changed water pump, now won't start

hey all,
i changed out my water pump the other day on a 91 gsx. when we put the timing belt back on, it wouldn't fire up. it turns over just fine, all timing marks are lined up, it's getting plenty of spark and fuel... but no start.

any suggestions? i've seen posts about checking the MPI fuse... but where is it?


thanks in advance,
Aaron

Hey is it possible that your timing is out 180 degrees? I had that problem with my car. Then after I fixed that My balance shaft was out 180 degrees so the motor ran really ruff tooo. Thats what I'd check.

well, we thought of that as well. my dad, the car "guru" has never had to work on a car with two different timing belts so we are basically just guessing.

we tried taking the main belt off, keeping the camshaft gears lined up with eachother, then turning the crankshaft until it's mark lined up.

should we be turning the camshaft gears a full turn, instead of the crankshaft? i am not understanding the whole situation, we have all marks lined up.

oh lord this sucks.

If your timing is off by 180, you bent your valves! Timing these cars do suck, you might be one tooth off at the cam gears. but check this out:

http://www.vfaq.com/mods/timingbelt-1G.html

the car ran fine except for overheating. found out it was the water pump. my dad and i changed it and didn't take into consideration having to remove the timing belt.

when we put it back together, it didn't start. maybe we moved one of the gears, i don't know. we then took it back apart, and lined up all of the timing marks. still no start.

so in that time, you're saying it was possible to bend the valves?


btw, the link you posted is what we followed to fix it.

It is possible that your cams are 180 off. I always use a straight edge on my cams cause there is actually two marks on each cam. If the straight edge lines up perfectly with all lines youre good to go. Once you get it set take a paint pen and mark the inside line so you don't make the mistake again.

well, they were already marked. i went out again just to double check that i had no. 1 at top dead center. then checked all timing marks. oil pump gear was off so i took the belt off and reset it.

still no luck. not starting.

cylinder 1 is at top dead center, crankshaft timing mark is dead on, cam timing marks are dead on, oil pump gear timing mark is dead on, and silent cam timing mark is dead on. getting spark, plenty of fuel pressure, injectors are injecting. what's wrong with this scenario?


btw, thanks for all of the help so far.

one thought... could it be the ignition timing?
it's advanced as far as it will go. (set this way
by the guy i bought it from.)

could it be i need to set it back to center or
retard it a little?

or, will this not matter at all.

When you trid to start it did you have the motor mount in? If its out of aligmnet it wont run either. I just chnged my water pump and outer timing belt 2 days ago, so i know how much of a pain in the ass it is. Make sure the cam gears are aligned like the book says, lobes both up and marks aligned. Then check the silent shaft (look in book). Then check and align the crankshaft to the mark, once its all done, put the new belt on, apply the tensioner, rotate the crank 2 times, let sit 15 min, start, run for a while, shut off then check your marks.
Let us know.

If your timing is off by 180, you bent your valves!

I thought these were non-interference motors?

yes. set it to 5 degrees BTDC (before top dead center. it should never need to be advanced ALL the way

they are INTERFERENCE motors. i forget which direction but having one of the cams off by 1 tooth can smash the valves

I thought these were non-interference motors?
My old cylinder head will disagree :)

It's hard to say if you have all the marks lined up exactly by me not seeing it. The first timing belt job i ever did was on my talon, about 2 months ago. I remember having to take a wrench and turning one of the cam gears clockwise so that the tooth DID NOT line up with the other gear. Then when the belt was wrapped around the gear, i let off the wrench and the gear moved counter-clockwise so that the timing marks lined up. Did you have to do anything like that? Now if it was off by 1 tooth, it still might start but idle horribly, but i doubt that would bend valves, highly doubt it actually. If you are worried about it do a compression test. This will see if you did, and will also help you diagnose your problem with the car not starting.

I'd say if your GSX ran fine before taking off your timing belt, and the only other thing you did was change the water pump, your timing is off. Unless you inadvertently unplugged a critical sensor. For some reason this comes to mind: there are 3 fuses at your positive battery terminal. One labeld MPI. Your car will turn over but not start if that fuse is blown. I took mine out the other night to prime my new turbo. Check that, you never know.

if it bent the valves, would you be able to hear it (either when it bent them, or after)? would it still turn over just as easy as can be?

i really don't want to take the damn head off to check it, just to find out they're all ok. would a compression test let me know?

btw, i checked the MPI fuse and it was ok.

one more thing....

thanks again for all the help you are all giving me. it is really appreciated.


Aaron

ok, i just did a compression test (albeit, on a cold engine) and here is the results...

no compression... none. the needle did not move at all.


the first time we checked (prior to this whole mess) it was reading 150, 150, 145, 150.

so, i assume the valves are bent. any tips on changing these out?

first you need to pull the head off. then you need a special valve spring compressor tool ora standard overhead valve compressor tool with spark plug sockets welded on it to make it the right size. check VFAQ.com they have a lot of info. it would probably be easiest to just send the head to a machine shop. i paid about 300 to get mine cleaned, pressure tested, a valve job(lap valves, replace valve stem seals and valve guides) and 6 valves. they also checked it for flatness.