

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  • 1 month later...

So far the truck has been running great. And I have put about 5000 miles on it since buying.

 

Last night I had a bit over quarter tank and seemed to run out of fuel going uphill. Truck would start and sputter.

I put in 2 gallons of gas and no go. At this point the gauge reads over half a tank.

Thinking its my relay I jumper it and hear the pump cut on. I cycled the key about 5 times then started right up and away I went.

Once I got going I pulled the jumper wire and drove 15 miles home no problem.

 

I ran it out once but it ran out at excactly empty.

 

Does this sound like the relay is failing, or was I just out of gas? Clogged pickup tube?

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I just checked it before reading this post. It does seem a bit restrictive. Its getting replaced today.

 

Also I added a modification to the truck. I installed an electric driver seat out of a buick park avenue.

It is about an inch higher than stock, and it bolted in with no modification to the seat frame.

The stock nissan seat belt is still implemented.

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  • 2 weeks later...

got the filter changed that day. Old one wasnt that bad.

 

Last night the truck died on me. I was going about 55 on a highway with no shoulder. I managed to coast off the highway and up a hill then stopped after the peak.

I had quite a bit of momentum leaving the highway allowing me to make it up and over the hill. Truck starts then dies. Same thing again.

 

Well the hill I was on was a good first stop because there was little to no traffic. Only problem The whole street was a fire zone.

I had a pushing start from a 98 sentra, and down the hill I went. I coasted about 1/8 mile downhill at highspeed into an empty office park parking lot.

This didnt seem like a good place to leave my truck. I was fearing the worst that it would be gone when I retured today.

 

I returned this morning after traffic had subsided to find the truck nestled in a packed parking lot. Last night I looked up a carb rebuild on ratsun. So I thought I would check the filter in the carb first thing. I removed the banjo fitting to find no filter. like an idiot I removed the needle seat as if the filter was deeper in the carb. Now the needle had slid off the float. At this point the security guard has driven by but hasnt said anything.

 

I removed the carb and headed home to take off the float cover to reinstall the needle. At once I removed the float bowl cover, and found the problem. The primary jet was clogged with red rtv silicone that had been used to seal the float bowl cover in the past.

 

I got a ride to my truck and proceded to install the carburetor. The security guy drives by once more didnt say a thing. I got it started, and hit the road.

 

The belt was squalling. The mixture was rich the idle was high, but off I went. As I passed the security guard he waved me off.

 

I made it home just fine adjusted the mixture and idle and off I went. The truck runs smoother now. I think it had been starving for fuel since I bought it.

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32mpg. Thats pretty impressive in a truck.

 

Mine is getting right at 25mpg on the highway with bursts up to 90mph.

I feel like this can be improved upon by removing the tail gate, and using skinnier tires.

 

The gasket paper is still has the carb sealed.

 

Does anyone here use any other than the recomended fuel filter?

I believe that it is somewhat restrictive. I cut the old one open and there was less filter media than you will find on an aircooled vw.

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