No Power in Boost: Help Please

[Wildfire007]

Ok just to start this off I did check what codes the car is throwing. Here were my findings.

32- HAC Sensor Signal
51- (This one is probably because the entire AC System was removed by the PO) Possible TPS issue.
52- Knock Sensor

Now that we are passed that I'll describe the problem.

First it starts up fine with every turn of the key, never any trouble. It idles like it has always idled for the passed 3 years, smooth around 1k(yes I know its a little high but it hasn't caused any problems for years). When you drive the car easy it accelerates easily with no hesitation and rpms climb smoothly. This is with shifting no higher than 2.5k for gas saving driving.
Once you start getting into boost however it has no power like it just flat lines. I can hear the turbo spooling like always, and the bov expels air when I let of the throttle, once again like always but there is no increase in acceleration or power. In fact the rpms almost stop climbing all together when the boost starts kicking in.

Its a stock turbo with 3in IC pipes and IC. Both installed by PO and been on the car for the last 3 years. The Turbo was replaced about a year and a half ago with a used turbo and new seals.
On the way to work yesterday it ran strong and pulled hard like always, then after 8 hours of work on the drive home it started acting like described above. I checked the couplers on the pipes and they were all attached fine. Also I do not have a working boost gauge in the car so I can't say what the boost is climbing to when I drive.

Please can anyone tell me what the issue most likely is?

 

[Dan_Gyoba]

Fix codes first.

I don't know about the 32, but 52 will have the TCCS retard ignition timing, since it can't monitor knock. You won't get any power that way.

 

[3p141592654]

Fix the codes. The idle is off because the TPS is not set properly, hence code 51. Both 52 and 32 affect timing and fuel control.

 

[IndigoMKII]

If you think it pulled hard before, heh.

 

[Wildfire007]

Stupid question I guess by how would I fix the codes? If its one of those things where I just need to research and no one is willing to explain then just say so lol. No need to blast me.

 

[Dan_Gyoba]

Why not look in the TSRM.

Page FI-27 Diagnostic code 32 reference

Page FI-57 diagnose air flow meter circuit (Code 32)

Page FI=28 Diagnosic code 51 and 52 reference

Page FI-101 Inspect and adjust TPS

You get the idea? The knock sensor is probably a busted wire, lots of info on knock sensor rewiring for small effort looking.

 

[jetjock]

Stupid question I guess by how would I fix the codes? If its one of those things where I just need to research and no one is willing to explain then just say so lol. No need to blast me.

I'll never understand why people come here with codes while crying the car doesn't run right....

 

[Dan_Gyoba]

I'm still new enough around here that I'll try to help. Caveat there being that I'm still new enough around here that I don't know everything that JJ, IJ and the like know.

 

[Wildfire007]

I appreciate you not tearing me a new one JJ lol. I've been a member of the forum for years now and I am no stranger to seeing JJ up there totally massacre a supranoob for asking something stupid. I feel fortunate not to be among the victims haha.

 

[IndigoMKII]

I appreciate you not tearing me a new one JJ lol. I've been a member of the forum for years now and I am no stranger to seeing JJ up there totally massacre a supranoob for asking something stupid. I feel fortunate not to be among the victims haha.

Fix the codes, all of them. If I was to unplug one of my KS on my car, I doubt I could even chirp second when I can normally roast second.

Like I said earlier, if you think your car pulls hard now.. Wait til the codes are fixed

 

[jetjock]

I appreciate you not tearing me a new one JJ lol. I've been a member of the forum for years now and I am no stranger to seeing JJ up there totally massacre a supranoob for asking something stupid. I feel fortunate not to be among the victims haha.

Probably because you don't write like an 8 year old, which is more than I can say about many here. You should have RTFM though...

 

[Wildfire007]

Just an update. Tomorrow I am going to recalibrate my tps using a step by step guide I found online. Then will take care of the knock sensor problem and HAC code. I'll let you guys know how it goes. Should be something of a learning experience.

 

[Dan_Gyoba]

what's wrong with the TSRM proceedure found on page FI-101 which I linked on the last page? (Well, except that was just checking. To adjust, you need to go 2 more pages forward to FI-103.)

 

[Wildfire007]

Ahh that was what was wrong, I did not go forward lol. Once again I suppose JJ's comment about reading more would be appropriate.

 

[Wildfire007]

Ok so I recalibrated my tps(or at least followed the instructions and hope that I did it right) and the car idles real pretty. However, when you give it any gas it stumbles all over itself and can barely manage to rev. I'm pretty sure I fell victim to the mistake of "cleaning" my afm and ruining it. *thumbs up* After resetting the codes for the ECU the only code that pops back up while the car is idling is 32. Tomorrow I'm going to go grab another guy's AFM and put it on my car and see if it fixes the running issue.

 

[Wildfire007]

Ok this is getting tiresome I'm sure and let me be the first to say that outside the realm of following the directions I have no fucking clue what I am doing. I have never taken an automotive course, let alone an automotive electrical course so this is like sending a blind monkey into store to pick up certain color crayons. He could get lucky and grab the right box, but it would be so much easier if he had someone to just put the box in his hands lol. On that note I am more than willing to listen and learn. I have no intention of being a sponge on the community.

Codes: 32, 24, and 52.

32: After ruining my AFM(the car wouldn't rev passed 3k rpms and stumbled all over itself in free rev after "cleaning it") I replaced it with a "known working" AFM from a guy down the road from me. The car free revs great, and its back to exactly the way it was before I ever touched anything for "repairs". Still no power in boost and still a code 32.

24: This code wasn't showing up until I changed my AFM with the "known working" AFM. I know this is Air Temp so does that mean that this AFM is also bad? Between THA and E2 I am showing 1291 Resistance with my Multimeter at 77 degrees outside temp and probably closer to 90+ in the engine bay. According to the TSRM that should be about right given the engine bay temp yes?

52: Yes I know its the Knock Sensor and no I haven't fixed it since the original post. Honestly it intimidates me and its going to be a full day job for me. (I work 6 days a week and the Supra is my daily)

51: This is the only code that hasn't reappeared even while revving the engine or while driving. I did Calibrate my tps so I'm guessing this is the only problem I fixed.

Please people, a guiding hand. I know I'm just serving to piss off JetJock but I've got no where else to turn. As far as code 32 is that guaranteed an AFM code(This is a very night and day difference between having the "Known Working" AFM plugged up or not so it should be good) The TSRM says for the GTE its an HAC code(High Altitude Control?). I am not at a very high elevation(898ft) so should this code effect power output greatly? Should I purchase a used HAC from a guy on the forum? My car is an 88 so its not combined into the ECU.

 

[3p141592654]

Looks like you have a yellow plug ECU. In that case your HAC sensor plugs into the ECU. Make sure it is there and plugged in. If it is plugged in, then you'll need to find a replacement assuming the wiring checks out.

 

[DeMoN2318]

You gotta fix that knock sensor...it REALLY makes the car a dog. Here is the rewire guide

http://oldschool.supracentral.com/htm/knock.htm

 

[3p141592654]

What he said. The air temp sensor is part of the AFM. Either its bad or the wiring/connector is bad. Plug your old AFM back in and see if the 24 disappears.

 

[Dan_Gyoba]

The rewire isn't as daunting as it might seem. Probably the hardest thing is getting to the knock sensors under the intake manifold. I always have fun in particular with the rear one, becuase it involves my least favorite fastener anywhere on my MA70, which is the nut behind the starter.

If the AFM Air temp sensor is checking out according to the TSRM (HINT: Check the troubleshooting with volt/ohmmeter section on page FI-49) then you're okay. It is probably worthwhile to drop the glove box and check wiring from the ECU harness straight through. This checks everything that the ECU sees, so if there's a wiring fault, it will show here, too. This is generally good troubleshooting practice for ECU sensors anyway.

1 code down, 3 to go.

Code 32: TSRM says open circuit in E2 or short circuit between VC and VS. (Note, I think that VS is a typo, and it actually means KS.) Refer to FI-57. It's probably worth checking that E2 gets a good connection to ground at the ECU and AFM as well, since it's very easy to test with a multimeter. (Remember that the pin diagram of the ECU in the online TSRM is for a grey-plug, yours will be different, but the procedure is the same.)

Code 24: Clean your AFM wiring connector and try again. These aren't the kinds of things that easily just go wrong.

Code 52: Check that the sensors are actually plugged in, and then there's nothing for it but to get down and do the work.