Some help!!!!! Car having hard time starting...

[mr2gixxer]

Well I am hoping someone will answer my questions. The past few threads, I havent got any replies to at all. First things first, I've done all the routine maintanence on the vehicle. Replaced spark plug wires, and plugs, changed air filter, changed oil, new alternator, new battery.

Now my ECU went out an I replaced it with a known good one a buddy let me borrow. The thing is, it will have a hard time starting up, and will idle really horrible and it is getting bad gas mileage. When driving, when decelerating, the car will stall out.

Secondly, my CEL light came on, telling me that my 02 sensor is bad, but I just replaced that less than 1000 miles ago.

What else would cause the 02 sensor to read faulty? Will a clogged catalytic converter cause this? Also, what are the possible reason for the car to have hard starting, poor idle, poor gas mileage, and stalling? I havent checked fuel, but will a dirty fuel filter or failing fuel pump cause this as well? Please help!!!!! Thanks.

 

[ImBoostedRu]

What year is the car? Have you checked all of the vacuum lines, that willmake the car run horribly and stall at idle or decelation. It could also be possible that you got a bad O2 sensor when you got the new one.

 

[nestamon99]

I just recently re-installed a rebuilt motor in my brother's 91 eagle talon. Initially the car would not start up right and when it did, you could smell gas. I checked everything....loose sensors, vaccuum leak, timing, and even firing order. Almost a month later, I found out that the coolant temerature sensor had corrosion inside the connector.. it was really hard to see it. This made it hard for the engine to tell if the car was hot or cold. It needs to see the coolant temperature in order to know how much fuel it needs to get it the engine to operating temperature. My ECU kept thinking the car was always cold and therefore it was giving it a lot of gas. There were also other problems with the car too, I accidently installed the plug wires wrong and my firing order was thrown off. I had a hard time figuring out why the car would not run smooth and now I found out what the problem was. Hope this helps you.

 

[mr2gixxer]

The car is a 1990. I noticed the tone of my fuel pump changed as well. I havent done the relay mod yet but will once I put in the new fuel pump. I'm pretty sure there are no vaccuum leaks because, when I first got it, it ran like a champ prior to the alternator change. ONce the alternator was changed, all hell started. ECU is good, what else could it be? My wires are in the right order(I did it one by one), no leak, still the same hard starting, rough idle, and stalling as well as the 02 sensor reading faulty. What could make the 02 sensor read faulty other than it being bad?

 

[SandmanGST]

my car just started with the stalling at idle and deceleration, but it has had the hard starting and gas smell as well as the o2 sensor CEL for a while now. any other ideas on what it could be would be great.

 

[92tsifwd]

My car has been doing kind of the same thing but, it starts up every time and then amediatly stalls even if you try to give it gas. Also my boost gauge reads zero psi at full throttle and my spark plugs are white so I think I am running lean but, don't know why because my car is mostly stock. It acts like it ain getting enouph fuel. I changed my timing belt, water pump, and fuel pump to a stock one. I checked my timing My car has been running crappy every sence. I really need to find out what the problem is.

 

[mr2gixxer]

ANY Ideas, problems never end. I started to notice that I'm gettting a minor coolant leak now. I'm gettin tired of this car!!!!

 

[SandmanGST]

are you venting your BOV to atmosphere? my stalling was fixed when i sealed up my dump tube. i was venting because my dump tube was broken and was leaking really bad so i covered the inlet on the intake and vented i soon after got the problem. now that the dump is back in the trouble is gone except for the o2 sensor and hard start that is.

 

[mr2gixxer]

No I'm not venting. I have a stock setup. This idle/stalling problem occured after I added some seafoam into the fuel tank. The 02 sensor CEL has been coming and goin when I first purchased the car not to long ago. The 02 Sensor is BRAND NEW, and it still throws that code. Any more ideas would help. Thanks.