mpfi swap problems ecu code 4 and 15

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fixed4 life

fixed4 life

New Member
I just recently did a mpfi swap on my 90 std hatch (w/stock engine)i am still having two problems.

1st one is if i use any other ecu besides a pm8 i get a code 4 which i have reserched is a CPS problem. I tried using a pm6,pg7,& a pr4 all obdo. I dont get this problem at all if i use the pm8 ecu. I dont understand why the pm6 doesnt work at all. I have had the pr4 working once for a couple of days and it stoped. The things i have done to pinpoint this problem are-
I have checked wiring over and over found no problems and used and tested two different correct distributors. I have also purposely wired the 2 CPS wires icorrectly to see if the pm8 ecu picks it up and it does. So it is not a faulty ecu. I have also swaped the pin location of the 2 CPS wires and it still doesnt work.

2nd problem is sometimes my pm8 ecu throws a # 15 code which i have researched is a ignition output signal. There is not a certain time it does this which is weired. It will do it a cold start, while i have been driving, sometimes it wil take 5-10 days before it acts up. Things i have done to pinpoint this problem are-
I have used 2 different correct distributors and have checked my wiring over and over and i find nothing.

I am going to swap a single cam vtec into my car soon and would like these two problems to go away. Any help would be nice. if there is someone local in fort worth that could help me that would be nice. The only thing i can think of doing is to redo the mpfi swap using a different dx harness or taking it to a local shop.
 
dude im in the same boat as you..
..wow just realized this post was dead
well i still havnt found an answer..but ive done the exact same thing this guy has to a T..
any help?
also in the ft worth area..wierd..
 
also i have read two diff things
the plugs on the ecu read across with the numbers on them
and that they are numbered up n down i have switched the c1 and c2 wires and that hasnt changed anything for better or worse..
and idk if i need to be more specific but i just did a d15b7 swap and obd1 conversion..and i have just barely got it running but it wont revv past 3000 rpms and im getting several codes and im thinking the one thats makin it hit the limiter is the code four..now even if the c1 and c2 arnt hooked up it will still run..
im not sure whats up with this
 
nobody? am i not giving enough info?
im down for any suggestions..
hell even if its put more air in your tires and all your change in your left pocket..
i gotta figure this out..im not askin to be spoon fed but i havnt any answers to my problems
im on a few other tech sites but still no luck..i know someone has had this before i just dont know how they fixed it
 
hey i have the same problem!!! i swaped a sohc zc block with a jdm sohc vtec head onto my ef sedan and converted dpfi to mpfi also converted it from auto to manual(si tranny) and my shit wont rev past 3500 rpm's. obd0 pm6 ecu and si dizzy obd0, c1 & c2 are where they go on the ecu.. i can disconnect c1 and c2 and the car still runs too.... timing is titS.......

i already doubble,triple,quadrouple checked all the wiring everything is perfect
tried (loaned) working distributors like 3 times and also bought a new one that is on now..
and all distributor wires are ok even the WHITE WIRES!!

ecu code 4 and nobody on the world wide web has posted usefull info to fix this for the past 2 weeks.......

im goin nutz and im about to push my car off the highest cliff i can find :mad:
 
check the dates on threads before replying.
you're more likely to get help by starting a new one or searching first.

good luck.
 
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