engine shutting off still....did a few things, any ideas guys?

[djomlas]

it started just randomly shutting off, took it to a shop and they diagnosed it to be a MAF. fine...

they wanted some outrageous price so i said forget it and ordered one from autohausaz and 2 days ago installed it, while i was at it i recharged the k&n filter, let it dry overnight, then disconnected the battery for 10 minutes or so to reset the ECU.

car turns right on, runs and idels nice.

drives fine too...unless, right as im about to stop, while the car is still moving rather fast, i push the clutch in and take it out of gear, and break......shuts right off...

unless im braking and just reving it it doesnt shut off. or if im going pretty slow, it stays on.

weird, that its affected by speed...maybe something inside the tank? i dunno

so far then the filter has been changed, new fuel filter put on as well, and cleaned MAF.

would cleaning the throttle body or something around there do anything??

any help is appreciated guys

[Loren]

What happens if you disconnect (unplug) the MAF?

[djomlas]

have not checked that. I replaced it when i was told by the shop that it was faulty and throwing codes pointing all over to it according to them.

I will try that when i get back home

[djomlas]

BTW Loren, you talking about unscrewing the MAF itself, or disconnecting the electrical part from the top of it?

[Loren]

BTW Loren, you talking about unscrewing the MAF itself, or disconnecting the electrical part from the top of it?

Just unplug the electrical connector.

The car will rev rough above 4500 RPM but that should not be needed for this test.

[djomlas]

ok, ill be home later on tinight and try it.

what will this test figure out? if the MAF is faulty? or?

[Loren]

If it still does happen when the MAF is disconnected then the cause can not be the MAF.

[djomlas]

gotya.

then i will disconnect it and take it for a spin and see what happens.

[phillipj]

Loren,

He says it shuts off when he pushes in the clutch to come to a stop....Could it be his clutch pedal switch? Is that possible?

[Loren]

The clutch switch is a start inhibit at the DME - I don't think it would affect a started car.

[beauar]

could it be a bad fuel pump? seems that the pump might not be pulling gas properly to feed the engine

[djomlas]

i opened the cover to unplug the MAF and noticed that those clamps on rubber boots were reallllly loose on one side, tightened them up and it runs much better. seems to be a bit of vacum leak

i only drove it for alittle bit and it seems to be much better.

will report tomorrow after a drive to work.

BTW, when i unplug the MAF, the car jsut shuts right off....

[wvicary]

A good practice is to only disconnect electrical components when the ignition key is off, reduces the risk of damage to ECU's.

[djomlas]

heres a quick pic of the parts (fasteners) that were loose (circled in red, actually they on the other side, but still hehe)

i hope the pic shows up, i usually use tinypic but im at work and cant so i uploaded it

Edited June 10, 2009 by djomlas

[djomlas]

drove it all the way to work and back, not one time did it turn off or hesitate.

of course, once i got home and was pulling into the driveway, it turned off again... grrrr

[djomlas]

yup, so it seems to be still shutting off once in a while randomly...

only kinda corelation i can see is that its always once i have the clutch in and out of gear or ready to put it in the gear from another higher gear...

dont know if that matters...

anyone?

[ericinboca]

yup, so it seems to be still shutting off once in a while randomly...

only kinda corelation i can see is that its always once i have the clutch in and out of gear or ready to put it in the gear from another higher gear...

dont know if that matters...

anyone?

Have you gone back and looked closely at the collars on the air distributor tubes? Those collars are hard to get in the right place. I liked the vaccum leak theory - if you had a loose clamp, I wonder if the collars are fully seated. You have to feel around the edges, pushing at them to be be sure.

[djomlas]

i did. looks all good.

took the intake off and cleaned the throttle body good, WOW was that thing dirty.

idle calmed down right away, and ran fine.

since its so random when it turns off, ill have to drive around some more and see if it shuts off, drove for 25 or so miles and it was fine.

could that have solved it?

[ericinboca]

i did. looks all good.

took the intake off and cleaned the throttle body good, WOW was that thing dirty.

idle calmed down right away, and ran fine.

since its so random when it turns off, ill have to drive around some more and see if it shuts off, drove for 25 or so miles and it was fine.

could that have solved it?

I've not had a dirty throttle body problem on my 986, but I've seen many posts on them. It does seem to cause idle problems....and maybe when you press the clutch, pop out of gear, and let the RPMs drop down the idle speed, it shuts off like an idle problem.

I gather no check engine lights? You can, as you know, get fault codes without a check engine light though. Do you have a Durametric to check to see if it has triggered any codes?

And after it shuts off, does it start right back up?

I would not do anything else to it right now because we will just confuse ourselves by adding more variables. Having said that, I would look at the air cleaner, be sure it is clean.

Keep posting - interested in this one.

[djomlas]

thanks man,

yes, once it shuts off, all the lights come on, i turn the key as it rolls, and starts right up.

air intake and filter are clean.

so, as of now i will drive it like this and hope it doesnt turn off again, if it does we will go more into it some more and look around.

i looked under the AOS to see if theres anything loose or broken/torn, and couldnt see anything.

But, it is greasy and oily around there all over, not sure what to look at and check where the stuff is coming from...

[RFM]

djomlas

Have you already removed and cleaned the idle valve on the left side of the throttle body? (non E-gas system, as showed on your pic.)

[djomlas]

no i havent.

what is this part that you speak of?

[RFM]

The black plastic unit on the throttle body left side, as shown in the pic. you have posted above.

[djomlas]

the long black tube?

that part was loose when i bought the car, and i cleaned that part at that time, and havent touched it since. its kind of a pain in the ... to take off...

if this is even the part that you are referring to...

[RFM]

That's strange, it's a part of the throttle body (bolted on with two small bolts) and delivered as a unit. The part is approx. square and black.