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1995 3000GT Spyder DOCH Non-turbo
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Discussion Starter · #1 ·
Hi guys, I would really appreciate feedback on this one.
I have a 1995 Spyder SL with a engine who runs poorly, possibly stuck in emergency mode. I have replaced most sensors and lots of parts without identifying the actual issue (s). I have spent over 5.000 USD on troubleshooting undertaken by Mitsubishi garages/shops. Without getting it fixed馃樀.
I have one possible solution left to try, replace the engine. My question is :

Will the engine on a 1992 Mitsubishi Sigma (Diamante) fit in my Spyder?. I bought this car yesterday for 500,- USD. It has the 6G72 engine, but with SOHC, not DOHC. I reckon I must replace the main computer too, possibly some of the electrical harnesses also. Plus, my Spyder has the automatic transmission, the Sigma has the 5 speed manual transmission.
Greetings from the ass-end of the planet-Norway
 

SDSU Alumnus
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LOL 馃槅 that final note was unexpectedly awesome...

Do you mean swap entirely to rule out everything? It does not sound like the current engine is bad per se (explains why you have not mentioned or explored rebuilding)

Are you sure it is not related to the A/T?

-sent from my Galaxy Note 9
 

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93 NA ATX 3000gt DOHC
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1995 Spyder SL with a engine who runs poorly, possibly stuck in emergency mode.
Any chance you鈥檙e talking about what is generally referred to as Limp Mode here in our part of the world? Which is an automatic transmission that only has 3rd gear forward, doesn鈥檛 shift into 1st, 2nd or 4th gear. This certainly makes car feel sluggish from a stop up to 30 to 40 mph range and causes it to run at higher RPM鈥檚 at high crushing speeds.

Like @bboyalan, I鈥檓 also questioning whether you鈥檙e sure it鈥檚 not A/T related. If not could you explain 鈥渞uns poorly鈥 in a little more detail.
 

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1995 3000GT Spyder DOCH Non-turbo
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48 Posts
Discussion Starter · #4 ·
Any chance you鈥檙e talking about what is generally referred to as Limp Mode here in our part of the world? Which is an automatic transmission that only has 3rd gear forward, doesn鈥檛 shift into 1st, 2nd or 4th gear. This certainly makes car feel sluggish from a stop up to 30 to 40 mph range and causes it to run at higher RPM鈥檚 at high crushing speeds.

Like @bboyalan, I鈥檓 also questioning whether you鈥檙e sure it鈥檚 not A/T related. If not could you explain 鈥渞uns poorly鈥 in a little more detail.
Hi, thanks for your reply. The gearbox is functioning perfectly. And it runs thru all gears, but with a powerloss above 50 %. Mitsubishi (who has taken 5 k for fixing nothing) suggests that there is a sensor malfunction. The ECU is good, I tested it in a 94 SL, no problem there. I get no fault codes when turning on the ignition. Mitsubishi informed me that they didn't have the proper instruments to read error codes, due to production year.
I have have a new fuel pump, filter, and the injectors are all cleaned and adjusted. New coils, sparkplugs and cables. New waterpump and main belt. The plenum is cleaned up, new gaskets.
The list is endless, I'm drained trying and Mitsubishi can't fix this engine. That's why I capitulate and seek to get this car going with a engine swap.
 

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1995 3000GT Spyder DOCH Non-turbo
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48 Posts
Discussion Starter · #5 ·
LOL 馃槅 that final note was unexpectedly awesome...

Do you mean swap entirely to rule out everything? It does not sound like the current engine is bad per se (explains why you have not mentioned or explored rebuilding)

Are you sure it is not related to the A/T?

-sent from my Galaxy Note 9
Hi, thanks馃檹. Yes, the automatic transmission gearbox is functioning properly. I suspect the real problem is lack of competent mechanics in this frigid arm-pit godforsaken country.馃樀.
 

SDSU Alumnus
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Lmao I appreciate a good sense of humor and would look at it if I were over there 馃ぃ

You mentioned that the plenum was cleaned up. Was the VICS motor removed at some point? If improperly reinstalled or broken, it could cause the power loss that you are describing.

"Limp mode" is pretty gutless even at low load. Has it always been doing this, or do you recall a time afterward that it became noticeable?

-sent from my Galaxy Note 9
 

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93 NA ATX 3000gt DOHC
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3,754 Posts
Hi, thanks for your reply. The gearbox is functioning perfectly. And it runs thru all gears, but with a powerloss above 50 %. Mitsubishi (who has taken 5 k for fixing nothing) suggests that there is a sensor malfunction. The ECU is good, I tested it in a 94 SL, no problem there. I get no fault codes when turning on the ignition. Mitsubishi informed me that they didn't have the proper instruments to read error codes, due to production year.
I have have a new fuel pump, filter, and the injectors are all cleaned and adjusted. New coils, sparkplugs and cables. New waterpump and main belt. The plenum is cleaned up, new gaskets.
The list is endless, I'm drained trying and Mitsubishi can't fix this engine. That's why I capitulate and seek to get this car going with a engine swap.
For sure it sounds like the problem has been incompetent mechanics dealing with your car, which is obvious by them not even knowing how to pull codes on 鈥94 & 鈥95 model cars without 鈥proper instruments鈥, because it can be done with a paper clip and short piece of wire. Just FYI some codes are retained even when there鈥檚 no CEL indication showing, if they haven鈥檛 been cleared by disconnecting battery for a period of time.

I鈥檓 sorry to hear about your bad experiences and with engine only having a problem in higher torque demand range, it鈥檚 possible it could be corrected with possibly minor corrections by someone that knows theses engines (similar to what @bboyalan posted about VICS motor in above post #6). However it might require some time for them to recheck all the previous work by the inept mechanics. But everything needed to swap the engine from SOHC car in to a DOHC car would also require a very knowledgeable mechanic both in mechanical and electrical aspects of these cars, that doesn鈥檛 sound like is available to you. Don鈥檛 know if you have the abilities, tools, time and etc. to do it yourself even with online guidance like from this site. :unsure:
 

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1995 3000GT Spyder DOCH Non-turbo
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Discussion Starter · #8 ·
For sure it sounds like the problem has been incompetent mechanics dealing with your car, which is obvious by them not even knowing how to pull codes on 鈥94 & 鈥95 model cars without 鈥proper instruments鈥, because it can be done with a paper clip and short piece of wire. Just FYI some codes are retained even when there鈥檚 no CEL indication showing, if they haven鈥檛 been cleared by disconnecting battery for a period of time.

I鈥檓 sorry to hear about your bad experiences and with engine only having a problem in higher torque demand range, it鈥檚 possible it could be corrected with possibly minor corrections by someone that knows theses engines (similar to what @bboyalan posted about VICS motor in above post #6). However it might require some time for them to recheck all the previous work by the inept mechanics. But everything needed to swap the engine from SOHC car in to a DOHC car would also require a very knowledgeable mechanic both in mechanical and electrical aspects of these cars, that doesn鈥檛 sound like is available to you. Don鈥檛 know if you have the abilities, tools, time and etc. to do it yourself even with online guidance like from this site. :unsure:
Hi, I see you nailed it in regards of incompetent mechanics failing to understand.

The Sigma engine is running smoothly and has no iseues. I mean to swap the engine and gearbox over with all components attached
 

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1992 3000GT VR4
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This could be a good bit of things
willing to keep the original engine ?

No CEL hummmm
Does it stall upon cold start up ? Or any other time ?
Back fire upon heavy acceleration?...

(I'm thinking bad Catalytic converters / Cam - Crank sensors - MAF) just what I'm thinking of at the moment
Guesses pretty much...

If your willing to diag it these fellas that have posted prior to me .... will in deed get you where you wanna be either way ( Swap or OEM) DOHC - SOHC...
 

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1995 3000GT Spyder DOCH Non-turbo
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48 Posts
Discussion Starter · #10 ·
This could be a good bit of things
willing to keep the original engine ?

No CEL hummmm
Does it stall upon cold start up ? Or any other time ?
Back fire upon heavy acceleration?...

(I'm thinking bad Catalytic converters / Cam - Crank sensors - MAF) just what I'm thinking of at the moment
Guesses pretty much...

If your willing to diag it these fellas that have posted prior to me .... will in deed get you where you wanna be either way ( Swap or OEM) DOHC - SOHC...
Hi,
I have replaced the MAF, that is ok. The cam-crank sensor is the original though. But i'm thru trying, will the 92 Sigma SOHC fit in my engine room?
 

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93 NA ATX 3000gt DOHC
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Will the engine on a 1992 Mitsubishi Sigma (Diamante) fit in my Spyder?. ................. It has the 6G72 engine, but with SOHC, not DOHC.
The Sigma engine is running smoothly and has no iseues. I mean to swap the engine and gearbox over with all components attached
But i'm thru trying, will the 92 Sigma SOHC fit in my engine room?
The SOHC engine itself can be switched and will fit in place of the DOHC engine.

BUT I suspect you鈥檙e overlooking many major problems. Even if manual trans is same between models :unsure:, all the components like shifter, under dash peddles/linkage, safety switches, wiring, etc. will not be switchable between the different body types. Most likely even CV axles are different because of body width differences and I鈥檓 sure the exhaust system connections are different between the two body types. Just first few things that hits my mind, I鈥檓 sure there鈥檚 many more.

Even if you swap just the engines, you鈥檒l still have exhaust system modifications and few other mechanical issues to deal with. The electrical changes required will be large, because of component location differences like alternator on back of SOHC verses front of DOHC engine (just one example), and the wiring harness from the Diamante is not going to work in the Spyder. The headaches will be much more than you鈥檙e expecting.
 

Lovbyts
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Hi, I understand your frustration and wanting to just make a big change thinking it will fix the smaller problem also but I agree with the others, you are stepping over $1 to pick up $0.10. I know you have spent far to much already but you are about to spend even more than you have and most likely it wont fix the problem.

If you arent capable or dont trust your own mechanical skills to check these problems you really need to find someone who is more reliable than a Stealership. They are usually the last person I would trust with my car that is not under warranty and even then???

As mentioned check the VICS motor and also check, double and triple check your timing belt. I ran mine for months being 1 notch off and it ran decent, just a lack of power, slow revving in neutral.
 

Verified Seller
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Having built several of these engines from the ground up, on several of these cars, I鈥檓 going to tell you the same thing everyone else is. We understand you鈥檙e frustrated, but swapping the motors is a thing you will regret. It will come with its own host of issues, and will cost you far more time and money.

You鈥檙e not going to like this answer, but let鈥檚 start at ground zero- how do you know there鈥檚 no codes? Have you gotten a proper scanner and checked? I鈥檝e seen CEL鈥檚 taped over, bulbs removed, etc. Especially when someone is trying to move a car quickly. After you confirm there鈥檚 no codes, the next obvious answers are the VICS and the MAF. Remember- these cars are old enough to drink and have kids. That means you should be checking the wiring, connectors, pins, etc. I鈥檝e had a broken insulator cause a short in a diagnostics wire that killed the whole car. To test these things, you will need a basic multimeter, wiring diagrams, and patience. If you鈥檙e short on the latter, it鈥檚 ok to walk away and take a break.
 

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1995 3000GT Spyder DOCH Non-turbo
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Discussion Starter · #15 ·
The SOHC engine itself can be switched and will fit in place of the DOHC engine.

BUT I suspect you鈥檙e overlooking many major problems. Even if manual trans is same between models :unsure:, all the components like shifter, under dash peddles/linkage, safety switches, wiring, etc. will not be switchable between the different body types. Most likely even CV axles are different because of body width differences and I鈥檓 sure the exhaust system connections are different between the two body types. Just first few things that hits my mind, I鈥檓 sure there鈥檚 many more.

Even if you swap just the engines, you鈥檒l still have exhaust system modifications and few other mechanical issues to deal with. The electrical changes required will be large, because of component location differences like alternator on back of SOHC verses front of DOHC engine (just one example), and the wiring harness from the Diamante is not going to work in the Spyder. The headaches will be much more than you鈥檙e expecting.
Hi White93, thanks for your reply and concerns馃檹, also to Paul, Hackurs and more 馃檹.
What you write is most likely correct, and I must find another way to get this car going馃槶. I feel I have turned every stone trying to fix this. I am seriously considering torching the car and claim to be temporarily insane.....馃く.
I am dumping the Diamante engine. You guys have saved me doing bad to worse馃憤.

OK, new question. Will installing a 94/95 6G72 DOCH engine be "doable" ?. Without all the electrical/wiring issues and more mechanical compatibility?

I really appreciate your positivity and knowledge you guys give me. I really love this car and hope it can be street-ready this summer馃檹
Regards from Norway馃榾
 

Verified Seller
Joined
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Hi White93, thanks for your reply and concerns馃檹, also to Paul, Hackurs and more 馃檹.
What you write is most likely correct, and I must find another way to get this car going馃槶. I feel I have turned every stone trying to fix this. I am seriously considering torching the car and claim to be temporarily insane.....馃く.
I am dumping the Diamante engine. You guys have saved me doing bad to worse馃憤.

OK, new question. Will installing a 94/95 6G72 DOCH engine be "doable" ?. Without all the electrical/wiring issues and more mechanical compatibility?

I really appreciate your positivity and knowledge you guys give me. I really love this car and hope it can be street-ready this summer馃檹
Regards from Norway馃榾
I think you鈥檒l be surprised by how much work it won鈥檛 take to get the current engine working. We are all confident and have positive vibes because we have gone through this exact trial by fire, and been tempered into something stronger. I know I鈥檓 not the only one that鈥檚 had a time when they鈥檝e just walked away in tears of frustration. Take this one step at a time, methodically. You will save so much more time and money that way.
 

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93 NA ATX 3000gt DOHC
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OK, new question. Will installing a 94/95 6G72 DOCH engine be "doable" ?. Without all the electrical/wiring issues and more mechanical compatibility?
Yes, that would be much easier as wiring and mechanical connections would be the same, as long as it is a Non-turbo engine like yours and not a turbo engine which would also have some electrical and mechanical differences.

The only question then would be if there's someone near you that's capable enough to make the swap without messing something up in the process.
 

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1995 3000GT Spyder DOCH Non-turbo
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Discussion Starter · #18 ·
Yes, that would be much easier as wiring and mechanical connections would be the same, as long as it is a Non-turbo engine like yours and not a turbo engine which would also have some electrical and mechanical differences.

The only question then would be if there's someone near you that's capable enough to make the swap without messing something up in the process.
Hi White93,
I will start looking for a identical engine, N/A certainly 馃憤. While searching I will start with what you are suggesting, checkinall sensors, wiring, connectors ++. Hopefully at one point identify actual errors.

I noted you guys mentioning the VICS engine as a possible fault. I have as a matter of fact disassembled the plenum, cleaning and checking. The VICS are supposed to kick in when revving higher than 3000 rpm's, correct?. The engine stutter and runs dirty from idle and up, so that eliminates the VICS? (I hope?...). Sometimes if I run thru low gears above 4/5000 rpm's the engine seems to "wake up" a little. But that never lasts more than a few seconds馃槶
 

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1995 3000GT Spyder DOCH Non-turbo
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Discussion Starter · #19 ·
I think you鈥檒l be surprised by how much work it won鈥檛 take to get the current engine working. We are all confident and have positive vibes because we have gone through this exact trial by fire, and been tempered into something stronger. I know I鈥檓 not the only one that鈥檚 had a time when they鈥檝e just walked away in tears of frustration. Take this one step at a time, methodically. You will save so much more time and money that way.
Thanks a lot 馃檹. I think you guys have saved me from doing something expensive and counter productive, to say the least. I will do as advised, check systematically following the Mitsubishi Manual for my model
Thanks guys馃檹
 
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