Help with 91 sl

[dsmnoob91]

okay so i got this 1991 3000gt sl about a week ago not running... the motor in it has to be a fresh jasper re build it has never been fired he said he built it and never finished its out of a 94 the crank and cam sensors are the only two sensors not plugged in because i cannot find the plugs in the harness for them... did it switch between years did the 91's have a different set up for the sensors? please help

[CoreyB]

Yes the 91 has a single cam/crank sensor combo up at the end of the rear intake cam. The 94 has them separate. You just need to rewire it for the seperate sensors, and if you dont want any latency issues you should replace the ECU with a 94 ECU. Not sure if its important on a NA though.

[n2nsanity]

that's because the 91 doesn't have the wiring for them

but, u can just mount the cas sensor on the pass side of the rear head. the same way it mounts on a 91
leave the cam/crank sensors unplugged. i've seen this done a few times.
u can use a 93+ dohc on any year 3/s that's dohc

[dsmnoob91]

cas? what is that? and your saying i can leave them un plugged and get a different sensor and plug it in somewhere else and it should start?

[dsmnoob91]

never mind i looked it up will that work on my newer motor tho?

[n2nsanity]

yes, should work fine

you don't need the 2 sensors on the drivers side (cam, crank)
because you'll be using the single sensor on the pass side (cas) instead

remove the cas from the rear head on the old engine, mount it on the new engine
they do the same thing, but the cas is adjustable, so some people actually prefer that
if you look at the 2 engines, side by side, it will make sense

u should also check to see if both are fed spec or not
this could cause some minor, but fixable issues
count the # of vacuum lines on throttlebody of each engine, that's the easiest way
if they both have 1 or both have 3, that will be one less thing to worry about

also, in case you didn't know, our car's aren't "dsm's"
most people don't

[dsmnoob91]

they aren't dsm? and mine has one vac line on the tb but my other ? is the cas going to bolt right up to my motor they just leave a spot for it on the 93 up ones? or am i going to have to mod it?

[n2nsanity]

nope, not dsm's, not that there's really that much of a difference.
1 vac line means most likely you have a fed spec engine and if your car is also fed spec, should make things easier
so everything's installed and all together?
don't still have the original engine?

if you don't know what you're looking for, here is the cas
http://www.stealth316.com/images/cas-discon.jpg

Stealth 316 - CAS Replacement - DOHC 1991-1992 (http://www.stealth316.com/2-cas-91-92.htm)

what's the story here? what are you trying to do?
is it finished? have you tried to start it already?

[dsmnoob91]

this is the story with it... i got it and it didnt have driv shafts no fluids but oil no breaks and just a mess i got breaks got the clutch working (blead it) the guy i got it from said he had a motor built for it no the motor looks fresh and you can tell has never fired... the timing was off so i set it and put a starter in today turned it over since the timing and did a compression test and was not good cyl1 20lbs, 3 80lbs, 80lbs the rear bank 6 had 180lbs 4 had 180 and 2 had 120lbs so bent valves on the front? also there is a cas hooked up and still no spark. and no i do not have origonal engine and i want to drive it

[n2nsanity]

somethings not right...
anything less than 100 per cylinder, i don't think it will start
hope you didn't pay too much for this thing
i'd have probably have someone look at it at this point
if you're up for a long road trip, i have a running engine i'm selling for cheap :p

[dsmnoob91]

im going to try putting valves in it and my plan is to put a vr4 in it my buddy got one also we timed it an his runs great we are twin turboing his now with stock vr4 turbos just waiting on the oil pan to come in...

[dsmnoob91]

as long as get the compression up i know someone who get's wet over wiring issues so i think he can figure out the no spark i hope

[TT4ME]

No spark is the least of your worries.

[dsmnoob91]

i really think its valves the timing was way off when i got it

[n2nsanity]

that would mean he or you tried to start it without setting timing properly
in which case, you might need new valves and pistons
i'd definitely go ahead and have a shop check it out
good luck with it
these are fun cars and can be very reliable if you take care of them
i've been a fan for 17 years

[jessecain1]

sounds like he may have told you a bit of a story on that rebuild if your comp numbers are that low. Not sure about New york but some states have a lemon law that not only applys to dealers but private sellers as well. Id have a reputable mechanic check it out and if it applys take legal action. I'd be pissed if i was in your shoes.

[dsmnoob91]

im not mad about buying it... ill find out whats wrong when i pull the head more than likely just valves and like i said you can tell it has never been fired the thing is clean

[dsmnoob91]

okay pulled the heads i think they were re built they are new looking no carbon at all they have never been fired so that means she needs new rings so she is going to the machine shop im pulling the motor tomorrow here is my ? i plan on boosting it so should i do it right and get a set of stock vr4 pistons? or keep my stock na's and run low boost