TPS

[notacarlo]

While hunting down issues, I found that my TPS sensor value koeo was 1.24v. What kind of drivability issues would that have caused?

It is now set at .94/5 and 1.5

Thanks,


Dan

[MikeFleming]

What is the "1.5" value??

Typically we expect to see a code 23 (TPS out of range) and a steady high idle when hot, ~2000 RPM with the closed throttle TPS value that high. This also depends on the EEC calibration.

[notacarlo]

Mike,

On occasion after a hot restart the car will idle at 2000 rpm. Blip the throttle a couple times and it returns to around 900. It does not do this all the time. Maybe once or twice a week.

Correction on the WOT value, it is 4.5 not 1.5

I ran codes the other day and I did not get 23. I did however get MAP value out of range and found that the MAP sensor had been unplugged...for how long I have no idea. The dealer installed cruise control servo rides against the connector and had worn off the lock tabs. I guess it eventually fell out from vibration and what not. After I fixed that, I got another code (67 i believe) which related to several things including AC clutch. The clutch fell off my car last year and I suppose that is why I get that code coming back. I then cleared the memory and everything went away but the 67.

I am chasing drivability issues and started with the basics. Idle and TPS. Plugs, wires, rotor, cap are new.

The car picks up fine in first, but starts detonating at the top of second, third, and so on. Boost is set at 15 on the nose, factory BCS removed and using a grainger valve. I noticed my PCV valve had come out of the rubber tube next to the head yesterday. I set that back in place and I'm trying to find a new PCV valve. This ones easily 27 years old. The only other modification to this car is a K&N that I only use in the summer. I put the factory air cleaner set up back on in winter. I have not modified this car in any other way since I purchased it. I have been slowly replacing 20+ year old parts as I get time. Fuel pump is next, regulator is in the passenger seat.

Thanks,


Dan

[notacarlo]

I should add I drive this car EVERY DAY without fail. I'm not gonna lie, it's seen some snow and I highly recommend not driving a car with this kind of weight distribution in snow. New undies.

Since I reset the TPS, the car picks up stronger and so far I am not really getting the detonation described above. I also have not been able to beat on it since it rained here today. I will say it feels like it picked up a bit.

[MikeFleming]

Correction on the WOT value, it is 4.5 not 1.5 Sounds more better.


I then cleared the memory and everything went away but the 67. You will find SVO EEC codes translated off the main SVOCOP.COM webpage, under Tech Articles, here:

http://www.svocop.com/Articles/7/index.html

Sounds like you're testing in Unleaded (regular) mode. That will give a 67. You can ignore it for now.


The car picks up fine in first, but starts detonating at the top of second, third, and so on. Verify fuel pressure under boost. Looks like that's on your list already though.

Be sure to get a turbo-specific PCV valve.


... I highly recommend not driving a car with this kind of weight distribution in snow. New undies.
...
I also have not been able to beat on it since it rained here today. You just need weather-appropriate tires. That's MUCH more important than weight distribution.

[notacarlo]

Check, check and check. Waiting for my FP gauge to show up. Accidentally sold it with my old car. Keeping my foot out of it for the most part until I test the fuel system anyway. That's the fuse for the bomb as I see it.

Cheers,

Dan

[notacarlo]

Fixed

It seems that an out of range TPS (even a little out of range) will cause drivability issues. Since the TPS is used as a reference by the ECU it can cause all kinds of havoc. In my particular situation, The car would accelerate fine in first, but quickly run out of steam and detonate at the upper end of 2nd, 3rd, etc (running conservative boost 14-15psi). Now the TPS is not the only reason my car was running poorly. It was PART of the problem.

Other contributions so far to my running issues are : Premium fuel switch (also now fixed), fuel pressure (38 static), fuel pump (27 years old).

The car has really woken up, but keeping the stock boost level or a little lower until I get into the tank to replace the pump with a 255lph Wally.