Starts, idles for 2 seconds, then dies / Bad o2 Sensor?

[iguanahotsauce]

I have been reading through pages and pages of different threads trying to figure out my problems. I am currently getting about 15.5mpg and I only boost a few times a tank. At first I figured it was because I was working on the car a lot and letting it idle a lot. But now I'm on my third tank of gas and I have 125 miles at half way in between 1/4 and 1/2. When my car hit's E it takes exactly 13 gallons to fill it up. I added a can of seafoam into my last tank to see if that would help because the car had been sitting for six years when I got it and it had bad fuel in it. So What I am thinking is that my o2 sensor is bad and causing me to run very rich. I tested it with a voltmeter and it's bouncing around but it's not going constantly from .1 to .7 it's going from 0 to .4 or .5 and then back down to 0 and then up to .675 and then it repeats. What I am trying to figure out is if it is actually bad or if I am having some other problem that's causing me to get bad gas mileage.

 

[XiKeiyaZI]

If your cel light does not come on anymore I would look towards the ECM and being a issue. Before you go buying a new one i would just pull my cluster and check the bulb. It would be bad to replace the ECM for a burnt bulb.

Or... before we suggest replacing the ECU we could suggest pulling the ECU and check it for burnt/popped traces, foul smells, and/or leaking/bulging caps?

 

[empie1]

Check the coolant sensor on the thermostat housing. Not the single wire one for the gauge, the two wire one for the ecu. Mine did the same thing when one of these wires was brittle and not making a good connection.

 

[Calan]

...I unplugged my MAS connector and plugged it back in to make sure it was plugged in correctly and now my car starts, Hits about 2500 rpm's and then dies and I can't figure out why. I need to fix this ASAP as it's how I get to school D=

Have you pulled the fuel line and checked fuel flow at the rail, and replaced the fuel filter recently? It does sound like a possible MAF issue, but you need to eliminate all the easy possibilities before digging into the ECU, etc.

 

[JusMX141]

Similar thread topic on two threads started within 4 hours of each other by the same member = Merged thread.

 

[Bishikid]

did you ever try unplugging your MAF and turning on your car???

 

[95gsttsi]

Couldn't it also be the tps? Throttle positioning sensor. I've had issues in the past with theses and they can shut your car down. The only issue I can see with a o2 is bogging down or running lean

 

[Bishikid]

http://www.dsmtuners.com/forums/newbie-forum/395307-car-starts-idles-fine-minute.html

http://www.dsmtuners.com/forums/newbie-forum/394403-car-turns-but-wont-stay.html

check those, they should help a lot!

and I also had the car start for only 1 or 2 seconds on me about a month ago. My problem was that my balance shaft belt snapped!!! and it was just dangling inside the timing cover. check that out because if thats what happenning to you, you can bet the loose torn balance belt will snap your timing belt! mine was on its way to snap my timing belt!

 

[tsi209]

Hey bro if you need a maf I have one that you can have. Just pm me and cover shipping and it's yours

 

[iguanahotsauce]

Wow thanks for all the responses everyone . I didn't get a chance to work on it today as I am pretty busy with school. But tomorrow after I get done with class the rest of the day will be devoted to fixing this issue. Lets see, where to start:

XiKeiyaZI: I have not had any funny smells. But my car still stinks from the fire so it might be masking the smell of something on the ECU burning. I will pull it out and check the traces and the capacitors.

empie1: Just replaced the coolant temp sensor But I noticed one of the wires is coming off the plug so I will fix that and see if that effects it.

calan: No I have not checked the fuel line and checked the flow at the rail. Should I just pull the hose that goes into the rail? and I replaced the fuel filter when I replaced the fuel pump.

jusmx141: Sorry about that. I was in a big panic because it wasn't working.

Bishikid: Yes I did try that. It does the same thing except it idles really rough and then dies instead of idling at about 2200 - 2500 rpms. I will also check the belt and see if that's causing my problems.

95gsttsi: I have no idea what the tps or where it is but I will find out and make sure it is working correctly.

tsi209: Sending you a pm now.

 

[empie1]

empie1: Just replaced the coolant temp sensor But I noticed one of the wires is coming off the plug so I will fix that and see if that effects it..

I bet that might be your problem.

 

[iguanahotsauce]

I bet that might be your problem.

When I installed the sensor I forgot to plug the wires back in and the car still ran so I don't know if that would keep it from running now

 

[dsmspickdad]

Which is it? Does it start and idle then dies or the terrible fuel consumption? Ever check the cam and crank sensors?

 

[tips000]

my car was running rough and getting bad mileage... i cleaned the throttle body, got new plugs, new wires, and made sure my boost leak was not too bad... if you have your BOV just a little too ard it can do this... id say if its been sitting for a few years then definately clean the throttle body...

also... seafoam actually decreases mileage... dont get me wrong i love the stuff... it actually cleans your fuel system and engine well... after this tank with seafoam i would say dont put anymore in
"
but instead start throwing a bottle of "lucas oil" "upper cylinder lubricant" in each tank... it helps mileage while maintaining the cleaning that the seafoam did... its like 5 dollars a bottle or you can get a bulk sized one for like 10-15 that will get you like 10 or so tanks worth

 

[empie1]

When I installed the sensor I forgot to plug the wires back in and the car still ran so I don't know if that would keep it from running now

What sensor are you refering to? The wires dont "plug" im..its a plug. Either the wires are attached or they arnt. If one is not attached it wont run.

 

[iguanahotsauce]

Which is it? Does it start and idle then dies or the terrible fuel consumption? Ever check the cam and crank sensors?

It's both. I was having problems with getting bad gas mileage but the car was running fine. Now as of the 7th the car starts, idles high for a couple seconds, then dies. I am going to check all of the stuff that has been suggested to check and the CAS is one of them. I checked the wiring on it before and it's all good and I tried wiggling the wires but it didn't do anything. Is there a way to check the CAS to see if it's bad?

my car was running rough and getting bad mileage... i cleaned the throttle body, got new plugs, new wires, and made sure my boost leak was not too bad... if you have your BOV just a little too ard it can do this... id say if its been sitting for a few years then definately clean the throttle body...

I plan on pulling off the tb and cleaning it. What do you mean if I have my BOV too hard? Sorry I am still new to working on cars and don't know a whole lot. I know where the BOV is and the hoses are still connected so it is recirculating.

What sensor are you refering to? The wires dont "plug" im..its a plug. Either the wires are attached or they arnt. If one is not attached it wont run.

I am talking about the ECS. The Sensor that has the two pins in the shape of a T. That's the one that has a plug with a wire disconnected. But when replaced the sensor I forgot to put the plug back on the sensor and the car still ran.

So I just finished putting everything back together. Today I pulled out the aircan and checked out the MAF. It looks perfect, no loose wires at all. I also checked the voltages on the plug and I was getting correct voltages. I then tried to perform a boost leak test but accidently drilled too big of a hole in my pvc end for my valve stem so I need to go get a new pvc end before I can do a boost leak test. Then I checked out the BOV and the hoses that connect to it and everything seemed fine but I don't know how to tell if the BOV is "too hard" so if someone could explain to me how to tell id it is that would be great. Then I pulled off the CAS and tried checking the voltages while I spun it and got nothing so I am thinking my CAS might be bad, but would the car even start if the CAS was bad? Tomorrow if it's not raining I plan on pulling the CAS off again and testing it again. I am also going to pull off the TPS and make sure it's set correctly and I will check the ECU and see if there is anything wrong there. Any help or advice is greatly appreciated

 

[blaze12]

This sounds so much like a bad MAF.

 

[Bishikid]

http://www.dsmtuners.com/forums/newbie-forum/395307-car-starts-idles-fine-minute.html

http://www.dsmtuners.com/forums/newbie-forum/394403-car-turns-but-wont-stay.html

check those, they should help a lot!

and I also had the car start for only 1 or 2 seconds on me about a month ago. My problem was that my balance shaft belt snapped!!! and it was just dangling inside the timing cover. check that out because if thats what happenning to you, you can bet the loose torn balance belt will snap your timing belt! mine was on its way to snap my timing belt!

... Did you EVER check inside your timing cover???

 

[iguanahotsauce]

I did check inside the timing belt cover. The timing belt is fine but I'm not exactly sure where the balance shaft belt is and would I be able to see it with the top cover over the timing belt off or do I need to remove another cover to see it?

 

[XiKeiyaZI]

I did check inside the timing belt cover. The timing belt is fine but I'm not exactly sure where the balance shaft belt is and would I be able to see it with the top cover over the timing belt off or do I need to remove another cover to see it?

Balance shaft belt is located under the lower timing belt cover, behind the crank pulley. You would need to remove all of your belts, pulleys, and driver side motor mount. It is a small belt that you can't miss. Runs off of the crank.

 

[iguanahotsauce]

Is there any other way to tell if it's broken? Because I am very new to working on cars and have no idea how to do all that and it sounds pretty complicated

 

[kchaazz]

Is there any other way to tell if it's broken? Because I am very new to working on cars and have no idea how to do all that and it sounds pretty complicated

Yeah. You should feel a bit more vibration in the steeringwheel at idle than usual. Also, remove your upper timing cover and look at the timing belt. See, most of the time when the balancer belt snaps, it bends the plate in between the timingbelt and balancer belt sprockets, and the bent plate chews into the timing belt. This will be accompanied by a slight chunking, squealing sound. Ask me how I know Anyway, if youre ever worried about that, dont run the engine until youve verified whether or not that belts gone cause it can easily cost you a motor.

One more thing, regarding your check engine light. When you turn the key to the ON position, does the factory boost gauge come up to 0? If the check engine light isnt coming on and going off, and the boost gauge isnt coming to the 0 position, the ecu or its power supply is in question.

 

[iguanahotsauce]

Actually the last coupld days I was driving it before it broke down I noticed the steering wheel was vibrating a little more than usual. Is there a guid on how to pull everything off ot check it?

 

[kchaazz]

Go to VFAQ.COM, there will be a how- to with pictures there. Also, look into a balance shaft elimination kit, if you know anyone local who knows how and is willing to help you with it. See, when the balance shaft belt dies, its usually because the bearings for that shaft are toast, causing the shaft to seize up, which causes the belt to break. Course, a 20 year old belt is bound to fail at some point anyway, so if you remove all this stuff, and you can easily spin the balance shaft sprocket by hand with no resistance, it might be ok. You might as well get in there and replace the camshaft seals, front main seal, and the small seal behind the oil pump sprocket, along with the timing belt, tensioner, timing belt pulleys and the water pump while youre at it as well. This is a BIG job if youre not experienced, so its important to either have experienced assistance, or a good shop with reasonable labor rates to do this. Youd be looking at around 250- ish just for parts, which isnt all that bad.

 

[iguanahotsauce]

$250 is defiantly not within my budget right now. When the timing belt is replaced by the shop do they normally replace the balance shaft belt as well? Because the timing belt snapped on the previous owner about 1000 miles ago and so he had to have everything redone

 

[kchaazz]

$250 is defiantly not within my budget right now. When the timing belt is replaced by the shop do they normally replace the balance shaft belt as well? Because the timing belt snapped on the previous owner about 1000 miles ago and so he had to have everything redone

A good shop would KNOW to replace both belts, the tensioner, tensioner pulley, and also the water pump while theyre in there. The oil seals I mentioned are just a precaution but most leak at this point given their age, so the need for replacement would have been obvious. Are you able to contact the previous owner and perhaps look at an itemized receipt for the services performed on the car? If the timing belt snapped before, id make sure they fixed whetever bent valves there might have been and gone over the head to make sure it was ok before putting it back on the car. Bottom line is, provided the belts were installed correctly and assuming the proper components were replaced, if the balance shaft belt is dead, youre going to need to install a balance shaft elimination kit as the bearings for that shaft are toast. Of course, this is a big IF, since you havent checked to see if the belt is messed up yet.