Car hesitates on takeoff I replaced timing belt and it runs a little better but still hesitates a little on takeoff. I also cleaned the intake manifold out. How do I tell if it is the EGR or the Crank case sensor or something else
You will have to scan for trouble codes to see if a component like the crankshaft postion sensor is failing.
Check the fuel pressure as that is a common issue and you can check it manually with a test gauge using a test port on the fuel rail.
September, 23, 2011 AT 6:44 PM
I have no check engine light. If crank sensor is out wont it show up at least with the light
September, 23, 2011 AT 6:58 PM
Sometimes failing components won't throw a code. Especially if it is an electrical part and is failing slowly or intermitantly.
September, 23, 2011 AT 8:33 PM
Ok check engine light came on while trying to drive it around. Got it scanned and it said it was the downbank o2 sensor. I havnt replaced it yet since I am pretty sure that wont cause it to backfire and not have power. After I get the car up to around 20 it will still hesitate a little. Getting really frustrated with this car. I hate to just replace parts but should I try the crank sensor. It is the only thing I can think of
September, 23, 2011 AT 9:21 PM
Actually it is possible for a failed O2 sensor to cause a backfire. If it reads a lean fuel/air ratio it will dump fuel in the engine which gets ignited in the catylitic converter.
The lack of power is from the rich mixture. It can make a big difference.
Have you noticed if the car is consuming more gas?
With the mileage on the car a new O2 sensor is due for replacement.
It will be worth getting the trouble code scannow as the intermitantly or slowly degrading part has now fallen far enough out of spec that it is throwing a code and that will be worth the 15-30 minutes of labor you might be charged at a repair shop. If you plan to keep the car, readers are getting cheap enough to purchase. Under $100.00. We will always be here to translate codes for you if need be.
I will keep an eye on this post for your reply.
September, 23, 2011 AT 9:28 PM
But it is the downstream o2 I thought that just worked with the Catalytic converter. That is the only reason I didnt replace that at this time. Does the downsteam deal with fuel management at all?
September, 23, 2011 AT 10:15 PM
That is correct. I traced it as going back to the Powertrain Control Module. It is part of it only in the sense of high gas levels in the emissions, but not like the upstream O2.
It could be a leak in the exhaust near the O2 sensors or the air injection tube. Irregular fuel pressure could be an issue.
Of course the crankshaft and camshaft positon sneors could have the timing off.
Checking the trouble codes will be well worth it.