Mitsubishi 3000GT & Dodge Stealth Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
Hey guys,

Just purchased a 92 3000GT VR4 with 65000 miles on it. Had an issue upon delivery unfortunately and wanted to see if you guys could recommend some places to start so I can start tracking this issue down. Everything works great on the car at startup but the engine light does come on( I'm having someone read it and they'll give me the breakdown Monday). It also had plugs changed just before I bought it 2 weeks ago. But besides engine light it looks like it's making boost but it incredibly sluggish and boggy. It won't even reach 3500 RPM. I know the code would help a bunch and I'll update the thread once I have the answer back. But right now 50MPH is a struggle. Thanks guys and glad to be apart of the community. I'm sure this will get fixed and I'll be able to enjoy the car.
 

·
SDSU Alumnus
Joined
·
3,199 Posts
Welcome to the board!

Aside from reporting the DTC(s) behind the CEL, it is just pretty standard routine... double-check that vacuum lines are intact + routed correctly and perform a pressure-test for boost/vacuum leaks. If the person "reading" the codes is using a logger, then it will help to datalog the ECU. Also, which exact plugs were installed and at what gap?

-sent from my Galaxy Note 9
 

·
Registered
Joined
·
10 Posts
Discussion Starter #3
Good question at the end I'll get that from the previous owner. Yes they are able to log the data. He has something able to read OBD1 which is helpful.
 

·
SDSU Alumnus
Joined
·
3,199 Posts
It's throwing a knock sensor code, air temp sensor and baro prs sensor code.
I would pull the ECU and inspect the board for a leaking capacitor(s); you can search the forum for multiple threads on this topic. Aside from simply swapping, there are tests that can be performed on the above mentioned before throwing money at it.

Not that it is entirely related, but is the sport and tour light flashing on the cluster for ECS?

-sent from my Galaxy Note 9
 

·
Senior **i.e. OLD** Member
Joined
·
13,316 Posts
If I recall correctly, the air temp and baro pressure comes off the MAF (Mass Airflow). It could be that the connector that plugs into the MAF is loose or not connected at all.
286931


That is a MAF, the connector plugs on the protrusion between the two screws.

The KNOCK sensor is a total different connector, it is being touched in the picture below..

286932


Hope I've at least pointed you in the right direction.

BTW, those errors are retained, so correcting the issue will probably not get rid of the error, you have to use one of the available tools to clear the errors..

Bob.
 

·
Senior **i.e. OLD** Member
Joined
·
13,316 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #8
I would pull the ECU and inspect the board for a leaking capacitor(s); you can search the forum for multiple threads on this topic. Aside from simply swapping, there are tests that can be performed on the above mentioned before throwing money at it.

Not that it is entirely related, but is the sport and tour light flashing on the cluster for ECS?

-sent from my Galaxy Note 9
It most certainly is in answer to your last question. We checked the vacuum lines. They seem to be fine. The previous owner did say he replaced the MAF.
 

·
SDSU Alumnus
Joined
·
3,199 Posts
Bob - Haha! ? Also, if the knock sensor has completely crapped out to the point that knock counts are constant, then you will have a bad time... (as you have so far have experienced with normal driving) datalog will quickly verify that.

Try unplugging the ECS computer behind one of the panels in the hatch.



-sent from my Galaxy Note 9
 

·
Senior **i.e. OLD** Member
Joined
·
13,316 Posts
The same (possibly) leaking capacitors (type, brand) were used in both the ECU and the ECS computers.
They are NOTORIOUS for failure and cause all types of drivability issues.
 

·
Senior **i.e. OLD** Member
Joined
·
13,316 Posts
I believe Alan was suggested you unplugg the ECS computer, not the ECU (Engine Control).
The link I posted earlier was for ECU removal and inspection...
 

·
Senior **i.e. OLD** Member
Joined
·
13,316 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #15
Welp found out where the issues were. The knock sensor was bad for sure. A mouse chewed up a ton of the vacuum lines too. The car was sitting for 8-10 years. Guy only drove it 50 miles a year for that period. After fixing all of that the codes are all gone and it definitely runs better. Exhaust is toast though. The car has seen some Florida salt. No rot in the frame or anything but the exhaust is really corroded. This car just needs some TLC as far as cleaning and it should be fine. Texas will be much nicer to it. Replacing the exhaust is my next step though.
 

·
Registered
Joined
·
359 Posts
Well let me see if I can help. You said you had the plugs changed two week prior to purchase.




Most likely, during engine tear down, they either forgot to secure the intercooler lines tight or they worked there way loose during maintenance.

Are you boosting high and going no where?

Are you pushing out black smoke the tail pipe?

Maybe your intercooler lines are loose.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #17
Well let me see if I can help. You said you had the plugs changed two week prior to purchase.




Most likely, during engine tear down, they either forgot to secure the intercooler lines tight or they worked there way loose during maintenance.

Are you boosting high and going no where?

Are you pushing out black smoke the tail pipe?

Maybe your intercooler lines are loose.
Hi Ohio,

We got it all figured out. Mainly it was the cut vacuum lines and the bad knock sensor. Once those were fixed it's running just fine now.Thank you for your input though I appreciate it. Downpipe replacement is next
 

·
Registered
Joined
·
159 Posts
Well let me see if I can help. You said you had the plugs changed two week prior to purchase.




Most likely, during engine tear down, they either forgot to secure the intercooler lines tight or they worked there way loose during maintenance.

Are you boosting high and going no where?

Are you pushing out black smoke the tail pipe?

Maybe your intercooler lines are loose.
That's what I was thinking right off the bat if the vacuum leaks don't fix it. Every single time I leave one of those clamps loose and they either blow off or it's like there's no power. The big bang/stall is always a crowd pleaser.

Another issue is that when they did the plugs that rear turbo line that goes along the driver side past the intake may have a damaged (or missing or mis-seated) O ring. I had to wrap 2 dozen layers of teflon tape around mine to get it to seat tight. Couldn't figure out why the darned thing was losing boost.

But, I'd still pull that ECU and check it, first thing if not sooner.
 
1 - 18 of 18 Posts
Top