speedsk899

Hello, I am new to the forum and I am here because I have a problem I am having trouble figuring out.

The car: 1994 Honda Civic Hatchback, 5 spd

The car is bone stock. 248,000 miles. Last timing belt was about a year ago and has ran fine ever since. Car runs fine but needs base timing set.

A couple weeks ago I was driving home from work and the car started running poorly. Surging, low power, rich. Got code 43.

I changed out the cap, rotor, and plugs (because it had been a while and the contacts in the cap looked bad) but it didn't help. I checked the fuel pressure and it is good. I probed the O2 and it was reading maxed out rich, I could get it to fluctuate by revving it up but it would go back to full rich. I followed all the troubleshooting steps in the Haynes manuals and everything checked out. I then checked continuity from the O2 to the ECU to make sure the signal was getting back there and it was good.

I decided to take a shot and replace the O2.....didn't fix it. I took the CAT off and punched it out still didn't fix it. I'm thinking the ECU is bad but the only extra one I have is the original which failed on me about 5 years ago and wont start the car. So I stopped by a little import shop in town and dropped the car off. He took the P06 ECU out and put in a P05 and it went right to a smooth idle. He also took the distributor and turned it to put the tabs in the middle (no timing light). Well the problems of the car running rich were solved but now there was no power and I figure its because he turned the distributor back.

I could see where it was set before so I moved it back. Seemed to be a lot better but I still had a small hesitation while accelerating at low RPMs. Turns out it was the spark plug wires.

I decided to set the timing to the 16 degrees (red mark) since he had turned it with out checking it and here is my issue.

I install a jumper in the service connector and start the car. Let it warm up a bit and the red timing mark is off to the right (advanced) by about 45 degrees.....If I remove the jumper its in the same place. If I move the distributor the mark moves just as it should. I can not figure out how to get the mark to the top of the balancer so I can set it with the mark.

Is there any chance the balancer is not in the right location? If I remember right there is a key way that would prevent it from being installed incorrectly.

Has anyone seen this problem before and what do I do about it?

Sorry for the long write up but wanted to show how I got to where I am and hopefully answer any preliminary questions. The car is running fine but I would like to get the base timing set correctly. Thanks for the help.

Former User

Civic DX or CX? What engine (D15B7 or D15B8) is in your car? The ECU MUST match the engine.

P05 = D15B8 engine
P06 = D15B7 engine

speedsk899

Dx. Not sure what engine but I'm going to guess the D15B7 since the car had a P06 in it originally.

I have no idea about these and I was told there was really no difference between them by the shop that put the P05 in.

Is this going to cause a problem in my car? Gas mileage difference?

Former User

Read the block code (engine ID code) on your engine:

https://honda-tech.com/forums/showpo...5&postcount=12

This^ raises serious concerns about the shop.

Yes, if the the ECU does not match the engine.

speedsk899

I will check it out. I never said it was a good shop......haha

What kind of issues can it cause?

Former User

The engines and hence the ECUs are different.

https://honda-tech.com/forums/showpo...97&postcount=7

For example, the B8 has a 1-wire O2 sensor and an EGR system, whereas the B7 has a 4-wire O2 sensor and lacks an EGR system.

The B8 is designed purely for fuel economy, whereas the B7 is a balance between economy and performance.

Post the block and head codes for your engine (you may need to remove the header heat shield to see the head code).

Also check whether the O2 sensor plugged into the header has 1 or 4 wires.

What CEL codes is the ECU throwing? Click the Codes link in my signature.

speedsk899

I will look at the block and head codes when I get home. It has a 4 wire O2 and no EGR. It is throwing no codes (no CEL and the light stays solid when the connector is jumped) and runs fine but does lack some power.

Former User

A stock P05 ECU should throw CEL codes when used with a stock D15B7 engine. For example, the P05 should look for an EGR system and throw code 12 because your D15B7 lacks this system.

Remove the passenger kick panel to expose the ECU. Post a picture of the ECU verifying it as a stock P05. Another possibility is that the P05 ECU is chipped. You'd have to remove the ECU and open it up to look for the chip.

You should also pose these reasonable concerns to the shop that claimed to install a P05 ECU in your car. Their responses would likely prove insightful.

speedsk899

I will pull it and check out the label and pull the cover to see if it has been chipped. I will let you know what I find. Thanks for the help

speedsk899

The ECU is a P05-A00. The computer that came out of the car originally and the second one I had in there are P06-A02.

The engine code is D15B7 (3524215) and the head is a 93 (PM9-1, after looking at the thread with the code list maybe the head is a PMS-1).

The ECU doesn't look chipped to me. I added two pictures.

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I still have no codes and the car runs good just weak. The gas mileage seems to be down too.

Former User

Post a picture of the head code.

You need a P06 ECU for a manual transmission.

speedsk899

I will try to remember to get a picture tonight.

I have a P06-A02 that should be delivered today. Still doesn't explain why the P05 is not setting any codes......

Former User

Call the shop that lied and ripped you off. They seem to operate by the smoke and mirror principle. Also tell them that you'd like the original P06 returned to you.

It looks like the D15B8 doesn't have an EGR system, so that explains the absence of code 12.

Code 1 is probably not thrown because all the P05 ECU looks for is one O2 sensor wire, which is present. However, your D15B7 4-wire O2 sensor cannot work with only one wire connected to the ECU. The latter issue and the already mentioned differences between the D15B8 and D15B7 engines are making your car run like crap.

speedsk899

Makes sense. I already have the P06. I wasn't going to let him keep it. Could be a good troubleshooting tool down the road. It is definitely bad. I plugged it back in the other night and it went straight to a horrible idle and missing.

I set the number 1 piston to TDC last night and the timing mark is off to the right just like when I point the timing light at it. Looks like the balancer is not lined up like it should be. I know the timing belt is good because the car runs good.

Former User

Properly set the mechanical timing of the engine and then retry the P06 ECU, along with properly adjusting the ignition timing. Who knows, you may find that the original P06 ECU is fine.

speedsk899

I put in the new P06 and the car runs great. Not sure why the timing marks are not lining up but I don't think the mechanical timing is off.