88 CRX HF, bad fuel mileage
 

Bought a one owner crx hf about a year ago, at first it was getting mid 20 mpg. It was really hard to start in first gear and kept losing power above 65mph I changed the plugs and wires, O2 sensor, the egr valve, after egr valve I started geting mid 30's. I recently adjusted the timing to full advance and it got 48 first time I refilled. It seemed like the car had really come to life at first, wasn't hard out of first and buzzed along great on the interstate over 70. Now I'm not so sure. I'm starting to think the timing belt may be on wrong because when I use the timing light on the engine nothing ever lines up which is why I put it to full advance cause it seemed the closest to getting the 3 and 9 o'clock marks flat with the head. The fuel mileage on my second fill-up went back down to 33 and I was really babying it. Its pretty frustrating getting such bad gas mileage in a car I hear regularly gets 50 mpg. the car has 136,000 miles. I know the previous owner changed the gas tank, and the fuel injectors. I also changed the fuel filter. I'm planing to change the spark plugs again soon.
I bought another crx, a 90 hf, just a couple weeks ago with 312,000 miles and a blown head gasket and warped head. Driving it around the block it seems like it would probably get better gas mileage. (I didn't drive it until I used the block and gasket repair liquid)

find out who changed the timing belt and water pump, if it hasn't been done then do it, but I suspect that it has been done and that is when they screwed things up, those heads have a number of marks on both the head, and the cam sprocket and you have to read the book to learn what mark to line up with what, if the mecanic figures that the biggest mark is what gets lined up with the top of the head then it will do exactly what you are having happen, so spend $15 on a book for it, and fix it, or buy the book and expalne the mistake to the person who is going to fix it.
also, how is the car running otherwise? my crx hf has had the tranny swaped to a tranny from a DX and it revs 1,000rpm higher now, giving it poor mileage, you might also have a back presure test done, to make sure you cat isn't cloged, and doing a normal full 60,000 mile tune up with a check list (shop manual has this) should help you alot!

I would wonder if they replaced the injectors with 240cc injectors instead of 190cc, do you have any way to find out who did the work in the past?

I have all the manuals for it, helms, haynes, and mitchell. I don't know about the injectors. I could call the guy he was pretty nice but I don't think he'd remember what type of injectors. He said they gave him the wrong ones the first time, he did it himself. When I lost power over 65 on the interstate it seemed it may have been flooding cause there was a "sweet spot" in the pedal and above that it bogged and lost speed.

on the cam sprocket there are 6 marks and an "UP" marking. there is a line at 3, 6, and 9 o'clock when "UP" is up. Then 2 numbers and a D. None of my manuals specify anything other than 12-16 degrees BTDC @ 650-750rpms at running temp with the jumper hooked up.

That was my first thought as well.

As for the 90 CRX HF, you can get a fairly new engine for around $500 shipped to your door from an importer. Might be worth looking into.

Sounds like your cam timing is off a tooth to me. You can often get away with adjusting it by simply loosening the belt tensioner and slipping the belt off the cam gear. Beats trying to remove the crank pulley.

Are the injectors the same in the 90 model? maybe I could switch them out, at least I could know if that was it or not.

I think all HF injectors are the same, so go for it.

03 Si
 

Yeah, my dad has a 2003 civic Si, the hatchback made in the UK, and hes got 120,000 or so on his. My 88 was parked by the previous owner for probably 5-8 years and then I drove it 120 miles round trip to and from work for a few months with that bad gas mileage and no a/c. The owner worked on it and another guy that was supposed to buy it worked on it... so its hard to know what happened to it. I didn't have time today, but I'm gonna pull those injectors from the 90 sometime this week. If that doesn't work I'll be attempting to move the timing belt, but I'm not sure which way to move it a notch. Am I correct in saying that the 3 and 9 o'clock marks are supposed to line up with the head? I don't know why I can't find documentation on which timing marks to use. Is there writing on the injectors that you can distinguish which ones you have? When I look them up online they only specify by model not by what cc they are.

Another thing that could be causing your car to run so bad is a clogged catalytic converter. If you can stand listening to it for a test, you might remove the cat and drive it around the block.

Have you done this before? There would be exhaust venting under the hood seems a little dangerous. I was/am thinking about changing the cat though.

Have you done this before? There would be exhaust venting under the hood seems a little dangerous. I was/am thinking about changing the cat though.

Sorry, I forgot a stock HF has 2 cats, one on the manifold and one after the downtube. (Mine has a header that eliminates the 1st cat) You definetly would not want to try this with the 1st cat, you would have an open manifold that could burn exhaust valves. You could try it with the second one, but I wouldn't drive it like that for more then a trip around the block.

hose crushed
 

It appears this hose off the intake manifold may be crushed... I have pictures from both cars so you can tell the one that looks kinda crushed... but I couldn't get it off... I tried on both cars and they appear to be maybe melted on a little bit or something. I thought there was only one cat but two mufflers. So there are two cats huh... that sucks. I need to replace my mid-pipe anyway (one of the bolts broke off in the flange when replacing the muffler). If you put anything other than OEM back on the front cat wouldn't that hurt gas mileage if it even moved the O2 sensor a little?

Is that the hose for the PCV valve? When hoses get that old they harden that sometimes you have to cut them off and then replace them.

The manual says to inspect the interior of the cat and if 50% of the element is clogged, to replace it.

Correct. You want to set the engine so no.1 cylinder (the one closest to the timing belt) is at top dead center (TDC) of it's compression stroke. If you line those notches up with the valve cover mating surface, the cam will be properly aligned.
https://www.fuelly.com/attachments/fo...5bb080a71d.jpg
If you look at the crank pulley (the pulley that drives the alternator and A/C belts), you should see 4 notches cut into it's rim. The cluster of 3 is for ignition timing, the 4th mark is TDC - the mark you need.
https://www.fuelly.com/attachments/fo...8d99f151b4.jpg
The with the cam marks where they should be, the TDC mark should be lined up with the pointer/sight thing molded into the lower timing belt cover. If not, your cam timing is off.
Loosen the timing belt tensioner - it's behind the black plug in the lower timing belt cover. Just carefully pry the plug out with a small flathead screwdriver. Break the tensioner bolt loose and then keep going two or three turns to free up some slack on the belt. Be careful not to unscrew the tensioner bolt all the way... You would likely have to remove the crank pulley and lower belt cover if you did.
Slip the belt off the side of the cam gear. The belt's not designed to bend the way you're trying to bend it, so don't be surprised if it's a little difficult.
Turn the crank until the TDC mark lines up with the pointer/sight thing on the timing belt cover.
Slip the belt back on the cam gear. Obviously you want to avoid moving either the crank or cam out of alignment while working the belt back on, but try to keep the front, long run of the timing belt tight if you can... It's the run that counts timing wise.
Once the belt is on, thread the tensioner bolt back in until you've picked up the slack (the point where you would go from simply threading it in to tightening), then back it off a half turn so the tensioner can move. Turn the crank counter-clockwise a quarter turn to put tension on that long run of the belt, and all the slack on the tensioner/water pump side. Tighten down the tensioner bolt... The torque spec is 33 ft/lbs if you have a torque wrench.
Keep turning the crank counter-clockwise until the cam is back at #1 TDC. Check that the crank is also at TDC.
Replace the tensioner bolt plug and upper timing belt cover.


Yeah, if you don't mind flames shooting out of the manifold at the back of your radiator. :D

Yeah, that's definately the PCV hose. Though if it were leaking, it shouldn't affect power at all. Hondas use a speed/density system to measure air flow, so there's no mass airflow sensor to bypass. If air leaks into the manifold, the pressure rises, the increase shows up on the MAP sensor and the ECU injects more fuel to compensate. If anything, you should see an increase in idle speed.
There is only one cat on a stock CRX. The HF cat is bolted to the exhaust manifold on the front of the engine, the DX and Si cat is under the car, just to the rear of the firewall. Oxygen sensor placement isn't critical beyond making sure it gets hot enough to operate. The CRX engine management system just isn't sophisticated enough for it to make a difference. Newer generations of Civic (most '92+ models) use a heated sensor, so placement is even less critical. I suppose putting the sensor close to the exhaust ports allows for quicker fuel mixture responses in closed loop operation. Putting it further from the ports would allow more time for the exhaust from individual cylinders to mix... If that makes a difference.

There is only one cat on a stock CRX.

I stand corrected. This misinformation was from the original owner of my CRX. My car has a header and a cat in the DX position. I asked the former owner for the original exhaust manifold if I need to put the car back to stock and when I saw it had a cat on it, the former owner said the stock car had 2 cats.

timing
 

I'm not sure what those instructions were for. Was that to set to TDC and properly align the belt? The engine is in the car... should I take out the driver's wheel and plastic housing to be able to see the crank pulley? Maybe tomorrow I can take a picture with the top belt cover off so someone can explain what i'm looking at.

Yeah. Since you described the cam gear earlier, I assumed you had gotten that far before.
You should take off the splash shield in the driver's wheel well so you can reach the pulley, and the upper timing belt cover. You'll need to remove the spark plug wires (they can stay attached to the distributor) and valve cover in order to remove the upper belt cover. The remaining chunk of belt cover is the lower timing belt cover. Most of the timing belt, the water pump, and the timing belt tensioner are all covered by the lower timing belt cover. You have to either remove the crank pulley or cut the cover to remove it. Removing the pulley is a PITA without either something to hold the crank still and lots of leverage, or a big mofo impact gun... So, the above instructions work around the cover instead of removing it.
Removing the upper cover will expose only the cam gear (the first pic I posted) and the section of belt running over it.

just to make sure
 

How exactly do you set the cam timing? I didn't have to remove anything else to get the top timing cover off, its a little tough, but the plastic flexes enough to push it down and slip it out of the grove. Getting it back in is actually harder, but I can do it pretty quick now. I read somewhere (possibly in the d15z1 swap thread) that you can remove the pulley in the car with it in gear, but it seems like you might have to have that wheel on so the car doesn't fall off a stand or move too much. Like I said before I can't get anything other than maybe the 1.6 liter mark to line up with anything (I think earlier I refered to it as 6 o'clock, but I can tell from your picture that it really isn't) Should I be trying to line it up to time it to the "D" mark? I can figure it out with your instructions if I just know what mark to use to time to. None of my manuals say, and I think you suggested using the 1.5 liter cam marks is supposed to set TDC on the cam? I feel like a dumb ***.

https://www.fuelly.com/attachments/fo...ed014b1d5c.jpg
You line them up with the joint between the valve cover and the rest of the cylinder head. It's only about half a belt tooth different when compared to the 1.6 liter mark and pointer, but that's enough to prevent you from installing the belt properly.

I have never heard of a 1.6 Liter mark.

In any case, your problem sounds to me like, most likely, your timing belt is off by one tooth. It is very easy to have it be off that much and not catch it, particularly if the person doing the replacement doesn't check their work, after they have tensioned the belt.

Most likely, you just need to reposition the belt.

You need to use the 2 marks on the camshaft, the blue lines in the picture, lined up with the bottom of the head. You then need to use TDC on the crankshaft. With both of those lined up you then need to add the timing belt. You need to tension it, like is described.

Then, after you have tensioned it, you need to put the Crankshaft to TDC and adjust your distributor so it is pointing to the number 1 spark plug wire.

Then connect a jumper wire to the test harness and set the timing using a timing light.

Go pick up a manual. Chilton's, Haynes, Honda... It's been in every single D-series manual I've read so far, and on every SOHC D-series cam gear I've seen. It gets lined up with the plastic pointer just under the cam gear, unlike the 1.5 liter marks.
What picture? All the cam gear and crank pulley marks I highlighted in blue are marks you should ignore. The only important thing I marked in blue was the valve cover to head mating surface.
You mean the bottom of the valve cover? The bottom of the head is on the floor in the pic I posted this morning.
The distributor rotor can only point one way. The distributor shaft is connected to the camshaft by an almost idiot-proof fitting... You can still take the fitting off the distributor shaft and put it on 180? out of phase. Loosening the bolts and moving the distributor housing back to the middle of it's adjustment range is probably a good idea, but I don't see how that relates to the no.1 spark plug wire or terminal.

Sorry if I sound like an ***, I just hate to let bad or questionable information stand as truth.

Okay, when I was attempting to set timing on the engine the only mark that would line up with anything was the 1.6 liter mark. I set the timing light full range from 0-60 degrees BTDC and no dice with the 1.5 liter marks and mating surface so the belt has to be off.

Now to recap, #1 cylinder, the one closest to the timing belt and the one you put your timing light pickup on, has to be set to TDC by adjusting the crank pulley correct? Then separately, the cam has to line up with the deck between head and valve cover, then you put the belt on and keep this relation as close as possible... Then you time with the light using what marks?

Your on course. When you get the marks lined up and the belt on, then you need to turn the crankshaft, to let the tensioner pull the timing belt tight. After you get the belt so it has tension, you need to tighten the tensioner bolt back down, to hold the tension. It is easy to have the tension on the belt not be as tight as it should because the piston and the camshaft have some pressure on them. If you turn the crankshaft counter clockwise, you can feel the tension in the timing belt by putting a finger on the belt, on the back side of the camshaft.

Once the belt is tensioned, reposition the TDC and check for the alignment on the two marks on the camshaft pully, relative to the head. Yeah, their *green* not *blue*. The distributor is slotted, so you should not need to change it, you should be able to just adjust it to roughly the middle of it's travel, to start with.

When you set the timing, on the crankshaft, you have the TDC mark, then about 1 1/2 inches away you have three marks close together. I don't know the exact number, but I usually set it to the middle mark, which is I think the 18 degrees it calls for. The other two marks are +/- 2 degrees, I believe.

I believe I read that the HF is 12-16 BTDC... but things are starting to make more sense... what do the marks on the Crank align with when timing? I was attempting to time using the camshaft not the crank. Thanks everyone for the help so far!

The timing marks on the crankshaft are measured relative to a plastic marker which is molded into the lower cover for the timing belt. If you look down an imaginary line drawn between the centers of the crankshaft and camshaft, the mark is about 3/4 of an inch towards the back of the car, behind that line. The mark on the timing cover is molded as a part of the plastic and it looks like more of a cast line, to me, than to a alignment mark, but heh, it is what it is.

As far as the actual numbers of the marks, the middle one maybe 14 degrees then.

One thing you might do is to get a bottle of white out and put a little white spot at each of the marks on the crankshaft. I always have a hard time seeing the marks on the crankshaft, using the light from the timing gun and it seems to help a lot to see them, if you have higher contrast.

Woah, what are you using the timing light for? The cam and crank adjustments I described above are done with the engine off, no strobe light or anything. You only need a timing light for adjusting the ignition timing. We're talking about cam timing here.
While you have the upper belt cover off, grab ahold of the crank pulley, or put a 17mm ratchet on it and turn the crank by hand (preferably counter-clockwise) until the cam gear marks are lined up. With the engine still off, look down the sight/pointer thing that you normally use for ignition timing. If the cam timing is correct, you will see the TDC mark on the crank pulley. If not, you need to adjust it. Go through the instructions I layed out before. Do not start the engine until you've gone through the whole proceedure.

I'm pretty sure he was just giving some general advice on setting the timing after he'd finished. No need to jump down anyone's throat.

timing
 

The cam is timed by the crank, ignition is timed by the ecu sensors in the distributor (driven by cam). The point here is that something with my engine timing is most likely ****ed up. I appreciate all the input, but the most confusing thing here has been what marks mean what and for what, not how the engine works... I want the valves and ignition to be working correctly when I finish. I want my FE damn it! Thats why I have two HFs in the first place. I happened upon this website a couple days ago and I can't stop reading, this place is as addictive as facebook was until it lost its "new".

Sorry for the confusion... I was refering to this:
That sounds to me like he's pointing the timing light at the cam gear, which to my knowledge is pointless.

:thumbup: I was confused at the flow of comments, :p

You're right
 

Bobski, You were right, I was trying to time the ignition from the cam gear, which I guess was stupid, I guess what I failed to think about was that I needed to time the spark to the point in the combustion cycle not in the valve timing. Its my first time using the light, and none of the instructions made sense because there were no pictures depicting the marks on the crank until you posted one. I was taking the 3,5, and 2 on the cam to be timing marks. I'll look at it tonight hopefully and have it completely figured out. I really appreciate the help, sorry I made such a stupid mistake.

Well, technically speaking, you could time the ignition from the cam gear. The crankshaft and camshaft are kept in sync by the timing belt, it's just that the crankshaft spins exactly twice as fast as the cam, so you can get a more precise measure of the timing by looking at the crankshaft.
Mistakes come with learning new material. You didn't know, so you made assumtions... No need to apologize.
What's the worst that could happen? You would break your own car.

exactly
 

and then I'd get to fix it.

Ok, I'm having timing issues and maybe a couple other things robbing fuel (cat, injectors?) in my 88 CRX HF 1.5. Today I went out and took off the drivers tire and discovered the plastic splash guard on that side is missing. (seems someone forgot to put it back on, probably when they changed the timing belt). I found the TDC mark on the crank pulley and lined it up with the plastic mark on the lower timing belt cover. Seems like the 1.5 liter marks are lined up on the cam and valve cover mating surface above. Now, when timing. . . if I set the timing light to 12-15 degrees BTDC (with the engine at 500-750 rpms and jumper installed) the marks move counter-clockwise away. I know honda engines are transverse mounted... does this mean that I need a timing light that will do -12 to -15 degrees BTDC, or rather 12 to 15 degrees After TDC?

Set your timing light to 0° and use the 3 ignition timing marks I labeled in my second pic... The one of the crank pulley. The center mark is ideal, the outer two are ±2°, but still within spec.

OK, but what I'm saying is with the timing light set at 0? it flashes when the TDC line passes the plastic marker, when I move the adjuster on the light towards 12-15 like its supposed to be set at the flash moves clockwise and the 3 lines are in the counterclockwise direction.

Also, since the crank and cam seem to be aligned properly, I think the real problem lies elsewhere because I don't think the ignition timing could kill my FE by 20 mpg.