Thanks for reading,

I have a 92 3.1 Camaro that will not start without starter fluid and once it does if you press the throttle it dies, but if you slowly and i mean slowly engage the throttle it will slowly rev up. So far i've changed the ECM, Spark plugs, New Distributor, Cleaned out the injectors, Cleaned out the gas tank (which was full of rust), New Fuel filter, New Fuel pump, Checked the fuel pressure and I am getting pressure, the injectors are getting power. I have literally been dealing with this for 2 years and 4 mechanics and no one seems to know why my car wont run (as in road ready). Also when we cleaned out the injectors the car did crank and run perfectly for every bit of 20 minutes before it started doing the exact same thing. If anyone can help it would be greatly appreciated.

 

did you flush all the fuel lines before firing it up with the clean injectors? I'm just wondering if there isn't a bunch of crap stuck in the top of the injectors from the rusted tank and stuff. You might have to send out the injectors to have individually cleaned, or whatever.
How did you set the timing after replacing the distributor?
Are all the sensors functioning correctly? (I've had coolant temp bad before, starts like poop)
lots of things can cause this. gotta start eliminating things, then will trickle down to the problem.

 

I didn't flush the lines I'll try that today, also i'm replacing the injectors with 17lb's today bc I also had the engine rebuilt a few weeks ago and it is doing the exact same thing it was before the build. We've set the timing numerous times, setting the distributor from -10 degrees to +10 degrees. also like i said when the car is idling, it wont rev up at all unless you slowly press the throttle. almost like it's chocking out. also i remember something weird happening when i accidentally turned the key while the car was still running. The car seemed to rev up perfectly for that split second .

 

try disconnecting the knock sensor and see how it runs. it shows to be slightly above the starter on the side of the block

 

When they rebuilt the engine they took out the knock sensor.

 

and you're trying to still run it with the computer???

sounds like you need to get everything hooked up correctly first, then start chasing problems.

 

They said they wanted to run it without the knock sensor. and the car is doing the same thing it was doing before i had it rebuilt.

 

Don't put new injectors in it until you blow all the crud out of the system from the gas tank to the fuel rail. The injectors probably got clogged up with the rust that formed in the fuel lines after you cleaned them out, so they need to either be professionally cleaned or just replaced. Followed by the fuel filter (crud in the sending unit and line between the pump and the filter). Was the strainer sock in the gas tank replaced with the pump? May seem obvious but some don't do this...

Those 17 lb injectors are WAY too big. Stock runs between 14.7 and 15.4.

At least make sure they put the knock sensor back in the side of the block... The engine will run with it disconnected but will throw a code 43.

 

blow out the fuel lines and everything as suggested.
my iroc did the same thing when i first got it, turns out it only had 20 psi of fuel presure, it would idle but wouldnt rev unless u very very slowly opened the throttle, i chased my tail on it for about a week before i finally got a fuel presure gauge to test actual fuel presure.

even with only 20 psi it had enough presure to shoot fuel 2ft in the ait when i pressed the shrader valve, so dont use the method of pushing the shrader valve in to see if it has presure cause all it will tell u is that the pump is turning on

 

OK so we pulled the fuel lines and there was gunk and rust all throughout the rubber lines. And you're right we figured since the shrader valve shot fuel up in the air like you said that the lines were OK. So today when i get off work i'm going to try and clean out the lines under the hood and blow out the line from the engine bay to the fuel filter. We did put a fuel sock on the pump when we cleaned out the tank. I'll let you guys know this evening. And i really want to thank you guys for helping out!

 

We set the timing, cleaned all the lines, put a new fuel filter, replaced the fuel log and regulator, and put in new injectors. And it still will not start without starting fluid. I dont know what to do next?

 

what is the fuel pressure?
what did you set the timing to?

 

Did you blow the crud out of the RETURN side of the fuel system? If the pressure side of the system was THAT nasty, chances are the return side is just as nasty, and too much fuel pressure is as bad as too little.

Get a fuel pressure gauge on it. If it reads over 47 PSI, the return side needs to be blown out, from the port in the middle of the pressure regulator (the brass fitting under the diaphragm) all the way to the tank. Just stick the blowgun nozzle into the brass fitting and hit the air... Every bit of crud will be blown out of the return side from the rail to the tank.

 

Ok so i cleaned out the injectors and put a fuel regulator in the log. The car started when i put starter fluid in it. But this time when i engaged the throttle it didnt stall out! since it was idling and responding to the throttle we hooked the computer up to it. It pulled a throttle position sensor and idle air control sensor error. I ordered them yesterday and am putting them on today. The Fuel Pressure stays at 40 psi... But i still cant figure out why the car wont cold start??? it only starts with starter fluid.

 

Also when we attempt to crank the car it has fuel pressure but immediately drops.

 

Make sure you got the screws for the FPR tight, and then you will need something to clamp off the fuel hoses by the engine that won't damage them.

 

We checked those and they were snug. Also we noticed that the care was only cranking at 40 psi and when running it was at the 36-38 range We clamped off the return line to see if the car would crank with the added pressure, when trying to crank it was at about 60psi but still nothing. Also like before as soon as you were done turning the key the pressure dropped back down to zero instantly. Also we decided to test drive it. and it didn't accelerate worth crap and just stalled out.

 

it should hold pressure when shut off.
if you can find some way to keep the fuel pressure gauge hooked up, plug the supply line before the fuel rail and see if it holds pressure. (if you can find correct fittings, just remove fuel supply from fuel rail and hook up your gauge to that) If it holds pressure, the problem is with an injector sticking open or the fuel pressure regulator.(fuel going into the intake/runner or back to the tank)
If it doesn't hold pressure then either the check valve in the pump is bad or one of the lines from the pump to the pass through of the fuel tank is split.

--been down that road before.....

what I have done before is to pull the pump assy and stick it in a large enough bucket of fuel and power up the pump with a battery. Watch to see where the fuel is coming out. Don't let the battery spark when hooking up the power (Biiiiiiig Baaaada Boom !) or at least move it far enough away so you don't light everything on fire...
You may have to restrict the outlet some or completely block it off to find where the leak is. If you plug the supply line, the pump WILL open it's bypass check valve -- it's supposed to, but it should retain pressure when shut off. You're looking for where it's leaking when shut off. That bypass check valve could have a piece of trash in it, keeping it open all the time.
The pump makes good pressure, so it's not bad, but if that bypass is stuck open, you have to replace it.

I am not sure it will fix your problem of not starting, though. If you have enough system pressure when cranking, it should start, whether or not the pump holds pressure.... you may have other issues still.

 

make sure that the pump isnt getting hot, if it is you have an electrical problem. Have you checked the wiring going to the pump? The insulation could have been taken off by something.

 

greggbruce I'm not really sure what you're asking me to do in reference to plugging the supply line? and the pump is in the tank so i really cant tell if it's hot or not.

 

Block it off, but but with a gauge attached somewhere so you can still measure the pressure the pump is making, and to see if the pressure goes away when you turn the pump off. It should hold a majority of the pressure when it's off. By disconnecting and plugging the fuel supply line at the fuel rail (or before, like at the filter) That will eliminate the injectors and pressure regulator to see where the problem is. But you will have to find a creative way to attach the pressure gauge, cuz the pressure tap is in the fuel rail, yes?


I could try to draw a picture if you want....

and yep, you have to lower the rear axle and remove the tank to get the pump out. Please don't cut a hole in the floor to access the pump with the tank still in the car. I just hate that....
I DO wish they would have made an access plate bolted in there like some cars have...

the pump will generate heat, but the flow of fuel and that it's submerged in fuel is supposed to keep it cool, and yes, I don't know how you could check if it's getting hot without driving it for an hour and then quick, pull the the pump out and see if it's hot....

 

OK i see where you're getting at. I'll let you know what happens when i get off of work.

 

Hey Guyz sorry for the loooong delay, I finally got back in the garage to work on the car. I replaced the fuel filter, fuel pump and sleeve. The problem with it immediately dropping pressure went away. but it STILL didnt start without help. and also it still choked out if you engaged the throttle too quickly.

 

Great News! After replacing the fuel pump, cleaning the injectors, blowing out the lines, bypassing the vats, and getting extremely frustrated the car finally cranks and runs! (No stater fluid needed) ... but now i have to figure out why it has no power under a load.. it'll rev up just fine in nuetral but as soon as you put it on the road it wants to bog down....

 

Reset the ECM first...

And then get a scanner hooked up so you can watch the O2S reading, and possibly the BLMs (if it will get that far). Also do another fuel pressure test on it. Just to make sure you're within specs. Keep in mind that the fuel pressure should be steady for a period of 20 minutes after the pump shuts off.

Did you check the resistance of the fuel injectors while they were being cleaned? Also make sure that you have power available to both banks.