JDM B18c1 - Down on power but running perfectly smooth - Ideas?

2821 Views 16 Replies 5 Participants Last post by Blade_Irl, Apr 4, 2009

Blade_Irl

Discussion Starter · Mar 14, 2009

3

Car: EK Civic 3door.
Engine: JDM 1995 B18c1(OBD1); Standard P72 ECU; Custom Intake(simple stainless steel pipe with K&N Filter). Spoon backbox. (engine is not adjusted in any way for emissions etc as I'm in Ireland so JDM cars/engines are road legal)
I was told the engine had ~45k miles on it when I bought it(i've done less than 2k miles since).

Not throwing any codes in normal use. Will throw one for the ELD if you jump the pins but does not show this unless you do as the ELD is not critical (simply adjusts the alternator a little when you use more electrics, but there was none in the original fusebox(d14a4 engine - 1.4L), nor the UKDM DC2 ITR one that I used to wire it. This was an OBD2 loom which I personally spliced into the original 1.4 underdash loom and added the necessary wires for the OBD1 B18c1 engine loom.

The engine pulls very smoothly right through the revs and idles smoothly(if a little high sometimes - ~1000rpm tho usually the correct 900rpm).

I put the engine in summer 07, and it then saw minimal use over the following 8months, at which point I moved to France for 6months & it sat up. I've driven it occasionally since returning home at Christmas. Its covered less than 2000miles since the engine went in(&therefore has not been serviced since then).

On a local rolling road yesterday it only put out 151bhp and 133lbs of Torque - with a very obvious sudden drop off in torque at 6000rpm - see dyno charts below.

The guy who owns the tuning center advised the timing is a little advanced, but that it would need to be a cog out by a tooth to cause such a power loss. Though, surely if it were out by a cog it would run like a dog? His next suggestion was to check fueling after I check the timing. I'm running a Walbro 255L/hr pump - that I got off Ebay though so I guess that could be an issue?

So, my plan at the moment is to check:
-Timing
-Change oil, oil filter, (& plugs?)
-Tappets are a little noisy - can someone tell me if these are hydraulic or adjusted by shims or whatever?
-Check Compression? Though surely if this was it it would not run/pull so smoothly?

Dyno Charts may offer some insight.

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1 - 17 of 17 Posts

Blade_Irl

Discussion Starter · #2 · Mar 14, 2009

3

Right, just checked the cams, and I think they are right? Marks seem lined up but cam "up" points are not both exactly "up"??
Photos below:

Pulley at TDC:

Cams:

Cams up close with marks visible

What do you think??

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mattliston

· #3 · Mar 14, 2009

That intake cam looks to have gone one tooth off. On the pic, it looks one off, anyway. Does it look straight up? One tooth can make a large difference at high rpm, where the timing distance is more critical. Many cars can be slightly off timing, idle smoothm, pull fine in the low and mid ranges, but suck at top end. check to confirm this, again, as it looks off by the picture.

Post back and let us know. In the mean time, you could pull the spark plugs and check them, pull the cap off the distributor and check that and the rotor. make sure those things are somewhat clean, and no burn spots or anything on the rotor metal or cap metal contacts.

MortsAccord

· #4 · Mar 16, 2009

I also agree that the intake cam looks off by a tooth, I thought that before even reading matt's reply.

I think you should check your compression every time you change your oil if you run your motor hard. It doesn't take that long to do and its cheap insurance. This helps if you know how your engines compression normally check out, you'll be able to spot a potential problem easier. With that cam possibly being off a tooth it would also show on a compression check, as your numbers would be slightly lower for no other explainable reason. Usually compression numbers rise as an engine ages... to a point. Then they dwindle back down as the rings begin to stick/wear out.

Is the belt old? Have you changed your timing belt recently and ensured the correct tension is applied to the belt? Have you accidently over-revved your engine?

Randomhero

· #5 · Mar 16, 2009

MortsAccord said:
I also agree that the intake cam looks off by a tooth, I thought that before even reading matt's reply.

I think you should check your compression every time you change your oil if you run your motor hard. It doesn't take that long to do and its cheap insurance. This helps if you know how your engines compression normally check out, you'll be able to spot a potential problem easier. With that cam possibly being off a tooth it would also show on a compression check, as your numbers would be slightly lower for no other explainable reason. Usually compression numbers rise as an engine ages... to a point. Then they dwindle back down as the rings begin to stick/wear out.

Is the belt old? Have you changed your timing belt recently and ensured the correct tension is applied to the belt? Have you accidently over-revved your engine?

x2. up doesnt look like its exactly up.

MQTGSR

· #6 · Mar 16, 2009

werd, what they said.

Blade_Irl

Discussion Starter · #7 · Mar 18, 2009

5

Right, I'm an idiot. For the photos I posted before I did not have the engine at TDC on Cylinder 1! I set it using the dizzy yesterday and the intake cam was definitely out by a tooth(photos to come).

So, following a friend's advice, I removed the cam covers & retainers, and tilted the intake cam just enough so that the belt was on the edge of the cam gear and I could turn it one tooth - without having to releast tension on the belt or remove the pulley etc etc.

I then set the dizzy at center of the top mounting point (which is apparently roughly right for most B18?) and took it for a drive.

I'm pretty certain I could feel more pull up top - to the point that I let it bounce the limiter by accident - which I think tells me I'm not used to it revving that fast high in the revs?

It does feel less responsive lower down though. However, as the dizzy timing is not done yet I don't want to judge it.

The Dizzy Rotor arm looks a bit worn, I think- though I'll post a photo as I'm not sure. I replaced the Dizzy cap when the engine went in as the original was broken but I don't think I replaced the arm. If I replace the arm, should I also replace the cap? Its pretty fresh as its only seen like 2000miles.

With engine at TDC Cylinder 1:

After I changed it:

Dizzy Arm:

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Blade_Irl

Discussion Starter · #8 · Mar 18, 2009

And the timing belt was changed around 1000miles ago. OEM Honda ITR belt. (JDM parts quite awkward/expensive to get without a chassis number - and over-priced for what is almost always the exact same part as the Irish ITR)

Blade_Irl

Discussion Starter · #9 · Mar 18, 2009

4

Oh, and this is the exhaust, looks 2" or 2.25" to me but I don't have a Vernier Calipers to be sure. Its either EK4 or EK9. I'm thinking EK4 as it looks more like 2".
Clearly not a difference that would loose big power but be nice to know:

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mattliston

· #10 · Mar 18, 2009

Timing belt looks a little loose, but the cam does look closer to be lined up.

Your graph for the horsepower looks really good, just has less overall power then what should be there. have you tried any sort of additives or cleaners? I recently cleaned my enguine with seafoam run through a vacuum line, and it feeel a lot more alive, HIlls that it would struggle to go up in turned into hills that it only strained a little. iIm also getting better gasmileage, 280 per tanke turned into 350, same driving style and conditions.

As for the exhaust, the difference between 2 and 2.25 is barely noticable, so I wouldnt worry about it

MortsAccord

· #11 · Mar 18, 2009

Kudos on getting yor hands dirty and fixing your car man, most people never do it.(rep)

Extremely long drives(a soft long drive) with a great oil help with how a car runs too, I get to take long trips in my accord(460 miles 1 way non stop) and it made a difference in how it runs. I like to flush my engine every other oil change.

mattliston

· #12 · Mar 18, 2009

Agreed, long drives are the only way to really clean your engine internally. Gas gets in there from cold starts, detergents in the oil dont get a chance to work 100% if it doesnt flow through a warm system for a long time.

MQTGSR

· #13 · Mar 18, 2009

Thats why I I bike around town most of the time. Thoes short trips are sooo hard on your car, and not to mention bad on gas.

If I dont have to take my car, I dont take it. Prob. is why my car with as many miles as it has still runs well and has had a minimium of stuff break on it.

Blade_Irl

Discussion Starter · #14 · Mar 19, 2009

I'm way ahead of you there guys, I had a ~200mile round trip to do last Sunday (before doing the cam unfortunately...

) and I put a can of BG44K Fuel System cleaner in the night before on top of a full tank, to allow it time to mix somewhat, then did the drive the next day - ~100 miles each way at ~110mph for a lot of it so I'm pretty sure the engine is well cleaned out now! Just hoping now that I didn't do any damage on that trip or before now with the cam out by a tooth - though I doubt thats enough to do anything really??

My cat is likely to need replacing also. I'm picking up an EK9 center section for fairly cheap this weekend - they are 2.25" diameter - not a huge difference but for the price I'm getting it it's worth doing. I'm also going to see if it will allow me to use a JDM DC2 ITR cat that I have (shortest OEM cat, & has a stupid big flange!)

Blade_Irl

Discussion Starter · #15 · Mar 19, 2009

As for the kudos in getting my hands dirty, thats not new to me, I built this car, with a lot of help from friends though I will admit - except on the wiring which was all me (1.4 wiring is v.different to normal ODB1/2) the underdash loom is my custom merge of a UKDM ITR loom with my OEM 1.4 loom, with an end result of everything in the car working. I've done suspension, brakes, bushings, exhaust etc, but, this was the first time I went "inside" the engine itself. Feels good to have sorted it myself - with some advice from friends of course though.

Blade_Irl

Discussion Starter · #16 · Mar 19, 2009

On the exhaust, ... just thinking that the 2" exhaust is probably helping my low-mid range torque...

Blade_Irl

Discussion Starter · #17 · Apr 4, 2009

I'm just back from getting it re-tested.

177.1bhp @7331rpm (Was [email protected])
148.5bhp at the wheels
140.3lbs @5984rpm (Was [email protected]) (so according to Honda's figures she's up 15lbs??...)
And both curves are significantly up right across the revs (bar a tiny drop in torque from 2200-3000rpm).

Very happy with that. Especially given its an EK4 (1.6) exhaust center section(2"),&a pretty fcuked cat. & standard otherwise bar the custom intake. Thats also on normal ~95-98RON fuel with no additives.(JDM being 100RON)

I picked up an OEM 96spec JDM DC2 ITR 4-2-1 manifold a short while ago - for free as it has a small crack in one of the pipes but I doesnt look to go right through.

So tomorrow I'll be putting that on with the JDM DC2 ITR Cat and EK9 center section. Based on the above numbers I'm guess I should see 5-7bhp from that? Especially if the cat is blocked up. She will probably peak a little higher with those I'd say too - she's already peaking nearly 300rpm below factory spec - 7600rpm.

The tuner guy said that she is running perfectly, just a little restricted in the exhaust.

I'm off to change the oil&filter!

Thanks for the help!

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