Cons of a 1990 DSM

[gijoe985]

I feel like I remember there was a reason why I used to want a 91 DSM over a 90. I haven't been looking for a while, but found a cheap 90 gsx with a bad ecu. I know that I avoided 7 bolt 1g cars because if I wanted to deal with crankwalk, I'd rather it be in a 2g body.

Anyway, cons of a 90? Vs let's say a 91...

 

[GsXdSmKingGsX]

I'll give you a con of both.. They're 1g's

But honestly.. The 90 has a ton of differences making it a liiiitle harder to work on..

 

[gijoe985]

Jog my memory of what those differences are... I remember the ECU is specific to that year.

 

[GsXdSmKingGsX]

Throttle Body
TPS
ECU
Cruise Control is located in a different spot
Speedometer Registers starting at 5mph not 0
Transmission is Different internally as well as having a 22 spline output shaft to the T-case
Ignition coil has a tach adapter for the tach to work properly. It has a 4 prong plug where as a '91 has 3prong.
External air oil cooler

 

[Ryan4dc]

The ecu is specific to that year. As well as the throttle body, power translator, coil pack, cluster, and the air to air oil cooler. I may have missed some but thoughs are at the top of my head. I bought a 1990 plymoth laser rs fwd turbo for a parts car before.

Edit: beat me to it.

 

[3kgt2nv]

the ecu can be swapped to a 91 to 94 by switching 2 wires though

 

[3kgt2nv]

, but the good news is almost all 90 ECUs had EPROMs

not any of the ones ive seen. And I have 3 90 specific ecus for gsx's

 

[Trav83]

Edit: beat me to it.

Haha yeah I was about to post a reply too and after I did 2 other people already answered OP question . DSMtuner members are quick

 

[Dhan]

Throttle Body
TPS
ECU
Cruise Control is located in a different spot
Speedometer Registers starting at 5mph not 0
Transmission is Different internally as well as having a 22 spline output shaft to the T-case
Ignition coil has a tach adapter for the tach to work properly. It has a 4 prong plug where as a '91 has 3prong.
External air oil cooler

What's are the differences with the throttle body and can you switch from the air oil cooler to the water? Is it worth it?

 

[Trav83]

not any of the ones ive seen. And I have 3 90 specific ecus for gsx's

See they're so quick they'll even reply to posts I've already deleted

 

[3kgt2nv]

I dont really think that the air oil cooler is an issue. I think its something that can easily be worked around by simply going to a larger core and using some proper ducting.

See they're so quick they'll even reply to posts I've already deleted

This place is like jeopardy, its all about buzzing in with the right answer the fastest.

 

[Ryan4dc]

See they're so quick they'll even reply to posts I've already deleted

Haha. Well you tried.

The 90 throttle body is one piece with the idle speed motor where the 91+, they are held on by like 3 bolts or so.

 

[Trav83]

This place is like jeopardy, its all about buzzing in with the right answer the fastest.

Well then you lose for not putting it in the form of a question but as far as the 90 ECUs being mostly EPROMs, I read that some where off the vfaq/1000q... could have sworn I did anyway

 

[3kgt2nv]

here is what the 1000vfaq says about the eprom

How can I tell if my ECU has an EPROM?

You would already know this (hint, hint) if you had used the FAQ Locator. Read Todd Day's EPROM check webpage.

One fact that is not mentioned on this page is how to quickly check ECUs *after 1990* for an EPROM. There is a label on the top of the ECU (not the sides). If this label has an "E" in the lower right-hand corner, you have an EPROM. If it has an "M" or "T" in that corner, you do not have an EPROM. 1990 owners have to open the ECU to find out, as there are both EPROM and non-EPROM 1990 ECUs. This tip is also on this page from the developers of the DSMlink.

Galant VR-4 owners, again, have an edge - owing to the low production volume of that model, GVR4s are almost guaranteed to have an EPROM.

The Last Word: Hey, not ALL 1990s have EPROMs. Can't you read?

 

[DSM1G90]

but as far as the 90 ECUs being mostly EPROMs

Mine isn't - it has a non EPROM ECU (Course, it's FWD instead of AWD in which I do believe why the ECU had that extra chip-to help with power due to the extra weight of the chassis).

'90 vs '91 is like dealing with first product that comes off the shelf and the next year's product has small changes (even though, in all technical sense, mine is a 1989 being built in the late spring of that year), but I'd rather have the air cooled oil cooler than the water cooled oil cooler any day of the week.

This is one area that I don't understand why Mitsu made that change.

-DSM

 

[3kgt2nv]

3000gts kept the air cooled oil cooler thru 99 when they were discontinued because it was better at preventing overheating.

 

[Dhan]

'90 vs '91 is like dealing with first product that comes off the shelf and the next year's product has small changes (even though, in all technical sense, mine is a 1989 being built in the late spring of that year), but I'd rather have the air cooled oil cooler than the water cooled oil cooler any day of the week.

This is one area that I don't understand why Mitsu made that change.

Maybe it was a cost issue, material acquisitions, logistical reasons, etc. Who knows why corporations make the decisions they do?

Just out of curiosity, why do you prefer the air cooled over water? Simplicity?

 

[Ryan4dc]

I have researched the forward facing oil filter housings and seen people not install an oil cooler. I would assume less places for oil to leak, but I would rather have that chance over a chance of the oil cooler mixing oil and coolant.

 

[donniekak]

Maybe it was a cost issue, material acquisitions, logistical reasons, etc. Who knows why corporations make the decisions they do?

Just out of curiosity, why do you prefer the air cooled over water? Simplicity?

Because, the water oil cooler is cooling with a 200* medium, whereas the air oil cooler cools with ambient temps. Any type of race car uses an air oil cooler, they work better, flat out.

 

[19Eclipse90]

Here's a nice little thread about the differences, pros, cons, whatever, between 1990 and 1991 DSMs:
http://www.dsmtuners.com/forums/newbie-forum/359492-90-vs-91-dsm-s.html

 

[Dhan]

Here's a nice little thread about the differences, pros, cons, whatever, between 1990 and 1991 DSMs:
http://www.dsmtuners.com/forums/newbie-forum/359492-90-vs-91-dsm-s.html

Thanks, interesting read, if not a little discouraging. I didn't know the '90s could be such a headache

Are the differences between 90s and 91-94 drastic enough to warrant getting the corresponding shop manual? I've got the 91 year shop manual already.

 

[19Eclipse90]

Not necessarily. I think most differences -- electrically speaking and in my opinion most concerning -- are documented on this site one way or another. The problem is locating that information. Personally I would like to have one simply for the convenience factor instead of searching through all of steve's posts to find '90 specific information when I need it.

 

[DSM1G90]

Any type of race car uses an air oil cooler, they work better, flat out.

Same thing why I like an ATF air cooler - get the fluid out of the radiator area and into the cool air.

With my '91 4G37 DD with the automatic, I plan on doing the external transmission fluid cooler which makes the fluid last dozens longer than running though the radiator with that 200* min temp range.

I remember seeing an external fin kit for spin-on filters to radiate the heat from the filter to actually cool down the oil before it heads back into the sump .. anytime you can cool lubrication fluids down, they last longer.

Our 2007 KIA Rondo has an external ATF cooler so I know the fluid is going to last ...

Seems like the big argument with that link is ECU and tranny differences between the two years ....

-DSM