Weird D15B2 Timing problem

I posted this in a few places before, but never thought to post it here for some reason.

This is a 1991 2WD Civic Wagon with the DPFI D15B2. The car ran fine when we first got it with 75k miles. Didn't have a lot of power, but I didn't really expect much anyway. It didn't take long to start pinging, probably after adding fuel (87 octane) for the first time. Trying higher octane fuel stopped the pinging, but this engine shouldn't need it.

So I checked the timing. The first thing I noticed was the distributer was advanced all the way. Easy fix, right? With a jumper in the timing check connector, the timing marks wouldn't line up. According to the timing marks, it was still retarded and moving the distributer only retarded it even further. The distributer couldn't be advanced enough to get the marks lined up. I checked the cam timing and the marks were correct according to the factory manual. While I was in there, I installed an OEM timing belt. I ended up setting the timing by ear to stop the pinging on 87 octane. Of course that took away even more power.

Somebody gave us a 1990 Wagon for parts, identical except it had air conditioning. It had a lot more miles and the driver's side had lost an argument with a tree. But it was still drivable and had a noticeably more power than the "good" car. I thought I'd try more troubleshooting, so I tried swapping the distributer and ECU. No difference at all. Cam timing on both cars is identical.

The car actually runs OK, just has very little power. Hills sometimes require WOT in third gear to maintain 50 mph. Gas mileage is fine at about 38 MPG. Car has about 166k miles now and it has been running like this 100% of the time. Burns very little oil and has good compression. It probably doesn't really need to be fixed, it just annoys me.

So let's review:
-Distributer cannot be physically advanced far enough to get timing correct
-Engines pings anyway
-Runs OK

Have I missed anything?

Comments

  • wagodizzlewagodizzle Council Member and EDM expert
    sounds like the timing belt is off a couple teeth on the cam gear.

    im not sure if that would contribute to such a lack of power though.

    when was the car last serviced? could just need new spark plugs, wires, fuel filter, air filter, etc...
  • Thanks for the reply! :)

    The timing belt is where it should be according to the FSM. And the more powerful parts car has the belt timed the same. Sometimes I'm tempted to retard it a tooth and see what happens.

    The plugs, wires and filters have all been changed. None of it made a difference. This problem has been consistent for the whole 91,000 miles we've had it. Runs smooth from idle to the rev limiter, but the power really drops off after 5k RPM. You'd never know something was wrong if you didn't have an identical car to compare it to, or try to set the ignition timing.

    Forget the lack of power for a second. Why can't I correctly set the ignition timing? I was able to get the ignition timing perfect on the parts car. Is it possible that one of the timing belt pulleys is the wrong part?
  • wagodizzlewagodizzle Council Member and EDM expert
    try this: take off the top timing belt cover, then set the #1 piston at TDC (a very easy ghetto way is take out the spark plug and stick a long screw driver in the hole, the rotate the crank pulley until the piston is at the very top and the cam gear shows "UP". after that happens check to see if the two timing marks on the cam gear are parallel with the cylinder head. it might be off a tooth or two. mine was, and i couldnt tell at all by the driving till i got a supercharger.
  • There are actually two different ways to set the timing marks on the crank pulley and cam gear according to even the factory service manual, and sometimes they get mixed up.

    First of all make SURE you're going by the D15B2 specs and not the 1.6L D16A6 specs as they actually use different timing marks.

    Now if you're 100% certain the marks are being lined up or as close to it, yet the engine still seems to be off them perhaps someone milled the shit out of the head somewhere in the past. That's what happened with my mom's 90 DX wagon. It runs best with the timing belt intentionally off a tooth, and the head has definately been off some time in the past prior to our purchase of the car. Tried two different dizzys with the same result.

    I'd bet the timing cannot be set properly due to a milled head. I guess an adjustable cam gear would take care of the issue, but honestly hers gets good mpg at perhaps the cost of a touch of power - I can't complain really.

    I might have the actual HELM/Honda timing spec pics I can upload here to see which ones you're following.
  • I used the "DX" setting (lines parallel to head) from the 1st edition 1990 service manual. Cam timing is set correctly unless the book is wrong.

    I did the screwdriver trick to make sure the TDC mark on the crank pulley was correct.

    The milled head on a 75k mile one-owner car seems kinda unlikely, but it would explain the weird timing and pinging. Any easy way to tell? I guess I can try measuring the head height, book says 94.95-95.05 mm. I'll check the timing marks again, but I don't remember them being off a little. Being off a tooth would be pretty obvious, but it might be hard to tell if it's off by a degree or two with the vague timing method Honda used on the D15B2.

    I have no service history other than something about the distributor written on the underside of the hood. Something like "dist" and then a date, if I recall correctly. Maybe a failed attempt at fixing it?
  • Well low mileage is good, but think about this - timing belts are supposed to be good for 90K or 6 years, which ever comes first. If someone rode on the original t-belt it could have broken even at say, 80K, if it was 10 years old. If it broke and some valves got tinked some ignorant machine shop could have milled that head to the tabs while they had it off to do a simple valve job.

    Just a hypothesis about how a low mileage clean stock car could end up that way. My mom's wagon came from a buy here pay here and there's no telling how many owners it's had, but it was all stock. Upon a closer inspection of the engine bay (after the purchase) I realized the head way much cleaner (as if bead blasted) that the block, etc. It's definately been off, and due to the timing woes that's my best theory.

    I tried lining her timing up both ways (level with head and at the pointer) and all sorts of ways in between yet nothing really worked to get it perfect. I'm pretty sure it's intentionally off a tooth because dead set correctly it had no power.

    It's nice to know other people do use the service manuals from Honda/HELM and understand the difference between the white and red timing marks on the crank, and also know that there are two ways to set the cam gear either level with the head or with the pointer on the inner cover, etc. Sounds like you've got those things down.

    Anyways good luck man.
  • B18C5-EH2 wrote:
    Anyways good luck man.
    Thanks. Your theory is the best one I've ever gotten about the problem. I'll update when I look into it. I'm in no rush and it's still very cold out in NY.
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