[JG26_Irish]

Turbo & O2 related Codes - Advice Needed

Hi, I just purchased a 1991 MR2 Turbo. Bone stock. It is high miles and spent most of the last 6 months sitting as the owner had moved away leaving the car with his uncle to sell. All in all it runs fine. Sort of feels like it could use a good tune-up and in fact I am in the process of running thru it giving a a little TLC that it deserves.

I am not a stranger to turbo vehicles having owned a few in the past but am new to the MR2.

I have checked and list the following CEL codes:

14 - Igniter ckt/no IGF signal to ECU/Ignition coil/ECU
21 - O2 sensor (open or short in O2 sensor or signal
24 - Intake temp ckt/intake temp sensor/ECU
34 - Turbo Pressure - Abnormal TC pressure/Turbo unit/Air flow meter/TC pressure sensor/Intercooler system/ECU

A few observations. While the car runs pretty good, the seat of the pants says that is is not doing 0-60 in 6.3 sec. Feel closer to 7.5 to me. No blue or black smoke but it does have a slight rich smell to exhaust. When running under load (up hill for example) at about 2-3K rpm and partial throttle (less than half) I can hear the BOV which is stock OEM popping off from time to time emitting a "Woof" sound. This occurs as I modulate the trottle on-boost until I either let off or go to full throttle. This seems slightly worse when cold outside, but I have not driven it enough to know what normal feels like yet. Car does not miss or hesitate. The turbo spools up fast and spools down slow. I have no idea if the waste gate is fuctioning yet but have no reason to think that it is not (WG failure should cause BOV to operate at full throttle as well, right?)

Since it has been sitting all winter, I am checking all connections and wiring points where corrosion might be interrupting signals first. After all that is not too costly right? Still, any insight, suggestions, common failures to look for might speed the process. The four listed codes may or may not be related.

Suggestions or past experiences most welcome.

Irish

 

[billwot]

Error codes are stored forever, unless yo manually clear them. The fact tht there are error codes stored does NOT indicate there are any current issues. Unless you are getting a CEL, there are probably no current problems.

Clear teh codes by pulling the EFI15A fuse for 30-60 seconds, then drive for a few days and check again. Any codes that show up then are current.

bill

 

[JG26_Irish]

CEL

Thanks Bill,

Yes, I do have a yellow CEL on. I have gone thru the various sensor connectors and looked for loose, broken or corroded connections and any frayed or damaged wiring. Found the connector to the AFM almost off due to a missing clip. It was backed off far enough that some or all of the contacts may have not been secure. That may or may not fix the 24&34 codes.

I have not yet cleared the codes just cause I wanted to at least find something to fix before I did

The O2 sensor should? be a seperate issue and should be relatively easy to fix. I have had good luck with Techron in Porsches as a way to keep the O2 sensor cleaned of carbon and happier. That does not fix a bad sensor but will often cause one to last longer. Anybody here have any experience with that?

As for the 14 code, I am a bit clueless where to start with it, lol

Irish

 

[JG26_Irish]

Still have a code 14

I have fixed several wiring harness issues by checking and cleaning all the connectors and making sure they are secure. The car runs great but is still showing a code 14 following clearing the ECU.

That is the no IGF signal. I know what the coil is but what is the "Ignitor"? would that be the electronic pick-up sensor in the distributor? Just wanting to confirm what parts I should be looking to check or replace rather than just throwing $ at the problem.

Thanks!

Irish

 

[optimusprime8]

What wire/connection did you fix to get rid of code 34?