legacycentral bbs

This problem is probably over a year old. Sort of. When I first got my rob tune running with my patch harness that was crimped together for the wires that were wired up to the ignitors under the dash the car would die suddenly on bumpy roads. I figured out I could get it running again by jiggling the harness or holding pressure on the wires a certain direction. I pulled it and redid all the wires that were crimped but soldered them this time. It completely fixed it for about a year I'd guess. Then I came back but it was a little different. It's totally random now. Not bump related and jiggling the harness has no effect so I don't think its the same problem. The symptom is very similar except it only dies for a second and always comes back on when I give it gas and its never left me stranded.

Tonight I got in my car and it was the coldest its been in months. Probably 40-45F. I noticed immediately the check engine light was on. This has never happened before I don't think. At least not since I fixed the harness. I checked ghe. Odes and its coming up with 31 and 45. 31 is TPS and 45 is:

Pressure sensor and pressure exchange solenoid valve

Faulty sensor or pressure exchange solenoid valve inoperative

Prevents abnormal supercharging pressure using "fuel cut" in relation to engine load

Kimo,
I'm sure you did this since you didn't have the code for a year, but for the EJ20G ECU:

Wiring
The ignition differences are described above, but the MAP sensor also needs addressed. Otherwise, it'll throw a code - 45. The solution is to remove pin 5 on B48 and join it with pin 21 on B48 @ the ECU connector.

I know I was getting the 45 when the wiring @ my sensor was bad - crimped originally>>>soldered to fix.

The TPS? I'd check that it's calibrated/set (Josh has instructions on here in multiple posts) or swap in another TB (NA or turbo) to test.

Otherwise, I'd double (or is that triple)-check your harness.

GL,
Td

Ok ill check the harness. I didn't do the harness, phyrram did it for me. I just redid (soldered) it because the crimp connections were failing. So I don't know if it was done correctly or not but jess knows his stuff so I highly doubt he did it wrong.

Jess does - lots of good info from him on here... but $#!+ happens...and I personally hate those crimps...probably my own dang fault...but soldering FTW.
Td

Yeah I see the solder debate all the time and I'm on the fence about it. In auto tech they taught us to always solder and never crimp. If you're going to crimp I think you really need to have an expensive quality crimp tool and know what you're doing. People argue that oem always crimp and that's true but perhaps its because of cost, not so much reliability or maybe not I don't know. Soldering has never failed me before and I've done a lot of soldering. Maybe this time it did but I haven't messed with that harness at all and its ziptied in place so it won't move.

Looked up the price up a new OEM TPS....over $270 but that's what I was expecting. The pressure exchange solenoid is about $72 OEM.

I don't have a spare of either so I'll have to hit up the junkyard if the TPS doesn't test right. Gonna break the FSM out now and go do that.

I checked the connector at the ECU while plugged into the ECU and that was all within spec.

Turn ignition to "on".
Measure voltage between ECU connector terminal and body.

(B58 connector/terminal) No. 2 - Body/
4.4 - 4.8 V (Throttle Fully Closed) Mine was something like 5.2 V I think, forgot to write it down.
0.7 - 1.6 V (Throttle Fully Closed) Mine was 1.7 V I'm pretty sure.

Ensure voltage smoothly decreases as throttle valve changes from "closed" to "open". (It did)

(B58 connector/terminal) No. 3 - Body/ 5 V (Checked out)
(B58 connector/terminal) No. 1 - Body/ 0 V (also good

That sounds legit to me but maybe 0.4 V higher than normal is not good?)

Check Throttle Sensor
Disconnect connector from throttle sensor. Measure resistance between throttle sensor terminals.
No. 2 - No. 3/ 12 Kilo-ohms (Mine was 8.8 K Ohm)
Measure resistance between terminals while slowly opening throttle valve from the "closed" position.
No. 2 - No. 4/ 10 - 12K Ohm (Throttle Fully Closed) Mine read 8.42 K Ohm
3 - 5 K Ohm (Throttle Fully Open) Mine read 1.8 K Ohm

Check harness connector between ECU and Throttle Sensor.
Disconnect harness connector B58 from ECU and Throttle Sensor connector. Measure resistance between both connectors.
B58 No. 1 - E8 No. 2 / 0 Ohm
B58 No. 2 - E8 No. 4 / 0 Ohm
B58 No. 3 - E8 No. 3 / 0 Ohm

These were all good. They read between 0.7 Ohm and 0.8 OHM which isn't bad I'm pretty sure since I tested the two prongs together on the multimeter I have (cheap craftsman POS) and it was 0.5 Ohms just from one prong to the other so we're talking 1/4 or less of an Ohm resistance in the harness and the connectors look to be in good shape; no cracking.

Measure resistance between throttle sensor connector (not the harness, the connector on the sensor) and body.
E8 No. 2 - Body/ 1 Mega Ohm, Min.
E8 No. 4 - Body/ 1 Mega Ohm, Min.
E8 No. 3 - Body/ 1 Mega Ohm, Min.

Good here too. This leads me to believe either the TPS is bad and needs to be replaced or maybe cleaned if that's possible or the problem lies elsewhere. I hate electrical work.

Thoughts anybody? Can it be cleaned?

Looks like cleaning the tps is out of the question. I found out another member tried it already and had to drill parts out it out to get it open. I guess the next question is would an aftermarket tps from rockauto be reliable? I'm sketched out about buying aftermarket engine components.

I also went back out and did all the tests for the idle switch and that tested out perfect.

Kimo,
As I mentioned, just get another used throttle body w/the TPS attached. The NA and turbo are the same. '90-94 will work, from my experience....or better yet borrow one from a working Legacy just to verify that's the issue.

Td

Alright I'll go to the junkyard. It's just a lot of work to mess with, especially the testing part with getting under the dash and stuff. Plus since the stupid IAC is on the wrong side with this JDM manifold I was forced to mount my throttle body upside down which made clamping on to those little electrical pins in the tps terminal was a real bitch. The terminal is pointing straight down and there's a mess of vacuum and coolant hoses right in the way from the IAC and pressure exchance solenoid. Also had to remove my strut brace and a intercooler to gain access to it due to it being upside down. GRRR.

Is there a JDM throttle body with the old style 1st gen legacy TPS that would work on my car? I could then also ditch the throttle body spacer and have more room for a larger TMIC or AWIC.

kimokalihi wrote: Is there a JDM throttle body with the old style 1st gen legacy TPS that would work on my car? I could then also ditch the throttle body spacer and have more room for a larger TMIC or AWIC.

Oh, yah...I wondered if you had the JDM....

Ask Mike Tracy about that or maybe Rob Files.....Look on Ebay JDM stuff...or maybe the 'Liberty' forums down under. NASIOCpost.

Td

I have an ej20g intake manifold (like the original one you got from Jake), and the throttle body and tps appear identical to my ej22t ones. Matter of fact I've ran both throttle bodies+tps's with the ej22t wiring.

So the throttle body would need to be chopped down and flipped like your current one, since it's the same.

How is it the same? Shouldn't the linkage be on the passenger side?

Nope, the throttle cable runs across the manifold to the same side as the SS.

Went to the junkyard to get a throttle body and some asshole took all the tps. And iac sensors! Probably 15 1st gens and no one had a tps and or iac. I know he's selling them on ebay or something. I didn't think bad tps were a very common problem.

So do you think the rockauto aftermarket tps is worth buying for $75?

Kimo, all your tests look ok on the TPS.

I personally don't think you should discount the fact you had previous issues with the igniter and wiring under the dash. I know it probably means more wiring troubleshooting, but if the tests work out ok, then there may be something else going on.

If someone has a spare throttle body, you could just hook it up without swapping yours, try clearing the codes and then see if they come back right away. If they come back right away, this tells you the problem is likely with wiring or the ECU, vs. the TPS.

Out of curiosity, have you checked the pressure exchange solenoid? Also, code 45 includes the MAP sensor. Not sure if those codes mean different things with the Rob tuned ECU.

No I haven't checked the pressure exchange solenoid yet or the map sensor. I had to put everything back together yesterday because I need the garage today to help my friend work on his car. I also forgot to check the wiring for the map sensor as was mentioned by wtdash.

Little update. I swapped in another throttle body I got from beatersubie with tps included and I unplugged the battery while I was doing the job to clear the ecu. It worked great for 5 days and today on my way to work it did it again for about 4 miles pretty badly and then was fine for the next 10 miles. I don't get it. I'm gonna buy a good multimeter. Haven't checked the codes yet. Anybody have a suggestion for a really good automotive geared multimeter? One that'll last me forever.

Any multimeter made by fluke is good to go, and used by the pro's.

That's what I was going to buy but there's a lot of different models and many are made specifically for things like elctronics or electricians work or other things. I haven't seen an automotive one yet. I don't want to pay more for features I won't use and I want it to have features that pertain to cars.

I’ve got an Extech multimeter. Here are all their multimeters.

http://www.extech-online.com/index.php? ... h=78_16_53

Depending on what you want to test, they’ve got a pretty wide range for under $100. Here are some that I would recommend

330
420
430

However, it really depends on what you want to test. Any of these should give you general testing capability, but if there is anything specific you need, you may want to find out before you get a meter.