30hp loss when first driving for the day

[newbs13]

So i have a 93 coupe ka24de and first time i drive the car after sitting over night it runs like s***. I feel about a 30whp difference until right around middle of the day of driving it and hour and half off and on. Its wierd i cant even kick the a** end out in 2nd until right around 2 o clock after that i can kick the a** end out in 3rd at 60mph all day. Its starting to get annoying I've changed spark plugs and fuel filter and it ran a little better but still doing the same thing.... DOes any body have an idea on what it could be.

[skyline084]

clean your maf with electrical parts cleaner

[rioredstang]

I would check the coolant temp sensor. It could be out of range. It may be biassed too cold and computer will richen the fuel mixture. As the temp comes up the engine will respond better.

[bmxer300zx]

oh look the coolant temp that i said it could be matt. lol hopefully bens parts will help u or u just need to cut the wheel harder lollooloollololololol

[skyline084]

yo rioredstang.. can the temp sensor really screw with fuel mixture? Right now i have the stock temp sensor unplugged, because im running autometer gauges. The only reason I care is b.c my ecu is throwing number 13 code (water temp sensor circuit) I've had the original sensor cut since i had the motor running, so i wouldn't be able to tell if it is performing differently

[rioredstang]

The coolant temp sensor is a (2) wire sensor. The temp sending unit for the gauge is a single wire sensor. The (2) wire sensor is for the computer, if you unplug this the computer thinks it is -40 degrees. This will make it run very rich.

If you have cut the single wire sensor, it will not have any effect on the running of the engine. The temp sending unit has no function to fuel mixture.

[liquid_cool]

what mods to the engine do you have?..aftermarket pistons?..if so what and what bore?..cams?..is this a turbo build?..need some more info on this one.

[skyline084]

okay , that's what i figured but i knew these computers like to run stupid. My rb ran retarded b.c my knock sensor wasn't plugged in all the way.

[OutToWinPAHC]

Number one..... Check engine health

Compression check
Check engine codes if any
Clean and check sensor connections
Then check your basic maintenance items and replace as needed (Plugs, Wires, clean IAC, clean throttle body, check intake manifold bolts, check and repalce vacuum lines, fuel filter, PCV valve, coolant, and oil)
Set the TPS
Check for cat cloggs
Chance and adjust timing

MAF clean only for a MAF, other stuff can leave a film behind.

[bmxer300zx]

hey thanks for the info my buddy is to slow to reply to his post so update is he replaced his maf,coolant sensor,cleaned spark plugs f"d with the timing and found a bad vacuum line the car is running alot better but still has its moments where it tends to feel under powered .the car is old has 212000 not really sure if its the o.e engine though cuz it doesnt smoke at high rpms burn oil doesnt even miss a beat at idle so idk.he got another ecu and other little things from a friend and is going to try them out and see wat happens

[newbs13]

Thank you mike haha, Ya I no longer own the car but I think it was the tps. I tapped it a few times and the car has no more issue's. The car runs strong for 212k miles and pulls harder than any ka i've been in. Doesnt burn oil and still kick's the rearend out in 3rd. But thanks for the effort I totally forgot about this thread.