1994 Mustang extremely hard to start...

[Black88GTA]

1994 Ford Mustang, 3.8L V6
@105k miles (give or take)

My parents have this car at their house they want to either sell or give to my brother when his van dies. The problem is, it is EXTREMELY hard to start...to the point where it just cranks until it drains the battery. However, once it catches and runs, it drives perfectly. The next day, you go out to start it and it's the same thing as before.

It will crank all day long, and constantly sound like it's just about to catch, but doesn't. Last time we got it started, it took 1.5 hours of nearly constant cranking before it finally started. We jumped it with my mom's car after we drained the battery cranking it, and continued to crank it some more until it finally caught and ran. In the 5 - 10 minutes before it finally started, it was sounding more "eager" to catch...would fire on its own a few times, then quit, etc.

I'm thinking it has something to do with fuel delivery, but don't know what. Anyone have any ideas? Sorry if my description sucks, it's sort of hard to accurately put into words.

 

[angry hampster]

Well if you haven't burned out the starter already from that useless cranking, you should put a new fuel pump in it and clean the injectors. Checking the plugs wouldn't hurt either.


1.5 hours? Seriously?

 

[Black88GTA]

Originally posted by: angry hampster
Well if you haven't burned out the starter already from that useless cranking, you should put a new fuel pump in it and clean the injectors. Checking the plugs wouldn't hurt either.


1.5 hours? Seriously?

We took breaks Crank for a little bit, inspect for any weirdness / leaking, check to see everything is in place, crank a bit more, etc. It's not like I was sitting there with the key on for the full 90 minutes.

Normally I would have given up after ~20 minutes, but I was extremely motivated to get it running...since it was looking like it was the only car available that could get me to the airport the next day. I had to catch a flight home, and both of my parents were unavailable. Fortunately, I was able to get a ride so I didn't miss my plane, but still.

I'll do a fuel pressure test when I'm home next, and maybe run a can of Seafoam through the fuel system and try to clean it out some. I'd rather not tear the whole engine apart, since I can only be home a couple days at a time. I'll check the plugs while I'm there too. The reason I originally didn't suspect any of these things is because it runs perfectly once it's going.

 

[LTC8K6]

Try turning the key to on and then off at about a 3 second interval a few times, and on the last time, try to start it. About 3 seconds on, and one second off, each time.

This is to try to build fuel pressure. When you first turn the key on. the pump should run for a bit to prime the system. You should hear the pump running when you turn the key on. If necessary, get someone to listen near the gas cap.

If pressure is leaking down, hopefully the key on/off routine will build enough pressure.

 

[Black88GTA]

Originally posted by: LTC8K6
Try turning the key to on and then off at about a 3 second interval a few times, and on the last time, try to start it. About 3 seconds on, and one second off, each time.

This is to try to build fuel pressure. When you first turn the key on. the pump should run for a bit to prime the system. You should hear the pump running when you turn the key on. If necessary, get someone to listen near the gas cap.

If pressure is leaking down, hopefully the key on/off routine will build enough pressure.

Well, I had the same thought when I was home and messing with it...I did this a couple times, but it didn't seem to have any effect on getting it to start. I could hear the pump priming up when I did it though.

 

[cardiac]

Does it throw any check engine codes? Try and do the cheap stuff first. Clean the Idle Air Control valve (I would bet this is what is wrong), new fuel filter, etc.

Bob

 

[LTC8K6]

IAC usually doesn't affect starting though.

Back to the basics. Fuel and spark.

 

[Vetterin]

Have you tired starting it with the gas pedal pushed down to the floor? Also, when was the last time you replaced the fuel filter?

 

[bruceb]

Definitely a fuel pressure issue. Either the pump is not outputting the right pressure, the injectors are leaking when the engine is OFF or the Fuel Pressure regulator is bad. The pressure regulator is on the fuel rail and will have a vacuum line going to it. It is intended to not only regulate pressure while running, but also to keep the fuel rail pressurized when off, so the engine has fuel to start quickly. There is one other very slight possibility and that could be a bad or failing Crank Position Sensor (if the car uses one) which tells the Ignition when to fire based on where the crank & pistons are at. If it is not sending the correct signal to the engine computer, it will take longer to start (or not start at all)

 

[exdeath]

Does it start any differently depending on of it's already been running or not? Does it run fine under all conditions once it's started or do you have hesitation, stumbling, loss of power, etc? Has it ever suddenly died while running? Any codes or engine light?

Doubt it's a spark or fuel problem, as those would manifest while running too, especially during transitions (eg: from cruise to wide open). Look to the things that can affect initial start that don't affect running. Assuming fuel and spark are good, as the car can run fine once started, look to things that would cause an improper start environment (EGR, evap purge, temp sensor, etc). An engine can run with a slightly off mixture from these things and more often than not the computer can compensate and you'd never know save for the check engine light. But starting, esp cold, is another story.

Misc inputs to the computer such as oil pressure are also required before the computer will allow the engine to start, but which aren't considered once running.

A common issue is the FRPS (fuel rail pressure sensor) but that normally causes it to run like crap too.

 

[Black88GTA]

This car used to belong to my youngest brother, who didn't take the best care of it...and my parents also suck at the maintenance, so I would bet money that the fuel filter hasn't been replaced probably since we've owned it (maybe 4 - 5 years??). They took the car to some shop when the head gaskets went bad and had them replaced. This was done a couple years ago. I am assuming they did plugs at the same time (possibly fuel filter as well, but I doubt it).

No check engine light...didn't check for codes that may be stored that don't trip the light though. The car has been sitting around with nobody using it for a while...probably a couple years (maybe more), although it has been started and driven around every couple months at least during that time. When we were messing with it trying to get it going, I tried it without touching the pedal, and also with the pedal mashed to the floor. Cranking it with the pedal pushed down seemed to help a little, but I may have been imagining it.

This all took place in late December, when it was maybe 20 degrees out. I don't know how it behaves when it's warmer outside, as I'm not nearby to check it out.

It does behave very differently once it's been running. It seemed like it ran pretty good once we had it going - I didn't notice anything weird driveability wise. Never died or anything. Once the car was running and we had driven it around a bit, we could turn it off, come back a few minutes later, and it would fire right up. Come back the next morning, and it's back to its old tricks...so it makes sense that something may have gone bad causing fuel pressure to slowly bleed off over time. And if there is a leak somewhere in the fuel system, it would take lots of time to pressurize it enough to deliver enough fuel to the injectors to make it run...hence the hard starting?

I'm not sure about the temp sensors, EGR, etc...I wasn't really able to look closely enough at it when this was all going on, as it was nighttime and freezing outside when we were doing this. I'm not at all familiar with this car either, so I would have had to google for all of the component locations, and then figure out how to test them all.

 

[exdeath]

Originally posted by: Black88GTA
...This all took place in late December, when it was maybe 20 degrees out...

... Once the car was running and we had driven it around a bit, we could turn it off, come back a few minutes later, and it would fire right up. Come back the next morning, and it's back to its old tricks...

...as it was nighttime and freezing outside when we were doing this.

Those are symptoms of a faulty coolant temp sensor. The computer needs an accurate engine temperature reading to perform cold start enrichment, esp in that extreme cold.

Try pulling a plug out after it fails to start for a while. If it's cold starting properly there should be very strong fuel smell. If little to no fuel smell, then it's probably the coolant temp sensor.

Pull a vacuum hose off the intake and spray a bunch of carb cleaner in there and see if it starts easier.

And if there is a leak somewhere in the fuel system, it would take lots of time to pressurize it enough to deliver enough fuel to the injectors to make it run...hence the hard starting?

It takes seconds for the fuel system to pressurize. If there was a big enough leak to cause the starting problems you describe you would hear/see/smell fuel immediately. A ghetto way of checking fuel pressure without a gauge is with the key on, pull the fuel pump relay from under the hood where you can hear things and wait a few minutes. Plug it back in and you'll hear the fuel system pressurize for a second and feel the rubber hoses plump up. It sounds kind of like a toilet just as it shuts off.

Though again, if it was fuel or ignition related, you'd have driveability issues such as stumbling and random stalls.

 

[SparkyJJO]

I had a weird issue similar to that on my car. Fuel pressure regulator was bad. Dropping fuel pressure AND was leaking fuel into the vacuum lines, so trying to regain pressure was nearly impossible. Once it started it was OK, just getting it started wasn't fun.

 

[exdeath]

Originally posted by: SparkyJJO
I had a weird issue similar to that on my car. Fuel pressure regulator was bad. Dropping fuel pressure AND was leaking fuel into the vacuum lines, so trying to regain pressure was nearly impossible. Once it started it was OK, just getting it started wasn't fun.

You probably had starting problems even after shutting down while warm and restarting it a few minutes later right? OP only has start problems on the initial cold start and no other symptoms, it starts fine if the car has been running for a while and shut off recently.

 

[lsd]

You can pick up a fuel pressure gauge and inline tee @ jegs for about $30. I'd change the fuel filter too. Most engine coolant temp sensors are resistance based and you should be able to ohm out the ect to see if it's within spec.
Have you tried using starting fluid?

 

[SparkyJJO]

Originally posted by: exdeath

Originally posted by: SparkyJJO
I had a weird issue similar to that on my car. Fuel pressure regulator was bad. Dropping fuel pressure AND was leaking fuel into the vacuum lines, so trying to regain pressure was nearly impossible. Once it started it was OK, just getting it started wasn't fun.

You probably had starting problems even after shutting down while warm and restarting it a few minutes later right? OP only has start problems on the initial cold start and no other symptoms, it starts fine if the car has been running for a while and shut off recently.

No, once it was running for a bit and I'd shut it off a few minutes later it would start right back up. The fuel pressure would remain up for a little bit after it was shut off. It would take 30min + before it would be hard to get started again.

 

[LTC8K6]

Regulator failure does not necessarily mean fuel is leaking anywhere or that you'd smell any fuel, imo. There is a tank return line.

I would think one thing he could do is to leave the key on and see if the fuel pump cycles on and off fairly rapidly. If the system is not holding fuel rail pressure, then the pump will be cycling quickly instead of staying off for a while, won't it?

Normally it would pressurize and stay off, because the system usually holds pressure pretty well.

Then again, the coolant temp sensor is a cheap and easy try at curing the problem.

 

[SparkyJJO]

Mine leaked into the vac lines of the motor so there was no fuel smell.

The pump doesn't cycle. When you turn the key it just primes the pump a couple seconds and that's it until you start the motor (at which point the pump runs constantly). There isn't any feedback system to the pump on how much pressure there is at the motor.

 

[LTC8K6]

That's right, I have the same engine in my 1995 Taurus.

 

[Black88GTA]

Hmm, coolant temp sensor is a good idea. Hadn't thought a bad reading from that would screw things up so badly. I'll definitely check that out when I'm back next - looks like I'll have to do some research on the proper resistance values to look for.

I actually do have a fuel pressure gauge, just didn't have it with me at the time - I'll play around with that as well, and see if the rail holds pressure or bleeds down. I haven't tried starting fluid on it, as my parents aren't really "car people" and don't keep that stuff around. A bad regulator makes sense, since the internal diaphragm could have gone bad from sitting.

Looks like a coolant temperature sensor is ~$18 at Autozone, and a FPR is ~$55. Not too bad, if it's one of these.

 

[dirtyd1911]

so which one was it? I'm struggling with this issue RIGHT NOW! help dude!

 

[toronado97]

Super necro'd thread, but I had a 1995 Beretta doing the exact same stuff as mentioned in the OP, and it ended up being the fuel pump.