Own a 94. No frills just my first vette. Starting to have a lawn ornament. Here it is.

Started last year with going out for a ride with my wife and it just dies. Instant dead. Cranks but won't fire over. Have no codes. Replaced the following.
Opti, fuel pump, fuel pressure regulator, injectior rings, installed a vats bypass from ecklers, oil pressure sending unit, oil pressure switch, icm, tps, and replaced all fuel relays.
Im so confused at what is the issue. It will run fine and just stop. I swear its bi polar.
anyone have any other advice. Oh btw it has 0the fuel pressure when this is happening.
Thanks
jeff

 

Id pull the fuel pump and see if your connections are loose
Check the rubber line coming off there too
Its under the filler cap easy job.
Im assuming the relay is good if it starts

 

So...does it run for a short time then shut down? If so, are you sure you have the right VATS bypass?

 

As I just had injector problems, it seems every time I read about a car the runs then stops I think it is injectors. My car ran good some times, sometimes poor and every now and then died and would not fire.

From this forum someone suggested I check the injector resistance. Two were non functional, 3 were way off and 3 were good.

If you have not checked, it takes about 15 minutes.

 

It will run for 3 or 4 days And then just not start for 2 or 3 days I pulled the fuel sending unit And check the connections last week It happened the other day, When I came home to do the oil change, And wouldn't start again.

 

How do I check the resistance. I have a multi meter and I have noid lights.

 

Check with your noid light to see if the injectors are getting pulsed while cranking. Are you getting spark during cranking?

Gary

 

There is no injector pulse as per noid light testing . Now what am i looking for. Btw i have spark.

 

Okay, so I got bored fiddled around underneath the right bolster, was looking at the different wires on there, tried to car again and it started. can someone please tell me what would cause that underneath there. It's a mess of wires and I don't have a manual.

 

dufus must know, what is a bolster?

 

Also called hush pannel. By pass knees where relays are hidden

 

I used some autozone noid lights on a running 94 and they did nothing for about 10 seconds before they started flashing. a volt meter is a bit more accurate. all i am saying is don't take the noid lights as fact. Check for fuel pressure and spark. you can also use a short length of hose as a stethescope to listen to the injector clicking although this is much easier on a running engine

 

You could take it in to a dealer and get a diagnostic check.
But don't let them fix anything just pay your $70 get your printout and leave.
I did this a couple of yrs. back on a 97 Taurus I got on the cheap $700, PO thought the head gasket was bad, it wasn't.
The dealer diagnostic and estimate to repair was $1300. I said hey I will junk this thing and take a 3 or 4 hundred hit before I put that much into it. The body was perfect no dents or broken glass etc. Still is.
So I started on the list and started doing what I could and hiring out what I couldn't.
1. example of crazy dealers.
Replace spark plugs $60 parts and $60 labor this is a 6 cyl by the way. My cost $24 Advance Auto plugs and 30 min. labor.
2. Replace MIP switch $75 parts $100 labor. (What the heck is a MIP switch I thought) Went online found out dealer calls it MIP just to confuse you I guess, its really a TR (transmission range switch) Ordered from Auto Zone $35 dollars paid a friend $25 to install. Not real hard once you pull the battery and air intake hose.
Anyways I went down the list and fixed for less than half of dealer estimate and the car has ran well for 50k since.

 

But the $70 was money well spent, the dealers diagnostic machine is like a
15k unit and I was no longer guessing at what to do.

 

Hey, another CF member in RI! It's a movement!

As you have found, an intermittent problem is the worst, and likely impossible to find when the car is running. The next time it won't start, spray a small sniff of ether into the intake while someone cranks the car. If it tries to start, you have a fuel delivery issue. If nothing, look for an ignition problem. Once you know narrow it down, you can troubleshoot from there. Keep us posted!

 

I am a Retired navy seabee. Nice to meet you steve. Will update as sky clears over the week. Dont want the precious opti to get wet and open another can of worms.

 

Been exactly in your shoes - stalled when hot (without codes).

Short answer - my gremlin lived in a broken wire within the harness from the ECM to the MAP sensor... now fixed.
Was not the opti-spark; which had very similar symptoms.

Long answer*- the raised temperature affected the continuity/resistance within the wire harness. With bad MAP signals - threw off the A/F mixture and spark advance. Left me stalled after 10 minutes - every time. Replaced every fuel-related item from sending unit to injectors, replaced plugs, wires, coil, IAC, IAC, TPS. Verified ECM and MAP sensors. Have already bought Opti/waterpump for future replacement.

* - The PO did not do ANY Preventive Maintenance; the fuel filter was still original - had undercoating overspray on it.
Decided to catch up and invest to restore the car's reliability - being 20 years old and 61,000 miles.

Now it pulls strong, fresh and young again.
Good luck.

 

I'd forget the dealer diagnostic, unless they had someone who really knows these cars. Not that they are that special, they're just old. This is pre-OBDII so they just can't plug it in and scan it like new stuff.

Figure out if your problem is fuel or spark related and go from there. I had an issue similar where the wires were pulling out of the back of the fuel pump relay. Ended up having to cut the wires and replace the plug with one from NAPA

.

Retired Army Motor Sergeant

 

fuel filter; passenger side on frame rail, outboard of cataslytic converter

 

There is your problem. Engines require fuel, air and in the correct ratio, spark and spark at the right time and compression in order to start and continue to run. You can spray starter fluid into the air inlet and if it is the injectors not working the engine should start and quit. The optispark sends pulses to the computer which operates the injectors so you need to determine if pulses are getting to the computer and if they are then the computer is suspect.