alright you guys ive been on this problem for about 2 weeks now, and i think ive narrowed my problem down to fuel injector problem. I have a obd1 b16 in my 88 dx hatch.... so ill give u a brief description of my problem. when i start my car, once warm it will misfire and run like crap, it will misfire while im idling and driving below 3000rpm, once i get passed 3000 rpm, i still feel loss of power. so i decided to do a full ignition tune up, (cap, rotor, plugs, and wires) and changed fuel filter, checked my timing and still same problem. so i finally gave up and took it into vegas shop called "Hondoctors" they charged me $110 to tell me it was in cylinder 2 and that i had good compression in every cylinder(they did cylinder leakdown test), so eliminating HG problem. they also said all my ignition parts where working properly and they said it could misfire could be due to sticky valves or valve clearances being to tight. so i decided to buy a new fuel injector and replaced cylinder 2, and miraculously my huge misfire stopped and i had more power. i was still misfiring a little bit. anyways today in the morning it started doing it again. So this time i pulled out my multimeter and while the car running i checked every injector clip and cylinders 1,3,and 4 showed about 14V, but cylinder 2 only showed 7V, which gave me a huge break. because that is one of the wires that is messed with in dpfi to mpfi conversion. i checked the positive prong on connector and used a stronger ground and i was getting 14V on cylinder 2, but only 7 when i used the ground on the connector. i also used the ground on the connector and checked my battery voltage and it showed that my battery was only at 8V, which i know was incorrect cuz i had my s300 hooked up to my laptop and on the datalog it showed 14V. so im guessing i have a bad ground, but i dont know how far to go with the wire, cuz the wire has a couple of solder points here is a small sketch

*: means solder point
---:wire


EcuA3---*-----*inline fuse*------*connector in engine bay*--------*injector connnector

the problem is that when i use grounds straight from obd1 pins A1,A3,A5,A2 when car is running, and check for batt voltage on battery i only get 1.5V, but once they reach injectors they all give good grounds except for cylinder 2. oh and when car is turned off, cylinder 2 connector gives me a good ground cuz when i check it on my battery it gives me 12V. so could this also be an ecu problem?

 

all those solder points decrease your voltage and cause the injector to run less effecient because its happen to my friends b16 and it would also not let it hit vtec. also check your timing and then just go ahead and run a whole new wire and see what happens and check if the ecus are burned in the inside. the wire is very easy to replace and you seem more than able to handle. Good luck!

 

Ok and is soldering better than using butt connectors? I imagine it is but before in my old car when I did the dpfi to mpfi I used butt connectors and never had this problem. But like u said its prolly all these solder points.

 

your friend probably used way too much solder. you're suppose to use the least amount as possible. also, using a low grade solder will also have more resistance.

OP, i dont think its your ecu. my guess would have to be the way you have it wired. why dont you have just one wire from the ecu to the fuse? are the other injectors wired the same way? i would definitely go back and check your ground to the injector

 

yea ok i didnt know the more solder the worse, and i just pulled out harness and realized that theat injector has speaker wire going to ecu not regular wire, does that make a difference? and the gauge on the wire is real small like 18-20

 

if that wire is smaller than it will have more resistance when compared to the 18 gauge wire you should be using. lowering your voltage. you can get regular automotive wiring in various lengths at auto stores instead of using speaker wire. just make sure you use the same gauge as the wire on the harness and you'll be ok