2000 GT Starting Problem

[Metalli485]

I have a stock 2000 Mustang GT with 90,000 miles. I can’t get the car started and I know that the fuel pump does not run when the key is first turned or while the engine is cranking (can’t hear the whining noise like usual). There is no pressure at the fuel rail when I try to start the engine. The problem started up about a month ago when the cold weather came through. It would take me a couple of extra cranks to get the car started and now it refuses to start at all. But when I could get it running, it would start right up instantly as long as the engine was semi warm. Right now it’s at a shop and I’m having doubts about their diagnosis.

The shop said they need to replace the fuel pump but couldn’t guarantee that it would fix the problem. I assumed that they did a poor job of troubleshooting and told them to not replace the pump. Right now it seems like the culprits could be PATS, PCM, CCRM, FPDM, inertia switch, fuel pump, bad ground or short, or the camshaft position sensor.

Another strange thing is during the past couple of months the tach would stay at zero for a second or two after the engine fired up and then functioned like normal. The tach used to move instantly when the engine started. Could this have anything to do with my fuel delivery problem (faulty electronics)? I hope I can get this issue solved soon as this is my only means of transportation and I work 20 miles from home. Thanks for the help!

 

[Metalli485]

I forgot to mention that the theft light stays on for a couple of seconds when I turn the key to on and then the light turns off. When I try to start the engine, the light turns on again for a second and then turns off. Doesn't look like PATS is acting up based on the theft light but I have read that the PATS system in my car allows the engine to crank but disables the fuel system.

 

[wmburns]

PM your email address and I will send you a Ford document on trouble shooting the PATS system. It is TOO large to post. It is written for the Ford tech and does assume some special tools. However, it does have some very good information.

The fact that the theft light comes on a 2nd time suggests there is something going on PATS related.

Other things that come to mind are leaky fuel injectors or fuel pump check valve allowing the fuel pressure to bleed down.

Try this. Cycle the key on/off several times without starting the car. Then try to start. If the condition improves, suspect fuel pressure leak down.

Then there is the fuel filter and/or trash in the fuel tank angle.

A bad crank shaft position sensor (CKP) could cause a no start. However, one would expect them to be much worse as the CKP is vital to the engine running (DTC likely to result).

A bad/dirty MAF can cause all kinds of problems. At the very least, clean the MAF to rule it out.

A bad IAC can cause a no start condition. Try cracking the throttle. If it starts, then suspect IAC. However, this is not likely in this case.

IMO, the best way to diagnose a FP problem is by monitoring the fuel pressure with an ODB2 scanner. For the Mustang, the fuel pressure should be in the 38-42 PSI range. I just don't think it is possible that a bad FP won't show up as a decrease in fuel pressure.

For this to be a power related issue (CCRM/Fuse), then one would suspect no power at the FPRM all of the time. The power to the FPRM is NOT cycled. The FPRM has power anytime the key is on. Once power has been verifed to the FPRM, suggest looking elsewhere.

A noid light can be used to verify that the injectors are firing. Also check the COP to see if firing. If both are firing, then not a PATS problem. Suspect fuel pump problem (or other problem).

The Speedo on my 2000 has stopped reading once for an unknown reason. The PCM communicates with the cluster via SCP commands sent over a private LAN network. The car speed and tach is received via SCP commands. Perhaps the PCM was busy process other things. Maybe it is a problem. I am not really sure.

 

[Metalli485]

Wow thanks for all the info. PM sent.

Try this. Cycle the key on/off several times without starting the car. Then try to start. If the condition improves, suspect fuel pressure leak down.

I tried that on Friday with no signs of improvement. I cycled the key on and off at least 10 times and I didn't hear the fuel pump make a peep. I also accessed the schrader valve on the fuel rail and there was absolutely no pressure in the fuel system.

A bad IAC can cause a no start condition. Try cracking the throttle. If it starts, then suspect IAC. However, this is not likely in this case.

I tried giving it some throttle without any improvement as well. Actually I replaced the IAC just a couple of months ago since my old one bit the dust.

 

[Metalli485]

Today I got a more experienced mechanic to diagnose the problem. He said that he is indeed seeing 12 volts at the inertia switch and didn't note any problems with the switch itself. Please correct me if I'm wrong but if he's seeing 12 volts at the inertia switch than that should rule out any problems with the PATS, PCM, CCRM or FPDM.

Assuming the wiring between the inertia switch and fuel pump isn't causing the problem, it looks like my fuel pump may be the problem after all. Seems simple enough that the pump is bad if it doesn't turn on when it gets power.

I looked over the PATS document but I couldn't figure out if the PATS system (2000 model year) disables power to the fuel pump. I would think that a PATS issue would result in 0 volts at the inertia switch.

 

[wmburns]

Today I got a more experienced mechanic to diagnose the problem. He said that he is indeed seeing 12 volts at the inertia switch and didn't note any problems with the switch itself. Please correct me if I'm wrong but if he's seeing 12 volts at the inertia switch than that should rule out any problems with the PATS, PCM, CCRM or FPDM.

Assuming the wiring between the inertia switch and fuel pump isn't causing the problem, it looks like my fuel pump may be the problem after all. Seems simple enough that the pump is bad if it doesn't turn on when it gets power.

I looked over the PATS document but I couldn't figure out if the PATS system (2000 model year) disables power to the fuel pump. I would think that a PATS issue would result in 0 volts at the inertia switch.

For the 1999-2004, when PATS is activated, the PCM disables the fuel and spark. It does so by not sending commands to the FPRM to allow the fuel pump to start/run. For the spark, the PCM simply does not activate any COP's. The same for the fuel injectors. The PCM does not command any to fire.

There is always 12 volts to the FPRM when ever the key is in the on position. The power does not pulse. Remember, the PCM sends commands to the FPRM and it is the FPRM that acts upon those commands to get the requested fuel pressure. So having 12v at the IFS only proves the Fuse and CCRM. Nothing else.

Your problem may turn out to be the fuel pump. But based on the information above, a PATS problem has NOT been ruled out.

Suggest putting a noid light on the fuel injectors and COP. If PATS has indeed disabled the fuel/spark, the noid light will not flash. If the light flashes, then PATS is not causing the no-start.

 

[Metalli485]

My mechanic verified the injectors and COP are working. Crossed my fingers and decided to replace the fuel pump.

The Mustang is alive again!!!

I was one of the few people who actually had a bad fuel pump instead of an electrical problem. Thanks to wmburns for all the helpful info.

 

[trombonedemon]

Yea WM Burns, I honestly enjoy reading your posts! Sweet, your actually more helpful than my manual!

 

[Metalli485]

I had a shop replace my fuel pump a week ago and everything looked good until I filled up my gas tank a couple of days ago. I keep my car parked in the garage and overnight it makes the garage smell like gas. I’ve checked under the tank several times and there is never a drop of gas on the ground. They replaced the filler neck gasket so I don’t think its leaking there. I would expect to see gas on the ground if it was leaking at the filler neck gasket.

When I picked up my car last week the fuel level was at 3/4 full and I never noticed any gas smell until I fueled up again several days later. It’s not strong enough to smell inside the car while I’m driving it so it must be a small leak. Any ideas of where the tank might be leaking? I’m stumped since I never see any gas on the ground.

 

[wmburns]

Fuel pump O-ring to tank gasket? Was a new tank/pump O-ring used?

I got hit up by this one myself (not a Mustang). The O-ring was too big but I forced it anyway. The O-ring folded up when the fuel pump ring was tightened up. Everything looked just great until the first fill up. Gas came out of the top of the tank and onto the ground.

I am not sure if exactly the same thing would happen the same way on a Mustang.

If not the tank O-ring, then there are several vent and vapor lines on top of the gas tank that the mechanic may not have installed correctly.

I have found that sometimes the vapor line quick disconnects are fragle on older Fords. The connectors release OK, but the tiny O-ring inside sticks to the male connector. This results in the O-ring being pushed back on the male end. Of course it does not seal as designed.

A smoke test would nail this down. However, that is out of the reach of the home mechanic. Since you paid for the work, suggest that you go back to the mechanic that did the work.

 

[Metalli485]

Yeah its very possible that they didn't replace the o-ring between the fuel pump and tank. The gas is probably sloshing around when I drive and pooling up on top of the tank.

I'm taking it back to the shop for sure to get this fixed.

 

[hotdog71]

Hi,

I had the fuel pump gasket thing happen to my Ford Focus when i lived in the UK it was Ford dealer over there that did the work and put on wrong gasket, of course we didn't find out until about a week later when we had filled up and parked the car and smelled fuel and look under the car and it was dipping out. So I pulled up the back seat and there was fuel around the pump and tank.

Good luck!