Engine Performance problem
1991 Toyota Celica 4 cyl Front Wheel Drive Automatic 198000 miles
Hi, I have a 1991 Celica GT convertible (calif), 5SFE engine, automatic trans with a strange miss after warming up. There is a cut out (bucking) when accelerating and the car lacks power. It would barely climb a hill. This problem occurred 3-4 days after changing the oil and getting fuel. For oil, I went from 10w40 to 10w30. I use ethanol-free gas. So far, I've replaced the injectors and seals, pump strainer, fuel filter, both o2 sensors, map sensor, TPS, coil, igniter, coolant temp sensor and plugs.
I've ohm checked the distributor (and checked gap and no oil inside), cold start injector, EGR VSV, ISC and plug wires. I vacuum checked the EGR valve and looked for vacuum leaks. Also looked for bad ground. All are good. Fuel pressure was within spec.
Last night, I replaced the distributor and cap (rotor and wires only 1 yr old) and strangely the power is mostly back. Especially on take off and it will climb a hill without much problem. The miss is still there but seems to be showing up around 40mph. The lack of power is not as bad as before. I can actually pull out in traffic but there is a bucking when accelerating.
Before all of this happened, the car ran good but would vibrate when stopped at a light and in drive. Sometimes worse than others.
Could a fuel pump cause these issues? The pressure was good and it's never left me stranded.
Any ideas? Help!
Tuesday, April 13th, 2010 AT 12:14 PM