88 EF Hatch

alright so i have an obd1 jdm b16a in my obd0 dx hatch. i used to run an ls in my hatch. all my ignition tune up parts are new. when my car is cold, it runs really strong and is very responsive, but of course no vtec b/c car is cold. once it warms up, it isnt very responsive, and when give it full throttle, lightly feels like motor kind of jerks, and accelerates slower than it does when it is cold, but of course when vtec hits, it speeds up faster. it didnt do it with the ls, but the only difference betweeen my ls swap and b16 swap is that i re did dpfi to mpfi wiring and instead of using butt connectors i soldered wires this time. i have two guesses, my fuel filter needs to be changed(this doesnt explain why car runs the way it runs in different temperatures), or i did a lousy job soldering and grounds to ecu aren't very strong, although i have tested for continuity and its there, and thats why when car warms up, wires warm up and car is weak. does anybody have any other ideas or know what it is? thanks you guys

pmrhonda

im guessing u converted to obd1 right?

88 EF Hatch

yes i did, so my clutch went out and i replaced it but when i looked at the old cluth, the side that faces pressure plate was fully worn down to meTAL. and there was clutch residue every where and i even found a couple of broken pieces in the flywheel/clutch housing, do you think that had anything to do with it?

PyroProblem

I would think not..Perhaps your ECT sensor is failing. The ecu uses this sensor to adjust fuel enrichment for cold/hot conditions...Do you notice black smoke out the exhaust when the engine is warm?
Id try and get ahold of a wideband o2 sensor to see what your a/f ratios are while the car acts up...Good luck

88 EF Hatch

omg! man thanks i think you just gave me a huge break, cuz my car takes a while for it to start when its cold, and check this out, if i crank engine over when cold, it will take about 10 seconds for it to start, and it starts real rough, but if engine is cold and i crank for like 4 or 5 seconds, stop for like1 or 2 seconds and try again it will start as soon as i crank motor again, but still very rough. and i dont think i get black smoke out of exhaust but then again i really havent looked. so what do you think?

88 EF Hatch

oh i read up on this the only thing is though my car isnt running rich, cuz i get pretty good gas mileage still

88 EF Hatch

oh i forgot to mention i am using hondata s300 on my car so i can datalog to view my what my ect reads once my car is at operating temperature, what degrees farenheit should my ect read when my car is at operating temperature?

PyroProblem

Normal operating temp should be around 190-200 degrees F.
Since you have hondata, I think you should be able to modify the cranking fuel calibrations (while cranking/starting add or subtract fuel to see what the engine likes)
I would also check fuel pressure while cranking and idling.... If you think you may need a new fuel filter, id throw one in there too. Theyre cheap and easy enough to replace.

88 EF Hatch

ok can fuel filter also cause problem?

placid888

i think o2 sensor, lazy o2 sensor will effect engine performance but does not trigger engine light, what im saying is the sensor is weak but not completely gone.

looseOFFboost

I would check the regulator before I went crazy with everything else. And would explain the hard start and crappy vtec. In both instances you need the most pressure and that when your havingproblems.

88 EF Hatch

ok my fuel pressure regulator is relatively new, bought off a parts store (AutoZone) about 3 months ago, but ive only driven car about 3K miles. I dont have an 02 sensor, I am running hondata s300 and have disabled my 02 sensor and am running in an open loop. So I changed my fuel filter, and it helped a lot but still slight engine hesitation. Still hard to start. So i read that if i run in open loop my car takes readings from ECT sensor for fuel, and when i datalogg, my ect reads between 180F-185F once engine has fully warmed up, my fan is on all the time so maybe that is why it doesnt reach the 190F-200F. A local shop (Hondoctors) told me that the nut that goes at the end of the fuel rail banjo fitting matters, and can restrict fuel flow. I used to use my ls one for the b16 fuel rail but i lost it so i went to the junkyard and picked up an eg SOHC one. The one i had was the one that looks like a mushroom., now i am just using the one that looks like a banjo nut. do those nuts really matter? if so can SOHC one be giving me this problem? I still have difficult starts, takes a good couple of seconds to crank when engine is cold. Next day off I plan on draining coolant, replacing ECT, cleaning FITV and IACV, using new coolant, and finding a different fuel rail banjo nut. but if you guys have other sugestions it would be great.