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Discussion Starter #1 (Edited)
So my car has recently started to run rich at idle/cruising. It's running right around 8.85-10 range when it's running crappy and the normal 13.5-14.5 when it's not. I initially got the codes run and it came up as the VVTI Solenoid needed to be replaced. I replaced it as well as cleaned the filter and the intermittent shitty AFR's continues. Would this more likely be the O2 sensors? I only run the 2 primary's because I'm running a single. If anyone has any ideas I'd love to hear them.

Specs:
NA-T with Supra internals
60mm Turbo
62lb injectors and a 255 Walbro fuel pump
Haltech Elite 2000
 

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Ok, that’s a full standalone, right?

I would look into the IAT sensor reading next time the car goes rich. Though I don’t know if a false IAT reading could enrichen it that much. Since you have a standalone you can datalog everything and figure it out pretty easily. How old is the wide band sensor ? It’s connected to the Haltech for closed loop fuel control?

I bet you have a “bad “VVTi solenoid code because the Haltech is controlling it, not the Lexus ecu. I don’t believe it’s your stock primary O2’s because they are just there to appease the Lexus ecu at this point. All fuel/timing control should be on the Haltech.
 

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Discussion Starter #5
Ok, that’s a full standalone, right?

I would look into the IAT sensor reading next time the car goes rich. Though I don’t know if a false IAT reading could enrichen it that much. Since you have a standalone you can datalog everything and figure it out pretty easily. How old is the wide band sensor ? It’s connected to the Haltech for closed loop fuel control?

I bet you have a “bad “VVTi solenoid code because the Haltech is controlling it, not the Lexus ecu. I don’t believe it’s your stock primary O2’s because they are just there to appease the Lexus ecu at this point. All fuel/timing control should be on the Haltech.
Kris, thank you for the suggestion on the IAT! The wideband is newly installed, maybe 2 months ago tops. I'm not sure if it's connected to the Haltech though - Titan Motorsports did the install. I'll give them a call on Monday and ask. Thank you so much for taking the time to respond. I'll reply back here with any of my findings.
 

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You’re welcome!


The wideband *should* be on the Haltech...all these modern standalone can utilize the WB for closed loop idle/cruise AF feedback. If the car was mapped correctly (and Titan is a big name in this game so I am sure it was) then there’s got to be some sensor reading incorrectly and causing the Haltech to overfuel. At least, that’s my opinion.
 

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My NA-T car had *exactly* the same symptoms.

Ecu was an ancient Haltech E6k controlling fuel and spark ONLY. Toyota ecu fully hooked up, otherwise, and controlling everything BUT fuel/spark.

Traced problem back to the TPS signal intermittently flaking out. Sometimes signal would read properly, other times it would dither rapidly between about 25% and 50% - which was triggering the accelerator pump/throttle pump/accel enrichment feature of the calibration...

Each time the Haltech saw the TPS percentage rise, it would put an extra shot of fuel into the engine. When that happened rapidly and continuously - I wound up with an extremely rich condition.

In my case, the Haltech was spliced into the TPS signal right at the Toyota ecu connector. Unfortunately, even after re-doing the splice, the problem remained. I was not able to find anything wrong with the wiring, so I re-wired it altogether. Problem remained. The E6k is almost older than the internet so Google isn't very helpful, but I did see a post by Haltech themselves, saying it was a "known issue" on those old controllers

Doubt it's an issue on your elite 2000, but perhaps your problem is similar in nature to mine. Hope this gives some helpful food for thought/diagnosis.

I ended up turning off the throttle pump feature altogether, which solved the problem - but did make the car slightly "cold blooded", meaning it doesn't take throttle properly in cold weather when the engine coolant temp is below ~120.
 

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Discussion Starter #8
You guys are great. So my issue came down to my VCT solenoid connector. One wire slightly backed itself out which I believe is my culprit right now. I'm about to go run a log on my lunch break to confirm. I'll keep you posted.
 

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Well, the bad VVTi code makes sense if the Lexus Ecu is still controlling VVTi. IMO the tuner/installer should have given control to the Haltech ecu as it is fully capable of controlling it though. I’m not certain a failed or disconnected VVTi solenoid can make it run rich so it will be interesting to hear back.
 

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Well, the bad VVTi code makes sense if the Lexus Ecu is still controlling VVTi. IMO the tuner/installer should have given control to the Haltech ecu as it is fully capable of controlling it though. I’m not certain a failed or disconnected VVTi solenoid can make it run rich so it will be interesting to hear back.
I don't see anything wrong with allowing the oem ecu to control the VVTi. However, i agree that it's hard to envision how improper VVTi function is causing a 40% swing towards the rich side in fuel mixture.
 

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Nothing “bad” per se, but you may as well control the advance/retard if you’ve got the means. Agree, I think something more is afoot. Before I had the VVTi tuned, you could tell a difference in the powerband but tuning VVTi required no changes to the VE table. It’s a separate table where you can set the advance. So, I don’t think it would plunge AFR’s to the 10’s if it was disconnected. It’s got to be a rogue sensor reading that’s incorrectly calling for more fueling.

If you live where emissions are required, putting the VVTi control back to OEM means just one less CEL to have to beat!
 

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Discussion Starter #12
Small update - I replaced the VVTI Solenoid connector and I found that the insides of the old one were all busted apart. Bad news is now it runs rich (8.5-9.5) consistently with only short periods of it running right. I ended up going for a ride last night and doing some logging to send over to Titan. I'm hoping they will help since they did the Haltech install. I can post the log here later tonite if you guys are interested.
 

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Yeah for sure, I’d like to see a screenshot.

I wonder if you have a stuck-open injector? Is the oil level rising on the dipstick?
 

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Discussion Starter #14 (Edited)
Kris, I attached the CSV log. I started logging when I first started the car so you can see the rich condition at startup. Then it usually floats back up to the expected 14.5-14.7 AFR. After a few minutes it will start running rich again. You can see this in the start of the log and the last 30-40 seconds. I just checked my oil and it's perfect. It does smell like fuel a bit, but wouldn't it running rich cause that issue anyways?
 

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Hey the link is dead, but I’d still like to see the log. I will PM my email to you, if you want to send via that method.

Yeah, the oil is going to smell a bit like fuel no matter what, IMO. Just as long as you aren’t “making” oil. That’s never good.
 

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Ok, so I got the log to work in the log viewer.

Looking at it all the data, it looks like the wideband is Analog volt input #6 . It’s volt tracing matches the wideband tracing.

Anyways, I wonder if your calibration on the wideband could be wrong? When I look at the Target lambda vs Actual lambda, it gets off track and then matches back up and then gets back off. And the lambda displayed doesn’t really match up to what the expected wideband voltage should be.

It could be a ground loop between the Haltech and the Wideband sensor causing a voltage discrepancy, too. The IAT and TPS don’t appear to be doing anything weird to cause it. I can’t find a fuel pressure tracing to look at that value, and I dont see individual injector duty cycle either.

What did Titan say?
 

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Discussion Starter #17
Ok, so I got the log to work in the log viewer.

.....It could be a ground loop between the Haltech and the Wideband sensor causing a voltage discrepancy, too. ....
Wow thanks for the detailed response! Concerning the quoted text above - Do you know how I'd check that? Titan hasn't gotten back to me yet. I'll let you know as soon as they do.
 

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You can get a ground loop when you have two physically separated pieces of equipment, that because of the distance between them, they each have a different voltage potential. The way to correct it, is to run a ground wire between the two pieces of equipment, so the ground is equalized.

I don’t really think this is causing your problem, but it’s something to rule out for sure.

I don’t know what wideband you’ve got installed, but the wiring is pretty similar between them.

https://www.aemelectronics.com/files/instructions/30-4900 Wideband Failsafe Gauge.pdf

For example, if you look at that manual, in the table on page 5, pin 14 is the ground loop isolater wire. Also in the table on page 16 it has the various translations from voltage to AFR/Lambda, so it wouldn’t be a bad idea to make sure the calibrations are entered into the ecu correct.

Barring all of that being the problem, I wonder how old the wideband is, and would still try to check the injectors to confirm there isn’t a sticky one.
 

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Discussion Starter #20
Sorry it's been awhile. I had my car in a shop and they were unable to resolve the problem. Right now I'm not able to rev the car at all besides that last 15% thats mechanically driven. The car is running an LS400 throttle body and I have 2 others that I've swapped in it's place but the problem persists. I've gone over and all the wiring to ensure there's no breaks and I see none. Does anyone know a competent mechanic in the Jacksonville area that won't kill me on labor to fix this thing?
 
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