I purchased a 1991 Civic sedan DX with a JDM D15B swap, MPFI and OBD1 conversion already done. 4 wire O2 sensor & injectors wired, TPS wires swapped. It's running on the JDM ECU & the original DPFI engine harness was converted. The engine had come out of a friends eg & ran great. Now after the swap it runs great for about 20 miles until the plugs foul out because it runs so rich. I have fixed numerous issues already but can't seem to figure this out. I replaced complete dizzy, plugs, MAP sensor, IACv, soldered the main relay, set the ignition timing (19deg), checked timing belt, set TPS to .5v, checked ECT sensor, cleaned the PCV valve, checked the cat for damage and fuel press is a constant 37-39psi. The only DTC it sets is 14 for the IACv but nothing changed when I swapped it with a known good valve. The fuel injector resistance was .011 ohms which seems very low but are the same as my B-series set that runs great w/o a resistor box. I may have forgotten a few details but this is most of it. Thanx & any help is appreciated.

 

For starters your timing should be 16 degrees (+/- 2)

 

I was told the spec was 18 +/- 2deg but it still ran poorly when it was at 15deg.

 

I would recheck the wiring. One rule of thumb for me, don't trust what the previous owner did. His mistakes are your headaches

 

I couldn't agree with you more. I have fixed so much with this swap already & don't know what to check next. I have had to repin the OBD0 to OBD1 jumper harness already, so maybe I'll check the MAP sensor wiring. What do you think about the injector resistance?

 

Depends on which injectors you are using. Are u using obd1 or obd0 injectors? What did they come out of?

 

OBD1 from either a 95 eg or they came with the d15b.

 

So you deleted the resistor box, right? In which case you should be seeing closer to 12v at the injector plugs

 

Correct, no resistor box due to the OBD1 conversion. This engine ran great in a friends eg w/ & w/o a turbo. It was pulld out for an F20B swap & sold to another friend who put it into the 91 4dr dpfi. He did tl he mpfi & OBD1 conversion. It's running on the same fuel system & ecu.

 

Ok, so I used a different DVOM because all 3 sets of my saturated injectors read .011 ohms. Now they ALL read approx 11.6 ohms. I must have been on the wrong ohm scale. Now that that's out of the way I can worry about something else.

 

Can someone help please this is the problem i'm having i have a 88 ef sedan lx i just converted to mpfi and obd1 I have checked my wiring and can't figure out my problem it seams to run decent at low RPM's around 3k. But if i get over that it starts like falling on its face like stops pulling it backfires and shuts off I'm throwing a code 4, code 7, code 9, and code 15. I've tried 2 new distributors and still does the same thing. Can someone please give me some idea's. Thanks for any help that I recieve.

Code 4 Crank position sensor

Code 7 Throttle position sensor

Code 9 No.1 cylinder position sensor

Code 15 Ignition output signal

 

3 of your 4 codes are distributor related.. are you running the Si/hf dizzy?

 

No i'm running a d15b7 obd1 dizzy.

 

I'm running a obd1 dizzy, obd1 complete zc intake manifold with obd1 injectors

 

what ecu

 

p06 ecu, I tried running a p28 no change at all it's no longer throwing a code 15 but it still cutting out and some times hitting a 3k rev limiter "LIMP MODE" Could it be the tps causing all of this? I jsut checked all my wires one again and everything is strongly connected.

 

Thanx 4 the HYJACK 88efsedanlx! My issue is mainly @ idle & cruise but you can run the h3ll out of it so long as a plug hasn't fouled yet. I had a miswired OBD0-OBD1 jumper harness for code 9 cyp. I haven't thrown a code in a while. Also, you need to pull your ecu fuse to clear all your codes & then drive & retest.

 

I have went through the wiring on the ecu over the past few days. But I haven't tried pulling the ecu fuse at all.

 

You say that you checked your wiring & it's all connected tight, but did you check all the pin locations from each sensor to the ecu?

 

Well last night the only code it through was a 41 then i got a Code 4 so i pulled back in my garage and now it wont start!