Frustrated Z28 Owner Needs Help

[30thAnnivZ28]

Hey fellow Camaro fans. I have a big dilemma that is making me want to trade in my 30th Anniversary Z28 for an economical 4 banger because of a problem that's been bugging me for over a year now. I also have tons of questions. I have a 97 LT1 Z and I have many mods on it. I've been reading your posts on fuel pumps and bad starts, etc and I have a similar problem. My car always takes about 2-3 turnovers to start after it's been sitting undriven for a couple hours or more. It is NOT a starter, battery, alternator, or air problem. I'm going to list what I have done to the car to help you help me figure out what's wrong. Mods are: Moroso CAI, 1LE elbow, Granatelli MAF, BBK 52mm TB w/foil, MAC Jet-Hot coated headers w/ y-pipe, MSD 6A Ignition, Flowmaster muffler, short shifter w/short stick, magnecor wires, NGK plugs, Hypertech Power Programmer III, 160 thermostat, cat back exhaust (3" all the way back), high-flow single cat (to reduce backfiring), 2 underdrive pullies, skip shift eliminator, Autometer air/fuel gauge, and some free mods. Yes, the car runs nice and fast after I hit 2nd and 3rd gear, but it feels like it wants to cut out right when I'm about to accelerate from 1st and at WOT (it sputters at WOT). I had an experienced muffler mechanic tell me the car runs WAY to rich because my exhaust tips USED to be chrome, but now are JET BLACK. I just put in the plugs, ignition, wires, and headers less than 2 months ago. Here's the weird part. Right when I unplugged the Granatelli MAF and took it for a spin, I smoked the SH!T out of a modded 1994 5.0 stang! Before I yanked out the wire from the MAF I couldn't dream of doing that. It was running at half power before I pulled the plug on my MAF. The Granatelli MAF did help me out a lot originally, why would unplugging it fix half my problem? The other half is the bad starts. I need to know all you guys can tell me about fuel pumps screwing up, cause that's what I think it is. I ALWAYS run my fuel tank bone dry before filling up. How can I TEST my fuel pump without spending precious mod $$$ to replace it before I know it's broke??? Would a performance TPS help?? What about an IAT?? PLEASE HELP MY WOUNDED BEAST!! THANKS!

Ever since I bought my car sometimes it takes 2 -3 times to start it also. if I turn the ignition on and off a few times this seems to help. Then last night we went to the local track. durning the last pass down the track my car just shut off. It wouldn't restart. I had to get her towed home .

Just this afternoon I went to a local parts house and bought a fuel pressure tester. Cost me about $40. Hooked it up to the scrader valve on the back of the intake. Turn the ignition on I have 0 psi of fuel pressure. It should be around 40 - 43 psi. I turned the ignition on and off several times and the guages showed about 10 psi but leaked back down.

If I were you I would go buy a fuel pressure tester for 40 and check the system. It is real easy to do. took me about 5 mins. In your case you could crank the car and watch the guage and see if the pressure fall off and any rpms.

maybe someone else can elaborate more for us, but this should get you started

[30thAnnivZ28]

hey thanks, I will try that. I had another question for anyone out there with an inline fuel pump (mounted out of the tank). Let's just assume that my fuel pump is deader than a doornail. In theory, could I install an inline pump and let it pick up the slack from my "dead" stock fuel pump? Is this a bad idea? will it not be enough to do the job? will this not even affect my bad start problem? I just don't want to open up my fuel tank, but I know my fuel pump is dead. Hey, just out of curiousity, if I fill my gas tank with 93 octane gas, and I DO NOT USE THE A/C once, I get 240 city miles on my engine before I refill gas. I was wondering if this is good or bad based on the mods I have. Thanks!

[DosJ_95Z]

yea...my 95 Z28 has jus started having starting problems... i know about the fuel pressure guage but im not sure where to hook it up...any help???

Originally posted by DosJ_95Z
yea...my 95 Z28 has jus started having starting problems... i know about the fuel pressure guage but im not sure where to hook it up...any help???

On the back of the intake under the dash, there is a scrader valve. It has a little black cap on it. Kinda looks like a valve stem on a tire I guess is the best way to explain it. The motor needs to be pretty cool to do this. You just hook the fitting up on the tester to it, real simple.

Hope this helps

Believe it or not, I just changed my fuel pump. Bought a new one from Thunder Racing Friday and installed it friday night- Saturday morning. It only took us about 4-5 hours to do it total. I chose to go in throught the trunk thought. I think this was the easiest route considering I work in a Fabrication Shop and had all the tools. I am working on a guide the help anyone interested.

I bought the Racetronix Walbro 255 with the wiring harness upgrade also.

[Lyle A]

Is that method easier than just dropping the tank?

[86RedRocket]

Originally posted by Lyle A
Is that method easier than just dropping the tank?

If you have the tools, it will be easier to cut an acess panel on top of the deck.

[along]

Hey Z28 (or anyone else who can help me),

My Z was getting progresively worse and last failure it just died at 70Mph on the Interstate. If I let it sit for about 30 mins, it will start and run for a bit and then die again. I am sure its a fuel pump.

Originally posted by Z28.com
Believe it or not, I just changed my fuel pump. Bought a new

I am working on a guide the help anyone interested.

Do you have a guide on how to do that fuel pump change ? I would be very grateful for any advice on how to change it and avoid the $500 the mechanic is quoting me for the change.

What about filter and pump brands ? I dont need performance, just one that will last and stock is fine. And where are the filters on this car ?

Thanks in Advance !

[WrathGrape]

A few things that I've heard of that could possibly result in difficulty starting even if the engine is warm are loose connections in the ignition system, and bad engine ground. One thing that could be aiding to it running rich could be bad oxygen sensors if you have any located before the catalytic converter. I don't know your exhaust config specifically, but those are just some possibilities if you haven't looked into them.

[Greaseymec]

Mr. Administrator. Was the fuel pump the final fix on your fuel pressure problem? Mine is doing the EXACT thing and I have a no start situation.

[88z2try]

Does it run fine once it starts?? If so then you do have a fuel pump problem. There is a valve in there that if its stuck open then when your pump primes before start up the fuel will just run right back into the tank. My 88 Z had that problem for about 2 weeks. But one day it just started working and the valve came unstuck. You might also notice the pump sounding extremely louder than normal. Thats just on the prime (when u turn the key on). Now for your other problem you ssaid you unplugged the MAF sensor and it seemed to fix that problem. This usually means your MAF sensor is bad. Hope there is some kind of warrenty on that thing. But for your fuel pump start up problem it may be stuck for good or it may fix itself.