Calling all tech wizards, here's a doozy....

[DREDD_LX93]

My car (93 LX 5.0) is not starting. The engine turns over, but it doesn't start.

Here's what I've verified:

1. There is spark at the spark plugs (visual and spark line test, brand new distributor, coil, spark plugs and wires, battery)
2. There is fuel at the rail and injectors (new fuel pump, fuel pump primes, fuel pressure reading at 40 psi, noid light flashes at #1 injector when distributor is rotated)
3. Timing verified to be correct (rotor pointing at #1 spark plug when timing is between 0-10 deg TDC).

So, if you have fuel, spark, accurate timing, and the engine is turning over/cranking, what would keep a car from starting (that reminds me, new starter as well)?????????????

 

[RatStang]

I'll be the first guesser.

How about IAC or TB position sensor?

Try screwing the TB stop all the way (so that the blade is cracked open) and see of you can get some sort rough idle going.

My next guess would be the EEC. Unplug it, plug it back in, and check for power.

Pull KOEO codes (if you can get codes, it's probably not the EEC).

Other than that... what's the recent maintenance history? What have you done and how did this start?

 

[liljoe07]

Verify that all injectors are pulsing.

 

[DREDD_LX93]

This car died on my while I was driving a few months ago.

I then replaced the fuel-filter, and it worked fine for a few days, then I started having trouble starting it, then it completely died. Over time, I've replaced the following:
1. Fuel pump
2. Fuel pump relay
3. Distributor (brand new MSD Pro Billet 5.0)
4. Spark plugs, wires, coil
5. ECM Relay
6. ECM (got a used one from ebay)

At first, it turns out that the injectors weren't pulsing because my ECM was bad. As soon as I connected the new ECM, the injectors fired, and I was able to start it, but after 30 seconds, it bogged and then died again.

I then thought my timing might be off, so I moved the rotor to where I though it should be, and when I turned the key and cranked it, there was a loud pop, and blue smoke came out of my cold-air filter, and since then, it doesn't turn back on. I noticed that some of the air filter element was burnt and it smelled as much.

Since then, a mechanic came over, we reset the timing manually by pointing the rotor at #1 spark plug when engine was at 0 deg TDC, but still, no start.

I've replaced every critical electrical component I can think of, and I know for sure it's not a fuel issue, so I'm at my wits end as to what it could be. Last I heard, gas was very flammable so if there is spark coming out of my spark plug, and it's getting sprayed with gas, I should see some action.

 

[liljoe07]

Im curious, did the mechanic point the rotor to the #1 cylinder in the block? Or on the cap? What direction is the TFI pointing at?

 

[DREDD_LX93]

Here's how he did it:

He removed the #1 spark plug, then he had me crank the engine once at a time until he felt pressure at the #1 cylinder and the timing marks were at 0 deg TDC. We then popped the distributor cap, and the rotor was 180 degress from where it should've been (it was pointing at the #6 spark plug). So he took the distributor back out and rotated the rotor to point at #1 spark plug. TFI pointing at NW from top view.

I had previously set the rotor incorrectly by mistake, like I mentioned before, and when I turned the key, there was a very loud pop and blue smoke came out of the air filter. Then it would just turn over and that was it. After that is when the mechanic came and we did the above.

 

[BlackGT89]

Take the cap off and watch the rotor while you crank it, make sure it's spinning. I'm thinking timing chain problems. When the timing chain gets old it can stretch, the engine just gets more and more tired until it just won't run anymore. You can still get valve motion, but it's so far behind where it should be, there's no power being made. If you can, turn the crank by hand and see if there is a lag in the motion of the rotor. There is an acceptible amount, but this might give you a clue if the TC is the problem.

 

[MustangBill87]

these are 4-stroke motors timing mark will hit TDC twice in one cycle. Pull the RT Valve cover turn engine over by hand and when both rockers(intake and exhaust) are up and the timing mark is on TDC this is when you want the rotor pointing towards #1 cylinder / second bolt back on the pass side of the intake manifold (4-stroke cycle /-intake-compression-power-exhaust)

 

[stang&2Birds]

WTF? Where did my first post go. Hmm, some thread likely has some weird reply then.

Try unplugging the MAF. See if the car will run/start.

Also, what are the codes??
IMHO, you're wasting time and money until you read the codes.

 

[stang&2Birds]

I'll be the first guesser.
How about IAC or TB position sensor?

Try screwing the TB stop all the way (so that the blade is cracked open) and see of you can get some sort rough idle going.

Where you the one that also suggested TPS for a no start condition?


Basically, ****ing around with the TPS is a Ricer mod and a Ricer screw-around! I think that sums it up.
IMHO, if the TPS isn't creating a black hole and sucking in the universe, then leave it the **** alone!!

FYI:
Mustang TPS FAQ

Other than the misinformation you where likely given about the TPS and therefore repeated, you had good ideas and suggestions.


Also, about the TPS:
As posted by Joel5.0 on another site.
A Google search will find the original thread.
TPS Strategy as contained in the EEC-IV - GUFB. - Google Search

Joel5.0
Re: Summarized/Corrected Base Idle Reset Procedure

Adjusting the TPS......a case in Mythology
Summarized EEC-IV logic for the TPS......​

The following is a very short explanation of the EEC-IV Idle/TPS Strategy as contained in the EEC-IV Strategy Book - GUFB. Every time the Ign Switch is turned to the ON position.....the EEC-IV will do the following for the TPS signal:

• Minimum voltage at closed throttle over .49 vdc. , less than .49 and codes 23 and 63 will set as failures.
• Max voltage closed throttle should not exceed 1.2 vdc, or codes 23 & 53 will set as failures.
• TPS voltage between .5vdc and 1.19 = no codes, TPS ...then EEC-IV system is (TPS wise)

►Closed throttle TPS value is reset by the system to the lowest value read when ignition is turned on every time. Or as explained by the EEC-IV RATCH algorithm:

Quote
The variable RATCH is the output of a ratchet algorithm which continuously seeks the minimum throttle angle corresponding to a CLOSED THROTTLE position. This alleviates the necessity to set the throttle position sensor at an absolute position and compensates for system changes and differences between vehicles. The ratchet algorithm uses filtered throttle position for the determination of RATCH.

► A voltage increase of .04 vdc from the minimum registered will id part throttle status.
► Minimum WOT value of 3.21 vdc (.5 + 2.71) and not higher than actual Voltage REFerence (VREF) generated by the ECM to access WOT strategy.

....This does not include the other registers and functions, the system uses to id acceleration, deceleration, cruise...etc, like:

APT = At Part Throttle flag

Quote
The value of APT is determined by a logic. Briefly, throttle angle breakpoints, in terms of counts, are used to define the CLOSED/PART_THROTTLE and PART/WIDE_OPEN_THROTTLE transitions.

OLDTP = Previous TP sensor value, counts.
TAR = Throttle Angle Rate of change, deg/sec.
TP = Throttle position sensor.
N331B = A multiplier as a function of the present throttle angle minus the lowest measured throttle angle (TP - RATCH)
Etc, etc, etc

Adjusting the TPS is a MYTH....or more proof is needed?

 

[stang&2Birds]

Dup post. Not my day.

 

[DonMaximo]

Popping... smoke...???

You've made quite a few changes... and I'm sorry to point out the obvious...

As you know, the dizzy rotor spins counter clock-wise

Are you certain you've run your wires correctly ??

Typical 5.0 is: 1-8-4-5-6-2-7-3


You would not be the first person to make this mistake...

Good luck !

 

[DREDD_LX93]

Ok, a couple of questions on the latest replies:

1. What do I need to read the codes? How do I do this? And where can I find what the codes mean?

2. About the firing order DonMaximo just posted: 1-8-4-5-6-2-7-3
I thought the firing order for EFI 5.0s was 1-3-7-2-6-5-4-8.

Which one is correct? I have it setup as 1-3-7-2-6-5-4-8 going counter-clockwise.

 

[Saleen0679]

Reading codes can be accomplished using an analog meter, test light, check engine light, or code reader. Info on reading codes can be found all over the forum and elsewhere online. Here's one site: Troublcodes.net

The firing order for the 5.0L HO is 1-3-7-2-6-5-4-8. I believe DonMaximo was showing the clockwise pattern on the distributor cap.

 

[DonMaximo]

Saleen:: That is correct

Dredd:: Sorry about the confusion...

I'm kind of old-school and have learned to see it this way... Goes back to my 351-Cleveland days...where I also worked on GM stuff.

Since you have the wiring right...then we don't need to dwell on that subject further.

Back to the problem...
This popping through the intake/air filter sounds so much like a timing issue.
A cylinder is firing when the intake valve is open.
I too, begin to wonder if your timing chain has skipped.

Regards & Good Luck !

-D

 

[RatStang]

Where you the one that also suggested TPS for a no start condition?


Basically, ****ing around with the TPS is a Ricer mod and a Ricer screw-around! I think that sums it up.
IMHO, if the TPS isn't creating a black hole and sucking in the universe, then leave it the **** alone!!

You're right, it's not your day. If you'd read my post then you'd see that it was referring to whether or not the TPS was working at all. There was no suggestion at all about "ADJUSTING" the TPS. I think most folks are aware that the TPS is referenced at startup.

 

[liljoe07]

You can start the car with the TPS unhooked.

On the very unlikely chance that the TPS may be reading WOT at closed throttle, then there is the issue of it cutting the injectors off. Full Flood mode.

 

[DREDD_LX93]

It's raining today, can't do much. But from the looks of it, it's time to break out the voltmeter and test light and start testing wires left and right. It's time to get methodical and scientific.

I really wished it was a mechanical problem, it's so frustrating chasing after electrical issues. I mean, it could literally be ANYTHING! I read in another thread about another 'Stanger going through the same problem, and it turned out to be mice had eaten through one of his wires!

UUuuuuggghhh, to be so new to the Mustang world and face such a problem.

Anywho, thanks guys, I'll keep you posted on what I find.

 

[DREDD_LX93]

Ok guys, I think I'm getting closer!!!! I can feel it!!!!

So here's what I just did:

I verified I was getting fuel and spark at the #1 and #5 cylinders.
I pulled all the wires off the dizzy cap and I pulled the dizzy cap itself.

I pulled the #1 spark plug, stuffed a piece of paper towel in the plug hole, and cranked the engine once at a time, waiting for it to be blown out when there was compression on the #1 cylinder. It was finally blown out and the timing marks were at absolute 0 deg (it was ATC....10....0....10....20).
I looked at the rotor and placed the dizzy cap on top. I noticed it was pointing at the #8 plug.
I then took out the dizzy and adjusted the rotor so it would point at the #1 plug.
I then took put the dizzy cap back on and connected the wires again -> 1-3-7-2-6-5-4-8 CCW.

I then primed the fuel pump and tried to start it.

It still didn't start, but THIS TIME, as the engine was turning over, it started kicking intermittently, like as if it was about to turn on, but never did. I think I'm close.

So what could it be now? Should I keep playing with the timing?

 

[liljoe07]

Try advancing the distributor a little clockwise. Then try again. Plugs might be gas fouled. Make sure the spout is out when you mess with the timing.