New Engine Still Won't Fire!

For something as huge as this (with a new motor, where you have touched everything under the hood), I would refer to Jrichker's 'Cranks but wont start checklist'.

With that list, you can systematically troubleshoot and not forget something or recursively test.

Good luck.

Cranks OK, but No Start Checklist for Fuel Injected Mustangs

1.) Remove push on connector from starter solenoid and turn ignition switch on. Place car in neutral or Park. Remove coil wire from distributor & and hold 3/8” away from engine block. Jumper the screw to the big bolt on the starter solenoid that has the battery wire connected to it. You should get a nice fat blue spark.
Most of the items are electrical in nature, so a test light, or even better, a voltmeter, is helpful to be sure they have power to them.
No spark, possible failed items in order of their probability:
A.) MSD or Crane ignition box if so equipped
B.) Coil
C.) TFI module
D.) PIP sensor in distributor
E.) ECC relay next to computer - look for 12 volts at the fuel injector red wires
F.) Fuse links in wiring harness - look for 12 volts at the fuel injector red wires. All the fuse links live in a bundle up near the starter solenoid.
G.) Ignition switch - look for 12 volts at the ignition coil red/lt green wire.
H.) Computer

See the following links for wiring diagrams...

http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp for 79-88 model cars

http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp for 89-93 model cars

http://www.autozone.com/servlet/UiB..._us/0900823d/80/1d/db/3c/0900823d801ddb3c.jsp for 94-98 model cars


2.) Spark at coil wire, pull #1 plug wire off at the spark plug and check to see spark. No spark, possible failed items in order of their probability:
A.) Moisture inside distributor – remove cap, dry off & spray with WD40
B.) Distributor cap
C.) Rotor
D.) Spark Plug wires
E.) Coil weak or intermittent - you should see 3/8" fat blue spark with a good coil

3.) Spark at spark plug, but no start.
Next, get a can of starting fluid (ether) from your local auto parts store: costs a $1.30 or so. Then pull the air duct off at the throttle body elbow, open the throttle, and spray the ether in it. Reconnect the air duct and try to start the car. Do not try to start the car without reconnecting the air duct.
Two reasons:
1.) If it backfires, the chance for a serious fire is increased.
2.) On Mass Air cars, the computer needs to measure the MAF flow once the engine starts.
If it starts then, you have a fuel management issue. Continue the checklist with emphasis of fuel related items that follow. If it doesn’t, then it is a computer or timing issue: see Step 4.

Clue – listen for the fuel pump to prime when you first turn the ignition switch on. It should run for 5-20 seconds and shut off. To trick the fuel pump into running, find the ECC test connector and jump the connector in the lower RH corner to ground. See http://www.mustangworks.com/article...c-iv_codes.html for a description of the test connector. If the relay & inertia switch are OK, you will have power to the pump. Check fuel pressure – remove the cap from the schrader valve behind the alternator and depress the core. Fuel should squirt out, catch it in a rag. Beware of fire hazard when you do this. In pinch you can use a tire pressure gauge to measure the fuel pressure. It may not be completely accurate, but you will have some clue as to how much pressure you have.

No fuel pressure, possible failed items in order of their probability:
A.) Tripped inertia switch – Coupe & hatch cars hide it under the plastic trim covering the driver's side taillight. Use the voltmeter or test light to make sure you have power to both sides of the switch
B.) Fuel pump power relay – located under the driver’s seat in most stangs built before 92. On 92 and later model cars it is located below the Mass Air Flow meter. Look for 12 volts at the Pink/Black wire on the fuel pump relay.
C.) Clogged fuel filter
D.) Failed fuel pump
E.) Blown fuse link in wiring harness. Look for 12 volts at the Orange/Lt Blue wire on the fuel pump relay. The fuse links live in the wiring harness near the starter solenoid.
F.) Fuel pressure regulator failed. Remove vacuum line from regulator and inspect for fuel escaping while pump is running.

Fuel pressure OK, the injectors are not firing.

A.) A Noid light available from Autozone, is one way to test the injector wiring.
B.) I like to use an old injector with compressed air applied to the injector where the fuel rail would normally connect. I hook the whole thing up, apply compressed air to the injector and stick it in a paper cup of soapy water. When the engine cranks with the ignition switch on, if the injector fires, it makes bubbles. Cheap if you have the stuff laying around, and works good too.

a.) Pull an injector wire connector off and look for 12 volts on the red wire when the ignition switch is on.
b.) No power, then look for problems with the 10 pin connecter (salt & pepper shakers at the rear of the upper manifold).
c.) No power and the 10 pin connections are good: look for broken wiring between the orange/black wire on the ECC relay and the red wire for the 10 pin connectors.


4.) Spark & fuel pressure OK.

A.) Failed IAB (no airflow to start engine). Press the throttle ¼ way down and try to start the car.
B.) Failed computer (not very likely)
C.) Engine ignition or cam timing off: only likely if the engine has been worked on recently).
D.) Firing order off: HO & 351 use a different firing order from the non HO engines.
HO & 351W 1-3-7-2-6-5-4-8
Non HO 1-5-4-2-6-3-7-8
E.) No start when hot - Press the throttle to the floor & try starting it if you get this far. If it starts, replace the ECT.

riceeater87 said:

ttt

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Post what you found while going through Mr. Richker's checklist, as that diagnostic info will help people to help you.

Good luck.

riceeater87 said:

So far i found that i have spark throughout the entire ignition system. It is not a fat blue spark though, instead it is a thin spark. Not sure if this indicates a weak coil. It still smarts a bit when you get zapped though...lol. Moving on to the fuel side of things this weekend.

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Fix the poor quailty spark before you do anything else. The poor quality spark snake has bitten me before on my Mustang...

Sound advice from JR.

Is the battery charged up or is it run down from downtime and trying to start it a lot?
I have chased spark issues on bikes before (coil packs) and keeping that lame little battery charged up was key to doing any decent diagnostics.

Good luck.

make sure your not hanging valves open, happend to me. i did a compression test and readjusted all the valves to get max compression.

Just to add- I beleive you can check conditon of the spark. (see if it's enough voltage). By checking spark at the plug. I don't remember how far of a gap it should jump. We usually use a spark tester. plugs right in, if it jumps there's suffecient voltage. (I think it's somewhere around 1/2 gap????)

It can be hard to factor in the turbulent conditions in the chambers by checking the spark using a testing tool outside of the motor. Compression, air/fuel, etc all tend to want to snuff out the spark.

The gapping tool (or an old plug gapped to 0.056") can work as a crude test - if it wont jump the gap outside the chamber, how can it inside.

Good luck.

riceeater87 said:

Would switching my stock coil back in be a worthy test? My battery is fully charged so thats not the reason for weak spark.

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Very good idea. Do it.

hmmmm

i would like to add that someone stated earlier to check your valves... And as to me if you have spark and you have fuel.... seems to me that your missing the number 3 thing you need in order for an engine to fire and thats compression...

please check to see if your valves are improperly adjusted... as to maybe being to tight and holding the valves open.... do a compression test to see what your readings are... and if all is good try another processor... efi fuel injected mustangs dont require much to start....

OHHHHH also forgot 1 big thing
make sure your number 1 cylinder is at tdc ( top dead center) and your distributor was dropped in with the rotor in the correct position ... also check your firing order
should be 13726548

let us know
thanks

tds

I was about to say make sure its at TDS... you might have it off just a little bit.. like one tooth...

KDK1988GT said:

I was about to say make sure its at TDS... you might have it off just a little bit.. like one tooth...

Click to expand...

Or a few degrees.