Hi guys... its been a LONG time.

The olds has been parked for a few years since I got a new vehicle. Some one is interested in buying it now, so I am trying to get everything working right again.

The car is a 1988 delta88. 3.8L vin 3 (not the 3800 engine).

Despite the WASP's nest that was built in my muffler (you should have seen the smoke!!!) everything worked well, car drove OK, tires werent too blocky. But, I have a problem that wont go over well with the buyer.

The problem is my check engine light comes on once things warm up for a few minutes. The code is 22 (tps low voltage), and when I run my ALDL program and watch the voltage, it sits at 0.04v. It should sit at 0.42v optimal idle voltage.

Adjusting the sensor, or manually operating it with my finger makes absolutely no difference to the output voltage. When I put my meter across the sensor, and operate it, I can see the resistance go down uniformly as I increase throttle. This tells me that the sensor is working the way it should. I check for 5v at the sensor, and it is there.

My initial thought was the ECM might be on the fritz. I dont beleive in throwing parts at a problem to find a solution. Any suggestions?

ok... looking things up a bit more shows this:

Code 22 : Throttle position sensor ( TPS ) signal voltage is low during engine idle
OR : Fuel cutoff relay circuit open or shorted to ground

I wonder if this could have something to do with my issue... What triggers this fuel cutoff relay, and when is it supposed to cut off fuel? I dont think this car has an impact sensor. Fuel is definately flowing to the engine, and its running RICH (open loop)

Where did you find that info? There is no OR for the code in this case, it just means TPS circuit (signal voltage low).

The only relay in the fuel system is for the fuel pump. The ECM drives the coil of the fuel pump relay, but otherwise it is totally isolated from the TPS circuit.

When you checked for 5 volt reference, did you check with the other lead on the ground (black wire) of the TPS harness? Although if it was the sensor ground, you'd probably have codes for the CTS and MAT since they share the same ground. Doesn't mean it can't be poorly connected after that splice.
Very simple circuit...you have the gray wire (5v reference) going straight to the ecm, the dark blue wire (throttle position signal) going straight to the ecm, and there's the analog low (ground) which is also connected to the ecm.

TOC Admin
Brando

Thanks Brando! I am still alive and kicking - I now have a 4 year old and one on the way, so I've been busy lately.

I tested the ground connection, there is a solid ground. I will go through it all again tonight!

Thanks for the trouble shooting diagram also, that is great information.

TTYL, I'll let you know how I make out.

Ok. The test results are in. TPS sensor is the offender. Again. I didnt test it right, as I only ran my ohmeter across the +5v to the signal pin of the sensor. That part works. There is NO continuity to the ground of the sensor at all.

I have replaced the TPS sensor on this car twice since i've owned it. I dont know why?!!! I bought the first one at Canadian Tire, and I wasnt really suprised when it took a dump, but the NAPA one I am surprised. Most cars carry out thier lifetime without a throttle position sensor change, no???

Oh well, thanks for the help brando! How's things been, anyways? Still have the Intrigue? The delta? (how did the engine rebuild turnout? It has been forever!!!)

Glad to hear you got it figured out.

Yep, still have the Intrigue. It's BLACK now. In addition to the tinted tail lights, I just got 17% tint on the rear windows and 35% on the front sides. Verde black wheels. MURDERED. Will post pics soon. Just installed some custom hid projector retrofit headlights this week. It's like a new car really....looking at a Quaife Limited Slip Differential right now.
The delta is a different story...project is dead right now...kind of just sitting around....sad, but true.
Electrical is my specialty, studying to be an electrical engineer. Been doing a lot of automotive electrical. MECP basic certified, soon to be ASE A6, and J-STD-001 certified (I can solder like a pro). Working on getting my BSEE.

Still got the charger? What's new with you?

TOC Admin
Brando