My l98 wont stay running for more then 4 seconds, then it dies. I just put a few gallons in the fuel tank and chcked the injectors which showed at .017 ohms each. Also i was driving it the other day down the road and when i punched the gas hard it studdered some then putt putt and died, now with a rag with some gas on it sitting in throttle body and it starts for a few seconds then dies no matter what i do. Also i checked the fuel pump by disconnecting a line near motor and turned the key on and it shot gas everywhere, and the valve on rails squirts fuel out it if i push down on schrader valve, so it has fuel, please help me im very frustrated.

 

I also just put in new spark plugs, the other day, so since it starts it most likely isnt them causing the problem with it dieing

 

Will someone please help, I have started it like 30 times already and its the same stuff dies after 4 seconds, please help me

 

You are stating that you have fuel pressure coming from the schrader valve.. Have you tested it with a fuel pressure tested it with a guage or just put your finger on the valve.. You need to get a tester before you do anything else. Also while you are at it, change your fuel filter. It sounds like either the fuel pump is shot or the Pressure regulator is bad IMO..

 

I just pushed the valve down and fuel comes out, what i meant by that is that the fuel rails have gas in them, and when i disconected the out side line of the fuel filter and turned the ignition to on, the fuel pump shot fuel a few feet, so doesnt that most likely mean its good? Im just asking because im really confused since there is gas in the fuel rails that means the motor is getting that fuel so it means its something other then a fuel shortage problem rite? Also i dont have a fuel psi gauge to check the pressure

 

http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf

http://forum.grumpysperformance.com/...hp?f=32&t=1401

http://forum.grumpysperformance.com/...8&p=9217#p9217

http://forum.grumpysperformance.com/...sequence#p8895

 

You can rent fuel pressure guages at Autozone, Advance Auto and alot of other auto parts stores, they are fairly cheap. Is your L98 a TBI or TPI?

Grumpyvette was great to provide the links to testing your FP.. I think you have a fuel issue, Just because it shoot Fuel out of the schrader valve doesn't mean it is the right pressure. It just means that it is getting fuel. You really need to test the pressure to rule that out.. The more times you attempt to start it, the more it isn't going to start.. You are just wearing out the starter and battery.

 

Its a tuned port 350 iroc z motor somewhere in the late 80s year, and i understand now sorta what ur saying, basicaly if the rails dont have neough pressure from pump, then they wont let the gas get to the injectors, etc rite, and if i rent a fuel pressure tester will it rule in/out the problem being the fuel pump, also is there a way to check the fuel regulator, or the pump

 

Exactly, The fuel pressure tester will tell you if your pressure regulator is working but that is what you are testing.. The amount of pressure in the rails that the fuel pump puts there.

I would still change your Fuel Filter..

 

ok well i will see if i can get one in a few or it will be tommoro morning when i can get one then i will know finally, well hopefully

 

Ok, keep us informed with numbers.

 

I will thanx

 

What year iroc is it?

 

Its a 87,88, or 89 and i got a comression tester today as i was told it would work, anyways im returning tommoro and getting a fuel pressure tester

 

When you do your fuel pressure test and if the pressure is in spec, I would start looking at other things that could cause the problem. I would look at a MAF problem or a vaccum leak like pvc hose connection or brake booster hose connection. What have you done to the car, what year is it? Did you put this motor in or was it a factory 350 tpi car? Any mods?

 

Ok so im sorry for the long update but i just bought a fuel pressure tester and it checked out at 45 psi, when it was hooked up and just the key on, so im guessing the pump is good, rite, the injectors were good, and it starts with the rag and some gas on it so the spark plugs are good, so it has to be the regulator correct, thanx

 

A vaccum leak will cause the engine to run at a higher RPM

 

Ya i mean im thinking something in the regulator like a valve is stuck and is sending the fuel back threw return line, since it was running before this happened, and it still starts fr a few seconds with some fuel threw throttle body, so is the fuel reguator hard to replace, like taking the plenum off, and is anyone pretty sure it's the problem before i spend the $45 for adjustable one on ebay

 

Oh and the adjustable aftermarket ones are the only ones avaliable on ebay so thats what im stuck with, as i will never be adjusting it lol.

 

um, did I miss something or read your initial post wrong? injectors checkout out at .017 ohms? Did you mean 17 ohms? If not, recheck your injectors. If you have a shorted injectors, the ecm will shut down the injector drivers. If this is happening, you may have to replace the ecm too after replacing the injectors.

 

Ya .017 is what its supposed to be when checking with a meter, so I was told to buy this fuel pressure gauge for $45 and i got the fuel psi reading with the key on, so what is wrong the fuel regulator, or what?

 

The correct injector resistance is 16 ohms, if the meter you used is set to auto-range .017 is not good, but if the meter is set for 1000 ohm range then it is good.
Basically the engine isn't getting any fuel, with good pressure, resistance, 12v, and proper ECM injector signal you should have a running motor, unless the majority of injectors are not opening, or opening but are clogged very little or no fuel will get through to the cylinders. This is assuming correct initial timing and at least 80 psi compression per cylinder.
I would buy (like you got lots of money, right?) a noid light (injector signal tester), or just remove the MAF, put fuel in a spray bottle, spray fuel directly into the Throttle body with the blades open at part throttle while cranking, if it starts and stays running with the spray then it's the injectors, and or the ECM or something in between: loose wire, bad ground...etc.

 

Well it will start when ud put fuel on a rag in front of the throttle body, and only run for a few seconds since its not enough to stay running so that rules out low compression, and a eletrical problem most likely. Also i whatched a video on how to check the injectors and it was like 1000 or 2000 ohms, anyways they checked out fine, so that means they are good rite, or should i pull them out and clean them, if it's not to hard to do, thanx oh and how can i test a few things to rule them out like the ecm, and fuel regulator

 

Also my dad said something about bleeding the fuel out the injectors, or rails since it might have got a air pocket in between the injectors when it ran out of gas, can that happen?

 

If 1000 to 2000 ohms is correct, what is the resistance of your injectors? you earlier said .017 which is less than 1 ohm and not good at all.
See attached injector specification chart.

The rag wet with fuel test bypasses the injectors
45 psi means the regulator is working.
Air in the system? not likely but should purged out as fuel is returned to the gas tank.
A Noid light will test the ECM injector signal not the injector.
If you have a good injector signal, tray starting, but do not hold the accelerator down while cranking, if after several seconds of cranking and it doesn't start, pull a few spark plugs and see if they are wet with fuel, if they are bone dry your injectors are not working properly or not at all.
Fuel Injector Resistance.pdf

 

multiple threads on this one in one ear out the other.

https://www.thirdgen.org/forums/tech...ont-start.html

 

 

Ill try this a bit later on and post results, and thanx as this is probabley the most helpfull comment yet thats easy to understand also.