Q Computer swapping
Q Computer swapping
Hi all,Brand new member here. I have been lurking for a while to tryto get educated on this 92 Q I bought several months ago.Isn't it funny how hanging out with folks (physically or mentally)makes you want to do what they're doin'? Well I read about the TCU swaps you have done and immediately became dissatisfiedwith my second gear starts. I had been driving a leaping 95 Maxima and have bad habits of pulling out when my wife disapproves. I called over to T3 and was told a 93 or 94 TCUwould solve the start gear. I also read somewhere I should swap the ECU for a smoother 1-2 shift. So then I called the local junkmeisters and they quoted me $200 94 TCU and $250 94 ECU.I told them Charlie in Monroe quoted $100 TCU and they said ok$100 TCU , $250 ECU. I said I'll take the TCU only for now and see how it shifts. Well I get home and check this board again for installation hints, then open the driver's kickplate, and lo and behold it does not match. The plug seems to match the box in the passenger kickplate... I guess they gave me an ECU. Anyway now I wonder what to do with what I have. I have readother posts, now, that say only use the 93 TCU because of the different gearing in the trans. Please advise me: Should I A: Keep the $100 94 ECU, get a 94 TCU, install both 94's B: Go back to the junkyard and swap for only the 94 TCU and install that C: Get rid of the 94 ECU and get a 93 ECU and TCU, install both 93's D: Get rid of the 94 ECU and get just a 93 TCU and installThanks in advance Dennis and whoever else weighs in!
Hi max, thanx for the welcome-No I believe the plug would match IF they had given me a TCU....it looks like they handed me an ECU...at the timeI did not know what one or the other looked like. On the phone they blamed the part puller man. But it seems like I own a 94 ECU now at a good price, question is, do I want touse it with a 94 TCU or do something else.
As far as I know, swapping ECUs (except JWT) won't do anything to help you. What you'll want to do is get a 93-95 TCU (1st gear start). The '93 is the only year that had the higher gear ratios and 1st gear start. The 94-96s had 1st gear start but have LOW gear ratios. The problem with the '96s is that they're OBD II. So getting a 93-95 TCU should do you just fine.
Welcome to the forums Qfloater. Sorry, I didn't catch your name? All the best to you and your new car!
Corey
Welcome to the forums Qfloater. Sorry, I didn't catch your name? All the best to you and your new car!
Corey
Hey Corey,Barry here.The reason I was asking about the ECU was because I hadread a thread where someone said they swapped in a 93-95TCU, and, once he got used to the somewhat abrubt 1-2 shiftit was fine:pface . Then Q45tech/Dennis replied and said installing the matching ECU would make it shift smoothly, asthe ECU will retard the timing during the shift. However besidesthat one statement no one else ever mentions installing bothjust to get a first gear start. Also, the tech at T3 said no one bothers with the ECU, and the TCU takes care of the engine changes during the shift.That's why I am confused in my ignorance and ignorant in myconfusion.
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Q451990
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I have used both the 93TCU with my 90ECU and the 93TCU with a 93ECU. I like the matched pair better, but I wouldn't say that there's a HUGE difference. I've heard of some folks having issues with the rev limiter with a mis-matched combination. Mine shifts very nicely at redline with the 93/93 combination. I think the 1->2 shift is better, but sometimes things seem to improve after I put any labor or $$ into the Q. Maybe my mind trying to reward me to justify the cost?
Just to confirm what you bought... what are the numbers on the case? Should be something like A18-B10 P72 (not exactly, but in that format) if it is an ECU. The ECU also has a diagnostic screk on one side. and should have a label that says " Self Diagnosis Mode Select" marking the screw. Go ahead and post the numbers and I'll look them up for you to see what you bought.
If it's the TCU it should have some numbers to the right of the Nissan Logo that says something like 31036-64U20. Here again, not exactly those numbers, but close.
The idea that a 94-95 TCU will work on a 93 or earlier is a new one around here... with the transmissions using different gear ratios - and all of the differences in the update for the 94 model year, I'm skeptical.
As a side note - I do have a 93 ECU and 93 TCU that I pulled from a salvage car last fall. When I saw them, I went ahead and bought them with the idea that someone here would eventually want the pair. I tested them in my car for about 1000 miles and they work great. I'll be happy to sell the pair for $300.
This combination came out of a standard Q (no active or TCS) - does your car have any optional systems like that?
Good luck!
Heath
Just to confirm what you bought... what are the numbers on the case? Should be something like A18-B10 P72 (not exactly, but in that format) if it is an ECU. The ECU also has a diagnostic screk on one side. and should have a label that says " Self Diagnosis Mode Select" marking the screw. Go ahead and post the numbers and I'll look them up for you to see what you bought.
If it's the TCU it should have some numbers to the right of the Nissan Logo that says something like 31036-64U20. Here again, not exactly those numbers, but close.
The idea that a 94-95 TCU will work on a 93 or earlier is a new one around here... with the transmissions using different gear ratios - and all of the differences in the update for the 94 model year, I'm skeptical.
As a side note - I do have a 93 ECU and 93 TCU that I pulled from a salvage car last fall. When I saw them, I went ahead and bought them with the idea that someone here would eventually want the pair. I tested them in my car for about 1000 miles and they work great. I'll be happy to sell the pair for $300.
This combination came out of a standard Q (no active or TCS) - does your car have any optional systems like that?
Good luck!
Heath
Q451990 wrote:As a side note - I do have a 93 ECU and 93 TCU that I pulled from a salvage car last fall. When I saw them, I went ahead and bought them with the idea that someone here would eventually want the pair. I tested them in my car for about 1000 miles and they work great. I'll be happy to sell the pair for $300.
This combination came out of a standard Q (no active or TCS) - does your car have any optional systems like that?Heath
Heath - Any chance you can pass that onto me instead? Since Qfloater hasn't responded that he wanted it, I'd like an opportunity to grab it both: '93 TCU & ECU. You've got mail Heath!
I believe Rob's done it without incident. Don't quote me on that one though. He was the reference I was speaking of in any case. I believe Dennis had an explanation for it...Q451990 wrote:The idea that a 94-95 TCU will work on a 93 or earlier is a new one around here... with the transmissions using different gear ratios - and all of the differences in the update for the 94 model year, I'm skeptical.
Corey
SFBayQ45 wrote:Heath - Any chance you can pass that onto me instead? Since Qfloater hasn't responded that he wanted it, I'd like an opportunity to grab it both: '93 TCU & ECU. You've got mail Heath!
to SFBayQ45- You probably didn't think that over here on the east coast bedtime comes earlier. I was snoozing well when Heath posted his for sale. :oface That's ok I still want to hear from Dennis before I decide what to do. I shoulda woulda coulda thought to post here and ask if someone had some computers anyway to get the right thing from the knowledgables that would sell me the right thing. Go ahead and get them if you want, with my blessing- they don't seem to be that hard to come by. Heath: the numbers on this unit are 28491 67U00. The plug does not match the plug on the unit in my driver's kickplate.I'm not real worried about redline shifts except maybe first to second, even then it's not important unless the car would be harmed- it just needs to shift so I can keep moving. I tried to "shoot the gap" across the four lane the other day, forgot to pull it into first and almost got my emblems knocked off.And my wife said, ":rant "
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Q451990
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- Contact:
Qfloater wrote:Heath: the numbers on this unit are 28491 67U00. The plug does not match the plug on the unit in my driver's kickplate.
The list of P/N's that I have only extend through 1994, and that part number is not on it... I suspect you got an ECU from a 1995 model that was built in 1994. I'd take it back and keep looking elsewhere. Who knows what's different about the ECU?
Although the obvious differences are cosmetic - the 94 revision was pretty substantial. Different injectors, CAS, runner lengths, plenum (?), LAN electronics etc. A 94+ ECU is designed to control a completely different car.
Heath
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Q45tech
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1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
With in reason a 4.5 liter engine is a 4.5 liter engine. EXCEPT 96 ecu which are unswappable due to dozens of changes.....the least of which is the 96 has the driver transistors for the coils internal vs external in 90-95.
A 1-5% change in parameters probably wouldn't be feeable if tweeks were for emissions.
It's the add on sensors [egr temp/multiple temps, etc] or missing sensors Active/traction modules that throw codes and cause problems.
A 1-5% change in parameters probably wouldn't be feeable if tweeks were for emissions.
It's the add on sensors [egr temp/multiple temps, etc] or missing sensors Active/traction modules that throw codes and cause problems.