wont start help??
wont start help?? i just purchased a 94 z28 6spd. the motor is fresh, supposedly, but it just wont seem to fire up. i get small burps like it wants to but nothing. ive got 40psi fuel pressure, have injector pulse, have spark. when i first got it it turned over very slow, i took the timing cover and opti off and found the opti drive gear jammed into cam gear. so i set that up right and now turns over better but still nothing. i get a litlle better burp out of it when i use a little carb cleaner but i still cant get it started. any advice guys?
well i set number one at tdc and lined up the distributor gear correctly and then set the rotor facing number one wire on the cap which points straight down, so i think its right but im not sure, this motor has an aftermarket cam-dont know what kind, im just wondering if the distributor drive gear can be off with an aftermarket cam?
TECH Enthusiast
Joined: May 2005
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From: Charlotte, NC
stick a compression gauge (minus the gauge head) in the number 1 cyl, stick a plug in the number 1 plug wire. Hold your thumb over the gauge hose while someone cranks. Watch for spark at the same time you feel compression. Quick and nasty timing check.
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Verdad Gallardo TECH Enthusiast
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From: Charlotte, NC
Thats the direction everyone was going, so I just figured that I would supply an easy way to see.
If your timing is off, that will help show you unless it's only a tooth off.
As far as the compression, every time you crank the motor your injectors are firing. That gas washes down the cyls and will lower compression. If you know for sure that your pressure is good and the injectors are indeed firing, unhook them while you look into it.
I would pull the plugs, and let it air out. Check the timing with teh "test" that I posted, and crank it over for a little while to biuld up some oil on the walls, unless you want to throw some in the plug holes. I really would make sure that compression is indeed stable first and then get a comp reading on each cyl and go on from there.
If your timing is off, that will help show you unless it's only a tooth off.
As far as the compression, every time you crank the motor your injectors are firing. That gas washes down the cyls and will lower compression. If you know for sure that your pressure is good and the injectors are indeed firing, unhook them while you look into it.
I would pull the plugs, and let it air out. Check the timing with teh "test" that I posted, and crank it over for a little while to biuld up some oil on the walls, unless you want to throw some in the plug holes. I really would make sure that compression is indeed stable first and then get a comp reading on each cyl and go on from there.
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From: Charlotte, NC
distributor gear?
you can have either the crank and cam gear out of time, or you can have the dowel pin of the cam in the wrong slot of the opti (95-97) or the spline shaft in wrong(93-94).
you can have either the crank and cam gear out of time, or you can have the dowel pin of the cam in the wrong slot of the opti (95-97) or the spline shaft in wrong(93-94).
thats what i was wondering. the notches are in there correct spot but no start. when i first took it apart the gear was jammed into the cam and i needed to pry it out-so i figured it was probably wrong, but from what people are saying is that sometimes this gear could be off-meaning i just need to line it up with how the timing needs to be not where the slots are?
and by the way i have a 94-early style opti so i have the little cam-dist gear not the cam pin. im just wondering if anything behind the cover could be off. i checked the timing marks on the gears and they lined up corrctly but i dont know if the spline notch could be off? im lost right now so i rambling
im wondering if the cam could be off and that doublespline is in the wrong spot but then if i put the splines 180 off it should work. ive tried every postion with the shaft-i groung down one side to go into the cam and tried it in all positions and still nothing
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Joined: May 2005
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From: Charlotte, NC
you cant adjust with anything, you need it all to be correct. You need to have the cam/crank gears correctly aligned, and then you need to have the spline shaft in correctly. There is no other way going about it. There is no "all" positions, it only fits in one position. You severely compromised the job if you ground the spline shaft down to make it fit.
My best advise to give at this point is stop what your doing, and take it to a competent mechanic/engine builder.
My best advise to give at this point is stop what your doing, and take it to a competent mechanic/engine builder.
well i do know what im doin thankyou, i was doin this to possibly compensate for a cam being off and i have another drive gear to put in. i figured the problem to be a loss of compression. after i oiled the cylinders to build it back up i now have no comp on number one so its obvious this probobly wasnt a rebuilt motor or a very well built one