Erratic rough starts...

[ryan97cobra]

Every once in a while when i start my car for the first time in the morning it will run really really rough and chug along for a couple minutes while i let it warm up. It will clear up after a couple minutes idling or if i start down the road it clears up even quicker. Plugs are less than 6 months old and have been changed 3 times in the 2.5 years ive owned it, however the plug wires have never been changed while ive owned it so im thinking that is the best place to start just don't want to drop the $$ if its not necessary. Fuel filter was changed sometime in the last 10k miles don't remember exactly when. I have had an oil separator on the car for some time, and i seafoam the motor every time i change the oil, about every 4-5 months. I also just last fall did a very thorough injector cleaning.

The car runs fantastic 99% of the time except when it does this weird starting miss.

Any ideas?

 

[Tx_Diablous]

Any patterns....like temp below x....or it sat for y number of days? Could be something like a low bat....or a temp sensor that does not read right below 50 or something....Think of any patterns you can think of it might help.

 

[SNAKEYE]

How many miles/years since the plug wires were changed?

 

[03bluemach]

on my mach this would happen .. a friend told me to change the fuel filter and it made a world of a diff.. no problems with the 97 so far like that ,, give it a try

 

[03bluemach]

lol sorry didnt see you changed it

 

[ryan97cobra]

Any patterns....like temp below x....or it sat for y number of days? Could be something like a low bat....or a temp sensor that does not read right below 50 or something....Think of any patterns you can think of it might help.

The longer it sits the larger the chance it has of doing this, it did it to me this morning(monday) and it sat all day in the garage sunday without being started.

How many miles/years since the plug wires were changed?

it has been at least the 2.5 years since they have been changed i have no idea how many before that, and ive put a little under ~20k miles on it the time ive owned it.


It used to blow some gray smoke on start i believe a very very rich tip in when it was started, because it uses no oil except the very small amount i dump out of the oil separator every 2 weeks. Also i had someone follow me during the day and i got on it to ~7k rpms and it doesn't smoke at all at WOT. The motor only has 40k miles on it, it was a new ford stock crate motor at 98k miles and it has 138k now.

 

[tt54l32v]

just a guess but kinda sounds like a sticky injector, do a fuel pressure test and then shut the motor down and see how long it holds pressure. and pull the plugs and see if one looks any diff from the rest kinda gray and dirty looking, if so that is the problem cylinder.

 

[RoadZOmbie]

FPR maybe?:shrug:

 

[ryan97cobra]

just a guess but kinda sounds like a sticky injector, do a fuel pressure test and then shut the motor down and see how long it holds pressure. and pull the plugs and see if one looks any diff from the rest kinda gray and dirty looking, if so that is the problem cylinder.

I am going to pull the plugs this weekend and replace them, and ill look and see if any of them look funny. Im also going to make another batch of the intense injector cleaner, and run that through. I will probably also order some 9mm Ford wires since it has been so long since they have been replaced. I may also clean the MAF, and IAC.