Need quick question Answered please Regarding stock ECU's

[Turbo Habanero]

Ok so i have a 1989 Turbo 5speed car with a Grey plug ECU (California car) Part # 89661-14240 With Red letters that Read 7MGT M/T

Well it appears my ECU maybe shot! Witch of course sucks

But i do have a spare ecu but i'm not sure it will work it is a grey plug ECU but the part # is 89661-14260 and the letters 7MGT M/T appear in yellow text

I'm thinking this is just because it is not a California ECU ? My question is can i still use it and do i need to do anything to make it work besides plug it in?


All help is greatly appreciated !!

-Jordan

 

[GrimJack]

Your original ECU is indeed a California model.

Unfortunately, I've never actually dealt with one, so I don't know if there are any problems running a non-CA ecu...

 

[Turbo Habanero]

Your original ECU is indeed a California model.

Unfortunately, I've never actually dealt with one, so I don't know if there are any problems running a non-CA ecu...

Thanks Grim I also have the harness that came with this spare ecu I have.

Only difference I know of between cali cars and non cali cars is the EGR system so I was thinking if i find a non cali egr system swap it and then use the harness and ecu it should work ..... I dont know just a idea

 

[GrimJack]

CA cars also have a secondary O2 sensor, IIRC.

 

[hvyman]

Are you sure your Ecu is bad. 7m Ecu never go bad usually.

The non ca one should work on a ca harness. Only difference iirc is the egr temp probe.

 

[Turbo Habanero]

I'm not sure but I keep getting code 11 and all my power supply seems to be good I cleaned all my connections and the engine keeps cutting out while driving and its getting worse and worse

 

[hvyman]

Could be a number of things. Power and grounds for Ecu and some other things.
http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx

 

[GrimJack]

You do realize that there are two sides to the power circuit, right? Have you checked the grounds? And have you checked the grounds for the manifold they bolt to?

 

[jetjock]

It's very unlikely to be your ECU Jordan. How do you know your power and grounds are good? "Seem" doesn't cut it with electricity or anything else you can't see. You have to measure or substitute to know for sure.

 

[Turbo Habanero]

So how do I go about finding the problem I have no idea where to start :-(

Also this problem started after resetting my engine codes I was driving home and decided I'd reset my codes before working on the car so I pulled over and pulled the fuse waited then put it back in.

Jumped back into the car and pulled back

on the road not even before I hit maybe 20mph the car acted like I hit a brick wall and shot a couple flames in the process. Well the problem gets worse and is happening more often then not.

At first it only happened under full throttle now it doesn't matter

Thanks for the help guys.

 

[GrimJack]

Well, first off, do you have a multimeter? Second, do you know how to use it?

 

[Turbo Habanero]

yes i have a Multi meter, No i don't really know how to use it all that well to be honest.

I switched the ecu and drove the car to the store and at first it didn't do anything ran decent still slower then it should be but that's a different issue but on my way under full throttle in 3rd at about 50mph it did it again.

So you guys were right as always and so now i guess ill focus on the ignition switch and grounds.

 

[suprarx7nut]

An intermittent problem like that is always a pain. I have a similar issue with my truck. The ignition circuit seems to completely cut out for 1/4 second every 20 minutes of driving. Makes me really want to setup my work laptop with labview and datalog on my way to and from work, haha.

Hopefully you can find a bad connection, wiring terminal or ground eyelet.

 

[Turbo Habanero]

So looking over the car i the wires have seem to come out of the VSV closest to the Alternator. how badly could this F with the car ?

I'm sure it's not the jerking problem

But my car also has a pretty bad problem with lack of power at the moment and its running super rich also.

 

[Turbo Habanero]

Here is what i'm talking about

But here in the TSRM it shows only one..
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EC&P=4

 

[IndigoMKII]

What you see is the FPU(Fuel pressure up) VSV used to aid in hot starts by raising the vacuum to ambient pressure.

 

[Turbo Habanero]

Ah got ya thanks

 

[Turbo Habanero]

So i decided to take off the oil cap today and start the car completely cold and just watch it as it warmed up and nothing no smoke at all.

Until....

I pulled out the PVC hoses from the valve covers while at idle then smoke started to come from the oil cap as soon as i plugged it back up it went started to go away and about a minute later completely vanished.

EDIT: I let the car sit another 5 min at idle and when i blip the throttle it sometimes let a small puff out (doesn't smell like much of anything) when giving it a good rev it doesn't poor out any smoke out the oil cap or exhaust either some smoke comes from my exhaust leak (between downpipe and turbo elbow) every now and again very light though and just smells like exhaust

 

[Turbo Habanero]

So car has got to the point it is not able to really be driven.

Once up to speed it is fine but trying to get to speed is caos!

 

[IndigoMKII]

Have you tried using a few troubleshooting guides?

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=122

Have you also fixed your TPS problem and rechecked mechanical/ignition timing?

If the car is getting worse the more it is driven, stop driving it before something catastrophic happens over something ludicrous.