Shifting issues 99 A4 Z28

[mzoomora]

Hey guys. I have a 99 A4 Z28 with blt ons and a cam. It shifts from 1st to 4th on occasion, not all the time. It also is throwing a TPS code, but I checked that and it seems okay. I logged some driving and looked at the map and tps voltage and it all looks okay. The calculated load was only at 30-40%, but I dont know what that is supposed to be or if it even matters. If I hit it off the line it will go for a little, then hit 4th and fall on its face like it isnt even accelerating anymore, then after 5-10 seconds or so it will take off again. If I manually shift I have no problems. Any help is appreciated.

[mzoomora]

Okay guys, needing some help here. I double checked the tps and it is okay. I did a data log of a short 0-50 run where I had the problem. You can see in the log where I went full throttle, and also where it says the trans is in 4th gear.Let me know what you guys think. If you want to take a look at it I can email it to you. My email is mzoomora@msn.com. Any help is appreciated.

[joecar]

I thought a 1-4 shift would have thrown a DTC, did you get any...?

[joecar]

Document ID# 57985
1999 Chevrolet Camaro
Second/Third Gear Only or First/Fourth Gears Only

Checks
Causes
1-2 Shift Solenoid Valve (367A)

• Sediment is in the valves
• The electrical connection is faulty
• Damaged seal

It means that the 1-2 solenoid is not exhausting when turned off due to sludge/sediment build up in it's exhaust orifices, or the solenoid is always ON (either shorted to power, or stuck on).

With key-on-engine-off you could use EFILive to command the 1-2 shift solenoid on/off and listen for it clicking each time (listen carefully, open both doors, park next to a wall, or get under car with your laptop).

If you hear the solenoid click, you then have to drop the pan and pull out the 1-2 solenoid and check it's o-ring and clean out any sludge/sediment (don't use brake clean, use CRC DQ Electronic Cleaner or CRC MAF Cleaner, blow out the solenoid passages, follow by compressed air if you have it).

If you don't hear it click, then the wiring to it is shorted on or it's stuck on;
need to check it's connector using a voltmeter (drop pan, pull connector).

[joecar]

367A is the 1-2 shift solenoid (ON in 1st and 4th)
367B is the 2-3 shift solenoid (ON in 1st and 2nd)

[joecar]

Could also be 1-2 valve (366) stuck in the on position in the 1-2 valve bore;
with a pencil magnet try to move it, and if it's stuck then valve body has to be pulled.

[mzoomora]

Thanks.
I have a question though. It is intermittant, and doesnt happen if I manually shift. Does that sound like it could still be the problem? I may just take it to a trans shop.
It is giving a light- p0121 for the tps. It checks out okay though and looks good in the logs. Map looks good also. It also seem st ohold a high idle while coasting from a cruise at say about 30-40, it wil lmaintain speed by itself and if you place it in neutral while it is doing it it will stay at about 1400-1500 until you come to a complete stop almost.

[joecar]

Intermittent means that the 1-2 valve many be sticking in its bore (especially as temp. changes).

[foff667]

i had this same problem with my cam...i just had to disable the p0121 test...I would go wot and it would be in 4th by 30mph at wot. Disabled the test & all was well.

[mzoomora]

i had this same problem with my cam...i just had to disable the p0121 test...I would go wot and it would be in 4th by 30mph at wot. Disabled the test & all was well.

Cool. How do you go about disabling that test? Is that the same as removing the code? I am new to this, so I dont want to mess anything up.
Also, has anybody else done this? Just curious to hear what else people have done or if anybody else has had this problem.