DupermanDave

I'm getting codes 41, 51, and 71 now. I know 41 is TPS, is 51 TPS sensor related as well?

And as for 71, it's an EGR malfunction. Any way to fix/check this without a new EGR valve? A list I found says it's just incorrect temperature sensor/readings from the EGR. Is this something to worry about?

DupermanDave

anyone? before i go and blow $200 on sensors

jtruck79

its possible for ur tps to mess with your egr if the ecm doesnt know the correct time to open your egr.. the ecm will not open it at wot or closed throttle either so if your tps is faulting. fix it first then reset codes and run again in about 100 miles

DupermanDave

"fix it"....meaning re adjust the TPS or just replace the sucker? I adjusted it dead on when I got the new throttle body installed, but I guess it could have gotten mis adjusted while installing it.

I have had an idle surge lately, but I sort of fixed it by lowering the idle speed. When I got home I did the code scan and got these codes. (odd that the o2 sensor code and AFM code I had went away. Only been 3 months and nothing has changed.)

should I replace or just adjust it again? How do you know when a TPS needs replaced?

4Crawler

iTrader: (3)

Test the TPS and if it fails the tests (after adjustment) then it is bad. And if the TPS checks out fine (at the TPS connector), try the same tests at the ECU connector (where the TPS signals ultimately run to). Clean the EGR and also test it to see if it is working or not. EGR code is set if ECU tells EGR to turn on and within a set time, if the temp. sensor does not read hot, then the ECU assumes no (hot) exhaust gas is flowing through the EGR.

DupermanDave

Do you mean test the TPS as per the instructions on your site? I've done that before (and after) installing the throttle body, but I could do it again. Or is there another test for testing the TPS circuits themselves?

When I adjusted the TPS, it all adjusted fine. I didn't have any issues.

4Crawler

iTrader: (3)

Yes, test and adjust per the tests on my page or in the FSM. And if it tests OK at the TPS connector, re-test at the ECU connector pins as I mentioned above. The ECU pins are described on my TPS page as well. Think of it this way, you may have a good TPS, in and of itself, but if you took the wires that connect it to the ECU and cut one or more of them or shorted one or more of them, then the ECU sees a bad TPS, since it only sees the TPS as connected by the wiring harness.

DupermanDave

AH, I'll do that second test. DIdn't know there was one.

-edit-
Found the instructions, but I'm still clueless as to what to do for the ECU test. Do you jump a diagnostic terminal? Or am I using the ohm meter again?

DupermanDave

The check engine light came on suddenly and I havent adjusted the TPS since then.

how do I check TPS at the ECU? The 4crawler site says, "If TPS problems are suspected and the TPS itself checks out fine, then repeat the above tests at the ECU connector pins to verify they are reaching the ECU properly."

Where's the ECU connector pins? Are these the same pins in the same area that you jump to get the engine in diagnostic mode?

4Crawler

iTrader: (3)

No, you perform the same TPS tests only at the ECU connector (i.e. the big honking batch of wires that plug into the ECU itself - pinout below):
- http://www.4crawler.com/4x4/CheapTri...roubleshooting

DupermanDave

This is the cleanest picture I could find



So there's a plug that goes to the TPS (duh!) but where do I stick the ohm meter prongs? Just follow the cables to the other end (somewhere under the engine?) and find some sort of terminal? Or am I just testing the plug itself for a closed circuit?

-edit-
been doing some more searching. I finally found a pic of an ECU (never seen one before) I think I see what's going on. So I need to check the cable connection to the pins at the ECU?

4Crawler

iTrader: (3)

You stick the meter probes into the connector at the ECU, located in the passenger side kick panel area.

DupermanDave

Before I test the ECU, I'm still trying to adjust the TPS. I had it pretty darn close after about 3 hours on my feet at the workbench in the garage. It wasn't EXACT, but it was pretty dang close. Does the TPS adjustment have to be dead on? Reason I ask is because I still have a high idle and still having the same codes.

Can you adjust the TPS by ear, or is this very very frowned upon?

abecedarian

You're not testing the ECU. You're testing the TPS wiring before it connects to the ECU.

DupermanDave

Before I test the ECU/Wires, though, I'm still trying to adjust the TPS properly. Once that's set, im testing the rest. But I cant even do the TPS so far.

slacker

iTrader: (1)

holy crap .. thats MY old engine ... how cool is that ?


anyway ..


I suggest replacing your O2 sensor .. or at least cleaning it ... EGR also needs to be removed (3 bolts) and cleaned ...


.

DupermanDave

lol. Thanks for the picture (snagged it from google)

I cleaned the EGR already when I replaced the gasket on the intake manifold. Still need to do the o2 sensor though

abecedarian

4Crawler is suggesting you test / adjust the TPS using the corresponding wires to the ECU instead of testing at the TPS itself. That way you're sure the wiring from the TPS to the ECU is working properly. Otherwise you'll spend time testing the TPS then testing the TPS wires to the ECU... a little bit of a redundant procedure.
If you're happy doing things 2, 3 maybe 4 times, fine... do it that way.

DupermanDave

What am I looking for when testing the wires? Any sort of "closed loop"? Or just making sure there's a connection at the other end? Or am I looking for a certain ohm reading?

4Crawler

iTrader: (3)

You are looking for the SAME readings at the ECU connector as you get when you test at the TPS connector. The whole idea is that the ECU can only see the TPS resistances through the wiring between the two devices. You can have a perfect TPS sitting on your bench but unless it is connected to the ECU and the ECU can get the same readings, it is worthless.