jon@dakota-truck.net wrote:
> Terrible Tom <silvereightynine@aol.com> wrote:
>
>>My plans to adapt a factory-like TBI fuelie dealy just seems to not want
>>to work. I ran into electronics compatibilty issues between the SMECS -
>>the Ram units don't have provisions to control my 46RH trannys
>>electronic OD and converter lock up. And a Premag GenII (90/91) Dak 318
>>computer is not the same pinouts as 88-89 SMECS - they changed the ECM's
>>in 90.
>
>
>
> Tom,
>
> I assume you have studied the pinouts somewhat on the premag 318
> computer versus the pinout for Christine's existing wiring harness
> since you have mentioned the difference above. Is the connector
> itself the same, and its just that some of the wires have moved
> around?
It depends - the 88,89 connectors are the same. In 90 - it changed, but
I don't know if youc an physically plug them into the diffferent
applications.
I ran into trouble with the wire for the TBI temp sensor. The TBI's
between the V6 and V8 engines are the same Holley models - but they have
different injectors (which I am using 318 injectors) and teh V6 doesn't
use a temp sensor that the V8's do. I hooked up the sensor and patched
the wires in to the SMEC, but I did a sloppy job. I had trouble finding
a bullet terminal that would fit in the wire harness block... I
eventually drilled out the pin location (on the V6 harness block it was
still solid plastic for that particular pinout), crimped the bullet
connector on and got it to fit on the pin.
I bought a scantool - with a Chrysler OBDI adapter - but I never got
around to checkign the sensor output of this current configuration. I
don't know how well it worked, from a diagnostics standpoint.
>If so, have you considered punching those wires out of your
> harness and moving them to the locations that match the premag 318
> computer?
That thought had not occured to me honestly. Its worth looking into for
sure. Also - had I been thinking ahead - the truck I pulled the Premag
318 distrib off of - was an intact 91 Dakota 318. I should have pulled
the entire powertrain set up - ECm and harness off it - and just
transplanted that! I doubt that truck is still at the bone yard... but
I might inquire on that - or try and find another one.
>
> It sounds like the Ram computer has the correct pinout already, so
> it might be easier just installing a manual button to engage overdrive
> and lockup. Hot rodders who install the 46RH do that all the time.
> There might even be some electronics available to automate it
> somewhat, based on engine speed or something.
I did patch in a toggle switch to the solenoids in the trans, to test
the functions - thats how I confirmed the SMEC was not shifting the
trans into OD, but I honestly dont want to be bothered with having to
lock and unlock the TQ and OD units manually... to me thats a pain in
the ass.
> Heck, if you wanted to
> work on something, we might be able to whip something like that up
> ourselves. Its been years since I played around with microcontrollers
> so I'd have some relearning to do :-) but it seems like it would be
> rather straightforward to tie into the VSS and simply disable the
> OD/lockup below a certain speed (45mph?), and of course, there would
> be a button like stock to override overdrive entirely.
Hmmmmmm very interesting possibility there!!
>
> I did a quick google search, and here is a page that shows how to
> have the overdrive and lockup work automatically by using a vacuum
> switch as well as a couple of pressure switches:
>
> http://www.transmissioncenter.net/SwapInformation.htm
I did not look at that page yet - but when I have more time (and some
more sleep) I will take a look.
>
> BTW, why do the Ram computers not control the overdrive and lockup?
> Didn't Rams use the A518/46RH too?
>
Everything I have been able to find, seems to be that teh 318 model
88,89 Rams did not have A518/46RH transmissions... except for CA
Emissions models. CA emission models were the only models I could find
with a "4 speed" auto trans. Again - I did not check into this
important aspect when I found the SMEC and TBI unit donor truck. I
never bothered to see what trans it had. Its obvious however that the
SMEC does not have the programming to shift the transmission.
With the V8 SMEC in the truck, its driveable... but doesnt shift into OD
or lockup. The engine is spinning high RPM's on teh highway - yes I did
have her up to highway speeds for testing LOL - 65 MPH - give or take a
few MPH. The factory Tach also does not function. I had to hook up an
aftermarket tach to the coil.
With the V6 SMEC in - the engine RPM is lower at idle - almost to the
point it wants to stall. I cannot get it up over a certain speed or it
starts to buck. The factory tach is working but SERIOSULY out of
calibration - Its reading almost twice the actual engine speed. My
guess is the pick up unit in the distrib is sending normal 8 Cyl data
back to the SMEC - making the SMEC think the engine is turning faster
than it is. Its seeing 8 ignitions in the same time frame that it
expects to see only 6. However - it does shift into OD. The
Rev-limiter kicks in and the truck goes to die if I try and get above
say - 40 MPH and the RPMs are reading too high.
Also - I have no kick down linkage hooked up to the transmission. I am
litterally shifting through the gears with the colum shifter - like a
stick shift. The stock kickdown rod is too short for the set up - your
TBI spacer adapter plus the height of the Edelbrock manifild - causes
the TBI to sit up too high for the rod. I doubt this combination would
even fit under the hood if I didnt have a 3 inch body lift. The air
cleaner is REALLY close to the underside of the hood. I planned on
trying to bend a new kickdown rod - but - again I never got around to
it. This causes funky driveablity issues - as the transmission causes
the engine to lug if I dont shift manually at the right times. Which
has fouled my ability to judge how the truck is running.
I really do want to get this TBI set up working, just because this is
what I originally set out to do - because its never been done like this
before... and because it would keep the truck a premagger :D
it would also allow me to keep the 1995 Dakota intact - allowing for me
to get that one onthe road again some day hehe... after I replace the
rear axle, the transmission, the transfer case, the brakes, brake lines,
get a new bumper and grill because I sold them off the truck, clean the
interior... new tires........ (sigh)
-- ------------------------------------------------------------ An ordinary person spends his life avoiding tense situations! Repo man spends his life gettin' IN tense situations!!! ------------------------------------------------------------ TerribleTom - AIM & Yahoo: silvereightynine http://www.myspace.com/silvereightynine http://members.aol.com/silvereightynine ------------------------------------------------------------
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