Need help/mechanic in Calgary

[tomb]

M son is driving from BC to Ontario in a 240z with 10,000miles on a rebuilt L28 triple webers. 280 distributor, xr700/PS92 ignition. Fuel pressure is 3.5 psi. It ran fine for 12 hours to Calgary, in heavy rain.

Now , without any load, sitting in the driveway, he says it sounds perfect at idle, and it revs up high just fine. But as soon as he tries to let the clutch out to drive, it stumbles, coughs, won't develop power. It then tries to rev up and go, then stumbles again. At high RPMs it will go, but not up a hill. It will not maintain power up a hill, or under load.

He noticed a spark plug wire came off, and another lost the connector end, but that was fixed, and the problem remains.

Is there anyone in Calgary who I could send him to, mechanic or enthusiast. Will pay cash. Or any advice is appreciated.

This was my long term project/rebuild, that I put tons of time and money into. I donated to him as he is getting married. I ran it daily for a couple years. Then it sat for several years, and was run every couple months. But it ran fine for 10+ hours today over the Rockies.

Thanks for any advice.

Tom

[zKars]

Tom:

I can help! Really! Betting its a plugged fuel filter, stuff in the tank, plugged line. Pressure may be up there, but bet the flow isn't. That or the coil is failing. I have parts for all of this.

Call me in the morning after 8:00

Send me an email to z240@shaw.ca or pm here, and I'll send you the phone number!

Jim

Edited August 15, 2009 by zKars

[Unkle]

Clogged/blocked fuel filter ? Loose ign wire to box somewhere ? Bad gas ? Fuel system / float jarred / stuck ?

[tomb]

Thanks so much. I pmd Jim for a number. I am at tomb@uniserve.com .

Here is some more background.

The fuel filter is a large Fram HPG-1 that can be spun off and cleaned. He did that. Althoug the replaceable filter inside it has not been changed in years.

The fuel tank was renewed by some company that gives a warraty for life. Yet little bits of sand like stuff always built up in the filter. I washed them out regularly. So has he.

I replaced all the fuel lines 10 years ago, and it ran fine taday.

There is a fuel pressure regulater. It may be clogged. The Mallorry pressure gage on it was a bit rusty, worn out. He replaced it today.

I rebuilt the webers from a kit 8 years ago. They ran fine. But they sat for a long time before this trip. My son, Tommy, took off the air filters. They were filthy. He says he cleaned them up really well.

Tommy and I both suspect a fuel delivery problem. He just filled with 91 octane, but Mark Sayer always told me to use 92. I guess it could be bad fuel though.

Yes, I think there could be an issue inside the carbs: dirt, clogged/stuck float valve, something in the float chamber.

If Tommy is shy about money, I will fund any new parts/labour.

What a great forurm. I have browsed for years. Thanks for your help.

Tom

Edited August 15, 2009 by tomb

[fiveleaf]

Tommy here!

I first have to thank Jim (ZKars) for the amazing help... Four z's at the same house after I pulled up!

An entire chest for all original z nuts/bolts, a garage with every tool you can ask for for working on a car, an ally filled with about 20 large containers of parts, really everything you can think of! Amazing. Dad's dream garage. And backyard.

Spare maybe working on the triple webers... but that later.

So the pressure was really low, new (noisy) fuel pump installed (can't hear it idle while in traffic).

Problem update:

In the last two days, in chrono order:

Kamloops

Alternator replaced. (needed, was dead)

Water pump replaced. (needed, was leaking)

Calgary

Air filters cleaned. (Filthy, now looks new and rust-free)

>>nothing gritty in visible carb area, only some grime<<

Spark plugs cleaned and new distributor cap plugs installed.

Timing gun bought, timing played with.

Synthetic oil added

Fan clutch replaced. (needed)

Rad overflow installed (Why is this chrome? Don't ask me.)

Timing played with

Leaking gas tank fixed. -- w/ zkars

Burnt headlight fixed. -- w/ zkars

Fuel pump replaced with 280z fuel sensor and new pressure gadge.-- w/ zkars

Webers toyed with -- w/ zkars

Fuel pressure now at about 3psi (idle liked it more than 3.5psi)

Timing played with (now back up to 20* below TDC)

Webers toyed with (higher idle)

Problem:

It still luggs under load. At least I now know it's not fuel pressure.

Will lug even at high RPM if torque is applied. (I had not tried to accelerate hard in high rev third gear until today.)

Is running very rich. Could be the altitude change?

Backfires from carbs while trying to make it idle.

Backfires from exhaust while under load, very frequently, esp. at high rpm.

Hard to start.

Will die if left at idle.

Problem get's worse as temp. increases.

Diagnostic:

I still think this is a carb problem.

Whistler, BC --> Calgary, AB is possibly enough of an altitude change to mess with the webers? I'm going to keep going lower as I continue my journey to 400ft above sea, in Kingston ON.

I noticed it when I was first driving city Calgary at 3am (could I have descended too much from Baniff?)

Should I attempt to take the webers apart? I've never seen them inside out; only in diagrams... they look a little complicated and almost too precise to mess with.

Jet's should be changed so it run's more lean, but where to buy/swap them?

Again I need to thank zkars for your amazing help and pricing. $100 is not even fair to cover parts, let alone labor -- I would have paid you more had either you asked or I afford it!

To anyone working on anything near the gas tank: TAKE THE TIRE OFF for side access.

Edited August 16, 2009 by fiveleaf

[fiveleaf]

So... How bad is it to keep driving like this?

Anyone in Calgray (preferably) or east of Calgray that wants to play with triple webers?

Anyone have the equipment to sync them properly after I possibly attempt a clean and change of the jets?

Linkage is slightly loose, but I don't believe this is the main problem.

Any help appreciated.

Ty.

Tommy.

[fiveleaf]

Tank has been full of 94 Octane. Any comments on Octane booster for where I can't find 92+? I bought a couple, but am skeptical due to it's flashy advertising.

[zKars]

Tom:

Come on back if you like, we aren't done yet. I knew it didn't sound right when you drove away. Give me a call when you get a chance. Cell is best. Don't feel right about leaving you like this.

Jim

[Unkle]

It's in the carbs . If they're poorly sync'ed it will run like decribed. Sounds like a triple carb rebuild ! The gas octane isn't the issue here , the mix / fuel spray isn't right maybe ? Crap in somewhere vital ? Maybe install stock carbs/manifolds and worry about the triples later ?

Edited August 16, 2009 by Unkle

[tomb]

Just remember I drove it a lot for several years, from sea level to 2000 ft, with no issues. It sat and was started intermittently. Then you just drove over the Rockies without an issue. So something happened over the last hour of driving.

It can't be a jetting issue, althjough I'm sure they could use tweaking despite this problem. I can't imagine the carbs went seriously out of sync, but maybe.

I suspect if carbs are the problem, it's dirt or something. Especially since grime from the tank accumulates slowly in the HPG-1 filter. It's easy to check the filter on the carbs without taking them off, and without removing anything else. As you look down onto one of the carbs, look beside the cover that is fastened with the butterfly nut. Look for a cap nut just above where the fuel line connects. It's under that cap nut. There may be one inside where the fuel line is screwed on.

So, talk to Jim, he probably has more idea's. Do that b4 you tinker with the carbs. Can't thank you enough Jim

I'm off to Vancouver today to look at a new "rust free" 72 240 from Arizona, time to start over:) I'll be on my cel 604 966 8974

Tom

Edited August 16, 2009 by tomb

[fuzze]

Good luck to your son in making it to Ontario , I am envious to do a trip like yourself in my z one day .

Tom , the Z your going to look at today looks great from the pics on CL and as you probably know there has been a big price drop on that listing . A few months back it started at around 7500 $ if I remember correctly . At 4$ g now it could be time to strike a deal . When I bought my 71 it was advertised for over 5g$ and no one wanted it at that price . I drove it back home here in the lower mainland for 2800$ and have been smiling ever since .

Since you are so close to the city as well try to take in the show at waterfront park in North Vancouver on the second weekend in September , if all works out for me look for my Z in all black E-primer .

Z you all later

Chris

[doradox]

M son is driving from BC to Ontario in a 240z with 10,000miles on a rebuilt L28 triple webers. 280 distributor, xr700/PS92 ignition. Fuel pressure is 3.5 psi. It ran fine for 12 hours to Calgary, in heavy rain.

Now , without any load, sitting in the driveway, he says it sounds perfect at idle, and it revs up high just fine. But as soon as he tries to let the clutch out to drive, it stumbles, coughs, won't develop power. It then tries to rev up and go, then stumbles again. At high RPMs it will go, but not up a hill. It will not maintain power up a hill, or under load.

He noticed a spark plug wire came off, and another lost the connector end, but that was fixed, and the problem remains.

Is there anyone in Calgary who I could send him to, mechanic or enthusiast. Will pay cash. Or any advice is appreciated.

This was my long term project/rebuild, that I put tons of time and money into. I donated to him as he is getting married. I ran it daily for a couple years. Then it sat for several years, and was run every couple months. But it ran fine for 10+ hours today over the Rockies.

Thanks for any advice.

Tom

The part about the plug wires makes me wonder if the coil/cap/rotor are still OK. With a wire loose the high resistance will cause the coil output to increase dramatically. This can burn a coil, cap, or rotor. At low load and low voltage required to light the mixture the problem might not rear it's head. Add some load and the coil may no longer be able to supply the voltage needed or that voltage is finding it's way to ground via a crack or burnt spot in the cap and rotor.

Steve