PT Cruiser Tough Starting

[silicon]

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

or quite possibly the temperature sensor that will make the mixture more rich on first start.

 

[cardiac]

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

No accumulation of gas anywhere and no fumes at all.....

 

[cardiac]

or quite possibly the temperature sensor that will make the mixture more rich on first start.

Before I even attempt the temp sensor (It's in a tight spot and I have huge hands), would it not trigger a code? I have gotten conflicting answers.....

 

[boomerang]

Check the fuel pressure first.

The temp sensor will not set a code. A lot of sensors must output within a specific voltage range. The computer checks to make sure that's happening. If it's outside that range a code will be set. The temp sensor could be anywhere within a wide range and the computer does not have anything to reference to so that it can determine if what it is receiving is valid. It can't for instance compare it to outside temp. It's a "dumb" sensor. The above is a simple explanation.

There are two temp sensors. One for the computer and one for the dash. Make sure you're dealing with the correct one. But FP test first.

 

[slag]

It will be interesting to see what the problem is. I just hope the OP gets it correct the first time. I'm with boomer(and many others), the easiest thing to do seems to be to check the fuel pressure first at the rail. I know my car would always flood when it got cold and I could smell the fuel but you aren't experiencing that.

 

[cardiac]

fuel pressure is right at 40 psi. A tad low. Also, now that the weather has warmed up into the 40's and 50's, it has been starting the past few mornings...

 

[phucheneh]

fuel pressure is right at 40 psi. A tad low. Also, now that the weather has warmed up into the 40's and 50's, it has been starting the past few mornings...

You checked it while running. This does not troubleshoot your problem. Did it hold when you shut the engine off?

 

[cardiac]

It dropped maybe a lb or 2, but stayed up for a couple of hours. Was that long enough? I guess I should have left the gauge on overnight..... I'll try that.

 

[cardiac]

Fuel pressure holds for hours. Pulled the intake this morning and did plugs and wires, cleaned the throttle body and IAC valve. Throttle body and IAC were very dirty. It seems to run 100% better now. Plugs were kind of nasty. Worn pretty well. We will see how it starts in the morning...

 

[BUTCH1]

Temp sensor is $15 at rockauto.

just sayin'



*pokes ribs*

IIRC OBD2 cars when cold start in "open loop" mode, meaning the O2 sensors are not warm enough to supply a proper reading to the PCM, and it's pre-programed to supply a rich mixture because the engine is cold, once the O2 sensors warm up, (2-3 min.) the PCM then goes into "closed loop" and controls the injector pulse-width using data supplied via all the various sensors, (O2, MAF, CPS, TPS, coolant sensor and possibly air intake temp..

 

[cardiac]

2 Week follow up. The PT starts and runs fine. It is amazing what simple tune-up can do. When the plugs are crap, the wires are original, the IAC was filthy, as was the throttle body, it was amazing that it ran at all. Starts perfect every morning, smooth as silk, and pulling an average of 22-23 mpg.

Thanks for all of the ideas!

 

[phucheneh]

Probably just an airflow issue, then. Maybe the ETC, IAT, MAF or another sensor does fit the whole 'reading incorrectly but not out of range' thing, but in the end, the bigger issue was the engine just breathing enough air through a closed throttle for a cold start.

Did you ever mention if operating the gas pedal while cranking helped? A lot of people would instantly dismiss doing such as being irrelevant on fuel injection, but you're not doing it to prime the fuel system, you're doing it (opening the throttle slightly- no pumping, to clarify) to let a struggling engine breathe a little better. I thought you were describing more of a 'has to crank for a few seconds when cold, nothing helps' kinda deal. Not 'starts up instantly if you crack the throttle (see: all old GM V6 cars. Which are usually fixed with throttle cleaning and/or new IAC's).

Whatever the issue, it's good that it's now fixed and only required a minor time/money expenditure.

 

[FuzzyDunlop]

Good to hear you got 'er going again!

Thanks for the clarification Butch1. Some day Ill work on an OBD2 car and have an education.