Bringing a 1977 Z back life

[Av8ferg]

Okay. I’d consider switching to carbs if this pain doesn’t cease. My question is what is the total cost of this change? Do I need a new intake? I guess I’m asking what does this entail? I have an person I know who has brand new unopened dual Weber’s he was going to install in his 240z. He ended up selling the 240z. He realized the rust was beyond his expertise and had all these extra parts he intended to install. He’s just a guy I ran into a few months ago in VA. I was in the market for a 240 and looked at his for sale. It was a rust bucket but he said if I ever need carbs call him.
Other than the carbs, what else do I need? BTW he also has a totally rebuilt L24 long block and rebuilt 5 speed tranny if anyone is interested. He’s 70 and want to move all his extra stuff. He sold the car and still has that extra stuff.


Sent from my iPhone using Tapatalk

[Patcon]

If he has dual Webers they would not be my best choice for a Z. They work but they are fairly complicated. Nothing like a good set of simple SU's.

For an SU swap you would need the SU's w/ the connecting linkage, air cleaners, intake manifold, balance tube, low pressure fuel pump and some fuel fittings, maybe the throttle linkage...

[Zed Head]

You're very close at this point, and your problems are actually pretty simple.  Carb's won't be much easier.  You'll probably still have an electric fuel pump, with the same basic problems you have now.  Then you'll have to learn SU's.  

Notice that RossiZ made his EFI system work, before he switched to carb's.  Not because he couldn't make the EFI work.

[Dave WM]

The EFI works very well, before throwing in the towel, try to figure out why its not working. 1st guess on the high pressure readings is the FPR is defective, OR the rail is plugged up somewhere.

I would start by pulling the entire rail/injectors off (good to check for leaking injectors anyway). then try shooting in some compressed air into the inlet, starting out low and working up to 36psi, make sure that is when the FPR starts to release. May as well take all the fuel lines off that connect it up next and replace with all new and make sure you use proper injector hose clamps. check for blockages in the hard lines of the rail with compressed air. Take your time get it all worked out.

Don't get in a hurry just to hear it run, work the issues one at a time. I would start with resolving the fuel pump and lines to get it working, this may include making sure the hard lines are not rusted up causing blockage. Then resolve the FPR to make sure its working properly (per the above test with compressed air at 36psi). test all the injectors for spray pattern and flow rates with a test setup or just take them to a marine place that will clean and check for you, about 20-25$ per. Once you have all that then you can move on to the various testing of the ECU and sensors. Its a bit time consuming but once you have the EFI working as design you will be rewarded with instant startups and consistent performance regardless of outside temps.

[Av8ferg]

Great advice gents.  

As cool are going carbs sounds I think I need to try and work through this problem.  

I started reading the FSM and will methodically go through the trouble shooting steps.  I think that was sound advice about being patient and not jumping the gun.  The car hasn’t run since 1999 so I have to expect there are many gremlins to discover and then fix.  

Once I run the continuity checks I’ll have a better idea what happening with the ECU, FPR ect..  

I’ve already cleaned out the entire fuel rail and replaced all the lines in the engine compartment.  I really want to install a better rail, that doesn’t have all these small hoses on it.  It’s just more places for failure . I heard 78’s have a continuous rail.  Maybe an aftermarket rail is an option. 

I am suspicious about the fuel tank.  I drained and refilled it with 3 falls of fresh gas.  Yesterday when I pulled the pump out I disconnected the line exiting the tank.   When I lowered one end brown dust come out of the line.  I expected gas to come out because the other end was coming right from the tank. This leads me to suspect it’s clogged and or the tank is rusted.  The outside of the tank looks great.  I know that means nothing.  New tanks are over $500 and I’m not sure how to repair the one I have at a reasonable cost.  

Well the bad news is I’m going to have to put this project on a 2 weeks delay.  Taking the fam on vacation and then a week of work out of town.  I’ll have time to get smart and order parts I need.  

I was tempted to tow it to a shop but then realized there are no Z experts here and they’d probable take me to the cleaners anyway.  

[Dave WM]

the tank will always be suspect, I ended up paying to have mine cut open, sandblasted, coated. Expensive to say the least, but I did not want to be fighting it. the inline prefilter (clear fram G3) will quickly show junk. Fuel delivery to the rail in sufficient volume and pressures is critical for the EFI to work. Work that 1st with a good pump filter and testing for flow.

the rail while a bit of a PITA is not a huge problem. You will not be dealing with it much once you get things sorted. I ended up installing the injectors into the manifold 1st THEN installing the rail. again you just want to test everything out on the bench where possible. Mine is a 75 with the split rail, trying to deal with in all put together with the injectors installed was a major hassle, that is when I decided to just install the injector and then fit the rail, much easier. Also you want to make sure the injectors are clocked so the electrical connectors will not be a problem, watch for the installation screws to be clear of the plastic molded connector parts.

Its really not a complicated EFI, no feed back so no O2 sensors, but you do need to make sure all the electrical connections are good as are the grounds, then just follow the FSM for readings AT THE 36 pin connector to test for how well the sensors are doing their jobs.

 

 

 

Edited January 21, 2018 by Dave WM

[siteunseen]

There's a cheap way to clean and coat the tank also a couple of diy fuel rails.  I've got a efi car and a SU car.  The carbs scream and beg for more fuel/power.  Efi is nice and smells good.

I will gather up some post from older threads maybe tomorrow,  it's supposed to rain and I'll be stuck inside. You're going on vacation so we'll have plenty of time.

Enjoy yourself and time spent with the family.  Cliff

 

[Av8ferg]

So I finally got a couple of hours to work on the car.  I had a small disaster while away.  I left the fuel line detached from the fuel tank since it was clogged up anyway.  Well at some point the line began to leak.  I spilled at least two gallons of gas on the garage floor.  Needless to say my roommates and owner of the house were ticked off the whole house smelled like a gas station for 3 days.  Also stained his expoy floor.  

So, I have come to several conclusions. 

1, The fuel tank is rusted.

2. I have a fuel injection system wiring or component problem.  

I started running through the service manual and when I got to step 3 (page EF-22j) I got no continuity on check 3a and 3b.  This is the AFM check.   It says if  “contunity does not exist........N.G”  then check the circuit indicated on EF-39.   So I guess I need to pull the AFM connector and see if the wire has an open and if not it means I have a bad AFM?  I checked the connection and it was seated properly. Of note I have two other AFMs on hand.  

Upon inspection basically all my connections on the EFI wire harness are crap.  Most of them  really don’t stay seated and are brittle and fragile.  I suspect I need to rebuild all the connectors.  This won’t solve my starting problem but it will have to be done for any reliability. 

This EFI system is starting to wizz me off. I feel like I’ll be chasing one thing after another.   Today I really starting to think switching to carbs is the way to go.  Heck then if we are hit by an EMP I’ll have a car to drive. ?  

I have 2 weeks to get this car running or I’m going to have to tow it to NC and let it sit a year until my house is finished being built.  The owner of the crash pad in Memphis isn’t thrilled about a broken car sitting in his garage,  He’s given me 2 weeks,   I’m just not sure I can do it in that short of time.  I hate to put it in a storage unit for a year when I feel like I’m close.  Vest frustrated.  What do you guys think? 

 

Edited February 9, 2018 by Av8ferg
Typos

[Dave WM]

use the resistance setting rather than the continuity setting. The EFI works very well once sorted out, main issue is corrosion on connectors (clean and deoxit), hardened rubber covers (allow moisture and corrosion to start)  replace them. corrosion on various ground to chassis and fuse links. Then the sensors, mainly the temp sensor (not the temp gauge but the EFI sensor).

Lastly get the fuel system healthy. It takes some time to work the issues, but once done it works great. The AFM is often the go to thing to start messing with, it really should be the last thing to be messed with if at all. there are some youtube videos out there that you may find helpful in AFM checkout.

[Av8ferg]

Great advice. Why the resistance setting on the multimeter. What reading would I be looking for?

I think it might be best to check the entire harness out and put all new connections on. I forgot to mention that the fuel pump does not pump when installed in the car. It works fine when hard wired to the battery. So I know there is some electrical or relay issues I need to track down.
Alas even when I connect the pump directly and tried to start the car I got nothing but over pressure in the fuel line. I don’t think the injectors are getting the electrical signal to fire. I didn’t smell fuel from the tail pipe either.
I have multiple issues to address and really don’t know where to start. I guess the fuel tank?


Sent from my iPhone using Tapatalk

[siteunseen]

There's a guy on ebay that sales the plastic connectors in a kit for the 280s injectors and cold start valve. The thermotine and the coolant sensor also use them.  It comes with heat shrink to go over the soldered wires you'll have to connect.

 

[siteunseen]

Back in the beginning I linked what we call "Blue's Tech Tips", maybe my first reply?

Anyway on the "efi and fuel" category there's one sub that says "dropping a fuel tank".  Give that a look if you haven't already.