What can cause a hesitation in a 94 efi toyoto pickup? its a 22re . I have changed everytihing but egr valve.?

Question

I can pull out slowly and change to second and just ease along and all of a sudden it pulls down and when I open it up it goes on. Then when I shift to third it really hesitates. Then after I punch it it goes on. I tried to override the EGR Valve by unhooking it, but it still hesitates. I have changed the plugs, they were bad. I have changed the fuel filter, it was bad. I changed the wires, they were factory. I also have put some cleaner and octane booster in the fuel, didnt really help against hesitation, but all the changes did help with fuel mileage. I have tried cleaning the EGR Valve, cleaned throttle body with carb and choke cleaner, and cleaned and reoiled K&N filter, did not over oil. Followed directions to the Tee. What can be causing this?

Answer 1

d**n.

AS g*y as it sounds, re-replace your plug wires. Alot of times the wires can be faulty from the factory. It's happened to me before MORE THAN ONCE, and it's really REALLY frustrating because you think you've eliminated them as the problem already..

Do you have the stock rubber hose from your air filter to the manifold? Those have a habit of cracking in between the rubber ribs, resulting air loss which confuses your MAF sensor. Silicone or Shoe-Goo works good for that.

Try testing the fuel pump for proper voltage. When fuel pumps die, they die slow. So it may be working, but may be cutting out under load.

Vaccuum hoses are VERY IMPORTANT on older Toyota engines as well. If any have popped off or cracked or are plugged into the wrong fitting, it will run like a tank or hesitate all day long. Even the power-steering pump vaccum lines or lines running to the charcoal-canister are important for a balanced idle on these vehicles. Do a quick check of those...  The manual has a diagram.

If you own a manual for your truck, check out how to troubleshoot codes. You may have to take it to a shop if your computer is OBDII.

Those are the cheap checks. After that, you might be looking at throttle-position sensors or mass-air-flow sensors...  GOOD LUCK MAN!