i have a 93 del sol with a d16z6. it has the p28 ecu chipped with 2 step at 3500. i have ran this setup for about a year with no problems. about a week ago the car started to lose power in higher rpms almost like its hitting a fuel cut but only once i have driven the car for 10-15 miles and it has heated up. i replaced the timing belt last night thinking it was a timing issue. and the only thing i got out of it is a 75 dollar gates timing belt on a damn near stock motor. replaced plugs and wires(ngk) fuel injector cleaner and fuel filter. when the motor is cooler it runs fine. any ideas?

 

And the 2 step is for what?

 

You should have spent that $75 on a virgin p28. Considering your only modification is a chipped ecu, I would start there and replace it first.
Is it throwing any codes?

 

first off it had two step when i bought the car. and i kinda figured it was the ecu going out, or the fuel pump

 

Codes?

 

yes it does have a cel i have an appointment at my local honda dealer at 2 today and they are gonna run a full diagnostics for $56. i figure that is gonna be cheaper than buying parts and not quite knowing what it is

 

Paperclip and 5 minutes will tell you what code it's throwing. And it's free.

 

ive read about that, but dont quite know how to do it.

 

You must not have read it here.
How To Retrieve Check Engine Light (CEL) Codes/List of OBD1 CEL Codes

 

ok the light went off for about 3 seconds, then 3 fast flashes 2 long flashes and then one more short flash

 

look under your glove box. should be a little gray connector. bend paper clip insert paper clip read codes. its pretty hard to not understand. and marc was even nice enough to give you one with code lists.

i'd start looking at your ECU. no reason to chip and install what im assuming is 2 step launch? shoulda thrown it out right at finding that out.

 

Try that again and check it against the code list.

 

yes, i turn the key on no cel about two seconds later 3 short flashes 2 long flashes and one more short flash

 

30 Automatic transmission A signal or 3 MAP - manifold absolute pressure sensor (?)
21 VTEC spool solenoid valve

$56 please. Somebody make sure that's correct and if it's wrong pay THEM $56.

Is your car automatic?

 

sorry guys it was two differnt codes 03 and 21 map sensor and vtec sylenoid. thanks for all your help

 

no its a 5 speed, and i know 56 dollars would be stupid, but i was not sure how to do it myself before you sent me the link. thank you for helping me out. this is the first time i have messed with a fuel injected car.