Engine Fire Won't Start - Page 6 - Ford Mustang Forum
Reply
 
LinkBack Thread Tools
post #76 of 115 (permalink) Old 06-25-2015 Thread Starter
Apprentice
 
BuddysMustang's Avatar
 
Joined: Nov 2014
Location: Brick
Posts: 59
 
twotyred, If you had a pats issue you should see a blinking lock symbol on your dash when you turn the key. If you are not reading any fuel pressure at the fuel rail on a 2005 V6 Mustang when you turn the key it could be a faulty fuel rail pressure sensor (FRPS). Look at easyautodiagnostics.com for the test procedure. The FRPS tells the fuel pump how much pressure to send to the fuel rail. If pressure is low it sends a signal to the pump to increase pressure and so on. Obviously if the fuel pump is faulty or the fuel filter is clogged this would prevent the fuel from getting to the fuel rail so these are also possibilities.

G-Man, I think I have a different problem than the throttle body. I did a quick spark test at each cylinder by inserting a small screwdriver in the spark plug wire end and watched for spark from the screwdriver to ground. All cylinders have strong spark across 1/4 inch gap. knowing this and the fact that the noid test suggests that the injectors are firing while rail fuel pressure is present I should get something. I then sprayed starter fluid into a vacuum port and tried to start the engine. Nothing. Not even a backfire. I'm starting to think I have a compression issue or an air flow issue. It's not the air intake because I tried starting with MAFS and air plenum off and no change. I tried to feel vacuum on an air input port of the intake manifold but felt nothing. Since the engine starts momentarily on initial start ups my guess is that the crank-cam timing is good. My suspicion is a weak or bad engine (pistons, rings) or plugged exhaust (cat, etc). I think I'm going to perform a compression test next. Your thoughts?

BuddysMustang is offline  
Sponsored Links
Advertisement
 
PONY Member
 
gManTexas's Avatar
 
Joined: Mar 2015
Location: Austin
Posts: 702
 
Garage
I doubt that your engine lost compression, but you could do the test to rule it out.

If you believe the throttle position sensors are good, then possibly look at crank or cam position sensors, although they should throw codes.

I still believe it's related to the ECU.


2011 Race Red GT vert, 5.0 A6
FRPP ProCal, JLT oil separator, Boss 302 quads w/ Corsa Xtreme axle backs, Koni STR.T (orange), GT500 strut mounts, Steeda Sports, Steeda billet LCAs, Steeda adj UCA, Steeda adj rear swaybar, BMR adj panhard, BMR lca relocation brackets, Boss 302 lower front fascia
gManTexas is offline  
GT Member
4.6L Member
5.0L Member
 
TigerSN95guy's Avatar
 
Joined: Jan 2009
Location: Westerly
Posts: 1,196
 
Garage
Send a message via AIM to TigerSN95guy
Buddy, you said two things in this thread about you being an electrical engineer and an old school mechanic. .. instead of testing with $5 tools from harbor freight, why aren't you using a digital multi meter? I get mine out every time I have an issue like this.

Also, old school mechanic, try putting your foot down a notch while cranking. (Flood your carb) tell us if it runs longer than 4 sec. If it does, it's probably throttle body.

Also, after you got it to run and die, cycle the key with a one minute pause in between cycles. Listen for the pump. My pump on my 2015 GT is loud enough for me to hear from the driver's seat.

Do you hear any clicks every time you cycle the key? No clicks, replace the fuel pump relay in the fuse block under the hood.

I don't know about your generation car, but is there a second fuel pump on the frame somewhere that accelerates the pressure up to 50psi? My old 89 bronco did.

Try all that and let us know

2015 Mustang GT Premium with Track Pack (i think calling it the performance package was just dumb)
TigerSN95guy is offline  
 
post #79 of 115 (permalink) Old 06-25-2015 Thread Starter
Apprentice
 
BuddysMustang's Avatar
 
Joined: Nov 2014
Location: Brick
Posts: 59
 
Thanks for the feedback TigerSN95guy. I do use a DMM for testing and I had it out multiple times trying to track down this problem.... One of the first things I tried was to apply a slight amount of throttle when starting as well as adding throttle after engine started. No difference. It just dies. As far as the fuel supply goes, I have flushed out the fuel from the tank using a test port I installed at the fuel rail. New gas was added to the tank and flushed through the lines, and the new fuel filter, by turning the fuel pump on and off with the key turned from off to run. I also have a fuel pressure gauge attached to the fuel rail (harbor freight) and I can see the pump turn on each time the key is turned to run or start. The fuel pressure is a constant 52 psi. I also witnessed a good leak-down of the pressure with the key off. I'm confident that fuel is not the issue. Some of this has been covered in previous posts in this thread as well as the parts that were replaced to date. I know that there is a lot to read but there is a lot of good troubleshooting that could help somebody to.

G-Man, I replaced the crank and cam sensors because it was looking like a timing issue between when the fuel and spark both reached the cylinders. Also the cam sensor was burnt pretty bad in the fire and the crank sensor was cheap. In terms of the throttle position sensor, I used the DMM to map out the operation and position of the butterfly during gas peddle cycling and all looked good. No dead spots that I could see. If I really wanted to get fancy I could break out my oscilloscope to look at the traces but I don't think that is necessary. I guess it is still possible there could be a problem with the PCU however this does not explain why I see good spark at the pugs and the injectors are turning on and off with fuel present. Remember, I also sprayed starting fluid into the intake manifold without even a pop. How can this be explained if compression is good and air is flowing through the engine?
BuddysMustang is offline  
PONY Member
 
gManTexas's Avatar
 
Joined: Mar 2015
Location: Austin
Posts: 702
 
Garage
Buddy, we are running out of things to try here. The 4.0L is a relatively simple setup. So far, it seems that everything you have checked is operating properly.

Have you checked your fuse box? I can't remember if you replaced it or not.

How about the MAF sensor? Is it clean?

2011 Race Red GT vert, 5.0 A6
FRPP ProCal, JLT oil separator, Boss 302 quads w/ Corsa Xtreme axle backs, Koni STR.T (orange), GT500 strut mounts, Steeda Sports, Steeda billet LCAs, Steeda adj UCA, Steeda adj rear swaybar, BMR adj panhard, BMR lca relocation brackets, Boss 302 lower front fascia
gManTexas is offline  
post #81 of 115 (permalink) Old 06-26-2015 Thread Starter
Apprentice
 
BuddysMustang's Avatar
 
Joined: Nov 2014
Location: Brick
Posts: 59
 
hahahaha I agree G-Man. How do you think I feel. Last week I removed and cleaned the Throttle Body and the MAF Sensor. However, I have tried with the MAFS connected and dis-connected with the same result. In the dis-connected condition the computer should put the engine in limp-home mode which is just a rich fuel mixture condition to protect the engine from getting damaged from running to lean.

I did mention that I have a spare fuse box but I haven't tried it yet. It wouldn't take much time for me to swap it out tomorrow so I will give it a try. The thing that bothers me is it appears that I am getting fuel and spark at the cylinders. The only thing left is air flow. This is why I started to look at vacuum at the intake manifold. However, it is hard to do vacuum testing when the engine is not running.... I went back to the initial reason I bought this car so cheap. It had an engine fire. The air filter box was damaged by the fire but I don't know if the engine was running at the time the damage occurred. This is why I was asking about blockage in the exhaust system which could choke off the air flow... One time the engine started I stomped on the gas peddle but it just sounded like it was bogging down and then died. There must be a link that we don't see.... Like you said I could try to get a new PCU from the company I told you about but that doesn't explain why I get no action at all with starting fluid after the initial start for the day has been exhausted.

BTW, I wanted to tell you how much I appreciate your help with this rather frustrating problem. It means a lot to have people pulling for you during your struggle. Thanks Guy !!!
BuddysMustang is offline  
PONY Member
 
MirageII's Avatar
 
Joined: Aug 2013
Location: Oakdale
Posts: 297
 
Just wanted to let you know there are probably a lot of people like me watching this saga unfold. I personally have nothing at this time to offer in the way of actual help. It seems that every time I have an idea, someone else posts it before I do. Oh well. But I'm watching this with great interest and hoping the actual problem is resolved soon. Best of luck!


2005 V6 Convertible
MirageII is offline  
GT Member
4.6L Member
5.0L Member
 
TigerSN95guy's Avatar
 
Joined: Jan 2009
Location: Westerly
Posts: 1,196
 
Garage
Send a message via AIM to TigerSN95guy
I did actually read the first 8 pages, didn't see anything about you testing the things I suggested. I don't think it's a PCM as of this point. It sounds like it's getting flooded as of this point. Get a vacuum Guage and test all your lines. Fire could definitely crisp those up.
Also, do the compression test, unless I missed that you did. And if you did, what were the psi ratings in each cylinder? Stock should be around 135ish
Also, is your stock air box melted at all? I'm with you on it being air

2015 Mustang GT Premium with Track Pack (i think calling it the performance package was just dumb)
TigerSN95guy is offline  
post #84 of 115 (permalink) Old 06-26-2015 Thread Starter
Apprentice
 
BuddysMustang's Avatar
 
Joined: Nov 2014
Location: Brick
Posts: 59
 
Thanks MirageII, I hope it has a happy ending.

Hey Tiger, I'm not sure if I mentioned it specifically, but I don't here the fuel pump turn on and off or the relay clicking but I can witness the fuel pressure gauge I installed on the fuel rail, pump up instantly when I turn the key to run and it remains there during cranking.... I think you have something there about the flooding. I do smell gas if I crank it to much. Also, when I change the plugs they looked moist. Not dripping but definitely not dry like the engine was fuel starved.... This would also explain why the introduction of starting fluid had no effect at all.... How can I test the lines for vacuum if it won't start? I placed my finger on a vacuum port on the intake manifold (I think this port went to an air conditioning valve mounted on the inner wheel well) and had a friend crank the engine but I felt no vacuum. The problem is I can't be sure that this is normal for just cranking and during actual engine run the vacuum would be much greater. This is the problem with trying to troubleshoot the vacuum on an engine that won't start. I think your on to something but I just don't know how to prove it. Even if I do the compression test, and I will asap, if the exhaust is plugged I think it will throw off the readings. I could remove the exhaust and try to start the engine but this is probably a last resort test. Your thoughts?
BuddysMustang is offline  
post #85 of 115 (permalink) Old 06-26-2015 Thread Starter
Apprentice
 
BuddysMustang's Avatar
 
Joined: Nov 2014
Location: Brick
Posts: 59
 
OH, I'm sorry Tiger. Yes, the air box has a hole on the bottom about the size of a quarter. I just don't know if this happened during engine running or off.
BuddysMustang is offline  
PONY Member
 
gManTexas's Avatar
 
Joined: Mar 2015
Location: Austin
Posts: 702
 
Garage
Buddy,

If you believe the cats or exhaust is blocked, then disconnect them and try to start the car. You will throw O2 errors, but you can test your theory.

Now, I assumed (maybe mistakenly), that any vacuum lines that were damaged were replaced when you did the harness and other items.

2011 Race Red GT vert, 5.0 A6
FRPP ProCal, JLT oil separator, Boss 302 quads w/ Corsa Xtreme axle backs, Koni STR.T (orange), GT500 strut mounts, Steeda Sports, Steeda billet LCAs, Steeda adj UCA, Steeda adj rear swaybar, BMR adj panhard, BMR lca relocation brackets, Boss 302 lower front fascia
gManTexas is offline  
post #87 of 115 (permalink) Old 06-26-2015 Thread Starter
Apprentice
 
BuddysMustang's Avatar
 
Joined: Nov 2014
Location: Brick
Posts: 59
 
G-Man, I need to raise the front wheels and climb under the car to see how big of a job it is to remove the cats. I haven't gotten any O2 Sensor codes since I have owned the car because I believe the engine needs to be brought up to operating temp before the O2 Sensors will begin to work and I have never had the engine run that long. It looks like someone tried to make repairs before I got the car but I did replace a valve cover breather hose. All other hoses seem OK. However, I was thinking about investigating the power brake vacuum assist hose to rule out a bad brake booster diaphragm.... What do you think about Tigers Theory? Do you have any ideas how to test the air flow through an engine that won't start?
BuddysMustang is offline  
PONY Member
 
gManTexas's Avatar
 
Joined: Mar 2015
Location: Austin
Posts: 702
 
Garage
IMHO, it takes a really large vacuum leak to get a no start condition. Normally you'll see a rough idle and get some codes related to secondary air systems or related to a particular sensor that uses vacuum for a signal or operation.

If your airbox is not damaged and the filter is not clogged, you should be getting air to the throttle body. What is happening at the throttle body is the question.

As for measuring vacuum, you need to have the engine running in order to measure the vacuum being generated by the engine.

Go ahead and run your compression test, just to rule that out.

There has to be something we are missing. Double check you spark plug wire routing and that they are on the proper cylinders from the coil pack. Remember 5 & 6 are reversed on the coil pack. See this guide for a photo:

http://1.cdn.lib.americanmuscle.com/files/50200.pdf

2011 Race Red GT vert, 5.0 A6
FRPP ProCal, JLT oil separator, Boss 302 quads w/ Corsa Xtreme axle backs, Koni STR.T (orange), GT500 strut mounts, Steeda Sports, Steeda billet LCAs, Steeda adj UCA, Steeda adj rear swaybar, BMR adj panhard, BMR lca relocation brackets, Boss 302 lower front fascia
gManTexas is offline  
post #89 of 115 (permalink) Old 06-26-2015 Thread Starter
Apprentice
 
BuddysMustang's Avatar
 
Joined: Nov 2014
Location: Brick
Posts: 59
 
G-Man, I understand your point about a vacuum leak would need to be huge to prevent starting. I'm looking for anything to try at this point. Remember your one post where you said I had the patience of a saint or something like that? Well it is running very thin by now. lol

The air box is damaged but it would not restrict air flow to the throttle body. Do you still suspect the throttle body? I had it off and cleaned it pretty good. What actually goes bad with a throttle body anyhow? It just looks like a block with air flowing though it and places where some sensors are mounted.

I also concur the engine needs to be running to do real vacuum diagnostics. This is where I was stumped.

I can check the spark plug wires for proper firing order. I never really considered this because when it fired up it ran smooth. However it is an easy check and I will do it tomorrow along with the compression test.

There must be a clue with the fact that the engine starts and runs for several seconds after it has sat idle for several days. Then nothing until it sits idle again. What does that. I thought the coil pack could be warming up and then disconnecting but the spark remains strong at each cylinder. The Noid lights show activity at the injectors and I know I have fuel pressure to the rails that remains rather constant at 52 psi. Tiger made a good point about flooding which would explain why starting fluid did absolutely nothing. What would fail after a very short heat-up cycle? I know your thinking PCU but this doesn't explain the systems that seem to work. I'm totally baffled. I even went to my local Ford Dealer the other day and described the issue and all or the troubleshooting that we have done and they said they would get back to me after they talked to their Mustang expert (30+years experience) and they have yet to contact me. It doesn't look like they are very anxious to get involved in this one. If I was a jerk off I would just sell the car and let someone else deal with it but I wouldn't feel right doing this to someone else. Well enough venting... SEE, I told you it was getting to me. lol
BuddysMustang is offline  
PONY Member
 
gManTexas's Avatar
 
Joined: Mar 2015
Location: Austin
Posts: 702
 
Garage
FWIW, maybe something in this thread:

https://www.allfordmustangs.com/forum...odule-bad.html

Also, check your smart junction box in the passenger kick panel. Maybe the inertial switch or a faulty relay.

Just thought of something. Could be an issue with you ECT sensor. If the sensor is reading the wrong engine coolant temperature, it could throw off your A/F ratios.

Take a look at this guide:

http://troubleshootmyvehicle.com/for...-temp-sensor-1


2011 Race Red GT vert, 5.0 A6
FRPP ProCal, JLT oil separator, Boss 302 quads w/ Corsa Xtreme axle backs, Koni STR.T (orange), GT500 strut mounts, Steeda Sports, Steeda billet LCAs, Steeda adj UCA, Steeda adj rear swaybar, BMR adj panhard, BMR lca relocation brackets, Boss 302 lower front fascia
gManTexas is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a VALID email address for yourself, otherwise you will not receive the necessary confirmation email needed to confirm, validate and activate your new AFM member account.

Failure to provide a VALID email address, will result in the cancellation of your new AFM member account registration.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
 


Search Engine Friendly URLs by vBSEO 3.6.1