Intermittent Stalling

burnopoly · #1 01-06-2005, 07:44 PM

My T-Bird has developed a new problem that confuses both me and the service station. Sometimes it will stall on me a short distance after a I start the car and I will have to wait a minute or so before it will restart. It has happened 4 times so far and always in a parking lot. The last time it happened two times in succession but I gave it less time before I started it again on that occasion. I have had a complete diagnostic run and the problem could not be duplicated by the mechanic.

My uncle suggested vapor lock and the mechanic thought it was possible (after I explained that it takes a long time for the temperature guage to warm up) that a sticking thermostat could be somehow related. So I looked up vapor lock for connections with the thermostat and there does seem to be one. I just want to know if that sounds like a plausable explanation before I go and have the thermostat replaced. I really like driving this car when it runs and it would be a shame to have to offload it for something more reliable that I hate driving.

RickwithaTbird · #2 01-06-2005, 08:36 PM

I'm not engine savvy, so I dont know, but I can tell you this... the thermostat is about 5 bucks, and you can replace it in less than an hour if you suck. If youre good, you could probably have it done in 10 minutes. It took me about an hour. And I only spilled a few drops of coolant, and re used the rest. Oh yeah, remember to replace the white coolant drain cap before you start the engine. If youre stupid like me, you'll leave it off and start the car, only to see your engine imitate old faithful. (I didnt catch all the coolant that time lol)

J_ROC812004 · #3 01-08-2005, 07:56 AM

lol at rick for an hour i changed mine in about 15

flewthecoupe · #4 01-08-2005, 11:04 AM

Make sure your cooling system is full of coolant. Don't look at the overflow bottle, take the radiator cap off when the engine is cool. If you are too low on coolant, what you described can happen.

burnopoly · #5 01-08-2005, 03:24 PM

I know its not low on coolant, I just had the cooling system refilled. I imagine however that a thermostat that is stuck closed could starve the system of coolant. The problem has been occurring both before and after I changed the coolant. I was reading something about changing fuel as a possible way to stop vapor lock. Can't recall if I had just gotten fuel before the problem started though.

solaris=amazing · #6 01-09-2005, 01:32 AM

Hmmm.. Does it happen when you go from Park to Reverse.. The second your wheels spin, you stall..?? Or even from Park to Drive.. As soon as you move, you stall..?

If it does do what i described, i got news, it's your MAF sensor (mass air flow sensor). It might me dirty, or more likely putting out low voltage-mixing up all the air/fuel ratio's etc.

My maf sensor is coming in the mail, from www.directauto.com, that is the culprit of my 95 .46 v8 stalling.

solaris=amazing · #7 01-09-2005, 01:33 AM

BTW, i do believe the maf sensor would have came up on the check they did, but go to Autozone and have them scan it also, to see whats up.

burnopoly · #8 01-09-2005, 02:11 AM

Yeah they did check the MAF but I guess it couldn't hurt to have it checked elswhere too. However, as I understand it and from what the machanic said, running it for codes is useless unless the check engine light is on and in my case it isn't.
It seems to be doing it up to a hundred yards or so after I start moving. It's definately not immediate and some days I can drive it and have no problems. Anyway, I will be replacing the thermostat next weekend and we'll see how it goes. In the meantime I have to get a new job since the unreliability of this car caused me to lose my last one

RickwithaTbird · #9 01-09-2005, 02:15 AM

damn im sorry to hear that about your job. I hope you find one soon.

flewthecoupe · #10 01-09-2005, 08:58 AM

The CEL does not have to be on for you to pull codes. Hard codes turn the light on. Soft and intermittant codes do not. So, it is not useless.

Quote:

I imagine however that a thermostat that is stuck closed could starve the system of coolant.

A thermostat stuck closed will allow the engine to warm up normally but cause the engine to overheat because there is no circulation of coolant. If the t-stat is stuck open it will cause the engine to warm up much more slowly because the water pump is constantly circulating fluid and the engine is trying to warm all of the coolant at once. When a t-stat is closed there is no circulation of coolant through the engine. The engine warms up the coolant in the block and as the coolant in the block gets warm, around 185*, the temp of the coolant will start to open the t-stat and allow coolant to flow. The t-stat is a variable valve that allows just enough coolant through to keep engine temps normal.
Vapor lock is quite rare on fuel injected cars. If it is vapor locking it is because something (your engine) is getting way too hot and the fuel is boiling. The fuel is under much more pressure than on an old carbureted system that is running at 3-5psi and is much harder for it to turn to vapor. Not saying it couldn't happen, but not likely.

burnopoly · #11 01-17-2005, 02:07 AM

Update:

I have replaced the thermostat and it now warms up normaly. Not sure if that solves the stalling problem but at least I know it wasn't a waste of time to replace it. The old thermostat didn't seem to open nearly as wide as the new one and it was installed off center. I will have to drive it a while and see if the stalling returns. I also get heat now from the climate control so no more freezing my ass off.

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