Camaro Starting Issues

[bowtieguy]

Originally Posted by theholycow

If you turn it to "On" for a couple seconds (listening for the fuel pump to stop) before turning it to "Start", does it fire immediately?

Does "ignition on w/ motor off, PSI specs are fine" mean pressure is immediately correct, or that it becomes correct after a couple seconds?

sometimes it fires immediately and sometimes not(cold or hot, intermittently). the pressure is immediately correct. yes i've tried waiting--no difference.

i'm leaning towards a leaky injector because i recall a reputable source suggesting that the when the pump is the source of lost pressure it needs to be primed several times(like when the pressure has been released for filter change and such).

so it primes after one turn of the key AND sounds and acts like a "flooding" situation. 13 year old injectors? not sure but it's possible. it is going to the shop tomorrow, so i'll let you know!

[bowtieguy]

Originally Posted by JoeBob

I could be wrong, but that sounds pretty normal. If the pressure is there as soon as you turn on the key, you should be getting gas.

Maybe an intermittent electrical connection in the line to the distributor or coil pack?

In my experience, a clogged fuel filter will let the car idle or drive at low speeds OK, but bog down on the freeway or climbing steep hills. It would only stop the car if it is really clogged, e.g. gasoline attacking the stuff that the nice man coated the gas tank with to seal a pinhole leak (that happened to me a long time ago...).

ya, i did end up changing the fuel filter just in case(cheap item anyway). the car runs like a champ on the hwy. i suspected bad plug wires, so i changed the them and the plugs as well.

gonna check for a leaky injector or pump, then will move onto coil packs(tho my experience shows they have heat soak issues when starting to go bad--hot starting problems).

[theholycow]

Originally Posted by bowtieguy

sometimes it fires immediately and sometimes not(cold or hot, intermittently). the pressure is immediately correct. yes i've tried waiting--no difference.

i'm leaning towards a leaky injector because i recall a reputable source suggesting that the when the pump is the source of lost pressure it needs to be primed several times(like when the pressure has been released for filter change and such).

My pump is the source of lost pressure (and I won't spend $300 to repair this problem). It does not usually need to be primed twice, but one full priming is necessary. So I get in the truck, turn it to On, wait for the pump to stop, then I crank it and it starts immediately.

If I don't prime it at all - just get in, stick the key in, skip right past On and immediately crank it - it usually won't start at all until I stop and prime it.

[bowtieguy]

HC, i don't blame you for "milking" that for as long as you can. i've also tried your technique, and it doesn't always work. my mechanic seems to think its the starter, but i've already had it tested(it's fine). he tested the fuel pressure, and found it to be fine--he also says the pressure is supposed to drop after shut off.

i remember in the past, changing the fuel filter, and seeing a distinct release of pressure when the valve was pressed. this last time, almost no pressure(gas) was released when i changed the filter. so...

well, on a side, POSSIBLY related note, i noticed the MAF sensor was coming apart on top. i re-secured the top, moving around the protective jell, and the car has started every time since!!! coincidence? no codes previously regarding the sensor.

[R.I.D.E.]

Fuel pressure regulator leaking down. It would show as a nasty looking spark plug. Maybe only one or two nearest the regulator. I think it's buried in the manifold but I could be wrong.

If you pull the plugs and one or two look like they are fouled or have excess deposits, it is probably the regulator.

regards
Gary

[bowtieguy]

great guess gary, but it does check out, and the plugs were fine @ the time of change(recently). we've been chasing this bugger for a while. the regulator is on top of the manifold(driver side fuel rail) opposite the release valve(passenger side).

[theholycow]

Pressure is not supposed to drop after shutoff. GMs are supposed to hold their pressure pretty much forever. Before my fuel pump was replaced I could park it for a week and then start it without letting it prime at all.

My VW primes when you open the driver's door, so I assume that it's not expected to hold its pressure.

If you hadn't already checked it I'd suggest the pressure regulator too.

[bowtieguy]

Originally Posted by bowtieguy

well, on a side, POSSIBLY related note, i noticed the MAF sensor was coming apart on top. i re-secured the top, moving around the protective jell, and the car has started every time since!!! coincidence? no codes previously regarding the sensor.

just an update...

it seems it may have been the MAF sensor. the car continues to start every time. interestingly, i was talking to one of our shop guys at work, and he mentioned his wife had a starting issue as well. she actually broke down @ 7eleven and they had it towed to the dealer. the MAF sensor was replaced and it has started ever since.

the clincher is that their car has a 3800 chevy V6--same as our camaro! hopefully, this is it. thanks for your help guys.

[bowtieguy]

still having issues. on a side note, since i've watched the car so closely, i found the intake manifold leaking coolant. oil was in the coolant, and coolant in the cylinders.

had it replaced before hydro lock occured. i thought possibly that water was flooding a cylinder(s) causing the starting issues, but it still continues on rough starting.

i had a mechanic months ago recommend a starter change, now he thinks fuel pump. i think neither, and i'm not gonna throw parts at it! it's not getting worse, and starts right away given throttle starts, like carb fueled cars. i'm thinking it's gotta be fuel regulator related.

[theholycow]

Fuel pump is more likely than starter, considering that it cranks dependably. I can't imagine why he thought the starter could be at fault.

If it is the fuel pressure retention problem, which it certainly sounds like, it's not necessarily in the pump. The regulator is definitely a good place to start. I don't know if this diagnostic procedure works for yours, but for my truck:
1. Start engine
2. Pull thin hose off top of regulator (it's external)
3. If gasoline drips from hose, regulator is definitely bad

If you do decide to throw parts at it, that regulator is a likely and inexpensive part, so still a good place to start.