Hot Start Flooding?

50gt1988

New Member
Dec 25, 2004
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Spanaway, WA
Ok I've come to my insanity level with this hot start problem. I've been stranded in parking lots twice in the last week and am tired of it. My car will start on the first crank when its hot but if you miss that or let off the starter before it start it won't start untill its completely cooled down. I've tested EVERYTHING!!! The last thing I considered was the TFI on the brand new MSD Distributer but that's working fine. The car just instantly floods out as soon as I crank it over hot. As soon as the starter turns over you can smell the gas. It does this untill the car cools off. Will start perfectly fine cold everytime. Anyone have any more suggestions that I haven't already tried? Thanks.
 
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See the very last item in the checklist if all your problems are with a warm engine.

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.
attachment.php
. See the above graphic 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. This tells the computer to shut off the fuel injectors. If it starts, replace the ECT.
 
JR's right on. What size squirters do you run? It does sound like a cranking-fuel issue (a changable parameter).

Good luck.
 
I'm not great with mods but me-thinks those 30's might very well be the issue - too much cranking fuel.

Bump for JR's and others' thoughts.
Good luck.
 
can you pull your plugs and see if they are wet. i imagine they are if you say you can smell gas. perhaps you have a couple bad injectors. Also if you can smell gas odds are you are washing your cylinders and that gas is getting into your oil and breaking it down. Now your oil can possible not be working as it should and could lead to more catistrophic failures down the road. Aslo how much timing are you running? perhaps it is a issue with that.
 
50gt1988 said:
See I know it's not the injectors because the cars had this problem since the day I put the new motor in and I ran 19lb injectors for the first 500 miles.
Go through the checklist anf if you don't find anything that doesn't work, replace the ECT. Usually it will set a code if it is really bad.

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.
 
Yeah i already replaced the ect. The only thing left in this car that isn't new is the ECU iteself. The problem with pulling codes is that the only codes I ever get are the bogus codes that suggest a bad ground in the computer that I've been getting since I switched to mass air. So anyone other then me think bad ECU?
 
The power ground for the computer isn''t the small braided wire next
to the computer.
The computer has its own dedicated power ground that
comes off the ground pigtail on the battery ground wire. Due to
it's proximity to the battery, it may become corroded by acid
fumes from the battery. It is a black cylinder about 2 1/2" long
by 1" diameter with a black/lt green wire.You'll find it up next to
the starter solenoid where the wire goes into the wiring harness
 
Code 22 MAP (vacuum) or BARO signal out of range. The MAP or BARO sensor is pretty
much the same sensor for both Mass Air & Speed Density cars. The main difference is
where it is connected. Mass Air cars vent it to the atmosphere, while Speed Density cars
connect it to the intake manifold vacuum. Its purpose is to help set a baseline for the
air/fuel mixture by sensing changes in barometric pressure. The MAP or BAP sensor puts out
a 5 volt square wave that changes frequency with variations in atmospheric pressure. The
base is 154 HZ at 29.92" of mercury - dry sunny day at sea level, about 68-72 degrees.
You need an oscilloscope or frequency meter to measure it. There is no way you can use a
common cheap voltmeter or DVM to accurately measure the output signal.

The MAP/BARO sensor is mounted on the firewall behind the upper manifold.

Baro or MAP test using frequency meter - run the test key on engine off. The noise from
the ignition system will likely upset the frequency meter. I used a 10 x oscilloscope probe
connected from the frequency meter to the MAP/BAP to reduce the jitter in the meter's
readout.

If it is defective, your air/fuel ratio will be off and the car’s performance & emissions will suffer

Some basic checks you can make to be sure that the sensor is getting power & ground:

Note that all resistance tests must be done with power off. Measuring resistance with a
circuit powered on will give false readings and possibly damage the meter.

Check the resistance between the black/white wire on the MAP/BARO sensor and then the
black/white wire on the EGR and the same wire on the TPS. It should be less than 1.5 ohm.
Next check the resistance between the black/white wire and the negative battery cable.
It should be less than 1.5 ohm.

The following power on check requires you to turn the ignition switch to the Run position.
Use a DVM to check for 5 volts on the orange/white wire. If it is missing, look for +5 volts
at the orange/white wire on the TPS or EGR sensors. Use the black/white wire for the
ground for the DVM.

Code 53 - Throttle Position sensor too high – TPS – TPS out of adjustment, bad
connections, missing signal ground, bad sensor.

Here’s a TPS tip I got from NoGo50…

When you installed the sensor make sure you place it on the peg right and then tighten it
down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the
front screw enough so you can move it just a little in very small increments. I wouldn’t try
to adjust it using marks. Set it at .97v-.99v, the closer to .99v the better. Just don’t go
over .99, or you upset the fuel calibration and idle quality will suffer.

(copied from MustangMax, Glendale AZ)
1. Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a
bit if you can and get it nice and warm.

2. When you probe the leads of the TPS, do not use an engine ground, put the ground
probe into the lead of the TPS. You should be connecting both meter probes to the TPS
and not one to the TPS and the other to ground.

3. Always reset the computer whenever you adjust the TPS or clean/change any sensors.
I just pull the battery lead for 10 minutes.

4. Check the procedure for your year, on my 90 I have to turn the idle screw until it just
touches the tab, then insert a .010 feeler gauge and give it about one more turn. Then you
adjust the TPS voltage to .98v, reset the computer. Start it up, if the idle is to low then
turn the screw in until it is just right, then readjust the TPS voltage to .98v and reset the
computer and start it up. The key is to adjust the TPS voltage and reset the computer
whenever the idle screw is changed.
Check the black/white wire resistance. Connect one ohmmeter lead to the black/white wire
on the TPS and one lead to the negative post on the battery. You should see less than 1.5
ohm, more than that indicates a problem. Always take resistance measurements with
the circuit powered off.


Clean the 10 pin salt & pepper shaker connectors.
harness02.gif
.

See http://fordfuelinjection.com/index.php?p=85 for more help

Code 35 EVR - EVP sensor signal is/was high – Bad sensor, or possible missing ground for
EVR circuit. With the power off, measure the resistance between the black/white wire and
battery ground. You should see less than 1 ohm. Check the same black /white wire on the
TPS and MAP sensor. More than 1.5 ohm there and the wire is probably broken in the
harness between the engine and the computer. The 10 pin connectors pass the
black/white wire back to the computer, and can cause problems.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds
(website host)

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

See http://fordfuelinjection.com/index.php?p=6 for more wiring help & 10 pin connector diagrams

Code 51 Engine Coolant Temperature (ECT) sensor signal is/was too high -

Possible bad ECT sensor, or wiring. Possible missing signal ground –
black/wire wire broken or bad connection. With the power off, measure the
resistance between the black/white wire and battery ground. You should see
less than 1 ohm. Check the same black /white wire on the TPS and MAP
sensor. More than 1 ohm there and the wire is probably broken in the harness
between the engine and the computer. The 10 pin connectors pass the
black/white wire back to the computer, and can cause problems.

Pin 7 on the computer - ECT signal in. at 176 degrees F it should be .80 volts

Voltages may be measured across the ECT by probing the connector from the rear.
Use care in doing it so that you don't damage the wiring or connector.

Here's the table :

68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61

Note that all resistance tests must be done with power off. Measuring resistance
with a circuit powered on will give false readings and possibly damage the meter.


Ohms measures at the computer with the computer disconnected, or at the sensor with
the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms

Diagram courtesy of Tmoss & Stang&2birds

88-91_5.0_EEC_Wiring_Diagram.gif


See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

With all these codes, they all have the same thing in common: missing signal ground on the
black/white wire, pin 46 on the computer.