ascarberry

So after picking up another sedan and getting much better mileage than my current dd i decided to see whats off. Since I picked up the first one I have never been able to get the ignition timing close by light and have had to advance as much as I could by the distributor for optimal performance (which its still a slug). Well today went out found tdc and low and behold the cam gear where lines were perfectly horizontal... hmmm damn guess I was wrong.... wait a minute where it says "up" looked more like "dn" lol another words it was completely upside down!! haha how do u do that. I guess the last mechanic was drinking a lil too much during the belt swap haha. Now idk if I want to tackle that job today! Anyone know an easier way to resolve this haha. Jk it runs fine just lacks power so ill fix it sunday when Im off next. Honestly cant believe it runs!?!?!

4drEF

If your cam was 180* off the car would not run.
Performance wouldn't be an issue since the engine wouldn't even start.

Sounds like you found TDC on the piston, but not on the compression stroke.
Take a look at the timing mark on the CRANK and the CAM lines.

You didn't specify which engine so here is an example with the EG motors.


Are you putting a jumper in the service connector (the one you put a jumper in to retrieve fault codes) when you are setting ignition timing?
You NEED to or your ECU will try to correct it electronically.

jlicrx

what method did you use to find TDC? TDC on the crank pulley is the single (white) mark off to the right a little ways from the 3 ignition timing marks that are close together - if you put something like a screwdriver down the #1 spark plug hole and brought it up to TDC, you could be at TDC on compression on #1 and TDC on overlap on #4 or you could be at TDC on overlap on #1 and TDC on compression on #4 - sounds to me like you were at overlap on #1 and compression on #4, in which case the 'UP' arrows would be pointing down - on a 4 cycle engine, the crankshaft turns over twice for each time the camshaft turns over once

ascarberry

it was tdc using a straw down the hole and verified by the crank pulley

ascarberry

sorry it is a d15b2


You say it wouldnt run if it was upside down... do you know this for a fact? Or just engine theory cause to me I agree but I know what I was seeing!

On another note the distributor cannot be rotated 180 and installed correct? seems the slots are offset ground or something to prevent it, iirc?

ascarberry

yes I am using a jumper.

ascarberry

one car was getting 32mpg best as a dpfi motor now gets 30mpg w mpfi (car has apx 160k and in good shape fresh fluids and filters). The other is a dpfi gets 42mpg (car has apx 260k havent yet changed fluids or filters).

Obviously the car with the lower mpg is the car in question. I dont expect mpfi to be as fuel effecient but not 12 mpg different!

94eg!

iTrader: (2)

You have to verify TDC on the cam gear as well as the crank pulley (as shown in the diagram above). If you don't know your cam angle, you cannot tell.

A 4 stroke engine has two TDC's. TDC after compression and TDC after Exhaust storke. If you had the cam 180* around, the engine would be getting spark right after the exhaust stroke. At this time, both the intake and exhaust valves are open, so there would be no combustion (except maybe a backfire out the intake when you crank the starter). The engine CANNOT run like this.

jb2wheels

You guys crack me up - a cam can't be 180 out. Spin the crank another full turn and your cam will magically be perfectly timed...

You found "TDC" on the "blow" stroke of a four stroke suck-squeeze-bang-blow.

OneBadTurboCRV

Also known as...

Piston Down - Intake
Piston Up - Compression
Piston Down - Power
Piston Up - Exhaust

Also - I know for a FACT it will not run if the cam is 180* out and you will also have internal engine damage. Soo... you didn't check it right I can assure you because it is running... How much slop is in the timing belt?

4drEF

True - one key is a little bigger than the other and shouldn't fit into the cam 180*.
However, it can be mashed and forced in there.
Either way, car will not start up (much less run) with the distributor flipped 180*, the cam flipped 180*, or a combination of both.

Here is the D15B2 image for setting the belt:


That sounds like the belt is off a tooth and setting the cam retarded. You said you are disabling the electronic advance so you should be getting a nice steady view of where the marks are when you using the timing light. I'm assuming you know about the sights on the belt covers you need to use to set the timing. Where is it the crank pulley mark showing up when you try to set it?
For setting timing:

94eg!

iTrader: (2)

Why would you have internal engine damage?

ascarberry

Well I hate to start a pissing contest but you know it all's are wrong on this one. Rotated it back 180* and guess what it ran the same in fact honestly feels a little slower! Didn't have time to play w the timing so ill look into that TM. I agree It sounds impossible but in this motor its not. U can't assume everone on here is. 12 yo kid working on a car for the first time. The only noticeable difference is a little less gas popping in the exhaust when engine braking/ down shifting! Ill watch the MPG and update later.

Flame on!

tonylovesjdmEF9

Your dizzy 180 degrees off lol the car wont run it the cam was 180 off it would self destruct valves would hit the pistons

Efhatch277

tonylovesjdmEF9

Because of mechanical timing if your timing belt skips even a tooth it will cause the valve train to be a tooth behing the crank and as the engine spins the valves will open at the wrong moment and the top of the piston will hit them causing them to bend, break and fall in the combustion chamber causing more damge, it all depends what happens

94eg!

iTrader: (2)

Were not talking about 1 tooth. If you cam is 180 off, the valves will still be perfectly timed with the pistons, just on the wrong stroke. It's the fuel & spark that will be firing at the wrong time. lol

ascarberry

Well seeings how the distributor can only be in one way the timing follows the can and the fuel would as well! So yes wrong stroke but runs! Just the same in fact! Now would that work onmy Nos SBC!? Hell now but I can tell u w/o a doubt the car ran!

94eg!

iTrader: (2)

Ah!!!! Now that does make sense. I forgot the ECU reads everything about engine position off the camshaft. I guess the only difference would then be the timing-marks 180* out on the crank pulley. That would just make it impossible to read your ignition timing with a light since you won't see the marks. All that talk about ignition above must have gone over my head.

Of course flipping the cam around won't make much difference performance wise cause everything would be the same. You do run the risk of damaging the valves when you try to do it. I guess putting the crank at 90* ATDC when you take the belt off and attempt to roll the cam would be the safest bet. That way none of the pistons are at TDC. But getting the belt on correctly with the crank at 90* might be pretty tricky.

ascarberry

[/QUOTE]That sounds like the belt is off a tooth and setting the cam retarded. You said you are disabling the electronic advance so you should be getting a nice steady view of where the marks are when you using the timing light. I'm assuming you know about the sights on the belt covers you need to use to set the timing. Where is it the crank pulley mark showing up when you try to set it?[/QUOTE]

To be honest idk if its my older model snap on light or not but Im not getting a steady mark. In my haste to get it done real quick in may in fact be one tooth off now but Im seeing a mark where as before no matter where I was with the dial back light I was seeing nothing.

Yes I am aware of the marks.

Im still very disappointed with the mpg now that I know its potential! lol

hashish

I know it has been a while since this happened but just wanted to add to anyone who may come upon this thread.. It may be that you are not getting a steady mark is in this model of honda you have to short out the computer connector under the dash to be able to read the mark, otherwise the computer will be trying to adjust the timing.. I don't really understand why the timing would be fluctuating because of this but apparently it is.. so use a paperclip or a wire with uninsulated tips to short the little two prong connector and then the timing should be able to be more clearly read.. if not then its probably the light gun i guess if that is even possible.