Author Topic: Engine dies on hot starts (Read 6301 times)

flypenfly · « **on:** May 18, 2007, 12:27:22 PM »

On cold starts, it runs great, pulls strong, warms up quickly, stays cool.

If I turn the engine off, and then turn it on again without letting it cool off (say like a car wash), it stutters and coughs then dies UNLESS I give it a lot of gas.

So, it basically won't idle on hot restarts. It will drive ok if I keep giving it a lot of gas but sometimes still stuters. This lasts about 10-12 seconds after a hot restart, it seems to be fine after that.

Any ideas?

flypenfly · « **Reply #1 on:** May 21, 2007, 11:18:59 AM »

No ideas guys?

ecpreston · « **Reply #2 on:** May 21, 2007, 11:46:47 AM »

How many times has it done this? Was "like a car wash" a... car wash? Or does it do this also when you get gas or run into a store for a minute?

Have you checked ECU for any stored codes?

flypenfly · « **Reply #3 on:** May 21, 2007, 04:36:43 PM »

Haven't checked ECU but no lights have ever come on. It happens every time. By car wash I was just giving an example, sorry if it seemed confusing.

mbtech0 · « **Reply #4 on:** May 21, 2007, 08:28:51 PM »

I'm going to take a stab in the dark. Are you using premium fuel? You should be. If not, start doing so. It's not the octane, the Motronic will compensate, it's the additives in a good grade of premium fuel that helps to keep the injectors & valves clean, and free of carbon deposits. A bottle of Chevron Techron in a full tank of gas will help. Also, I'd replace the fuel filter, unless it's recent, and check the fuel pressure, the pumps failed on these now & then. Let us know.....I was going to buy your car, but you changed your mind, damn...I wanted a RED one, lol.

e9nine · « **Reply #5 on:** May 21, 2007, 08:37:05 PM »

I know this issue is related to fuel but have never really seen an ultimate solution or steps posted ever to completely get the issue taken care of.
I have experienced this issue on m20b25s and m42b18s to date.
Most often it happens when I have been driving and let the car sit for a while.
The worst time it ever happened was when I actually replaced the fuel pump in one of my m42s to a better one :confused:
Some say it's due to some gases in the fuel, others say it's due to the fuel filter or fuel pump, some say it's due to leaking injectors.
It's one of those things I have learnt to deal with and currently it's not to so bad as the car eventually cranks anyway :rolleyes:

thumper3ld · « **Reply #6 on:** May 22, 2007, 05:46:48 AM »

Quote from: e9nine;26272

I know this issue is related to fuel but have never really seen an ultimate solution or steps posted ever to completely get the issue taken care of.
I have experienced this issue on m20b25s and m42b18s to date.
Most often it happens when I have been driving and let the car sit for a while.
The worst time it ever happened was when I actually replaced the fuel pump in one of my m42s to a better one :confused:
Some say it's due to some gases in the fuel, others say it's due to the fuel filter or fuel pump, some say it's due to leaking injectors.
It's one of those things I have learnt to deal with and currently it's not to so bad as the car eventually cranks anyway :rolleyes:

I have this same issue and heards some where that it could be a bad o2 sensor. Not sure how or why but im pretty sure my o2 sensor needs to be changed anyway, so if someone knows which ford one i can use, i can try this out and let you know the results.

e9nine · « **Reply #7 on:** May 22, 2007, 07:54:04 AM »

I doubt the o2 sensor has anything to do with a hard cranking issue. I have used the generic and OEM sensors in the past...I personally prefer the OEM ones.

ecpreston · « **Reply #8 on:** May 22, 2007, 08:06:47 AM »

Sorry for having to be anal about the "car wash", I just wanted to make sure it wasn't really a water related thing!

I haven't had this car for very long, but I was under the impression it might have a stored code but not have the check engine light on. There's no reason for us to be guessing without that info first, just do the 5 pedal stomp thing and see.

Probably not the 02 sensor, the car should run just fine without it. And you would get a code if it were bad.

If the car runs great other than the first few seconds, I wouldn't think dirty injectors, fuel quality related stuff would be the issue either.

My GUESS would be a temp sensor, air or coolant, I don't yet know all the sensors on this car. And again, I would think the ECU would store a code. But the ECU is running in open loop when you first start the car, and if it's getting the wrong temp, it's miscalculating the mixture. Once you get moving, and it starts running fine, that's probably because it's gone to closed loop operation, running off the O2 sensor.

Idle issues are often due to vacuum leaks as well, so get a vacuum gauge and see if it's making what it should. They're cheap.

flypenfly · « **Reply #9 on:** May 22, 2007, 09:48:07 AM »

Thanks guys, I'll check the above. This is a pretty tricky thing to diagnose over the internet.

As for fuel, I've already run a bottle of techron and I'm only running premium.

e9nine · « **Reply #10 on:** May 22, 2007, 12:27:56 PM »

Quote from: flypenfly;26309

Thanks guys, I'll check the above. This is a pretty tricky thing to diagnose over the internet.

As for fuel, I've already run a bottle of techron and I'm only running premium.

Just to clarify: I didn't mean fuel quality per se - I meant "something with the fuel system."

thumper3ld · « **Reply #11 on:** May 22, 2007, 12:41:21 PM »

Quote from: e9nine;26302

I doubt the o2 sensor has anything to do with a hard cranking issue. I have used the generic and OEM sensors in the past...I personally prefer the OEM ones.

I dont believe its a hard cranking issue, the car starts up fine, however, it does seem like its not getting the right mixture. Almost like its getting too much fuel and flooding itself out. Once the car does cut out, it will start up fine and run normal, atleast mine does.

e9nine · « **Reply #12 on:** May 22, 2007, 01:20:54 PM »

..so this leads to either
(1) A case of not enough air. An AFM swap is an easy test for this or simply cleaning it or testing it.
(2) Excess fuel pressure due to a faulty FPR or fuel vapors not being getting rid off. We have a charcoal canister with the little valve thing on it. Perhaps a swap of this would help.
(3) Leaking injector seals could also cause this case that feels like "too much fuel" on start up especially if you notice black smoke. Rebuilt injectors are a remedy here.
:::::::::::::::Insert other options/tests here:::::::::::::::::::::::::::::

The 3 above steps are where I intend to look when I decide to try and tackle this issue someday.

flypenfly · « **Reply #13 on:** May 22, 2007, 01:53:55 PM »

Quote from: e9nine;26328

..so this leads to either
(1) A case of not enough air. An AFM swap is an easy test for this or simply cleaning it or testing it.
(2) Excess fuel pressure due to a faulty FPR or fuel vapors not being getting rid off. We have a charcoal canister with the little valve thing on it. Perhaps a swap of this would help.
(3) Leaking injector seals could also cause this case that feels like "too much fuel" on start up especially if you notice black smoke. Rebuilt injectors are a remedy here.
:::::::::::::::Insert other options/tests here:::::::::::::::::::::::::::::

The 3 above steps are where I intend to look when I decide to try and tackle this issue someday.

Wouldn't these affect the cold starts as well though? On a cold start, the car is perfectly happy and the engine purs (in a somewhat ticking way, hah).

e9nine · « **Reply #14 on:** May 22, 2007, 03:14:39 PM »

Quote from: flypenfly;26333

Wouldn't these affect the cold starts as well though? On a cold start, the car is perfectly happy and the engine purs (in a somewhat ticking way, hah).

Sometimes faulty components only show certain symptoms after prolonged use or sometimes or one component tries to compensate for the failure of another thus causing some of these odd things.

Like I said earlier - this isn't a guaranteed remedy and I haven't seen one to date. It might exist that we don't know of.

I am openly thinking solutions

and can wait till I find the golden solution (if ever) hence being hesitant to post in the beginning.