See UPDATE at bottom of the page. Now throwing a Code 9 after fixing the code 4.

Okay, long story short, my MPFI swap has not gone well. It is running, but it's running pretty poorly. Did initially have more problems than just a code 4 but that's all I'm dealing with at this point.

The distributor and the ECU have been swapped out for known good ECUs to no avail. Wiring has been checked and double checked, and solder has been redone in multiple spots but I'm still throwing the code. As per the factory service manual, resistance has been checked across B10 & B12, measured at ~400, within FSM spec.

Continuity has been checked across the solder at b10 & b12, and is fine. So questions are as follows - when repinning b10, could it be possible that for some reason or another the OEM pin could have been inserted wrong / not making contact with the ECU side? Is there an easy way to check this? (Resistance was checked from the back of the wires)

If that's not an issue, then it should be at the distributor side of the wiring for the problem, no? I do not have the distributor side connector for the MPFI, so I'm not running an OEM connector there; could this be causing the code due to interference between wires?

Does someone have a scan of the Honda electrical wiring diagram for what color wire is exactly what in the circuit between the distributor and the ECU? I've found around 3, one of which mispells Crank and isn't very detailed, another that was plain wrong and one that has a wire that my distributor does not have.

I can get pictures up later if it will help.

Thanks in advance for any help.


Modified by JustAnotherRex at 9:13 AM 7/9/2007

 

Damn, man I wish I had an answer for you. Free bump bish .

 

This scares me. I'm getting ready to go MPFI and I thought I had everything all figured out. Are MPFI swaps normally a pain in the sack? On paper, it looks fairly straight forward.

 

I had a Code 4 and it ended up being a loose connection in the connectors. Check the plugs for the ECU .. one of the pins probably arent secure

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blinger &raquo;</TD></TR><TR><TD CLASS="quote">I had a Code 4 and it ended up being a loose connection in the connectors. Check the plugs for the ECU .. one of the pins probably arent secure</TD></TR></TABLE>


happened to me, in my first mpfi swap.

 

NOTE: the Honda electrical service manual numbers the ECU pins different from Haynes, Chilton, etc. - they are numbered consecutively across the top row and then continue consecutively across the bottom row (pin #1 is in the the same palce) - for instance, on the B connector, the top row is numbered 1 thru 10 and the bottom row is numbered 11 thru 20 - so, when you are looking at this diagram you will see the orange Crank Sensor wire going to ECU pin 15 and the white one to ECU pin 16 - this corresponds to B10 and B12 - please note that all of the distributor wires are shielded in pairs to keep them from cross connecting

 

Problem Solved! Sort of.

Well, I have an update.

I decided to depin the wires at b10 and b12 and replace them with all new solid wires.

This did in fact get rid of my code 4. I don't know if there was a split along the way of the factory lines from wiring them up or what.

The bad news is that I am now throwing a code 9. From the searches I've done it looks like I need to replace the distributor I have for yet another distributor, as continuity & resistance checks out.

Thanks for all the help guys!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JustAnotherRex &raquo;</TD></TR><TR><TD CLASS="quote">Problem Solved! Sort of.

Well, I have an update.

I decided to depin the wires at b10 and b12 and replace them with all new solid wires.

This did in fact get rid of my code 4. I don't know if there was a split along the way of the factory lines from wiring them up or what.

The bad news is that I am now throwing a code 9. From the searches I've done it looks like I need to replace the distributor I have for yet another distributor, as continuity & resistance checks out.

Thanks for all the help guys!</TD></TR></TABLE>

I had to do this last week with a customers car, the pins basically were chewed up pretty bad from the last owner or did the swap, some people rip the pins out and don't depin them correctly.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RCautoworks &raquo;</TD></TR><TR><TD CLASS="quote">

I had to do this last week with a customers car, the pins basically were chewed up pretty bad from the last owner or did the swap, some people rip the pins out and don't depin them correctly. </TD></TR></TABLE>

Yeah, I'm about to pull them again and double check. The first depinning I did I was trying to depin from the back of the plug with the wire My wiring also looks like absolute crap at the moment, but I don't really feel like tidying it all up until I've got the D series out and my B ready to go in.

In any case, I figured depinning & repinning out now and it goes pretty damn easy, but I'm still thinking since I've swapped out the C1 & C2 pins, and the same issue, my 2nd try at a used distributor is the issue.

 

So a basic run down:

Throwing a Code 4 after an MPFI swap. Repinned the connectors and ran new wires from b10 and b12 to the distributor. This eliminated the code 4, in turn I now have a code 9.

The code 9 is the Cylinder position sensor which are the wires from C1 and C2 that you have to run when doing the MPFI swap. I've depinned those and repinned with better pins, and checked the wires I ran into the bay. All of that tests correctly for spec and is new wiring.

Should I presume the distributor is at fault at this point?

This is the second distributor I've used on it but both were used when I got them.

 

Is the car still running in limp mode because of the code? Glad to hear you got the code 4 fixed, it always seems like you take a step forward then two back doesn't it?

I'd say you try fidgeting with the wiring some more if this code appears across two distributors.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wiZCo &raquo;</TD></TR><TR><TD CLASS="quote">Is the car still running in limp mode because of the code? Glad to hear you got the code 4 fixed, it always seems like you take a step forward then two back doesn't it?

I'd say you try fidgeting with the wiring some more if this code appears across two distributors.</TD></TR></TABLE>

Yeah, I'm going to depin and repin today. It is still in limp mode due to the code. I plan to depin, repin tonight for C1 & C2 and solder up the wires that fixed the 4.

Pain in my ***, had I thought it'd be this bad I would have gone with boomslang. Oh well, already knee deep in **** might as well keep marching.

 

Whatsup george? Sounds like you still have wires crossed. I know my whole problem was 2 wires at my distributor crossed. I know its frustrating but it will all be worth it once you have the gsr in!

-chris

 

Have you taken the distributor off and checked to make sure the shaft bearing is good? I know if the the bearing has play and the shaft can move around it will mess with you cyl sensor.

-Chris

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by white90rexsi &raquo;</TD></TR><TR><TD CLASS="quote">Have you taken the distributor off and checked to make sure the shaft bearing is good? I know if the the bearing has play and the shaft can move around it will mess with you cyl sensor.

-Chris</TD></TR></TABLE>

I hadn't, I guess I'm going to have to. I'd been trying to figure out how to determine whether or not that sensor was screwy. I'll pull the distributor today and see what I can do on that. Thanks man!

 

Also, I doubt you have access to a lab scope but if you have a lab scope hooked up you could see the wave pattern and see if it is good as well. There should be an ohms spec on the sensor also. By the way.

-Chris

 

Checked the wires, swapped C1 and C2 again for good measure. No change, still code 9. I'll probably have to run those wires over and see if that doesn't change things, although I doubt it will.

In any case, I decided screw it, I'm going to take it around hte block and see how its running. Its not actually in limp even though I have a CEL!

Hooray! I didn't think I'd notice it, but MPFI is noticeably faster than DPFI.

 

After you re-pinned did you clear the ecu code?