someone please help nostart for a month now!!

[Oldskool153]

Hey guys my vets been down for over a month now and it breaks my heart. And my wallet to pay for a car that I can't use. Basicvally it turns over but will not start, I changed the fuel pump and pressure is good. Other then that I pulled 2 plugs and both are getting spark. I know its probably the opti,coil,ecm but are their tests I can do to narrow it down? My mechanics been restoring a z28 and is now on vacation so he hasn't had a chance to look at it. I just want to get it running someone please help. At age 23 paying for a vette, a streetbike, and a truck gets very expensive so my funds are limited.. If junk or vet oz reads this u guys have been helpin me out on here for 2 years now, hopefully I can get this figuredout this weekend.. I'm complelty stumped..thanks

 

[ex-x-fire]

So your saying you've got spark at the plugs & good fuel pressure (35psi or more)? You need to get a noid light, this hooks to the injector connection, it should flash if the system is working right. I'd check as many as you can get to. That would be a good time to ohm the injectors too. You'll need a DVOM meter.

 

[vetteboy86]

If you have a crank and no start with no back firing then either spark or fuel is lacking from the equation. The last variable is air.

When you pull the plugs after cranking are they wet? If they are not wet, then you have a fuel issue. If they are wet, then a spark issue. Either way pull the plugs after cranking and look at them. This is the first step.

 

[BPs vette]

I just went tru this make sure you have good gas.
I filled up and shortly after my vette would not start.
I Got a fuel pressure gauge to check pressure and noticed
the gas did not smell like gas I drained 3 gallons of water out of the pressure gauge bleed until I got all gas I put in a couple of heet dry gas
some octane boost aad some startron fuel treatment Got it to run and ran down the tank and refilled with new gas.

 

[John Robinson]

So Many possibilities

Things that will cause a no start.
1. Bad TPS
2. Bad grounds
3. Check connectors for corrosion
4. Bad Gas
A couple of things to try while cranking the engine
1. Floor the accelerator while cranking
2. While cranking have someone spray carb cleaner or starting fluid into the intake of the throttle body

If it starts do a search here for information on the TPS.

Don't jump at the Omni or the ECM just yet you are a long way from proving they are bad.

The ECM uses grounds to read information from various sensors and if the grounds are bad the ECM will get confused and stop delivering fuel to the injectors. Junk has posted many times the location of the grounds do a search for that information also. Good luck and keep us informed so we can continue to try to help you get your car back on the road.

 

[boomdriver]

Hey guys my vets been down for over a month now and it breaks my heart. And my wallet to pay for a car that I can't use. Basicvally it turns over but will not start, I changed the fuel pump and pressure is good. Other then that I pulled 2 plugs and both are getting spark. I know its probably the opti,coil,ecm but are their tests I can do to narrow it down? My mechanics been restoring a z28 and is now on vacation so he hasn't had a chance to look at it. I just want to get it running someone please help. At age 23 paying for a vette, a streetbike, and a truck gets very expensive so my funds are limited.. If junk or vet oz reads this u guys have been helpin me out on here for 2 years now, hopefully I can get this figuredout this weekend.. I'm complelty stumped..thanks

Sounds like you already performed the necessary test....by process of elimination. Fuel supply is good? pressure and flow? Spark is present? but intensity & timing? The only other thing, would be the correct atmosphere for combustion, air in compression and the odds of that being a factor are slim. Try adding a couple drops of gas to a couple spark plug holes then crank it. If it sputters for a second, that says fuel supply. If NOTHING happens..that says spark. Seeing a plug fire does not mean that its firing at the right time or hot enough to ignite.

If you have checked the fuel pressure and KNOW thats ok, everything else falls back on the OPTI-Spark that controls the spark in every way.
What you CAN do is go thru the connections, plugs and look and clean. Grounds are important also, Clean the bank of G-104 that are mounted behind the driver side of the block, usually on a trans bell housing bolt. Thats about 4 wires with a 5th thats a small strap that runs from the block over to the frame. The ECM ground is in this collection.

Nobody likes hearing that they need an expensive part.

Remember "Occams Razor", which states,
"The simplest solution is most often the correct one".
(translated with license)

Good luck with your car. Sounds like a nice toy collection..!

 

[JAKE]

What's the latest?

Man, there seems to be an epidemic of this kind of problem lately. Every Forum I visit has at least one on-going post from someone complaining about the same thing.

Keep us posted; whatever's causing it, it's solvable.

Jake

 

[Superc63]

Unplug inlet air temp sensor from under manifold and crank

Try unplugging your inlet air temp sensor from under the manifold and starting it. That helped mine big time.

Also, was any maintenance done to yours before this problem or did it just stop starting?