Stumped eveyone thus far

[yukon101]

Someone at FCP didn't put the right tracking number in so I don't have a number but I'd expect it Wednesday at the latest.

[yukon101]

There's been some changes, it will now buck when it's almost to operating temp (right before straight up) before that and it's okay and at op temp it's okay. At this point it does it at all ambient temps but still only 10-0mph. It I stop hard it will stall if I stop out normal it's still bucking but the rpms slowly recover. If I hit the gas while doing it, it will buck and the rpms go up and down then it corrects itself. New coolant temp sensor will be delivered tomorrow.

[yukon101]

Both have been replaced, the old coolant sensor was ridiculously corroded so it was on its way out, the old ground strap want just a corroded piece of copper with no insulation. It has now started a normal idle of 480 and today it finally threw a code 1221 while I was pulling into the gas station. Thoughts?

[ross1]

IF there are no vacuum leaks(I'm not convinced) then perhaps the ICV is struggling to keep up with it's commands.

[yukon101]

I just don't understand where they could be, I have taken every line off the system and looked for cracks. Icv maybe, it was swapped for another unit that I had that tested the exact same.

[84318i]

If you don't have any vacuum leaks, I would start pinning sensor connectors to the dme to rule out a bad connection/harness.

There are dme pin outs in etm, and you can then take an ohm meter and pin from the corresponding dme pins on one end to each sensor end .

[ross1]

I just don't understand where they could be, I have taken every line off the system and looked for cracks. Icv maybe, it was swapped for another unit that I had that tested the exact same.

V-8, right?
The PCV plate on the back of the intake is a know troublesome item.

[yukon101]

M60 V8, the rear pcv plate is a new Meyle one. I'm not getting a whistle that would indicate a bad one. What would point to a bad DME?

[84318i]

M60 V8, the rear pcv plate is a new Meyle one. I'm not getting a whistle that would indicate a bad one. What would point to a bad DME?

Before swapping parts I would at minimum do this:

1) smoke test to ensure you don't have vacuum leaks
2) test your wiring harness connectors , make sure you don't have connectors crossed at the front passenger side as some are very similar.
3) check your cps
4) see how it runs in open loop with maf disconnected
5) check fuel pressure

[yukon101]

4 I can answer right now and that it runs exactly the same connected or not, I don't want to try driving it since it puts the trans in limp mode. 2, possibly? It would've been the previous owner since I packed everything when I took it apart and wouldn't it be all kinds of screwed up if the knock sensors were switched?
3. CPS being crank or cam? I've seen the terminology switched before.

[yukon101]

Following correct terminology I went out during my lunch break and yanked off the cam position sensor and the car didn't run any different but I didn't ohm since I took my muiltimeter out of my car.

[yukon101]

I feel its something sensor related, it hasn't done the bucking since I replaced the two items and the idle has returned to 510~ however when it gets to its problem temperature the transmission acts really weird, it upshifts (all gears still) and downshifts really rough (not dropping out of gear) and hangs onto gears (the feeling you get if you downshift) but becomes perfect at full operating temp or when below the problem temp. That is the rpm it always idles at hot/cold, that is the temperature at which the trans acts up.IMG_20171215_201830.jpg

[yukon101]

It still does it just not as bad as before and with me downshifting to keep the RPMs up it doesn't happen. I tested the ohms on my cam and crank sensors and both showed open circuit no matter the setting but the engine won't start with the crank sensor not connected, this is confusing.

[Grim Reaper]

Vacuum leak

[yukon101]

I fixed the one vacuum leak in the system, it fixed the shifting part however it is still there. I was testing sensor again after I found the revised pins to test, crank pos sensor is perfectly fine. The cam pos sensor however wasn't anywhere near where it should be and only had some ohms when hot vs nothing when cold so a new one has been ordered.

[Sir Montalbon]

I'm still leaning towards vacuum leak. Get a smoke test done or build one.
https://youtu.be/2U5kFib1WxE

I built this with a spare MAF housing I had laying around and found a leak I didn't suspect nor could find with carb cleaner.

IMAG0553.jpg
IMAG0549.jpg

[yukon101]

New cam sensor installed, old one was stained and covered in gunk and the wires were on their way out anyhow. No change from that. I did notice that I forgot to screw a clamp on the intake on last time I had it out before TPS replacement, no change after that either. Its been acting up throughout the entire temp range now and doesn't stop until its been at full temp for a bit. I had the radio turned off and it sounds like the engine is cutting fuel/spark then it suddenly comes back so definitely CPS related. I did notice too however that when someone changed the sensors before they connected the crank sensor passenger side and cam sensor on the driver side which from everywhere I have seen is backwards. I will try swapping those after I get home then re-combing through the vacuum system.

[yukon101]

After searching the vacuum system again I found another clamp on the EVAP line not tightened, fixed that and no change. I think I have come to the conclusion that the torque converter lockup solenoid is sticking, at that temp if I push on the gas a bit the engine will start to pull then bog down and do that back and forth till it starts working fine again. If I am driving and it hits the temp the engine will drop about 100 rpm and continue from that rpm but still run perfectly fine. It is not slipping out of any gears, it will hold the gear itself just fine. The torque converter itself is fine, I can do 80 mph down the highway with 30mpg and 2k rpm. The current valve body in it is the updated model for the 5HP-30 but has at least 150k miles on it and at least the O-rings are leaking causing the whine (recent OEM filter change). I am heading to the junkyard today and I will pull a valve body from an E38 5HP-30 and rebuild that and swap to have minimal downtime on my E32 since it is my DD.