98 z doesnt like to start
josh1107, well usually it doesn't start when its hot outside. For example in the mornings it starts right up. But after i have drivin it and let it sit it won't start. It has done this since i bought the car, its really annoying. Also I have noticed if i turn the key but not cranked it a couple of times it helps it start when i crank. I think it has something to do with the fuel system.
Thread Starter
Launching!
Joined: Dec 2005
Posts: 226
Likes: 0
From: citrus springs, fl
alright, i check the pressure, and it deffently doesnt hold when hot, hope its not leaking past the injectors. i replaced the fuel filter, ill do some more checks and let you guys know
thanks
josh
thanks
josh
Thread Starter
Launching!
Joined: Dec 2005
Posts: 226
Likes: 0
From: citrus springs, fl
wow phoenix, it sounds exactly the same for me. per the haynes manual, and the other posts on here, connect a pressure gage to the "shrader" valve, i didnt, i just took a screwdriver and bleed off the gas(make sure you have some rags). when i just shut it off, there was alot of gas. i ran it again, then waited 1/2 hour, then checked again, nothing. i guess it is always supposed to be pressurized. the haynes manual has you do different checks to determine what is faulty. i will let you know when i get that far.
hope this helps
hope this helps
Thread Starter
Launching!
Joined: Dec 2005
Posts: 226
Likes: 0
From: citrus springs, fl
ok, i hooked up a pressure gage to the fuel line. i get 45 # with the key in on, the book says its supposed to be 55. with the car running, i get 50. the book says it is suppose to drop 3-10 pounds. PLease HELP!! oh and the pressure doesnt stay at 45, it slowly bleeds off.
thanks
josh
thanks
josh
Last edited by josh1107; Apr 18, 2006 at 01:28 PM. Reason: add
Teching In
Joined: Sep 2005
Posts: 26
Likes: 0
From: Bloomingdale Il
There is one of your problems Josh. Here are the steps I would take if I had your symptoms. The fuel pressure should not bleed off.You could have leaking injector(s)and they will have to be replaced. If I found one bad injector, I would change them all at 90k. If it is acting up more when its hot I would take an ohm meter and check the resistance on your injectors(when hot).
I don't know the specs on your injectors but a good rule of thumb is they should all be about the same . If one is really low it would cause your PCM to shut down and hard start or not start. It would get worse with time until you are stranded and need a tow ( I had a few of them) to fix at the dealer.I put new injectors in them and they were fine.
Now,to quickly check your injectors for leak down you have to pinch off your fuel return line and see if your fuel rail holds pressure on your gauge without bleeding down when you shut your car down. If it doesn't bleed down when you pinch it off,you have a bad fuel pressure regulator ( less costly) if it still does you have a bad injector(s).
Also have you ever replaced your fuel pump before ? I use to change them on cars about every 35k-50k at the Chevy dealer. A weak fuel pump or a clogged fuel filter could throw off O2 sensor codes because you are running lean with your low fuel pressure and the computer cannot trim your mixture enough.Try checking the above first. I hope It helps you Guys, Later
I don't know the specs on your injectors but a good rule of thumb is they should all be about the same . If one is really low it would cause your PCM to shut down and hard start or not start. It would get worse with time until you are stranded and need a tow ( I had a few of them) to fix at the dealer.I put new injectors in them and they were fine.
Now,to quickly check your injectors for leak down you have to pinch off your fuel return line and see if your fuel rail holds pressure on your gauge without bleeding down when you shut your car down. If it doesn't bleed down when you pinch it off,you have a bad fuel pressure regulator ( less costly) if it still does you have a bad injector(s).
Also have you ever replaced your fuel pump before ? I use to change them on cars about every 35k-50k at the Chevy dealer. A weak fuel pump or a clogged fuel filter could throw off O2 sensor codes because you are running lean with your low fuel pressure and the computer cannot trim your mixture enough.Try checking the above first. I hope It helps you Guys, Later
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
Launching!
Joined: Dec 2005
Posts: 226
Likes: 0
From: citrus springs, fl
thanks i really appreciate the response, i will check those, where is the fuel return line, or better yet, does anyone have a good picture or drawning of the fuel system?
thanks
josh
-from what i heard a weak fuel pump would only give me trouble when cold...true?
thanks
josh
-from what i heard a weak fuel pump would only give me trouble when cold...true?
Teching In
Joined: Sep 2005
Posts: 26
Likes: 0
From: Bloomingdale Il
Crank sensors do go bad ,but did you find out why your fuel system is bleeding down so fast? I would look into that before I start throwing parts at it. Make sure your fuel pressure is in specs because that will cause your issues also. Fuel injected engines are very temperamental to fuel pressure.
Thread Starter
Launching!
Joined: Dec 2005
Posts: 226
Likes: 0
From: citrus springs, fl
no, i dont know how to pinch off the fuel return line, please advise. so the fuel line is supposed to hold pressure? for how long? mine bled down to 10# in about 10 minutes.