Uneven Compression... any advice?

[xirdneh]

[quote="joes mama"]Hello,

I just bought a 1988 Toyota Tercel DX.



i wonder if someone messed with the timing
maybe they pulled the distributer and got it in wrong

1. you have enough compression to get it started
2. you tried starter fluid or a bit of gas in the carb to see if it caught and ran for a moment. if it ran for a bit then the carb is clogged or fuel pump is bad.
3. you replaced fuel pump.
4. you say it has spark

[joes mama]

there was one other thing that i noticed that i considered odd when i was checking to verify fuel delivery...

when looking down the mouth of the carb, the plate that covers the mouth of the carb, and opens when you pull the throttle cable, only opens about a quarter of an inch with the throttle cable held wide open. so i cant really see down into the carb at all...

is that normal?

[Soutthpaw]

/I agree with what others have said. I would suspect a timing/ign issue. Have you pulled each plug and held the plug to ground and cranked and made sure you have a nice spark on each plug?
if the answer is yes,

The entire shop manual is posted here somewhere, front page i thnk. Follow the directions and remove timing cover and distributor and check all is aligned correctly.

[coltarms]

That is the choke plate, and it is normal to be more closed than open until the thermostat warms up and allows the choke plate to open fully.

Download that manual, then use it to cover the list of items people have already typed up. Make sure that the camshaft timing is set correctly, as is the distributor ignition timing. Go down the list of thing I typed in this post. All the procedures you need are in that manual. Nobody here can tell you the one magic nut to tighten for your car to miraculously start.

Good luck.

PS - If you use some good hand lotion before you start, your hands will clean up a lot easier when your through gettin' 'em dirty....

[joes mama]

cool, i wont bug you guys again until i have exhausted every possibility brought up in this post so far. i really appreciate all of the help.

hopefully my next post will be to tell you all i have got her started.

[joes mama]

timing is OK... but:

the spark is actually a dull yellow across all four cylinders, not bright blue, as i previously reported...

what does this suggest?

[joes mama]

coil tests good, so do the wires, but the cap shows 35,000 ohms of resistance between the coil and the top of the rotor... i think i found the problem.

i'll report back after i get a new cap.

[joes mama]

w/ the new cap/rotor/wires installed:

the spark is still not blue but it IS brighter, and it almost started, (it turned over on its own for a couple of seconds, then died). i have to turn it over w/ the starter for about 10 seconds before it will start to run on its own, though.

i thought it strange that when i tested the brand new cap, the resistance is 15,000 ohms. that still seems high to me.

it still refuses to start w/ the carb primed.

and ideas of what besides the coil (which tests fine), the rotor (new), or the cap and wires (new), that could be causing the yellow spark?

the battery is strong as well.

thanks!

casey

[Typrus]

Yo.
Seafoam is good stuff. You know, it is intended for tank use or carb use.... Advance Auto Parts in my area sells it in pints ($5.85) or Gallon containers ($42.50)
Hows your coil? The FSM (Factory Service Manual) on the homepage (http://www.tercel4wd.com) will tell you the specs for various resistances inside the distributor.
If it was having issues before you did the cap and rotor, but now it'll stumble, it'd seem to potentially be an ignition issue. Or maybe camshaft timing.

I've never had success trying to start my car with the throttle fully depressed... I always had the best luck with a pump and crank approach. If you pump it 5 or 6 times, crank it and it stumbles then dies, then pump it 6-8 times. If it still stumbles then croaks, then use a process of finessing the throttle while its stumbling to try and get it passed that point.

I had a little 2-cyl 250cc feel incredibly gutless for the first 150 or so miles then one day, going up a hill at full throttle (cooincidence?) it literally had a "PING!" sound and suddenly I lost control and dropped it. It surged hard enough I flopped side to side then slid on some sand on the road and was on my side, blinking trying to figure out what happened. Was alright (thats why we wear our leathers!) and took off again. Been a whole new bike since.

[joes mama]

so... its running.

i just advanced the timing to make it run, but now i am having trouble setting the timing.

my timing light is one of the ones that clips over the coil wire, but this car has no coil wire, so i just clipped it on the #1 wire.

the timing mark is reading ridiculously advanced... like 60 BTDC (if that is even possible.)

am i doing something wrong with the timing light? i can't even get the timing mark close to TDC by turning the dizzy.

hmmm?

[coltarms]

Maybe it's just me, but I've never heard of hooking up a timing light to the coil wire. Seems like that would flash inconsistantly because the coil fires for every cylinder, and timing is typically in reference to the #1 cylinder at the TDC position. It would kinda be like the difference between 1/4 time and 4/4 time (for you musicians out there.)

Assuming the above to be correct, and assuming that your timing light is actually supposed to be clipped over the #1 wire, if you are hooked around the #1 spark plug wire and are seeing a constant 60deg BTDC then you need to adjust your timing. YOU MUST VERIFY THAT THE CAMSHAFT TIMING IS CORRECT AS PER THE MANUAL. YOU MUST VERIFY THAT THE POSITION OF THE ROTOR ON THE DISTRIBUTOR SHAFT IS CORRECT AS PER THE MANUAL. THEN YOU MUST FOLLOW THE PROCEDURE (IN THE MANUAL) FOR SETTING THE TIMING. This will require you to get familiar with your car. You will need to remove the air cleaner assy, valve cover, timing belt cover, distributor cap, rotor, and complete IIA assy (distributor.) It kinda sounds like someone may have done a little shadetree wrenching and not put this back together correctly.

And don't be impatient. I recently replaced my distributor assy and had to remove and re-install my distributor, indexed 1 more tooth, 4 times to get it in the proper position because A1-Cardone ground off the alignment marks on the gear shaft.

[ARCHINSTL]

...because A1-Cardone ground off the alignment marks on the gear shaft.

Cardone did this to the one I bought, too.
However, I did not have a problem wiith the reinstallation, as I had taken a pix of the inside of the old one before removing it and was therefore able to position the rotor in the correct spot. Of course, I did not turn the engine while the distributor was out - guess this made a difference, huh?
Tom M.

[xirdneh]

[
am i doing something wrong with the timing light? i can't even get the timing mark close to TDC by turning the dizzy.



a quick check
pull number one spark plug
stuff toilet paper in spark plug hole
rotate crank pully around (clockwise ) and line up timing mark at zero degrees
the toilet paper will pop out before timing marks align
if it does not pop out rotate crank around again.
when paper pops out the number one piston is on the compression stroke
if you insert a small screwdrider into the spark plug hole it will hit the top of the piston (just don't leave it there)
now pull the distributor cap
the rotor should be pointing slightly below northwest

another way to tell if number one piston is at top of compression stroke
is to pull valve cover and look at the first two cam lobes
they will both be pointing down (but not straight down)
and if you wiggle both valve rocker arms they will be loose

[joes mama]

in an attempt to verify the timing i have found the following things:

while turning over the engine by hand via the socket on the pulley method, i can hear an audible hiss of air as i turn the engine over. like pressure being released (kind of like unplugging an air tool but quieter and less intense). is this normal?

the tiolet paper will only pop out of the #1 spark plug hole if i am turning the engine over quickly (by hand). when it does pop out, the rotor is not aligned to the #1 cylinder, it is aligned almost 180 deg out. also, the timing marks on the camshaft pulley do not line up (per the manual's instructions) when the engine is at TDC.

where should i go from here?

thanks!

[joes mama]

is there any way to verify that the timing belt has not slipped teeth other than checking the timing mark on the crankshaft timing gear?

i have gotten everything removed in order to get the lower timing belt cover off, but cannot for the life of me get the crankshaft pulley off. is there some way of verifying #1 compression stroke from where i am at?

the timing belt looks to be in good shape and tight, so i don't see how it could have skipped gears...