Help!!! 95Q45t turns off when coming to a stop.

[rubdog]

My 95 Q45t turns off when coming to a stop, It has been happening for the past week. So far it has turned off 3-4 times. No check engine ligths, but the car has been running little rought lately. A little history about the car, Had a tune up done about 4 months ago, oil change last month, Installed external transmission cooler about 4 months ago with new radiator, Replaced transmission oil. Any ideas what else can cause this, comments and ideas would really help! Thanks!

[maxnix]

What constituted the "tune up"? Intake path condition? Any maintenance? Clean IAC and EGR valve? TB?Filter (air and fuel) change interval? BG44K? Isoheet?

[Haitian_King]

My 95 Q45t turns off when coming to a stop, It has been happening for the past week. So far it has turned off 3-4 times. No check engine ligths, but the car has been running little rought lately. A little history about the car, Had a tune up done about 4 months ago, oil change last month, Installed external transmission cooler about 4 months ago with new radiator, Replaced transmission oil. Any ideas what else can cause this, comments and ideas would really help! Thanks!

I suspect MAF. Anyone else concur?

[elwesso]

As ANY PROPER diagnostician would do on a G50, you *****ALWAYS***** check fuel pressure before you start other things... Always assume its the fuel pump until you've triple checked yourself that its not the fuel pump.

People always refuse to believe that its the fuel pump until they've replaced every other component on the car.. Maybe not a bad plot to get people to replace a bunch of stuff and do everything.

[rubdog]

Thanks for the comments, As for the tune up I had changed the spark plugs cleaned the K & N intake filter, and replaced oil seals on both sides. As far as the EGR, MAF, and Fuel Pump I have not done anything them. What can I do to test each one of these?

[96Qowner]

As for the tune up I had changed the spark plugs ----> cleaned the K & N intake filter <----, and replaced oil seals on both sides. As far as the EGR, MAF, and Fuel Pump I have not done anything them. What can I do to test each one of these?

There's your problem - you got oil on the MAF element. Give it and its connector a good cleaning and go from there - free and easy.

http://www.q45.org/maf.html

K&N filters are notorious for messing up Q45 MAFs.

[maxnix]

And switch to the better and less expensive OEM paper one.

[rubdog]

Hey thanks alot just what I was looking for free and easy instructions. Thanks to everybody!

[GseaQ]

Hi rubdog,

Don't get excited just yet.

Wes has a valid point about the fuel pressure (pump).

I also have to suspect a faulty or leaking fuel injector.

The K&N oil on the MAF element sounds likely, but I've heard here that the engine should start and idle just fine with the MAF unplugged so I wonder why the engine would stall when at a stop - at which time it should idle without input from the MAF. Can somebody tell me this? Would unplugging the MAF and running the engine for a few minutes even in drive with the brakes on help diagnose?

Glenn

[96Qowner]

One of the symptoms of MAF trouble is stalling while coming to a stop - on decelleration. It won't stop while idling, but as you're coasting to a stop. It'll fire right back up and drive fine.

But yeah, could very well be an iffy fuel pump or something else. This is just a quick cheap thing to try.

[GseaQ]

Thanks for the clarification. I've never tried unplugging the MAF, just read that here somewhere.

[Haitian_King]

A quick and easy way to test a potential MAF connector issue is to wiggle it while idling. If there's a fluctuation in idle speed, it could be a loose connection or an opened pin that'll need recrimping.

There shouldn't be much play in a good MAF connection.

[slshearer]

Hi,

When I did my major service I also added the tran cooler and changed the oil for the transmission, I misread my levels and the tran was low which caused my engine to stall occasionally when I stopped, I adjusted the level to full and my car has never stalled since.

Just check the level of the transmission to make sure it is not that

Good Luck!

[96Qowner]

Yes, this has happened to others - if the fluid is low, the the transmission can lock up prematurely when coming to a stop and stall the engine. Thanks for posting it!