Ford Mustang Forum banner

2001 Ford Mustang v6 stalling when coasting or sometimes braking

4566 Views 7 Replies 2 Participants Last post by  WhiteSnake91
I received a 2001 Ford Mustang v6 with true dual exhaust (sounds nice ;D) in a trade about a week ago but recently have had some trouble with it stalling....first noticed it the other day when I was leaving my house to go to the court house to get the title officially in my name, stopped by the local garage to get a fuel pressure test and they did it and the man told me the fuel pressure isn't low, it's erratic going up and down which is puzzling to me.

I've done my share of reading, although I'm new to cars. I'd really like to get this thing in tip top shape. I've ordered brand new all Motorcraft brand spark plugs, spark plug wires, and ignition coil which are set to come this week. In an older forum post, a man had the same problem with the stalling/hesitation and replacing the ignition coil fixed it for him so hopefully it's an easy fix.

I replaced the fuel filter the other day but that didn't fix the stalling issue sadly, I don't think it had ever been changed before, was very hard to get off like it was almost bonded on, but after an entire afternoon of messing with it, I got it off and replaced it.

I need to solder the instrument cluster to get the odometer to work, it's sporadic, but I've already watched how to do that, and I need to get a new light bulb for the cluster since the check engine light doesn't light up at all. I have several codes I got when I scanned it with my scanner last night. Last night when going to the store and finding a parking space when coasting and braking at a turn in the parking lot, the car acted like it was about to stall again but didn't truly die, but the gas pedal did nothing even pressed down firmly, it sort of sputtered then surged ahead and I had to brake quickly and I parked it. When I was done at the store it cranked right back up though. The problem seems to be when coasting/braking...I saw how to put a fuel pump in, I heard Delphi is a really good brand especially considering the price. I just personally dread dropping the gas tank since getting the fuel filter off the other day took so long.

codes I have: p1233, p1131, p1151. The p1131 and p1151 are for both front o2 sensors, I'm thinking maybe it's just tied to the bad fuel pump, I don't have ANY history on the car so I don't even know if it's been changed before or if it's even the original motor/tranny, the ODO reads ~244k, a little high for a 2001 model, but it actually drives fine, appears to still have a good strong engine and transmission. My gas milage, is, okish. Not gas guzzling, but not the ~17mpg/25mpg highway the online specs say it should have. I'm not sure how much MPG the dual exhaust is supposed to increase it by, I know roughly in trucks it's supposed to give about maybe 4mpg more. So optimally with the dual exhaust I'd get about 21 city and 30 highway. Somebody can correct me on this, I mean again, I admit, I'm new to vehicles PERIOD, but I've done alot of reading/watching videos.

what I'm going to replace this week, all spark plugs, spark plug wires, ignition coil...all OEM Ford Motorcraft brand

What I think is bad: The fuel pump. Although my dad, and from reading up on it, both say if the fuel pump is bad the car will be hard to crank, which isn't true, it always starts right up, one or two times it's taken a second or 2 longer to crank, but it's always cranked right up. Battery says it was made in 9-15 on it, so not even a year old, oil doesn't look bad, the radiator reservior or hose has a small leak if I fill it too high, I'll be looking into fixing that sometime.

what could possible be bad:eek:ld worn out spark plugs, spark plug wires, ignition coil. I have no idea how many miles/how old they are sadly. The IAC could be bad, MAF could be dirty, Fuel Pressure Regulator on the fuel rail could be bad, fuel pump driver module in the trunk could be bad, fuel pump relay could be bad, or obviously again, the fuel pump. But you'd figure if the fuel pump was bad it wouldn't always crank right up and the pressure would be ok would it? The mechanic just said the pressure was erratic like going up and down.

If it IS the fuel pump, it's not the end of the world. I'd just like to not spend a bunch of money on one and that not be the right problem, I live on a tight budget and would feel very sad to throw money on parts I know wouldn't fix it. It did need a tune up the man I got it from said, and reading about ignition problems causing stalling also made me order the Motorcraft spark plugs,wire, and ignition coil.

Hope I was fairly descriptive with the problem and what I've researched on and what I think is the problem or what could be the problem. Thank you for any help.

also another quick question, it's not DIRE but is very annoying...I think the seat belt sensor in my seat is bad too, it's plugged in, I'm always paranoid about having my seatbelt on (which isn't a bad thing...), but, the dashboard light stays on and keeps BEEPING every so often, very annoying...just started doing that last night. Is there anyway to stop it...? Spray cleaner in the seat belt buckle?
See less See more
Not open for further replies.
1 - 3 of 8 Posts
You may not believe this but the stalling problem COULD be something as simple as a bad battery or loose battery cable. Recommend having the battery and alternator tested. Double check that the battery terminals are clean and tight. Pay special attention to the battery negative as it's bad about splitting when over tightened. Also check the grounds around the radiator core support.

Bottom line. Today's cars simply will not run right without a STRONG battery and charging system. Cut corners here at your own risk!

Double check that the fuel rail pressure sensor (FRPS) intake vacuum reference line is connected and leak free. Inspect the line for evidence of raw gas. If any is found replace the FRPS.

OBTW, IF this is a fuel pump problem it HAS to show up in the fuel pressure. If you want to avoid replacing parts that aren't needed, MEASURE the fuel pressure.
See less See more
A couple of things. The Mustang's oil sender is a simple on/off switch. It closes when the oil pressure is above 5-6 PSI (yes that's right). That means the dash gauge is a glorified idiot light. The position of the needle has no bearing on the amount of oil pressure.

The cluster volt meter does change with voltage. However it's not very accurate and is TERRIBLE to use for trouble shooting. I can confirm from personal experience that the volt meter doesn't move very much at all even with a failed alternator.

Lamp test. ALL of the cluster lights are programmed to turn on at initial key on. This is a lamp test to help you confirm the lamp actually works. So the fact the battery light comes on at initial key on does not mean there's a problem.

There is a ground behind the center console that is shared by multiple devices including the cluster and radio. It's sometimes messed up during a radio install. However I doubt this is your problem unless the ground connection is intermittent.

As almost every auto parts store will test batteries and alternators for free, there really isn't an excuse not to get a proper battery/alternator test. Then you can move on to additional trouble shooting with the knowledge that your problem isn't charging system related.

EDIT: I see that you did find a bad battery. Now you can go back and re-check all symptoms and go from there. If the new battery resolves the stalling problem, please update the thread so that others can benefit. There still are TONS of people out there that don't believe a bad battery can cause stalling AFTER the motor is started.
See less See more
Don't ignore any vacuum leaks as they could also be the source of the problem.

Would also be handy to know what the fuel pressure is.
1 - 3 of 8 Posts
Not open for further replies.