Well, not really, but figured I might get a response with a more exciting title. Here’s my problem:
My 2.7 L Takoma hesitates to the point of stalling if accelerator is pushed moderately or hard from idle. If the accelerator is eased, the truck runs fine. Seems to run well at higher RPMs. What could cause that?
A little background that might be helpful: Long story short, I had bad O2 sensor that I failed to replace fast enough, which resulted in a burned out cat, according to the OBD computer. Replaced the sensor, but drove with the bad cat for a long while. Eventually, the engine wouldn’t start one morning, and I discovered that the number 1 spark plug electrode insulator was broken, which motivated me to replace cat and plugs. Check engine light immediately went out when new cat was installed, but noticed hesitation ever since. Thought computer needed time to reset itself, but so far no improvement. Don’t know where to begin to look for the problem with a fuel injected engine.
stop pressing the accelerator so much.
and buy a fire extinguisher
problem solved.
oh, what WAS your problem?
How many miles on this truck? Oh, and it’s Tacoma not takoma.
160K miles. Always get my Toyota Tacoma and Takama Wash comfused.
When was the last time you replaced the fuel filter?
I thought you were going to post your results of the tests of the tps, and MAF? What are the results? Did you use the MAF cleaner yet? How about the cleaning of the iac (idle air control) valve, throttle plate and bore with the Carb/Throttle Body cleaner? Results?
What is the fuel pressure? Within limits?
Whohh…easy big fella. It’s night time. I just got these suggestions this evening. It’ll probably be the weekend before I have a chance to check anything.
I’m not positive that it’s ever been replaced. I know I haven’t done it myself, and I’ve only let a shop work on it once since I bought it in '95. I believe that I asked that it be replaced back in '05, but I’m not 100% positive.
It's past time. In fact It would appear that it is long past time to get all the recommended maintenance done on that truck. Some by miles and some by time (which ever comes first). If you don't know if it has been done or can't remember when, then do it now. Look in the owner's manual for the list, or if you don't have it stop at the auto part's store and buy a maintenance manual that covers your truck.
Not doing basic maintenance not only is an inconvenience but it also cost you more money in the long run.
You are just going to have to give up on a big night or two and get the work done. After that party on, drove sober and safe.I think what the guys are hinting at is a temporary lean condition when you open up the throttle plate and allow all that air in, meaning the injectors are not spraying enough gas to provide the proper richness.
The Throttle Position Sensor (TPS), the Mass Airflow sensor, and the Manifold Absolute Pressure sensor (MAP) are all signals that the ECU processes to adjust the injector pulsewidth, and these are all possibilities. The upstream oxygen sensor makes a final tweak, but the others are responsive immediately to opening the throttle.
The other line of reasoning is that you have insufficient fuel flow to provide sufficient spray. Thus the commend on the fuel filter, which may very well be true after all these years. Your admitted lack of proper maintenance may have also resulted in a gummed up injector orafice, which is what the fuel filter is there to protect. An outside possibility is a weak fuel pump.
It’s also possible that you have a cylinder not firing or even a weak spark. My impression is that you’ve gone way too ling without looking at the iegnition system. A cylinder or two not firing would definitely give you poor acceleration, and so would a weak spark. It’s time you look there even if the solution to your problem is elsewhere. You are overdue.
Have you inspected the plug wire ends at the distributor cap and coil? If you’ve been driving around for ages with a cracked spark plug this means that everything back down the line is suffering also. A bad spark plug can kill the plug wire, the coil, ignition module, rotor, cap, or anything else along the way.
It can also cause an oddball problem such as you have now. It could also be a fuel delivery problem; fuel filter, weak pump, etc. Should I even ask when if ever the fuel filter was changed?