Andrew's 122 turbo project

Well the car did really well in the mountains two weekends ago. It did around 750 miles and nothing needed any immediate attention. The car ran cool and the tune worked well enough to drive it around and have some fun. Now I have a list of things I want to change/fix after getting some substantial seat time.

Rear links - The heim joints in the rear end are too much. I'm going to shorten a set of torque rods/trailing arms and go back to rubber bushings if I can find a set.

Noise in MS - This is probably the most annoying issue so far. I have a bunch of noise in my CLT, MAT, TPS, and AFR signals. I've been poking around trying to find the source of this and I haven't come up with much yet. I originally had some things grounded to the chassis until I read that you shouldn't do that, so I switched everything to ground directly on the battery. I'm still having noise issues though and the TPS signal is making accel enrich do weird things. AFRs are kind of all over the place. I know that this wasn't a problem when everything was in Jared's 240 and I'm not sure what I've done differently but this is the one thing that's making me not want to drive the car right now. I can deal with rear end noise but this makes it a pain to drive around town.

This is just a short (~10 sec) datalog that shows the noise.

When I got my car fired up yesterday, it made a ridiculous screeching/whistling sound. Thanks to this thread, I instantly knew it was the TB flange leaking. Saved me a lot of time!

Andrew, double check that the signal wires for those are well clear of the coils, and injectors. I used some cable shield loom over my clt iat and tps signal wires and that solved the noise issues from having coil and injector wires in the same bundle. There's some stuff that looks like a Chinese finger trap that is tin coated copper and I ran it all the way to the sn connection and grounded at the furthest point I could.

You could twist the wires together and use some loom to help reduce the noise.

this is really similar what I used, found it at the local second hand scrap metal shop.

https://www.wirecare.com//interest/...4-10-ft-cuts?gclid=CIryiMrzrtQCFUiUfgodX-IAjw

I emailed DIY and they seemed to think I should be using the sensor return wire into the ECU instead of grounding my sensors to the battery. I still haven't tried it. The car is on jackstands again while I'm waiting for my wheels to get finished.

My harness is basically the same as it was in the car it came from so I don't know if that's my issue or not. If the problem persists, I'll start shielding wires and see what happens. I only modified the TPS wires because my TB was pushed so much further forward than it is on a B230 intake, but the noise is in all of the sensors.

This weekend I'm going to finish up swapping out my trailing arms and hope my wheels come back soon.

Your sensor ground goes to the battery? That's definitely your problem. Sensor ground goes to the ECU. ECU grounds to the battery.

Yeah, I used the sensor return as instructions say to, still had issues. Talked to a few local guys using ms on their wire tucked rabbits and stuff, and since they were all about the clean bay looks, they had all ran the entire harness in one loom and only short trips out to individual sensors, having all the signal wires running underneath their COP brackets and laying on top of the injectors, they battled noise issues, so started shielding things individually within the loom until the issues were gone. My harness is similar, the only thing that is not included in the big bundle is the wideband signal, RPM and 2nd trigger wire. My issue was that my IAT and CLT would spike and read 240F or -40F while at steady cruise. makes all sorts of issues when your cruising down the freeway and temp drops to -40. That was throwing it into warm up enrichment and well, then my AFRs went pig rich and ego was running in circles to correct it.

Yeah the biggest issue is that it makes accel enrich act up. The guy from DIY mentioned that the noise isn't really even that bad, but I'd like it to not be there and I know it shouldn't be.

I'm not really sure what my thinking was with the sensor grounds. I had read that you just ground them to the block and I want to say Jared never used the sensor return either. But it's also been three years since we took everything out of his car sooo...

Finally got some more work put in on this thing. I replaced my heim-joint trailing arms with a set of shortened factory arms with bushings. That helped my rear suspension clatter tremendously. Still a little there so I'll probably whip up a set of adjustable torque rods out of a pair of factory ones I have here. That should clear it up and make the rear end very civilized. Also went for another round of brake bleeding and they are feeling much better.

Still having issues with MS though. I moved all of my sensor grounds from the battery to the sensor return at the ECU (which fixed my sensor noise problem, yay!)and the car would no longer start (awwww). It would crank and sputter but never actually start. Showing sync loss reason #11. I started thinking I was having some issue with my CAS but before I got too invested in that, I wanted to move the ground back to the wrong spot and see what happens. I did and the car starts and runs as it did before. While using the sensor return, my tooth logger ended up looking like this:



Not real sure where to go from here. I've been reading up on this a lot and just trying to learn all I can about the way this whole thing works but it's still pretty out there for me. I finally got my LMs mounted though so at least it looks good.

I think I've resolved my noise and crank signal issues by separating the ground for my CAS to it's own location on the block. It should've been that way the whole time but, don't forget, I have no idea what I'm doing. I drove it to work the other day just because I felt like it. I was anxious about it but it did fine on the way there. After leaving work and turning onto the highway on-ramp I saw a massive cloud of smoke from the exhaust. Like Days of Thunder amounts of smoke. I pulled off and let it clear out and drove home without any issues.

It must be PCV related because when I pulled the intake off of the turbo, an obscene amount of oil came out. This caused some concern about my PCV setup. I'm running the Yoshifab catch can and crank case vent but I believe it wasn't draining well enough. I had replaced the long tube that goes down into the oil pan but I thought it might have kinked. I know a lot of engines don't even have a complete tube after they break off and float around in the oil pan for the rest of eternity. I pulled mine out and found that it had broken about halfway down the tube. I'm not sure if it was sitting in a way that caused it to back up or if my B20 oil pan has anything to do with it. I just cut the tube right below the upper flange so that any oil will just fall back down into the pan.

My one vent hose was also not completely open since it had to make kind of a hard 180 to get back to the block. I tried several configurations of angled fittings and couldn't find anything that worked well. I'm not sure that's the real cause of it but it couldn't have been helping. I was able to find a preformed Dodge hose (PN - 04694646) that worked almost too well.





I also added a second vent to the fuel pump block off plate. Unfortunately none of the local parts stores had an oil-safe 5/8" hose so I'll have to order some

I'll remember that for when I do the wiring for my CAS unit. Glad you got if figured out!

Thanks,

I ended up grounding my CAS at the thermostat housing. All other sensors use the sensor return ground at the ECU but still I have noise in my TPS and CTS signals. Approaching six months with this issue and I apparently still have not learned enough to work it out.

With so much noise in the TPS, accel enrich won't work as it should. I have at least learned that. I'm going to have another look at my main chassis grounds this weekend and see if that shows me anything.

Trying to make cars and coffee this Saturday but it ain't lookin' good.

Can you ohm the harness on the clt and tps signal lines, a tiny strand of wire will show continuity but extra resistance and a broken wire can give you funky noise.

I did have to extend my TPS wires when I switched to the Yoshifab intake. So it's definitely possible that something is weird in there.

Check the splice, or redo it anyway.

That probably wouldn't explain the noise in my coolant temp sensor though. I'll have a few days this weekend to mess with it and see what I can find.

Fixed my issues in MS (missing ground). No mountain meet for this thing though. Im on the hunt for a shortblock because this thing is done.

AndrewNance said:

Fixed my issues in MS (missing ground). No mountain meet for this thing though. Im on the hunt for a shortblock because this thing is done.

Click to expand...

Sorry to hear that.

This engine was basically free so I took a chance on it. I'm mostly mad at myself for not rebuilding it a couple years ago when I had more money. Now we're closing on a house in a month and I have $0 for car stuff.

No matter though. I'll grab another junkyard engine and swap it in so it doesn't stay down for too long. Then I'll have a spare to build after my bank account surfaces