Car won't start-turns over and sounds like it wants to but doesn't

[drummr8]

Fuel pressure has been tested and is 40psi at the rail. The car ran before disassembling the front end for cooling overhaul. The car sat for about 4 months, and when we tried to start it and it wouldn't, we figured the old gas was the culprit. We siphoned the old gas out and put fresh in and still no go. I replaced the fuel filter and checked the fuel pressure at the rail and it's 40 psi. I believe we are getting spark since the engine sounds like it is wanting to start when we turn it over. I'm not sure where to go from here... Suggestions?

It sounds like the car is very close to starting but not quite there

[Johnmadd]

Maybe unplug the battery for a few minutes and see if that helps.

[LivesNearCostco]

How is your battery voltage? Is it possible the battery is just slightly too weak to start it? But I assume if you already siphoned the gas, replaced the fuel filter and checked the fuel pressure, you must have already tried to jump it.

When you did the cooling system overhaul, did you disconnect any of the sensor plugs from the DISA, VANOS, MAF, camshaft position sensors (intake or exhaust), throttle body, or IACV?

[drummr8]

How is your battery voltage? Is it possible the battery is just slightly too weak to start it? But I assume if you already siphoned the gas, replaced the fuel filter and checked the fuel pressure, you must have already tried to jump it.

When you did the cooling system overhaul, did you disconnect any of the sensor plugs from the DISA, VANOS, MAF, camshaft position sensors (intake or exhaust), throttle body, or IACV?

The battery is good, we've been charging and maintaining between tries. Nothing else was disconnected. What we've found is that on the first attempt to start after waiting a period of time like an hour or so, the motor will sputter like it's about to start, but subsequent tries are just a turn over with no firing it seems. This most recent time my dad even said he could hear firing from the exhaust behind the car...

So, what could cause it to want to start on the first try but not latter attempts?

[ZHPRegistry.net]

Could be flooded. Pull out the plugs and check.

[LivesNearCostco]

Turns over but won't start: Bad or disconnected crankshaft position sensor, or disconnected coil packs, or loose grounds that affect the coil packs but not the starter. Rodent chewed some critical wires while car sat.

Almost starting starting only after a rest: Hmmmmm... Clogged air filter, clogged fuel filter, installed fuel filter or return line backwards, weak battery, failing fuel pump, flooded engine, starter fails when warm? Could try hitting starter with long breaker bar or wrench while cranking it.

I assume it's always turning over on every try, yes?

Maybe not enough gas is getting through but if it sits for a while, enough seeps through to almost start it. Clogged injectors?

[drummr8]

Another tidbit: the car started and ran fine before sitting the four months. Would the injectors just suddenly clog? Seems kind of weird. How can I check if injectors are clogged? It turns over every try, yes. All the wires around the coil packs looked fine to me (not chewed)

[drummr8]

Also, I read codes p2185 and p0070 for coolant temp circuit high and ambient temp sensor. Don't think these codes are related to the no start, but what do you guys think?

[LivesNearCostco]

I am not that familiar with injector clogs but if car sits for a long time the gas can form varnish deposits. They say to prevent that keep the tank as full as possible before storing and use something like Sta-Bil in the tank. Not sure exactly where those varnish deposits form--I guess they could form on the injectors?

My point is what can go wrong while storing a car, undriven, for 4 months? Most likely would be
--Gas goes bad and/or forms varnish
--Battery drains and/or goes bad
--Something rusts or corrodes (ground wire, sensor tips)
--Rodents chew some wires
--Moisture freezes somewhere

And then when you replace the fuel filter, it is possible to put it in backwards (rare with E46) or reverse the two lines in front (more likely).

Assuming no rodents chewed any wires, your new fuel filter is in correctly, and no ground connections corroded, I suspect battery. Did you disconnect battery before storing or use a battery tender? If not, the battery might not be able to hold a charge. I know you're charging the battery, but what is the measured voltage after you charge it? Did you try a jump start? And did you try tapping the starter while cranking the car?

Not too familiar with those two codes, but maybe it means thermostat has failed open or shut or the harness plug to the thermostat is disconnected? Would be worth verifying thermostat wire was plugged back in securely after the cooling system swap.

[LivesNearCostco]

More commentary, hope you don't mind. When I said check thermostat wire, that's only for the P2185 code.

P0070 looks like intake air temp sensor in left "pork chop" that attaches between bumper and left front fender liner. On a ZHP you remove the left foglight to check it. Sometimes the wires corrode and throw an error. It won't affect starting but could prevent the A/C from coming on. What external temperature does your OBC display show?

To start the motor needs spark, air, fuel and a spin from the starter.

What can prevent spark? Weak battery, CPS (crankshaft position sensor), anti-theft system (though I think that also disables starter), loose/corroded ground cables, failed coil packs, or loose/chewed cables to the coil packs. Can connect spark plug tester between coil pack and plug but either need long tester that can reach the plug or a spare spark pug you can stick in the coil pack to see if it sparks when cranking.

So if it were me, I would follow these troubleshooting steps:


Test battery voltage and/or jump the car
Remove plastic coil pack cover, verify all coil pack wires are secure.
Pull each coil pack out, verify spark plugs not loose and plug wells not oiled
Attach spark plug tester between coil and plug, or put spare plug into a coil and verify spark when testing. (If plugs are out, disconnect fuel pump fuse so you don't have gas spraying with open cylinder)
Up to you if you test each coil pack for spark or just one.
If have spark on any cylinders, ground wires and CPS should be okay. If no spark, check engine grounds and CPS.
Pull air filter box and intake boots, check for obstruction.
With boots out, tap starter with long wrench while someone else cranks the car.
If no spark and no luck tapping starter, check CPS wires which should be beneath or near starter. If CPS wires good and no spark, consider replacing CPS.


After all that, if you have spark and battery voltage is good enough (or doesn't start even with jump), then I think it's down to not enough fuel deliver or failing starter.

[BADCLOWN]

plug wires hooked up correctly?

[drummr8]

After testing every coil and reading good fuel pressure, we swapped out the spark plugs and kept trying a few more times. Eventually, it started, ran like absolute shit for a few minutes, then now it purs like a kitten :)

I believe maybe what happened is the ICV or something was stopped up and possibly frozen in place. Maybe it was dirty, then the car sat and it got stuck. I will clean it soon just in case that was it. But, that is the only reason I can think of for it not wanting to start since we had fuel and spark. The engine just couldn't breathe!

thanks for the help guys

[johnrando]

Whew!

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[danewilson77]

Whew!

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+1

"No flamesuit required"

[LivesNearCostco]

hey good news! Looks like I was wrong to focus so much on spark and fuel, and it was the air. Glad it's running now.