help i have 2003 evo with k&n drop in, works p3 and works axle back. i have 24,000 miles on stock clutch and never had 1 problem with my evo. now when accelerating
(like merging into traffic) and in 4th gear when rpm gets to 6000 it has a slight hessitation kinda like its cutting out or missing. ive taken to dealer and they could find no problems i started thinking mabey bad gas ( i only use mobil 1 ) but this is going on for 2 months now. now when accelerating from a stop no problems, clutch not slipping and no hessitation engine pulls hard until i get to about 6000 rpm, then this #%@!* hessitation starts. please help with a clue to what it could be!

 

What's the temperature where you're at?

 

i live in dallas texas this problem has occured with the temp from 55-79 degrees

 

Mine does it too - and it's getting hesitant to pull in the morning till it warms up, check your plugs, given how pig rich EVO's run I wouldn't be surprised if they were fouled.

 

well i thought the same thing about the engine being cold but after driving about an hour and the outside temp being about 70 deg it still happens. i also check the plugs and they were fine. someone if you have a clue let me know because the retard dealer cant help, mabey i can help them figure it out.

 

come on people! someone please help. we can ask questions like what color evo you have and 50 people will email back. can i get someone to help answer my question.

 

could be fuel cut or spark plugs

 

well i have already check the sparkplugs and they were in perfect condition, fuel cut? i have the computer reprogramed from works with the p3 and never had this fuel cut problem. could you elaborate on this.

 

I had the same problem after installing a walbro. I was running so rich untill I got the tuning straitened out that I had fouled the plugs. I would get a missfire above 5500rpm on boost even after leaning the AF out to 12.0

The plugs may look clean...mine did when I swapped em, but had a good amount of carbon, but were not wet. I put new BPR7ES in and the missfire is gone. Make sure you set the gap down to .28 as well.

change your plugs...it's $12 in parts..cheapest thing to try out first.

ECU fuel cut is drastic...like you smack your head on the steering wheel harsh. engine just shuts off for a second and makes big noises

 

my evoIV used to do the same thing,except mine started to do it when it got 50 or colder. The british shops I talked to said it was mass air sensor acting up when it got cold. They said the only way to fix it was to switch to speed density type system. I'm not positive if that is all correct but I did hear that this was a common problem on older evo's. Hope this might help

 

maybe a IC pipe leak, (did you tighten up your hose clamps ?) I guess you would prolly see this before 6K, but its worth a look.

 

CHANGE YOUR SPARK PLUGS.. I had the same thing at 15k.. Then changed the plugs fixed it all.. Also go one step colder 8's I suggest NGK BPR8ES 4 of them from NAPA Auto parts.. Simple Cheap go great change every 10k.. Lots of research done on this.. Ull be happy.. Gap at .028-.030

 

I forgot to mention I have the same problem - I have a Walbro and my engine management is currently winging its way to me

 

Have The Same Problem They Might Look Good, The Pluges That Is, But If You Look Real Close The Gruyish Stuf None As Carbon Is From Pinging. And Slight Misfire Change The Pluges And Dont Use ****y Cali 91 Gas. I Got A Great Place For All South Cali Peeps For 103 Leaded. I Mean Leaded Fuel. All I Can Say Is Wow On Thist Fuel.

 

A tiny head gasket leak may have the same effect as well.