[Rough Idle (Video)]

tech - I have a stethoscope, didn't think to check the chain, thanks for the tip. And trust me I didn't want to buy those plugs, but they were the cheapest they had in stock.

 

Challenger - I think it is running rich..there is also a tiny pool of fuel that always gathers on the opening of the front carb. It's got a stock replacement mechanical pump

[Rough Idle (Video)]

Hi everyone, I have a 1971 240z with an L28 (N42) block and E88 head. The PO said it had been sitting for two years and it had a valve lash pop off due to sticky oil that I fixed. I also just redid the fuel system (newish 280z tank, new hoses, pump, filter. Carburetor float needles were stuck closed, but I soaked them in carb cleaner and they move freely now, cleaned the banjo fitting mesh filter. Also adjusted float level, timing and valve clearance as per FSM.

 

Here is a video of the car idling

 

Now to the problem. The car is idling very rough, engine is shaking, there is a loud clicking noise coming from somewhere and pulling spark plugs doesn't have much if any effect on the first 3 cylinders

 

So after switching plugs 3/4 and seeing a difference, I decided to try out all new plugs. I put them in, and #2-6 passed the plug test, while #1 failed. Pulled #1 plug and it looked like no fuel at all had gone near it, and there was a slow white smoke coming out of the plug hole (not steam).

 

Now after about 5 minutes of running, it seems the new plugs have started to foul again. Car is back to running like how it was with the old plugs.

 

Here is pictures of the old and new plugs (kind of erratic pattern of fouling on the new set)

 

Old

 

New

 

Any thoughts?

[3 Cylinders not firing]

Make sure the bottom of your mixture needle assembly (black plastic thing with a small line going to the float bowls) on the bottom of your carbs is pushed all the way up. Sometimes they stick after you release the choke.

 

Thanks for the tip, sure enough it was super gummy stuck on the front carb. I worked it free with a bit of carb cleaner. Still running rough though. I'm waiting on a flow meter to come in so I can attempt to sync the carbs.

[3 Cylinders not firing]

I'm having a similar problem on my 71 roundtop carbed Z. Instead, the first 3 cylinders were not firing. The plugs were definitely fouled and wet with fuel. Also there is a tiny pool of fuel sitting at the front cab air inlet.

 

I replaced the plugs and now they all are firing except for #1, which released white/blue smoke when I took out the sparkplug after running for a few minutes

[Valve retainer damage]

Here's a

of what it sounds like after putting the lash pad and rocker back on. (no muffler) I'm gonna check and adjust the valves now, do you guys hear any obvious issues with the idling?

[Valve retainer damage]

well I ended up just tapping the lash pad into the cap with a hammer. it didn't take much to get it in, and once it was in, it swiveled freely, so I figure it should be ok for now. I put the valve cover back on and started the car, the shaking seems to have gone away for the most part. but the tapping noise is still there. i listened to the valve cover with a screwdriver and it sounded normal. it really sounds like it's coming from the carburetor area, i couldn't pinpoint the noise with there either. I'll try to post a video later.

[Valve retainer damage]

sticky- I'm trying to get the spring cap (valve spring retainer?) off too, which I shouldn't do with a screwdriver, no?

[Valve retainer damage]

Well, I guess tomorrow the camshaft is coming out . Arghh

[Valve retainer damage]

Dr Sideways - I don't know if a cam/rocker pattern wipe was done because I didn't build this motor. It had supposedly been sitting for two years, and I just finished replacing the fuel tank, hoses, filter pump etc. Also it is a 240z e88 head with 280z n24 block

 

I'm not sure if I used the correct term for the part I'm talking about. It's the little circular thing that goes ontop of the valve spring retainer and has a groove for the rocker to slide on. I put a magnet to it and it is iron.

 

I'm not sure if it's clear in the picture, but the seat for the rocker guide is slightly smashed in from one side (from being hit by the rocker I assume)

 

Either I'm misunderstanding your answers or I've named the parts wrong. I'm probably being dumb haha, thanks for the help so far.

[Valve retainer damage]

I got my 71 240Z started for the first time today. It idled around 1000 rpm (very rough) and the engine was shaking kind of bad, and a loud ticking noise coming from under the valve cover. I took it off to investigate, and this is what I found.

 

The rocker guide (lash pad?) was sitting on the floor of the head and looks to be fully intact. The valve spring retainer on the other hand was mashed up a bit and is a little tight for the rocker guide (lash pad) to fit into.

 

If I want to get the retainer off, I'll have to take off the camshaft and rockers, because I only have one of those universal valve spring compressors that gets blocked by the camshaft. My question is, are there any ways around having to pull off the camshaft to get this issue sorted out? (grinding part of the rocker guide (lash pad) to make it fit?)

[First start in 2 years]

^^Will do.

 

I took off the float bowl covers and found them bone dry. After comparing the two float adjustments, they were way off of each other, I adjusted the one that wasn't fully actuating the valve to match the other. Both were dry though . Sprayed carb cleaner into the float valve, let it sit. Tried to blow from the input line through the valve but no air is getting through, whether the valve is in or out. This valve was also stuck open at first, but it eventually pushed down with a screwdriver.

 

So at least I've narrowed down the problem, but I don't know why the valve's wouldn't let fuel through. They both move up and down now.

 

Gah I wish I had a laptop to reference in the garage!!

[First start in 2 years]

Thanks for the links Arizona. I'm gonna try pouring fuel into the float bowls now and NOT the oil hole like i was doing

[First start in 2 years]

I'm still new to carburetors, not sure whats what. I do know that the cylinder inside the carburetor is slow to pull up (when I'm opening it to spray in starter fluid)

 

How do I check the floats?

[First start in 2 years]

Update: fuel is getting to the filter. The hardline between the pump and carbs is unobstructed. fuel hoses right up to the carb are wet with fuel from the tank. I don't know what to check from here.

 

Thanks for the help so far.

[First start in 2 years]

It's a mechanical fuel pump. I put in 2 and a half more gallons and still dont see any fuel in the clear filter. I put some fuel into the float bowls and it ran off of that fuel (for a few seconds) How many cranks does it usually take to get from a dry tank to the filter?

[First start in 2 years]

Thanks guys, I'll try that out.

[First start in 2 years]

Ok so I've replaced the fuel tank, fuel hoses, fuel filter and pump in my 71 240z. I put about a gallon of mid grade gas in it and try to start. It'll fire away for a second or two on starter fluid, but the clear fuel filter doesn't seem to be getting any fuel. I tested the pump outside of the car and it squirted fuel across the garage floor. It is pointed in the right direction. The filter is on the right direction. The hard lines are unobstructed (blew compressed air through them). Pulled the choke out halfway.

 

I'm thinking only one gallon might not be enough for the tank to pick up? Any ideas?

[Fuel hose adapters?]

Ok, took a trip to home depot today, and had no luck finding the a 1/2"(280z tank) to 5/16" (240z hardline) adapter.

 

I did find some brass barbed nptf fittings on hydraulichose.com though, will this be ok for fuel?

 

"Xnke: To the front of the car, the engine bay has a third vapor line on the driver's side."

This the line that goes from the top of the evap tank on the 240z setup? So I'll just bypass the evap tank in that case?

 

Thanks

[L28 N42 block E88 head]

cool, how's it working for you? do you need to run premium fuel with it?

[Fuel hose adapters?]

Thanks everyone.

 

Zgeezer - Thank you. That must be it. It's got the baffle, different fuel sender etc.

So I'm good to use the 280z sender without that extra filter looking part?

 

Xnke - I'm planning to block off 2 of the vent nipples at the evap tank and run the large nipple on the back of the 280z tank to the third vent nipple on the evap tank. What does the small vapor line on the 280z tank go to?

[independance day Z]

Pharoah - it's got rust in the classic spots...nothing too horrible though.

 

Daeron - Need door locking mechanisms too. I'll need to check back home for exactly what. I'm on vacation till Monday.

[Fuel hose adapters?]

Hey everyone, I've got a slightly weird situation here with my 71 240z. The size of the fuel hard lines leading to the tank are different sizes than the tank nipples (Don't know what tank it is. Slightly different tank than stock 240z, with 4 instead of 5 nipples, different locations see pics). I want to get and adapter (eg. 5/16" to 3/16") instead of over tightening one end of the hose, but I can't find adapters anywhere. Does anyone know where to get something like this? Or a better solution for my problem?

 

[independance day Z]

Thanks guys

Sweet!

Shane - Ill give you a call. Mainly I need some door panels.

Daeron - $1375 for the car, plus 350 towing from Naples.

[independance day Z]

Well, seems like there's alot of new Z owners lately, maybe it has something to do with the crappy economy. I've always wanted one, and now seemed like a good time to buy.

 

Anyway, after about a month and a half of searching and negotiating, I finally settled on this early 71 240z. It's got an L28 block with an early E88 head and SU carburetors. It's also got a decent sized speed hole under the driver's seat, that I'm gonna test my nonexistent welding skills on. Needs some fuel work to get running (starts fine on starter fluid) so hopefully within the next two weeks I'll have a running Z!

 

And here's the pictures! 12pm today, delivery! Pwhew!

 

 

 

[L28 N42 block E88 head]

according to the previous owner it is an early E88. I read somewhere on here that the valves on the E88 are a bit too small for the L28 block?