havent unpluged o2 sensor but if i unplug map sensor truck idles up but straightins uphavent unpluged o2 sensor but if i unplug map sensor truck idles up but straightins up
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
A dirty air filter, clogged or worn PCV valve or clogged EGR valve can cause engine surging. If those don't take care of the problem, get an ODB scan tool and watch what the engine is doing when it surges - especially the oxygen sensor output, injector dwell times and ignition timing (bring along a knowledgeable passenger to watch the tool while you drive, or get someone else to drive). Patterns here can give you a clue. Any check engine codes should be investigated. By now, you've spent enough money throwing parts at the problem to buy one of these, but many auto parts stores will let you rent or borrow one.
One item to particularly watch on the scan tool is injector dwell time. If the timings are highly variable at idle, the fuel pressure regulator may be bad. (Another symptom of a bad regulator is intermittent hard cold starting, and an odor of raw gas in the exhaust when the engine is cold. Prolonged or frequent operation at low RPM with a bad fuel pressure regulator can ruin a catalytic converter.)
Other causes of catalytic converter failure may also be behind the surging issue. Also, the engine computer is programmed with the assumption that there is a catalytic converter, so the reduced back pressure may be destabilizing the control loop that kicks in when the engine is warmed up.
The RockAuto catalytic converter pages list common causes of converter failure that should be checked before ordering a replacement. It's worth a look. Here's the link for your vehicle: Click the info button for any of the converters offered. If your state requires you to install a CARB-compliant converter, you may want to look for a used one.
My experience has been with later model vehicles, but a bad throttle position sensor most definetly causes this type of situation. Two torx screws, opposite side if the throttle body, should have a three wire plug.
check or replace pcv valve. check the hose also. remove and clean the idle air control with carb cleaner ( IAC ). they are usually located on or around the throttle body. check all hoses for a vacuum leak. good-day!
idl air control (IAC),may be bad,also,check the EGR valve,and all vacuum lines going and coming from the throttle body. yu can test the EGR,just try pushing the diaphram by hand from beneath. if you can move it easily its good,if its hard,or doesnt move,ot needs repaced. also a pcv valve and air filter are good ideas,considering you have replaced 80% of the emission system already.
HI, You may have some carbon build up in the throat of the throttle body itself. That buildup may also have plugged a small air hole in the throat. The carbon build up keeps the throttle plate from fully closing against the stop.
could bea few things. Excessive moisure, low fuel pressure, Faulty coil pack, spark plugs gap or wires. Have you changed any of those at all? Let me know
Wow you have replaced a lot of stuff. Lets go back to the Fuel pump. When you replaced it did you replace the hose between the pump and the sending unit. These are common for splitting. Have you hooked up a fuel pressure gauge to check what pressure you have? It should be real close to 13 psi and should raise to at least 18 or 19 when you pinch off the return line.
×