New Z owner problems

[Snakeyes711]

My son got a 76 280z for his 16th birthday, (lucky bastad!) Given to him by the original owner, my mom! Its got 86K original miles. But it needs work.

So far whats been done before we got it is, new inj. fuel tank flushed etched,a nd sealed. fuel pump, rebuilt transmission.

What we did is, new plugs, new ignition coil(still the factory!) replaced fuel pump, adjusted the TPS(thanks to a site flowing with info), cleaned lots of contacts under the hood. Drained about a quarter tank ,a nd filled a half tank of fresh 93.

The problem started when I drove it to the store about a mile from here to put the fuel in, I put about 5 gal. of 93 in, and took a ten minute drive in it, after a few minutes it started bogging if you pressed the gas peddle. Then I couldn't give it any gas at all or it would just fall on its face. I loped it back home luckily.

It starts, and idles fine, revs fine, if you take it up the street, by the time you get in third gear its bogging, and popping out the intake. If its cool it will run a little longer, not more then a few seconds.

I pulled a plug earlier today, (new plugs) it was sooted black. I adjusted the distributor air gap, and with the car started I pulled a plug wire off, with the old plug attached, it had a arc jump of about a 1/2" or so blue arc, looked strong, with that distinct snap sound you could hear.

I also measured the coolant temp sensor and got infinity reading. Also when I started searching the area I found the bullet connectors for two different sensors had been looped, or bypassed. One had red tape identifying it being the coolant temp sensor. the other was the thermo time? When probing both these sensors I read infinity.

Also the thermo time wires are (looped) if I unconnected them the car won't start at all.

One other note, if the car idles a few minute the problem goes a way for a few minutes, like the longer you wait the more the problem goes? Could that be the fuel pressure regulator?

Edited September 4, 2010 by Snakeyes711

[Nissanman]

Well, I think you have determined most of the problems.

NO sensor should be by-passed in the wiring OR read infinity.

Someone has been systematically by-passing these issues by doing wiring fudges.

I suggest that you replace the suspect sensors and take it from there.

[Travel'n Man]

Jake-

Welcome to the site - there is a ton of knowledge here so be sure to do a little searching and odds are it has been discussed in the past.

I live over in Boone and travel into the Winston Salem - Greensboro area weekly. It sounds like your son has hit the jack pot once you find the issues and get the car up and running.

Below is a link of a shop in Lewisville and the owner use to race Z Cars - I personally have not taken my car to him but I have heard very strong comments with his L24-26-28 engine knowledge.

http://www.b2byellowpages.com/company-information/89002350-r-v-performance-specialist.html

[Snakeyes711]

Well, I think you have determined most of the problems.

NO sensor should be by-passed in the wiring OR read infinity.

Someone has been systematically by-passing these issues by doing wiring fudges.

I suggest that you replace the suspect sensors and take it from there.

Thanks! Yeah I couldn't believe it? heres the thing, with the wiring like that, and it bogging, it still ran for at least ten minutes without a problem on the road...?

[Snakeyes711]

Jake-

Welcome to the site - there is a ton of knowledge here so be sure to do a little searching and odds are it has been discussed in the past.

I live over in Boone and travel into the Winston Salem - Greensboro area weekly. It sounds like your son has hit the jack pot once you find the issues and get the car up and running.

Below is a link of a shop in Lewisville and the owner use to race Z Cars - I personally have not taken my car to him but I have heard very strong comments with his L24-26-28 engine knowledge.

http://www.b2byellowpages.com/company-information/89002350-r-v-performance-specialist.html

Thanks, I did do some searching before I posted. I only got one hit with everything I put in. Maybe I can give him a call if I can't figure this thing out. He(son) has 250 dollars saved so thats what I'm working with right now to fix it.

[Snakeyes711]

New coolant temp sensor, new fuel pump, still bypassed thermo switch. I hear its ok for it to run like that. The thing is, it doesn't run .

I found out the Distributor is 180* wrong, I turned the shaft around in it to be correct, and am going to swap around all the wires tomorrow. Now the car won't even start....Black plugs, popping exhaust is about it.. I set the air gaps again, and the rubbing thing (inside dist) wasn't rubbing, I don't know if that would make it spark weak or what. at least he got a new fuel pump, and a coil out of the deal... Try again tomorrow.

[Snakeyes711]

I got the distributor swapped around, and the wires right, and it fired up. Runs but runs bad. I'm pretty sure the wires are gone last night I could see some of them arcing off on the engine. Si I'm going to try a wire set, and a new dist. cap. And fill it up with fresh 93 with some inj. cleaner, and seafoam,a nd run that out see how it does.

[Snakeyes711]

Pick up coils tested Adv. 750, Ret. 770. Is that good? Or is that in need of replace? That was tested under the pass. dash.

EDIT:

new plug wires, and plugs, idles nice, pull out the driveway has good power second gear nice and stiff, few seconds later, it hits a brick wall, and I have to limp back to the house. Plugs were sooty....I'm lost?...At a good note, the I got the tach working! Nice! Can anyone direct me without searching the wiring diagram for the tach signal to the ecu?

Edited September 6, 2010 by Snakeyes711

[Snakeyes711]

Pick up coils are good, I've exhausted my ideas. Now I can't even get it to rev sitting still.

[Snakeyes711]

My problem is solved. What I did to fix it is. Take off the fuel tank,a nd use a gallon of muratic acid to take the surface rust, and the spray lining that had been applied. The majority of the problem was the lining. It was brittle, and coming off in chunks looks like it didn't take too well on the inside.

The muratic acid ate that stuff right up. Be very careful if you used that stuff, as its 35% hydrochloric acid. I used a 3M respirator, and rubber gloves while handling it. A few times I dropped it on the concrete, and it immediately started smoking, and bubbling so its pretty damn strong.

Not to mention it cleaned off rust in minutes. I let it sit for a few hours to dissolve the lining then pressure washed it, and flushed it out with water. And did it again. Lather rinse repeat! This is what I saw when I first looked into the tank.

[zclocks]

Make sure to change your fuel filter after you complete rebuilding the gas tank.

Ron

[spitz17]

...This is what I saw when I first looked into the tank.

Any "after" pictures?