PT Cruiser Tough Starting

[cardiac]

A question for the guru's:

Wife has a 2003 PT Cruiser: 2.4l non-turbo auto. 60k miles.

After sitting overnight, it won't start. Cranks fine, sounds like it wants to catch, but won't fire. Light throttle pressure does nothing (Thinking TPS?).

Turn the key on and the fuel pump is audible for a bit.

However, if I lift the airbox lid and give a light squirt of ether, it fires right up and runs fine.

I don't know how old the fuel filter is.

Another thought is that perhaps the fuel pressure regulator went bad?

Camshaft position sensor is fairly new (OEM Mopar).

What say ye?

Thanks!

 

[silicon]

A question for the guru's:

Wife has a 2003 PT Cruiser: 2.4l non-turbo auto. 60k miles.

After sitting overnight, it won't start. Cranks fine, sounds like it wants to catch, but won't fire. Light throttle pressure does nothing (Thinking TPS?).

Turn the key on and the fuel pump is audible for a bit.

However, if I lift the airbox lid and give a light squirt of ether, it fires right up and runs fine.

I don't know how old the fuel filter is.

Another thought is that perhaps the fuel pressure regulator went bad?

Camshaft position sensor is fairly new (OEM Mopar).

What say ye?

Thanks!

I would stop using ether first of all...it could blow the motor up if you are not careful. Is there any code set in the computer?

 

[cardiac]

I actually used a squirt of gas today, I know how ether can be. No codes logged or pending. I'm kind of baffled. It does not do it every day. 7 out of 10 mornings.

 

[toronado97]

Fuel pump. 90% of the time it's the fuel pump. You can hear it, and that's great, but it might not have enough pressure in the fuel lines to keep gas flow. The fact that you sprayed starter fluid in and it started says it's probably not getting enough gas to get going. I just replaced the fuel pump in our old Beretta because of a similar issue. Crank the car for ages trying to get it started, but then it drove fine and would start fine for the rest of the day. Let it sit overnight and it would do it again the next day.

 

[cardiac]

After doing some research last night, I think you are right, tornado97. The fuel filter and pressure regulator are integral to the pump, so the options are cut short...... Crap, I don't want to drop the tank... (Or cut an access hole). Thx.

 

[toronado97]

Possible you have a fuel filter that needs to be replaced, but in my experience they're almost always in the gas tank anyway, and if you're dropping the tank to replace the filter, you might as well do the pump either way.

 

[boomerang]

Is the fuel pressure regulator integrated with the fuel pump?

 

[cardiac]

Yes, boomerang, it is a 3-in-1. Pump, regulator, and filter all in one. I am going to have a buddy with a gauge check the fuel pressure when it's cold. I think I know my answer though. Time to drop the tank.

 

[boomerang]

Yes, boomerang, it is a 3-in-1. Pump, regulator, and filter all in one. I am going to have a buddy with a gauge check the fuel pressure when it's cold. I think I know my answer though. Time to drop the tank.

Checking the pressure is an excellent idea. I think it's always best to do all the troubleshooting possible before throwing parts at a problem. The pressure test should tell the tale.

 

[FuzzyDunlop]

My bet is on faulty Cold Start Injector or Cold Start Injector Sensor if your car has them.
The sensor would read water temperature. If the water is cold then it sends a signal to the computer to inject more fuel while cranking. It's similar to a choke on a lawn mower. On my cars there is a seperate fuel injector which squirts directly into the intake manifold.
It could be as simple as the wiring leading to the sensor is loose or corroded.
That would be the next thing to check after pressure.

 

[cardiac]

My bet is on faulty Cold Start Injector or Cold Start Injector Sensor if your car has them.
The sensor would read water temperature. If the water is cold then it sends a signal to the computer to inject more fuel while cranking. It's similar to a choke on a lawn mower. On my cars there is a seperate fuel injector which squirts directly into the intake manifold.
It could be as simple as the wiring leading to the sensor is loose or corroded.
That would be the next thing to check after pressure.

I would think that if it was this, it would trigger a code, wouldn't it?

 

[boomerang]

I would think that if it was this, it would trigger a code, wouldn't it?

I see no listing for a cold start injector at rockauto although if it's not different than the other four, it might not be listed separately. Should be pretty easy to locate a fifth injector, it would have to be in the intake manifold.

But Fuzzy may have hit on something and the clue is in your OP. You say once you get it started, it runs fine. How about the coolant temp sensor? If the computer thinks the coolant is nice and warm, it won't enrich the mixture to allow it to start.

Another thought is that although you hear the FP running at key on, is current being provided to the FP when cranking?

This only happens when sitting overnight (in other words a long time)? Not when just making a short stop like going into a store?

 

[phucheneh]

Ether washes down the cylinder walls, which are intended to hold a miniscule amount of oil (the purpose of the crosshatched hone pattern). You are increasing engine wear and lowering compression/increasing blowby. Stop it.

The effect is more pronounced on a diesel, which is where ether is typically (mis)used. But it is still to be avoided.

When I read the thread title, I came in just to point out that your car has extra-long battery cables, which Chrysler was nice enough to make out of like 10 gauge wire (absurdly small). Slow cranking is very typical on those cars. But alas, that is apparently not your issue.

Luckily, though, ether did do one positive thing for you- it acted as a diagnostic aid. You can pretty much rule out spark issues. And if the plugs are firing, it should also be firing the injectors. Usually a CMP or CKP issue will result in loss of both, or at least loss of spark. Can't recall ever seeing an engine fire the plugs but not the injectors while trying to get a good RPM or sync signal.

Does it start fine when it's warm? Like just 1-2 seconds of cranking and them it fires up cleanly? If so, you are probably losing residual fuel pressure while the car is sitting overnight. The extra cranking is because you are waiting for the fuel system to build up enough pressure to get the injectors to function semi-properly. Nominal fuel pressure is usually about 35-45 on most modern port-injected cars. IIRC Chryslers are a little higher than most, and I think spec for your car is more like 55-60. You'll probably get normal starting (but other issues) with pressure as low at 20-30. Somewhere below that, fuel is just trickling out of the injectors and starting is difficult.

Typical causes of losing the prime on your fuel system, in order of prevalence: Bad vacuum-operated fuel pressure regulator (pull the vac line off of it and check for the presence of fuel, indicated the rubber diaphragm inside is busted), bad check valve in the fuel pump, or a leaking injector.

If this starting issue is NOT limited to cold starts, you are probably looking at a bad pump. IIRC you have no external fuel filter to clog, so you're pretty limited on options there. I'm pretty sure your fuel rail has a test port, so fuel pressure should not be hard to check.

 

[cardiac]

If it is a coolant sensor, would that trigger a code?

phucheneh, it starts normally after it's been driven a while. This only happens after it sits 8-10 hours. It has been below freezing at night, still, here in NW Indiana. No spring weather yet....

The pressure regulator is on the pump with the filter...

 

[FuzzyDunlop]

Doubtful that temp sensor would throw a code. It's probably giving a signal of a constant 150+ degrees and not allowing cold start injection.

My bet is still on the sensor or sensor wiring.

 

[phucheneh]

Oh, I didn't realize that was a returnless system. I was thinking those engines has a regulator on the fuel rail.

100% fuel pump, then, IMO. I would assume a new one is going to come as an assembly with the pump motor, level sensor, and regulator as one unit.

Rent a fuel pressure tester from the parts store. It's easy to confirm this. You shouldn't need 8-10 hours to confirm the issue- put the tester on it, start the car, note the fuel pressure. Shut the engine off. You will get some kind of initial drop, but it SHOULD level out within a few minutes and hold what it's got. Note that number and go make a sandwich and/or run some errands and/or watch some TV. Whatever burns up a couple hours. Recheck your gauge and see what you've got.

 

[phucheneh]

Doubtful that temp sensor would throw a code. It's probably giving a signal of a constant 150+ degrees and not allowing cold start injection.

My bet is still on the sensor or sensor wiring.

It's not a K-car. There's no cold start injector.

And if he's getting a long period of smooth cranking before a normal start, I would HIGHLY doubt that it's an issue of a lean fuel mixture. Again, get with the times. ;P It's not like operating the choke an old British roadster...if the PCM thinks the coolant is 150*, it's gonna run lean. But it'll start without a ton of effort. At worst, it will show signs of a problem...sputter, maybe even set a misfire code...but it won't just crank with no signs of combustion.

If the ECT is reading high, it's not even going to matter all that much, as the IAT and MAF are still going to give it a good ballmark of the temp and density of the air coming in. And again, other issues would manifest...the engine doesn't just get hot as soon as it starts...if the fueling was massively lean during warmup, it would run like piss and he'd probably have a fuel trim code, as well as the mentioned initial misfires, which may or may not actually get flagged.

 

[FuzzyDunlop]

I'm just going off the info in the OP. "sounds like it wants to catch. But won't fire" but starts with a boost of ether, and runs fine from that point on until cold again.

And I'm saying its probably the sensor NOT the injector (if there is one which I wouldn't be suprised of there isn't because ecu probably just programmed to add some PulseWidth during cold cranking).
I also said, it's the thing to check after fuel pressure.

Yes my experience is limitted, and I'm still green to cars, but the symptoms are very similar to what I have experienced at one point. And the basics should all be the same on any engine.

 

[slag]

I see no listing for a cold start injector at rockauto although if it's not different than the other four, it might not be listed separately. Should be pretty easy to locate a fifth injector, it would have to be in the intake manifold.

But Fuzzy may have hit on something and the clue is in your OP. You say once you get it started, it runs fine. How about the coolant temp sensor? If the computer thinks the coolant is nice and warm, it won't enrich the mixture to allow it to start.

Another thought is that although you hear the FP running at key on, is current being provided to the FP when cranking?

This only happens when sitting overnight (in other words a long time)? Not when just making a short stop like going into a store?

Had this happen to a car of mine. It was the temperature sensor. Car didn't know what temp it was so it didn't give the right mixture of gas to start up. Took forever to start that car until I got it fixed. No codes were thrown but it was an older fuel injected vehicle.

 

[phucheneh]

Had this happen to a car of mine. It was the temperature sensor. Car didn't know what temp it was so it didn't give the right mixture of gas to start up. Took forever to start that car until I got it fixed. No codes were thrown but it was an older fuel injected vehicle.

Probably OBD1, and I'd wager throttle-body injected?

I could be, have been, and will continue to sometimes be wrong. So I won't say this as 100% fact...but I just highly doubt that on a modern OBD2 port injected car, a bad-but-never-out-of-range ECT or IAT is to blame for an extended crank time. Rough start, maybe, but not just an extended crank.

I'm unclear on which the OP has, though. He did mention it 'sounds like it wants to catch,' which does imply that some combustion is being heard, but it is not managing to accelerate past cranking RPM.

Checking for a way-off sensor reading is just as easy as checking fuel pressure. Physically easier, technically, but you may actually have to purchase something. A <$50 pocket code reader (look for 'live data' under the listed features) will do this job, as will a $25 or less laptop cable. Fuel pressure, as mentioned, can be checked for free by renting a tool from a parts store. OP, I highly, highly recommend you actually check these things. I've seen all too often where someone will chase their tail for days or weeks because, for some reason, they have no problem spending time installing parts, but absolutely refuse to do any diagnostic work. Your next steps are spelled out pretty clearly here.

 

[FuzzyDunlop]

Temp sensor is $15 at rockauto.

just sayin'



*pokes ribs*

 

[slag]

A fuel pump going out would also typically have issues while the car is under load. OP says it's just a starting issue. Runs fine after starting, but doesn't start well sounds like a sensor issue or something out of whack other than the fuel pump but what do I know.. see my sig.

 

[toronado97]

I'm on record saying it once and I'll say it again: It's the fuel pump.

 

[cardiac]

It didn't start for her again this morning (28 degree night) and had a hard time firing with a spritz of gas down the air intake.

phuceneh, I am going to check the fuel pressure on Monday or Tuesday. When I say it cranks and sounds like it wants to catch, it does fire, but not enough to run on it's own (past starter spin speed). I had to play with the throttle to get it to stay running, and once it did, again, it ran fine. Checked spark when it was not wanting to start, and it was bright/strong.

Again, no codes. Fuel pressure test coming up....

 

[bryanl]

Is there a check valve in the fuel line or fuel accumulator that may be leaking?