Suggestion on how to proceed...

[semitch]

Ugh......:disappoin

Hopefully someone can give me some ideas on how to proceed. A couple of days ago I noticed that two of the fuel lines on the fuel rail on my 77 280z were leaking and I decided to change all of the hoses out.(PITA) I was able to remove the front and back fuel rails, change all of the hoses, and left the injectors in place. After all of this the car will now start but it stumbles and hesitates very badly whenever I try to hit the accelerator. I can here the injectors working per the FSM and have cleaned all of the connections. The only thing I can think of is that I may have had some garbage in the fuel rails that was stirred up and plugged the injectors. Is this a possibility? If so, should I now just pull the injectors and have them cleaned or replaced? Any suggestions would be helpful. thx

[webdawg1]

I would lean to the (crap in the fuel rail) idea. When I pulled mine off to clean up the fuel rails I sprayed carb cleaner thru the rails using the little red straw.... You would not believe what kind of CRAP came out of the rails....we're talking BIG old honking flakes of STUFF.... If you want to send them off (Your injectors) to be cleaned here's a url:

http://www.witchhunter.com/injectorserv1.htm

I would see about trying to clean up the inside of the fuel rails first tho...you might be able to clean up the fuel injectors with some carb cleaner, but it might be the better part of valor to just go ahead and send them off to be cleaned...your call on that one....

webdawg1

[sblake01]

I don't know, if your car ran okay before changing the hoses, I don't see how that could suddenly crud up the fuel rail. Before tearing it apart again, I would check and make sure that all of the connections that were removed during this process are clean and re connected properly.

[semitch]

Thanks for the suggestions guys. The car was running in good condition before I started. When I had everything apart I almost pulled the injectors to have them clean before I put everything back together. Last night while reading through a copy of the 280z fuel injection book I decided to go ahead and just re-check all of my EFI connection for the 5th or 6th time and see if I possibly knocked something else loose. I did change out some vacuum hoses and may have bumped something else in the engine compartment.

Some of my fuel injector connectors did have pretty corroded contacts. Anyone have an opinion about changing these out while I'm checking everything else. I came across the following website http://www.atlanticz.ca/zclub/techtips/ last night and it seems to cover the process of upgrading connectors thoroughly.

[DatsunZsRule]

cleaning the fuel pipes out isn't a bad idea just because it probably needs it but I agree with sblake. If it ran good prior to the disassembly then it must be something you forgot to tighten down or something got bumped by accident. Do you notice a gas smell when its running? If so then that answers it. You have a fuel leak somewhere.

Check the fuel pipes over good to. Mine just from old age developed a very small hair line fracture at the weld where it T's off and goes to the cold start valve just this weekend when I was going to take her out. I couldn't see it till I applied a small amount of pressure on it with my finger and it spayed as I did so you may want to double check the pipes too. When removing these, you have to handle them carefully.

Best of luck.

BTW, I hope you used High pressure rubber hose and not just regular rubber hose, and new hose clamps:) otherwise, you will be doing this job again soon.

[cremmenga]

is it possible that your clamps may not be tight in some location, I'm thinking it could be letting a little air in and that may be why you sputter, your car may be getting little air bubbles/ pockets in with the fuel in the lines! just a thought. good luck

[Z Excellence]

On my 76Z the injector wiring was too old and any little movement of the wiring would make the engine miss. The way to figure this out is to move the injector wiring around and notice if you hear any change in the miss. The fix is to splice in new wiring.

[semitch]

Hey all thanks for your comments and suggestions. Well what I thought was going to be a quick changing of a couple of fuel hoses on my new z has really started to bum me out. I've own the car for about 3 weeks and 5 of those days its been sitting in my garage. I may have 200 miles driven on the car...

I finally had sometime today before work to clean my injector connections, retrace all of my steps, and verify any hoses that I changed were still connected. After doing this I went ahead and started the car. At first the motor seem to run a little smoother and not stumble or hesitates as before. (I did get some black smoke out of the exhaust.) After it had run for a couple of minutes I tried to hit the accelerator. When I gave the motor some gas it would started running rough and began hesitating again. After a couple of more times the engine eventually stalled out as if it were starving for fuel. I'm now thinking that a may have a clogged fuel line or fuel filter.

Currently, I'm sitting at work with a freshly printed copy of the Fuel Injection Troubleshooting guide and the FSM in front of me trying to figure out where to start. I still can't figure out how my simple job of changing hose has evolved into this? I should have some free time this next week to start troubleshooting.

[semitch]

Ok, after a night of reading and searching through previous post I think that I need to check my fuel pressure after the fuel filter. The previous owner use to barely drive the car, and the day prior to finding the fuel line leaks and changing my fuel lines out I filled up the tank for the first time. Working on the car part time it took 2 days to change my hoses. I think that I may have loosened some crud in the tank when I filled it up and over the course of a couple of days it all settle to the bottom and plugged up my filter. Can I just pick up a guage at a hardware store and fab it up to my fuel line?

[sblake01]

Sure, that's how I made mine. All you need is a guage, a tee, and a couple of 5/16 hose barbs.

[webdawg1]

You can get kits already made up at Napa and other parts places like that. Start out around $40.00 or so for the basic kit all the way up to around $300-400 for the super deluxe kits. Just depends on which kit you think will work out best for you in the long run....

webdawg1

[DatsunZsRule]

Buying a guage to test fuel pressure after the filter is a great idea. I have a pretty expensive FI Pressure Test kit, but making your own like mentioned works just as good for what you'll use it for.

Yeah, it sure sounds like the symptoms of a clogged fuel filter to me. Thats what happens- Runs ok when you first start it, then later the crud gets stirred up and clogges up the filter restricting fuel flow and then it leans it out so much to the point where it kills the motor.

If I were you, I'd take a look inside that gas tank as I'm sure that will need to be cleaned out as well.