Why won't it start?

[JohnRardin]

I've replaced almost everything that could be the source of the problem so I cant figure out why it won't start. My car drove great all day but about an hour later when I tried to leave I realized I was stranded. I'm completely stumped. The battery is new and has plenty of charge. The starter is working properly. The fuel injectors are 550cc's that I've had for about a year. I tried resetting the ECU. I tried following the owner's manual instructions to start a flooded car, no luck. I even tried locking the car and allowing the security system to reset. Nothing seems to work.

Since everything electrical seems to be working, I can only assume that its not getting fuel. The only thing that I can think is maybe my fuel pumps bad.

Anyone had any experience with a bad fuel pump? Do they just stop working one day or is it gradual? Any other ideas? I really appreciate any help or advice.

 

[Nick M]

Just to make sure, does the engine crank over?

 

[jdub]

Wiggle the CPS wires...preferably with someone cranking the engine.

 

[Shima]

you made sure there's fuel in. iv made that mistake before damn sticky fuel guages :evil2:

 

[johnathan1]

Wiggle the CPS wires...preferably with someone cranking the engine.

I second this. The CPS wiring is right in between the valve cover and the power steering fluid reservoir. You should see a green (or grey) electrical connector. Just give it a wiggle, and then try starting it.

 

[JohnRardin]

Thats a start. I'll try right after I get off work today, but I doubt its anything so simple. I did notice when I popped the hood that the BOV hose had blown off, but I doubt its related. It has plenty of gas so I have no clue. My only hope is that somehow theres a fuse blown, but again I doubt it. What else could it be?

 

[Nick M]

A blow off valve, or stock bypass valve? Where was it blown off? If you have a massive vacuum leak, and not ported vacuum, it can stop you from starting.

I am assuming your engine cranks over.

 

[Mike Morris]

I agree about the cps. Worked for me many times.

If that fails borrow a testing light and hook it up to each coil pack to see if you are getting spark.

 

[MDCmotorsports]

Check the EFI fuse?

 

[noah89t]

cps wires.
could it be heat soak? sometimes my car doesn't like to start minutes after shut down after a long hard run. i used to think it was starter contacts, but since i replaced them and i know other things are working properly, i can only assume the the doesn't like to start when it is really hot. it does this when my greddy water temp guage is high, but when it cools off, it cranks.

 

[Whasian]

main replay?

 

[JohnRardin]

Ok I just got back from my second attempts to start the car or diagnose a problem with no change. I checked all fuses and hoses but nothing seems unusual.

I did notice the boost gauge is at 0, which means theres a vac leak somewhere......and.....I ran check engine codes. As I mentioned before I have 550cc injectors and a lexus AFM so I expected some codes but heres what I get:

1 pause 2...............12
2 pause 1...............21
3 pause 1...............31
3 pause 4...............34
4 pause 2...............42

Heres what Cygnus X1 says about it:




12 RPM Signal


Diagnosis

* No "NE" or "G" signal to ECU within 2 seconds after engine has been cranked.

Trouble Area

* Distributor, or CPS, circuit
* Distributor or CPS
* Starter signal circuit
* ECU

21 Oxygen Sensor Signal


Diagnosis

* Detection of oxygen sensor deterioration.

Trouble Area

* Oxygen sensor circuit
* Oxygen sensor
* ECU

31 Air Flow Meter Signal


Diagnosis

* (7M-GE) Open circuit in VC signal or short circuit between VS and E2 when idle contacts are closed.
* (7M-GTE) Open or short circuit in air flow meter signal.

Trouble Area

* Air flow meter circuit
* Air flow meter
* ECU

34 Turbocharger Pressure


Diagnosis

* The turbocharger pressure is abnormal.

Trouble Area

* Turbocharger
* Air flow meter
* ECU
* Intercooler system


42 Vehicle Speed Sensor Signal


Diagnosis

* No "SPD" signal to ECU for 8 seconds when engine speed is between 2,500RPM and 4,500RPM (7M-GE) or 4,000RPM (7M-GTE) and coolant temp is below 80°C(176°F) and neutral start switch is off.

Trouble Area

* Vehicle speed sensor circuit
* Vehicle speed sensor
* ECU




The AFM code is probably caused by the lexus AFM and the Speed signal code could be from my broken speedometer. Its been normal to have a check engine code but it usually goes away after driving over 60 for about 5 minutes. Anyone have any ideas? If I cant figure it out in the next couple days Im gunna have to have it towed and fixed by a mechanic. I've done all my own work the past 6 years I had the car so Id hate to start now. HELP!!!!!!

 

[jdub]

Did you wiggle the CPS wires while someone cranked it?

 

[JohnRardin]

Did you wiggle the CPS wires while someone cranked it?

Yea, didn't change anything. My mechanic says it sounds like a bad crank position sensor, but I cant find anything about that except on the 2JZ. Does it have one? He said it could also be called a "magnetic pulse generator". I know I have a spare one so I can easily try changing it but......what and where is it?

 

[jetjock]

I've done all my own work the past 6 years I had the car so Id hate to start now.

You must have a very reliable car.

 

[jdub]

CPS = Crank Position Sensor. I have a question. How can you wiggle the wires to it if you don't know "what and where it is"?

The CPS is behind the power steering reservoir and looks like this:
(wiggle the connector on top and the wires leading to it)

 

[JohnRardin]

CPS = Crank Position Sensor. I have a question. How can you wiggle the wires to it if you don't know "what and where it is"?

The CPS is behind the power steering reservoir and looks like this:
(wiggle the connector on top and the wires leading to it)

Wow I feel dumb...I totally thought all along that CPS was camshaft position sensor. Haha.....sweet I've changed it before and I have a spare so I'm going to try that ASAP. Thanks

 

[jdub]

The CPS can fail, but it's not common. The wiring to it gets hard/brittle at the connector, hence the wiggle tip...I would look there 1st and the wiring condition across the top of the motor.

 

[jetjock]

Fwiw the reason it gets brittle is because of the turbo water line. It can get 250+ F on that hose where it passes the CPS. The hose came from the factory with an insulating sleeve and the wiring also had one there. That stuff is probably long gone on many cars. I still have both and have never had any problems with the wiring or connector.

 

[JohnRardin]

You must have a very reliable car.

I wouldn't say that my car's reliable necessarily, more like I'm too poor to pay a mechanic so I've just kinda taught myself to fix whatever comes up.

Anyone know where I can find instructions for changing a CPS?

I know I've done it before but this time I'll have to do it in a parking lot instead of my big garage.