A friend of mine recently bought a '98 OBW with the 2.5. I'm doing some work on it to make sure that she has a reliable vehicle. But I have not been able to track down the this hesitation and stumble on acceleration from a stop. What its doing is that if you get on the gas fairly quickly it acts like it loads up, stumbles and chugs, and then catches after a second or two. I've cleaned the throtle body and the TPS, replaced the fuel filter, which was nearly clogged, and the air filter. I've checked for vacuum leaks and bad hoses and plan on running some injector cleaner through it tonight. Oh, and it isn't throwing any codes so I'm hoping that someone here can give me some ideas of what else I might want to check out to correct this. I'd prefer not to have to take it to a sub mechanic because she is a single mom and money is a little tight for her, so any help that can be offered will be greatly appreciated.

I've had a similar problem with my 96 2.2. At first I tried the injector cleaner stuff, no good. Then I replaced all 4 spark plugs with Bosch 4's. That worked fairly well, actually, for about a year. Then I replaced the fuel filter, and it's been just ok since. Still hesitates when it's cold. So, my limited knowledge would say replace the plugs, cuz it's cheap.

Yeah, change the plugs for sure. Make sure you don't overtighten the new plugs. I would recommend a small amount of copper grease on the threads - or fresh engine oil if you have no grease. Max half a turn after the gasket contacts the head.

 

My EJ22 was happy to use Bosch plugs, but I find that my newer EJ20 will only run really smooth with NGK.

 

NGK is also recommended in the owner's manual.