OK, here's my sad story:
about a month ago I got a nice new-to-me bone-stock Z28 with 80K miles...


BACKGROUND INFO:


it drove good at low rpm range, but had a strange knocking/rattling at rpm above 4000... then it started stalling after driving through puddles, and then one day it got so bad i had to restart it a dozen times just to barely get it home, and since then it would not start any more... so I figured that opti has gone bad and it needed a good tune up... when i took it apart, opti had oil leaking in it, and moisture prolly too... oil was all over the engine compartment as well...


long story short, I ended up doing some work in the last few weeks:
- new Accel Opti spark
- new Accel SuperCoil
- new Accel 8mm wires
- new Autolite 106 plugs gapped at 0.045
- new ACDelco water pump with new temp sensor
- new Opti and WaterPump round gaskets inside timing cover
- new Serpentine Belt
- new PCV valve
- new Fuel Filter
- redone Intake Manifold gasket with Permatex UltraCopper and Felpro


when I put it all back together, I made a slight boo-boo and confsed the two vacuum ports that are one-above-the-other on the pass-side of manifold - one goes to Fuel Pressure Regulator, and the other goes to HVAC check-valve... I tried to start the car at least a dozen times like that, and of course, it backfired a lot, but would not start... it also made a strong air-suction sound and a loud metal ping a couple of times, whatever that was... (could i have damaged much by this???)


i re-checked the diagrams, connected the vacuum lines to FPR like they are supposed to be... at first crank it backfired a bunch, and then blew out the pass-side valve-cover vent hose and oil dipstick (why?)... now it just turns, no backfire or any sounds any more, but still no start either...


TROUBLESHOOTING performed so far:


- tripple checked all vacuum lines and connectors to make sure they are plugged in right
- all spark plug wires go to the correct plugs
- pulled #1 plug and grounded it - sparks every 2 seconds, not too strong, but i dont know how strong it is supposed to be
- tried spraying some Gumout Carb Cleaner in the intake elbow, as per someone's suggestion, it backfired and smoked through the air filter pretty bad aftrer 3 squirts (is my MAFS screwed now?)
- tested Knock Sensor - good, its resistance is 3800 and the connector voltage is around 5v
- tested Opti-to-Coil Pathway, get over 11vdc when grounding ICM harness' pins A or D, which means ICM is getting power, also i get around 2vac on pin B while cranking, which means pulses trigger the coil to fire (i am not sure if this completely rules out the opti harness)
- finally tested fuel... not sure here... for the first 2 seconds when the pump works i get around 47 psi, then immediately it dropps down to 39 psi and stayes there regardless if the key is left on or turned off... is that not good??? is FPR not working??? or do i have a leak somewhere else??? or is it ok???



so,

- should i test anything else?
- can it be the Opti harness itself?
- can i test the ICM itself?
- does IAC need testing and/or resetting?
- can i test MAP and TPS sensors somehow?
- should i de-screen my MAFS ??? is there a way to check its resistance?
- can EGR valve have smth to do with this since it controlls engine temp?
- can other temp sensors (IAT, coolant, etc) cause this?
- how about anything with A.I.R. pump related?
- can and should i check any vacuum anywhere?
- can oxygen sensor cause this? i hear bad ones sometimes make it run rich...


ANY OTHER IDEAS???


please save me from towing the sob to the dealer, i am on a college-student budget...

 

should i test anything else?
- can it be the Opti harness itself? yes mine was.
- can i test the ICM itself? yes mine was this also
- does IAC need testing and/or resetting? should be fine
- can i test MAP and TPS sensors somehow? not sure
- should i de-screen my MAFS ??? is there a way to check its resistance? no need for this
- can EGR valve have smth to do with this since it controlls engine temp? I wouldnt think of this as an egr system failure
- can other temp sensors (IAT, coolant, etc) cause this? very well could be a bad sensor
- how about anything with A.I.R. pump related? ONshould i test anything else?
- can it be the Opti harness itself? IF YOU DIDNT PUT THE OPTI ON RIGHT IT WILL RUN LIKE THIS. THROWING THE COMPUTER ALL KINDS OF WEIRD ****.
-

 

Well just make sure you got the 3 basics to make an engine run first off. Air, Fuel, Spark. Fuel pressure should be around 43 or 44 psi I beleive.

 

Did you replace the coil wire going from the opti to the coil?

 

what were the exact symptoms of each ???
is there any way to test the ICM ???

i tried to allign the opti dowel correctly, cant really check that though

oh, and yes, all wires are new accel, same as coil and opti

 

so i just completed a compression test:
highest=170, lowest=135, prop=79%


drivers side:
1=135 , 3=160 , 5=145 , 7=155


pass side:
2=160 , 4=170 , 6=145 , 8=160


also, earlier today i have done the following:


- checked and got perfect 000 continuity on opti wiring harness
- cleaned MAFS with 99% alcohol - it was dirty and installed backwards
- reset the PCM by pulling the fuse and battery cables for 1 hour
- rechecked the grounds and spaced off the coil+icm assembly to keep cool


so now what???
looks like the timing chain and valves should be all right...
even if timing is ok, can it still be the opti-cam dowel misaligned???
how can i test the icm (and should i)???

 

so, it took me about an hour to take it all apart (im getting good), with hand tools on the side of the street... dumped coolant all over my new opti, its good that ive sealed all cracks with silicone before installing...



yup... it was 90 degrees off... how the **** that happened i have no clue, i tried to line it up properly the first time... so now its time for a short break, then putting it all back together again before it starts raining... maybe it will work better this time...

 

If you had oil leaking into your other opti-spark, and moisture prolly too... you could have a cloged opti-spark vent harness Filter/Regular.

Replace the vent harness.

 

well, it just never gets any easier... one of the three bolts holding the opti in snapped at about 30-40 lbs of torque, so now i guess i have to take the timing cover off and it looks like it will be sticking out of the block by a mm or two... more fun and joyful times to come soon im sure...


i guess i might as well replace the timing chain now too... i am open to suggestions as to what to get... they dont make gear drives for lt1 do they? and i am almost waiting for someone to talk me into taking the damn intake off again and putting in a hot cam... problem is that i wont be able to afford the valve-end components for a while...

 

Gee, the opti mounting bolts are suppposed to be torqued to 106 lb. in.

 

hell your so close to camming i can smell it.
If you have the cash do it, and dont look back. You have found out your problem, so it would make the whole operation easier to swallow.

I was in my car to change opti and did the cam install while there.(turned out it was just my coil!(intermittent issue)

 

yup, i guess 106 lbs/in is around 9 lbs/ft
now i also know how to pay attention to reading the specs

 

you only need the valvetrain upgrade kit if you put the 1.6 rockers on with the hotcam.so do the cam now and the valvetrain later when you get the cash.