running lean codes and stalling
 

as it says i have had my cel on for months with the code of running lean both banks and if you step on it quick and let off quick it stall w/o fail i had to break quickly in an intersection and it stalled which i have never had happen till last week some one said it might be my dpfe, i pulled it and there was corosion on the ports but didn't replace it. I have also replaced the tps and iac.
also my transmission shifts hard from 1st to 2nd don't know if its related or if its due to my x-cal. And some times after stalling it wont start right up and i have to give it gas to get it to start.
thanks

EDIT: i also checked for vacuum leaks and came up empty handed i also intentionally made a vacuum leak and tried starting fluid and propane and didn't get any response so ......

What year truck? Running lean and stalling in those situation point to vacuum leak.

its a 97 , but like i said i cant even get an rpm response with making an intentonal leak and i tested all the vacuum lines, im not saying its not a vacuum leak i have no way of testing it

OHV's were known for the intake manifold gaskets to leak, if you could get some carb cleaner sprayed around the engine's valley, that would help confirm.

you mean while it running spray it ? is this a pain to replace the gasket?

i tried spraying carb cleaner 2 times and nothing i even raised the rps to create more vac. and still nothing, also when you let off the gas from high rpms it slows down very quickly almost like there is a break on the crank shaft or something, or even excessive back pressure maybe? (this is in park not drive).

i replaced just about everything that could make it do that then i learned about that and then i replaced it and it sure enough worked, it depends how experienced you are, you have to take the power steering pump and its holder out as well as move the serpentine belt to along with the actual intake manifold but after that its easy lol

OK I'm down to two things aether the intake gasket/ fuel rail or the Iac which i replaced over a year ago but I've had stuff go like that.
I've read lots of other articles with the same problems which leads me to the two
Alex i take it your talking about the intake gasket , i think the 98's and up are a little different on the top.

Edit: also about 2 years ago just before i bought the truck the kid put new heads on the motor wich would involve new intake gaskets right? do you think the gasket could be bad already?

The fuel supply manifold gasket on the '97 OHV is for some reason especially prone to failure.

https://www.ranger-forums.com/forum2...84&postcount=3

hmmmm looks like a good possibility is this a hard fix? ill have to look at it tomorrow. thanks

It's not that difficult a repair. You have to remove the upper intake. Then you'll need a size E7 reverse torx socket to remove the studs that secure the fuel supply manifold to the lower intake.

Keep in mind that, when pulling the fuel supply manifold, you will also be pulling out the fuel injectors with it.

This should help you out, especially the part at the end that covers the fuel supply manifold gasket: REPLACING UPPER ENGINE GASKETS ON THE FORD 4.0L OHV

You should replace the upper intake gaskets while you are at it.

I know the '97s had a lot of problems with the intake, but I have been throwing the same codes for years (on and off) and I can't figure out why. The last time it has been happening, I finally replaced the MAF and the codes were gone for 8+ months then just recently came back on. I have never found a vaccuum leak either, so who knows.

My gas mileage has been dropping slowly, and is at about 11.7 mpg.

I don't mean to steal your thread, I have started a couple on this topic but it's hard to diagnose and resolve over the internet.

If it's not your intake gasket, check your MAF.

yeah i was going to go to ford and get the intake gasket and the fuel rail gasket and i might do my valve cover gasket too hopefually one will fix it.
yes i also noticed my gas mileage dropping from about 18 to now 15 mpg

all right im down to the fuel rail and i cant get it off i know the injectors have to come off but how? the plate is free and moving but i cant pull it up!

Try and work the injectors free of the lower intake by twisting while pulling gently at the same time.

all right i got it now im trying to put the upper intake back on and the egr pipe that goes into to it is a pain when lining up the bolt holes

well good and bad news good news is it runs ... the same bad news it still stalls :(
im stumped

There are settings within the tune that are called "dashpot". They tune how quickly the engine will decelerate. I'm pretty sure this controls only the IAC. It basicly controls the engine deceleration rate by controlling how quickly the IAC valve returns to its home position (not fully closed at idle).

I wonder if your IAC is clean and working properly?

Rich

i replaced it over a year ago maybe its bad ill have to go take it off and look.
... maybe its got a warranty lol

lol nah they usually go around 120,000

ok guys i did the upper intake gasket not the lower one seamed to help and no more codes untill 2 days ago the code came back (only one bank forgot which one ) and it still stalls when you hit the gas quick and let off i checked the vacuum lines, and nothing ive been reading its eather the o2 sensor or the lower intake gasket or possibly valve gasket?
and has a low idle and some times loops. i checked many times with carb cleaner and propane and no response.

bump
any one have any input i would like to do this this weekend and i need to order the gaskets soon to have then by saturday
and the code came back today, bank 2

My 97 Explorer (same engine) had bad upper intake manifold gaskets a little over 100k miles.
Threw the same codes, both banks lean. It only had a problem when it was cold, which led me to believe the rubber gaskets were getting weak, and expanding when they warmed up (sealing up properly). I replaced the upper gaskets like you, and it cured the problem. But I have heard many others who needed to replace the lower gasket... May have a bad one like this.
http://www.explorerforum.com/forums/...1&d=1180925125

Sorry I can't help any more than that though. I think I got lucky with the explorer, I hate trying to track that stuff down.

well went ahead and got the lower one and valve cover gaskets and toor every thing off yesterday and now im cleaning everything and painting it .
the lower manifold was loose and on the gasket you could see where it was rattling around i hope this is the problem
now as for that dang egr tube, can i cut the curved piece that goes into the intake off ? i dont see why not.

awwwww crap
 

well its all back toghter and runs good but still stalls when in gear and give it gas quick , also while in drive with my foot on the brake a reved it up and let off and the rpms where bouncing and wanted to die and kept going till i put in natural. so should i change the iac again.
im going to let is cool down and re tighten the manifold bolts maybe that's it.