***Long post.....I know....but please help if ya have a min or two...***

I know that similar questions have been numerously posted before, however, there are such wide variations to the problem that i just need to be absolutely sure that i know what is wrong.

My car has had trouble starting (since february 2002) where after sitting long periods of time (4+ hours) it takes about 2-4 seconds to start, or sometimes i let it crank 2 seconds, ignition off, ignition on and boom - instantly fires.

Well, one day a couple months ago car wouldnt start at ALL. Let it sit, finally jumped it - ran well until I let it sit for 2 minutes. Why 2 minutes? After locking doors and hearing factory alarm arm itself, the horn seemed kind of weak...sure enough, cranked - but no start. So, it seemed as if the LONGER i waited the easier it was to start.....?!?! Eventually I just took the car to NTB, where I had the check alternator and battery, said I needed new battery, so I got one. I asked what alternator output was, they didn't check - and after they did, it came back low output.

Well its been 4 months now...starts just like the day i got the new battery in, and my autos instructor at school tested my alternator output. It was about 45 idle, and 70-79 with wipers, brights, lights, stereo, etc on.... He felt that was high enough and it need not to be replaced.

So now its been another couple weeks - finally determine that the problem MUST be fuel related. Test fuel pressure, ignition on (not starting car) it read about 12psi....NOT good... Start it up, jumps to about 28 psi....let it sit, holds at 28.

So I knew now i had low fuel pressure. After realizing the fuel filter must be old, I purchased a new one - which was a good move because 1 hour later my car was running at about 400 RPMs until i shut it down in the middle of the street, coasted to the curb, jacked it up, noticed dark fuel leaking from fuel filter (must be restrictive) so I changed it on the spot, started it up, ran fine.

After running fine it did seem to hesitate above 3500 RPMs, of whenever I floored it, and felt a little sluggish. Tested fuel pressure again today, same 28 PSI at idle....however, this time it was jumping from 28-30-27-29-28-30 etc........ Drove home then fine, arrive home, let car sit for 2 hours, decide to start it to go purchase a fuel pressure gage so I don't have to use my teachers al the time, however, had trouble w/ car. It started fine, but it seemed as if the RPMs were slightly fluctuating from 900-1000... I assumed I needed a new fuel pump. The RPMs did stay up...but you could sense something was wrong. After about 1 min in garage allowing RPMs to stabilize, I decided to turn on the A/C.....the SECOND I did that, RPMs dropped to about 650RPMs and then back to 1,000 (in about 1.5 seconds).

What is going on?

Any info or quick suggestions to further diagnose this is GREATLY appreciated - thanks guys.

-Fred

 

Hey man. check out that coil. if you have a scope at your school I would suggest scoping it and check the secondary ignition system starting at the coil down to the plugs. If you have a Vat 40 at your school test the alternator with that. hope it works out for ya. see-ya,
-Paul

 

Your fuel pressure is still way low, find out why and fix that first as this is a definite problem that you know is there.
Fix the fuel system first and then go from there.

 

Could be your fuel pressure regulator bleeding off pressure. More than likely its your fuel pump man. Heh, have fun changing that puppy

 

hey just got doe doing my fuel pump 30 mins ago, not that bad
- just for s..ts and giggles, when car is just idleing, try turning steering wheel, do u here drop in idle, or turn on accesori and listen, if so the idle controler on bottem on trottle body might be sticking, just a thougt, fuel presure is low though to, here is the link for directions i followed,
http://www.geocities.com/formulapower2/fuelpump.html
took me maby two - three hours but not really hard the only thing i did different was used dremal to cut just corners and then big tin snips to slice the rest to minumize the spark factor, u dont have a lot of clearance so just get thru top with dream do not push all the way down, thats my 2 cents but good luck

 

wow - thank you all for the speedy replies. Gonna get it to the shop at school tomorrow, instructors are knowledgeable and should be able to perform all tests necessary to further diagnose this problem (hopefully)... car has 66,000 miles on it...I hate to have it be faulty fuel pump, but it doesnt seem to uncommon through the reading I've done on these boards. Fuel pressure gage read 25psi at idle....stayed steady at about 1500RPM, dropped after quick revs to 3,000 - 3,500 RPM.......shut off car, holding at 22psi now....leaving it attatched all night, before fuel filter replacement I had trouble starting fast in morning, so maybe there is leak somewhere...... Once again, thanks for all your advice and knowledge! If anyone else has any insight, it is also VERY welcome >: -> Also, im not jumping to conclusion yet, but if it is the pump itself that needs to be replaced, where is the best place to purchase a pump and what pump model will suit me well in accordance with my car? Any recommendations are helpful, a top-of-the line pump is not necessary since near future mods will most likely just include LTs and small stuff since its time to start saving for college next year. THANKS! -Fred

 

You definately have a fuel problem either pump or regulator.
That pressure is way too low, it aint gonna matter if it holds it all nite or for the rest of your life its too LOW.

 

If you have a fuel pressure gauge with a botton on the side that flows fuel from the line. Take a 20 ounce pop bottle and put the line into it. If the pump cant fill up that pop bottle in less then 30 sec your pump isn't flowing enough. Try that and see how it works. see-ya,
-Paul

 

Go online and buy an after market fuel pump for your car and look for the instructions on how to change the pump by cutting a hole in the trunk...

IT IS UR FUEL PUMP!

 

For what its worth....there is a GP in the for sale section for Walbro pumps. A lot of people swear by them. I have a year old OEM GM pump that is starting to read lower all of a sudden so I am going to try the Walbro and see how it goes. I replaced the regulator first and it reads exactly the same.

 

hey - Thanks again for all the replies - pressure dropped from 28-0 in under 3 hours last night.....time to start looking for a new pump, I couldn't find the GP for Walbro pumps......I found these prices on the internet though http://www.jdsperformance.com/index....tem&inmake=all ---of the two pumps for 5.7L Camaros...one of them says "high pressure" -- I just want the other walbro (not high pressure), is that correct? Or would the high pressure pump be better? -- From what I understand, my car currently needs the one not labeled high pressure since the only mods in the near future are some LT's.....please point me in the right direction, also, if anyone could send me to a link of the GP on Walbro pumps mentioned by badassT/A, that would be great -- thanks!

 

http://web.camaross.com/forums/showt...hreadid=177018 Heres the link.

 

$99.99, looks good to me - think i'll order today, - thanks again

--Fred