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No Crank or No Start

ZVOLV

<Master Tech>
Joined
Nov 19, 2002
Location
California
NO START:



image066.jpg


Photo courtesy of cleanflametrap

-PRELIMINARY CHECKS- GET A INCANDESCENT BULB TEST LAMP! (~$15) A meter is the wrong tool to confirm power circuits. One strand of wire can show 12V on a meter, but won't be enough current to operate the component.

1.) Confirm power to the fuel injectors: connect the test lamp between the coil postive and ground. Key on, lamp ON?
2.) Confirm igntion signal to the coil: connect the test lamp to the coil NEGATIVE to a good ground. Crank. BLINK?
3.) Confirm injector pulse: disconnect a fuel injector connector, peel back the boot, connect a test lamp between the two wires and crank the engine, (use a paperclip as a backprobe), BLINK?


- STEP 1: Check for spark! Unplug ignition wire going from the coil to the distributor. Ground it very close to a strut tower stud like in the picture above. Crank the engine. Do you see spark? If you see a consistent spark, go to the next step and do the starting fluid test. If no spark, inspect Crankshaft Sensor/Hall Sensor and do ignition diagnosis.

-STEP 2: STARTING FLUID! This will confirm that ignition, timing and mechanicals of the engine are good with one fast and easy test:


TO USE STARTING FLUID: Unplug the fuel injectors, pull the spark plugs and clean them of any fuel, crank the engine and air out the cylinders. (This will clear out any flooding of the cylinders from trying to start the engine.) Then reinstall the spark plugs, LEAVE INJECTORS UNPLUGGED, disconnect intake hose at throttle body, open throttle body, give it two long sprays, crank. Start? You should be able to keep it running PULSING the can of brake cleaner. If so, you have a fuel system issue. YOUTUBE VIDEO ("test fire without any fuel lines even installed in the car yet.)

If your car runs on starting fluid, the fuel system is suspect. Check for 12v at the fuel pumps/fuel pump fuse with the engine cranking. Check fuel pressure. A gauge that will bolt onto the fuel filter outlet (12mm banjo) is available from auto parts stores for a refundable deposit.

-Nothing wrong with doing a compression test!

-Check belt timing. The cam, crank, and aux shaft (on 240) all need to be aligned correctly.

-Check ignition timing. Approx 12 degrees BTDC.



NO CRANK:

1: Battery above 12v?

2: Still no crank? Backprobe yel/blu wire at starter. Crank. Have 12v? If not, neutral safety switch (if auto) or ignition switch suspect.

3. 12v at signal wire to starter and STILL no crank? Starter, battery, primary/ground wire issues.
 
Last edited:

mikep

The MP
Joined
May 24, 2003
Location
38? 27' N 75? 29' W
DISABLE IGNITION OR FIRE WILL HAPPEN, and point fuel rail into the air and crank engine and you should see injectors spray. This will tell you that the computer is working and you also have some fuel pressure.

Not a good idea for newbies to do this. Fire can still happen, and you can tell just as much by testing the signal at the wires.
If you rule out all other problems and have poor cold starting and idle, take the injectors to have the pattern checked, or do it the way you describe in a container of some sort.
Trust me, I have seen fires and other silliness with ignition disabled.
 

ZVOLV

<Master Tech>
Joined
Nov 19, 2002
Location
California
Crank Sensor Diagnosis

Do you think your crank sensor is bad?

Peel back rubber insulation on crank sensor connector at firewall. Backprobe the center wire, red/yellow, pin 2 with one lead, send other lead to battery ground. Multimeter to AC Volts, NOT DC, and crank engine. You should get approximately 0.4V AC cranking.

-Backprobe between Red/Yellow center wire and Blue/Yellow (pin 3). Check resistance. Spec should be around 200ohms (further data needed. Can vary), but if you see an open circuit here, sensor is bad.
 
Last edited:

Plus T

New member
Joined
Sep 15, 2015
Location
Philly
2. Locate fuel pump relay. Remove cover. Turn key on and watch contacts. The FIRST contact should close with key on and STAY closed. This is power for the computer system. SECOND contact is for the fuel pumps. It may/may not prime with key on. CRANK ENGINE. SECOND contact should close and also STAY CLOSED. If it doesn’t, you may not have a crank signal. Check hall effect sensor or crankshaft sensor. If the first contact EVER pops open with the key on, time for a new relay. Also check for corrosion at fuse panel and also at fuse at battery (if equipped)
I dont understand. How can you tell if the contacts in the fuel pump relay are opening/ closing? Do you have to take apart the relay and look inside it?
 

Plus T

New member
Joined
Sep 15, 2015
Location
Philly
Wow that is very helpful, I would have never known. That will definitely come in handy for working on my 240. Thanks.
 

PardoR

New member
Joined
Oct 18, 2015
Location
Quilpue, Chile
My car, after passed the shop runs fine but it can't start. It cranks OK ,it has spark, new rotor, new spark plugs, fuel pumps working fine, distributor works, injectors OK, FPR new... Ehat else can be??
 
Joined
Aug 30, 2016
I dont understand. How can you tell if the contacts in the fuel pump relay are opening/ closing? Do you have to take apart the relay and look inside it?

Don't have to open any relay to test
Use DVOM, high impedance, on computer side circuits and test light for B+ and switched
Good "T" pins for plug back probes also make it easier
Also test for good ground(s) to relay, like one for RSR if voltage/trigger is good
 
Joined
Aug 30, 2016
My car, after passed the shop runs fine but it can't start. It cranks OK ,it has spark, new rotor, new spark plugs, fuel pumps working fine, distributor works, injectors OK, FPR new... Ehat else can be??
How can run fine if won't start?
Anyway
Three parts of equation - FUEL FIRE COMPRESSION and all at right time
If injectors are pulsing and you have fuel on rail next thing to check is that the engine has compression if everything else you say is fact
Remove oil cap and look in hole to see if cam is turning while engine is cranking or being turned over by hand
If not turning it is seized up or your timing belt has broken
 
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