Now that the reconstruction of the entire driver side of my '93 z28 is finished, I have a few problems I have been putting off that I can't solve.

1.) My car takes about 5-7 seconds of the starter going before I can tell fuel is going to the engine. I'v e been told it's the pump by one person, the pressure regulator by another, and a bad fuel line by another. I have no clue. And guess and chack is out of the question, because i'm broke after the body work.

2.) The other problem has to do with my oil pressure. When I start my car up the oil pressure is fine, but as I driveit, mainly when I'm stopped, the oil pressure slowly goes down to barely nothing, at which time my car tries to stall alot.

I have no clue what any of these fixes could be, so any help is verymuch appreciated. Thank you.

 

A common failure is the fuel check valve, that holds pressure in the fuel rails for starting. Attach a fuel pressure gauge to your fuel rail Schrader valve and monitor the fuel pressure when you turn the key to ON, not start. Your fuel pump should prime for around 2 seconds and fuel pressure should rise to around 36 psi and hold steady. If the pressure drops off quickly after the pump shuts off, most likely your check valve is faulty. The check valve is inside the fuel pump, so the fuel pump will need to be replaced. Other items can cause your fuel pressure to drop off, leaky fuel injectors, a faulty fuel pressure regulator (diaphram broken allowing fuel to leak into the vacuum line) or a leaking fuel line.

 

oil
as your motor heats up your oil thins and pressure drops

however in 350 land, if you idle at like 700-800 rpm and have 10 psi of oil pressure you're fine, i think it's like 10 psi per 1000 rpm but dont quote me on that.

if you're worried about it change to a different brand of oil and step it up to like a 10w30 er 40 (assuming you're on 5w30 er somethin like that), maybe put a bottle of slick50 in. but at idle you really dont need much for oil pressure, worst case scenario is your bearings are wearing a bit and they'll need to be replaced eventually

for the fuel, i dk, i run mechanical pump

the only way anything oil related would affect your motor running is if there wasnt any at all.... and then....damn

 

Your oil pressure is due to the engine slowing down before stalling. Not the other way round. Since as someone pointed out, in order for low oil pressure to cause the engine to stall, it would only happen once. Then you would need a rebuild.

Don't continue to crank it over before starting as this will wear on the starter and prematurely kill it. Use the other method.
KOEO for a few seconds then key off then KOEO for a few seconds again. Do this 5 or 6 times before trying to crank it. IF this does not help, your problem is not fuel draining away from the fuel lines as mentioned by someone else.

As mentioned before a common problem is the check valve at the pump leaking fuel and allowing the fuel to drain back toward the tank. The testing method is a good one.

Now is the starting problem caused by the same problem that is causing your stalling or is it another problem.

One thing that could cause both problems is a leaking injector. It could be draining fuel into the intake and flooding the engine. Possibly causing the stalling issue as well as hard starting.

There would be a few indications if that was the case however. First, it could cause crankcase dilution. Check the oil for fuel contamination. Could be thinner or just smell of fuel.

Second, if flooding were the case, the easiest way to start the engine would be to floor the throttle while cranking it. This causes the PCM to go into "flood" mode and shuts down the injector pulses while cranking to stop adding fuel temporarily. Conversely, if flooding were the case, the KOEO method above would not improve the situation.

In any event, the fuel pressure should be monitored when it's starting, running, being driven and when the engine is shut down. Get a fuel pressure gage that has a hose so it can be taped to the windshield while you drive. This will eliminate fuel problems from the picture so you can focus on other issues if it wasn't fuel issues.

 

Thanks for all of your help. My reply is late because my computer took a crap on me.