Any chance this could be a crank keyway issue? I know if they start to get sheared, things go crazy. I know you said the timing is spot on, but not sure how you know that if it's not starting?

whats in egr?

The EGR valve consists of a poppet valve and a vacuum diaphragm. When vacuum is applied to the EGR valve diaphragm, it pulls the valve open allowing exhaust to pass from the exhaust manifold into the intake manifold. Some engines have "positive backpressure" EGR valves, while others have "negative backpressure" EGR valves. Both types contain a second diaphragm that modulates the action of the valve. This prevents the valve from opening unless there is a certain level of exhaust backpressure in the system. EGR valves are calibrated for specific engine applications. The wrong valve may flow too much or not enough exhaust and cause emission, driveability and detonation problems.

to see if this is a possible problem . just pench it shut . if its stuck open  it will plug it off  killing the possible vacuumed leak .
some systems , its not a problem to simply do away with it . not sure about on the Suzuki’s . but on my  4.3 . i just took it off and  built a plate to cap  the hole in the intake.
 if it gets carboned up and sticks open , it acts just like leaving the  back vacuum plug  of an elderbroc carb .  IE she sucks mass air

Any chance this could be a crank keyway issue? I know if they start to get sheared, things go crazy. I know you said the timing is spot on, but not sure how you know that if it's not starting?

I pulled the timing cover off, I had to pull the crank pulley as you know. There where no issues with the key way.

don’t get me wrong here . The engine will run without a cat . But there has to be restriction somewhere to build back pressure .IE  mandrel bent tubing .OR a heavily baffled muffler
 Folks un knowingly create  a restriction  and enough resistance to  make things work

another thing to look for if you are running an EFI  is  possibly a return line being plugged . The return line should carry no pressure .  If it does then the engine can run ruffle or  sometimes not at all .
 Sometimes if folks have done a lift or such  a return line gets unknowingly  pinched or plugged .  I find that most times however when this happens the engine will run for a bit then die

I would also check something else . You say your timing is on  and you have spark . But is your spark correct to the timing ?
. Take the #1 plug out  and bring the piston up to compression . You can tell this by simply placing your finger over the spark plug hole  and feel for compression building .
 Once the   piston comes to the top , stop and pull the Dist cap . Make sure the rotor is  pointing to the # 1 wire . . While you have the cap off , check for signs of cross firing , any hair line cracks  in the cap or  burnt contacts . Internal cracks  that don’t go all the way through can cause cross firing . If you find one , replace it .
 Remember the computer doesn’t tell the   system to fire  it only sends power to the  distributor . With some systems it will  also tell the  distributor to adjust  the advance . But if you have a vacuum ,it  adjusts by vacuum , not electronically .
 Even  on these systems  though ,  you have to have the   Dist , orientated correctly or   you wont get  the spark traveling correctly. Thus you can crank and crank  and nothing will happen .
As im sure you know , spark has to be check at the plug not at the  cap .

 hope that helps you out some . you probably know most of what i just said but i thought i would add it for those who may not

I will do a thurough

I will do a complete check for back pressure, My exhaust is like six months old, I run a true duel system with no cat (s) I custom built it as I didn't want 2 mufflers coming out of one pipe, I have 1 exhaust pipe per muffler coming all the way from front to rear.

Please keep your thoughts comming!
Thanks Ahead. George.   

Still stumped, I'd pull my hair out if I had any!

do you have a check engine light on with the key on and the engine off?

Have you checked to see if the timing marks line upon the crankshaft and the cam? It sounds like the timing belt skipped a tooth, or one of the woodruff keys on either the crank or cam sheared. As for exhaust pressure needed for it to start and run, these engines, and most automotive engines for that matter, will run with NO exhaust. Most have an oxygen sensor, so it will need the exhaust section up to the sensor for it to run correctly, but even without an oxygen sensor (I drove my 1990 tracker for 2 weeks without an oxygen sensor, and it worked fine, just plugged the hole in the manifold), it will still run. I also ran it with no cat and no exhaust.

 It will run without  an O2 . In fact wit should run without any sensors at all
 But the difference with most is that even when un plunged/ dead , they don’t create a vacuum leak  . IE the missing an O2 will just sound like you have a hole in your exhaust.
 Now  no map ? The engine will run but  as long as the vacuum line to it is not   left open , it will run , just not  telling  the ECM to adjust do barometric pressure and effecting the mix .
 But with the EGR if you don’t plug it somehow , you get a vacuum leak . If its working properly you can “ depending on the model  of egr ‘ simply un plug it . The egr will close and thus no vacuum leak . However if  it’s the type that requires vacuum to close  then you have a leak  or if it gets carboned up  and is stuck open , you have a leak  or if the diaphragm is  bad , you have a leak

 Without the sensors the ECM doesn’t know what to do . It gets no feed back  so it just  coverts to fail safe / limp home , or what ever you want to call it . The engine should run  as long as you have no major vac  problems
 Thus your MPG will take a very large dump   giving you 15-18  pall park MPG . But it will run .  In some cases if you have the right Distributor , you can even dump the ECM all together and run the  distributor in a loop . But the distributor has to have a vacuum advance  not an electronic one . I ran my  4.3  that way for years on a 4 barrel   before I built the TBI for it . i simply wired the electronic Dist  in a loop  which made it think the ecm was always sending it power , when infact there was NO Ecm at all .

All an engine needs to run  in basic form , is fuel , compression and spark All timed correctly
 You have to have those 3 things . If you have that then there is a problem with one of those 3 things .
 IE  you have Fuel  but , bad fuel , bad fuel air mix .
You have to have fuel  under compression in the cylinder    at time of spark  for the engine to run

Compression : low compression  or no compression .â€? bad rings , bad ring clearance , or dry cylinders . IE  no oil in the rings . Some engines can actual wash the cylinders dry  and not get compression to start .. You have to have fuel  under compression at time of spark .

Spark :   this can be weak spark , or incorrect spark /firing in a  open cylinder . This means your timing is off  some how . Either  from in correct orientation at the cap OR  incorrect alignment  of the distributor itself . With engines like the Suzuki  that  get drive off the cam  you can  have the cam  not aligned properly to the crank  thus giving you both a Compression and spark issue .IE the valves are open  or in some cases not opening  and thus not drawing  fuel into the cylinders . In which case you  don’t have fuel under compression at time of spark in the cylinder  .
 If your ECM has taken a dump   to the point it will not run the engine then you will not have spark or fuel  as the ecm will not  send power to the distributor OR   send power to fire the ejectors


 So basically once you have discerned that you have   the big 3  . yet if the engine still doesn’t run ,  you have to go back and find  where your having a problem inside those three .. The key is finding  what’s wrong inside those three .
 My  8 valave has two marks on the Came sprocket . You align to the  wrong mark and  you will have compression  but it will be out of  sink  with the crank . Thus giving spark at the wrong time . So  its best regardless of the  engine you working on to double check  that alignment  to  ensure it  is correct with the valve timing  and that the distributor is set to fire correctly .
 If that is off  then your not getting fuel , spark or compression at the correct times .

I know how this sucks . i been there . but in just about all the time , i  find im over looking or missing something . Timing is not set correctly ,  i had a bad vacuum leak . my engine wasnt grounding properly  ECM require  good ground"S" to work properly .
 but again  concerning that , you still have a problem with spark .
 so if you are getting all three as you are saying  the you have to not be getting them all at the right time

Just thouht I'd throw my two cents in, been a mechanic all my life, 4cyl. engines are really bad to lose compression around 200,000 mi., that is ,enough copm. to start. Put about a cap full of tranny fluid in each cyl. through the sparkplug hole, put the plugs back in and turn it over until it cranks. be sure not to hold the switch to long or you'll of course burn the starter up. This is just a quick fix, it will only get you through for a few months.

I am going to take a simple approach.  Check your fuse box.  There is a fuse for ignition fuel injection and so forth.  I had my sidekick die backing out and one of those main fuses had failed.

Granted typically for a fuse you expect the sudden off situation like I had versus your slow down but maybe it was a weak fuse not allowing enough current.  Go through the box and check all of them anyway.

If that isn't it I would go the route of a bad ground on the distributor or weak coil. Of course it doesnt sound like you ruled out the ecm yet Also if you haven't already you could pull your battery cable for a couple of minutes and reattaching to see if reseting the emc does anything.  Grasping at straws there.