electrical help

I have a '95 crank dohc Engine installed in my '92 sl2 car. What year of PCM
and wiring harness would be the easiest for me to plug in? I grabbed the '95
pcm and wiring harness and it won't connect to the existing electrical system,
ie dash, oil pres. sender, fuse block. I know a '91 - '92 won't work because
of the crank, but what about a 93-94? Any advise is appreciated, THank you.

 

I have a '93 motor in my '92 SC. I used a '93 PCM and ABS module as well.
I'd recommend 93 because I know it works, but 94 should be OK as well. The
gauge cluster changed in 95 along with a lot of other stuff.

Engine temp, coolant level, and possibly oil pressure sensing may not work
properly as far as the idiot lights are concerned when using a '93 or '94,
and you will also lose functionality of the oil pressure gauge in your stock
cluster. Other than that, it has worked fine for me in my race car. I did
not swap any harnesses or modify any of the wiring at all.

If you need a '93 or '94 PCM, I may have a spare. Drop me a line if you're
interested and I'll rummage around on my shelves.

There's some good info here on interchangeability:
http://www.saturnspot.com/forum/viewtopic.php?t=19927

Good luck,
Lane [ lane (at) evilplastic.com ]

 

As long as the PCM gets the right signals.

Possibly, I'll drop by the bone yard tommorow and see what they got.

The reason i got a 95 crank in my 92 car is i blew the 92 engine after
turboing it and running 16 psi. Fun. but stupid. Now i rebuilt a low
compression motor that should be able to safely handle 10-12 and got a high
flow recon. head. Let me know if you have any other advise. Thanks you for
your response. You must be QKSL2's buddy huh?

 

OK i picked up a harness/pcm from a 93. Everything seems to be powered on the
car but it will not start. I do have spark, and compression. The car fires
occasionaly while cranking but does not start. It is very very rich ????? any
ideas? I do have 46 lb injectors in but i have ran the engine with these
injectors prior to the rebuild and also with the 92 harness in and the car
did run. I'm using an safc to control pulse width and a fuel pressure
regulator. with 20 psi fuel and pulse with as low as possible it doesn't help.
Are you sure the '93 pcm will work with the 95 crank? The 95 pcm ran the
engine (like crap) using the 92 harnes.

 

Are you sure the '93 pcm will work with the 95 crank?

I'm 99% certain.

I have heard that going too much past the flow rate of the stock injectors
can cause problems for the PCM. You're attempting to run injectors that are
more than twice the size of stock? Do you currently have a turbo on this
motor? If not, go back to the stock injectors. If they're in proper
working order, they're more than capable of supplying all the fuel you need
(and more).

If it were me, I'd try your 92 harness with the '93 DOHC PCM, stock
injectors, and bypass the SAFC and see what the results are. That removes a
lot of variables. If that works, you can then work toward changing one
thing at a time to get it to your preferred set up. Did you have the new
pcm re-flashed? I had to have this done due to problems with my ABS (donor
PCM's car had an auto with traction control, I put it in my manual trans
'92). No idea if some programming mis-match would cause engine run problems
though. You'd be best finding a knowledgeable tech to help you out, or
posting in the technical-related forums at http://www.saturnfans.com,
http://www.saturnspot.com, or others.

Good luck,
Lane [ lane (at) evilplastic.com ]

 

Great News!!!! I got my toy back. Changed the injectors back to #19s to
lean it out, and the spark plugs i was using before the rebuild. Car fired up
and purred like a kitten. Drove around a few miles, no problems, no leaks,
idles good, boosts good. Got the wastegate set at 3 psi now though and stays
stoich mixture on my wideband 02, i know it wont be at 10 psi. eyeballing
some #30s on ebay, do you think that is enough fuel for 10 psi? Probably in
the 225 - 250 hp range. Also i would like to add my car to your sites car
collection. I fabbed everything including mounting the turbo where the
battery used to be and top mount IC. The hood i made though looks like shit,
but now being done with the engine project i can focus on finishing the new
hood that is looking sharp.

 

Lane,

I have a 93 dual cam automatic saturn that when I purchased it the A/C
didn't work. It was fall so didn't matter much. Now that is warming
up I also found that my cooling fan doesn't come on. I jumped the fan
motor and it works fine cabled direct to battery. I replaced the
coolant temp sensor and it still won't kick on. It only climbs to the
red when stopped in traffic or at idle. Is my next step the PCM? And,
do you still have a 93 PCM somewhere on your shelf? Please Help if
you can. THANKS

Bruce

 

I also found that my cooling fan doesn't come on.

Two tests I've done always have done the job at telling me if the fan is
working properly - either let the vehicle idle for a half hour on a warm
day, or turn the AC to the on position since that engages the fan. Or, I
believe the fan is supposed to be triggered to run when you jumper the ALDL
to put it in diagnostic mode (more on this below)...

Did you have the codes read to see if that reveals anything? If you have
not, that is your FIRST step. Don't start replacing stuff by guessing if
you can help it. Any Autozone store will read your codes for no charge.
Or, you can find instructions here to do it yourself with a paperclip:

http://www.differentracing.com/tech_articles/index.html (refer to section
'obd1 diagnostics')

Also, the AC system needs the system pressure to be at a certain point or I
believe the compressor won't engage. (AND, I'd be willing to wager that
reading the codes may reveal if this is an issue also.) It may need a
recharge and the only way to know is to have it checked. I'd assume you
could do this yourself with the proper tools if you'd like to save some
money. A few auto parts store chains loan or "rent" tools for no charge.

I wouldn't replace a PCM just because you think that's what it might be.
This is because any pcm from another car will most likely need to be
reflashed by the dealer to match the options & configuration of your car
before you can use it. I had to do this with my '92 after an engine swap
where I swapped the PCM as well. Generally that flash from the dealer isn't
as cheap as you'd like it to be.

Lane [ lane (at) evilplastic.com ]
---
Visit my Saturn Car Audio and Performance Page at http://www.evilplastic.com

 

If the temperature is above the limit threshold and the fan is not coming
on, then it could be the Coolant Temperature Sender (CTS). I believe the
pre-1996 Saturns actually used two CTS, one for the gauge and the other for
the fan control circuit. (I am sure others will correct me if this is not
right.)

If it just does not turn on when the AC is enabled, then this is likely due
to a leak in the refrigerant and not enough pressure in the system. This is
designed to disable the compressor clutch from activating since the
refrigerant acts as a lubricant and without it, the compressor would seize
up pretty quickly if it was turning.

Bob