Engine won't rev when set at 10 Degrees BTDC.

[1988MK3]

So I just finished my rebuild and have had the engine running. It idles rough and won't rev at all when I have the ignition timing set to 10 Degrees, it just stumbles and almost dies. I have advanced the ignition anywhere from 15-20 degrees and it will finally rev up. Is it okay to be running 15-20 degress BTDC? I have read to set the timing to 10 degrees. I use the jumper in the diagnostic block fyi. The CPS has been installed according to the directions, but the prong on the shaft does not line up with the inductor (not sure of the correct name) when the engine is at 0 and cams are straight up. I even turned the CPS back a tooth and it still wouldn't line up. I have done a ton of searching through the forums here, but I can't find my answer. I don't have any vacuum leaks that I can find. Everything is hooked up the way it came apart. I am new to supras, but I am not new to cars. I have an associates in automotive Tech and worked at a dealership for a few years. I quit that job 6 years ago and have been away from cars for that long as well, so I have forgotten tons of useful info. You guys gotta help me out!

Also, My Apexi Neo won't allow to select the Karmen option and doesn't show a Karmen voltage/any type of reading. Is this a problem? I installed a "new" (used from ebay) AFM from the Lexus (22204-42011) into my car, but didn't make any difference.

I am at my wits end here guys. I have jammed a ton of money into this car and I just want it to give me a boner instead my killing my buzz. Any help will be appreciated and I thank you guys for all the info I have already learned from SupraMania.

Here are my mods:
Brian Crower stage 2 cams, set right now at 3 degrees advance on exhaust and Intake. (any help on what I should set camsB at would be appreciated)
JE Pistons. .040 over
Eagle Rods
Titan 2MM MHG
Rebuilt Head, 3 angle valve job, not ported
Lexus AFM
Apexi Neo
Tru Boost wide band O2
Godspeed intercooler kit
T26 with 60-1
Blitz BOV
RC 550's
255 lph fuel pump
4" Exhaust all the way back, no Cats
I probably missed some.

THANKS,
BRAD.

---------- Post added at 10:55 PM ---------- Previous post was at 10:51 PM ----------

Sorry, didn't mean to put the exclamation point next to my thread. I will learn how to work these computers some day!

 

[whitemike]

My best suggestion is to remove the tuning device and try again. If it doesn't have the correct airflow option in it, it's not interpreting the input correctly nor is it sending the output to the ECU correctly.

Mike

 

[1988MK3]

Alright, So today I spent most of the day working on the Supra. I set my TPS according the the TSRM and immediately noticed a difference. The car would rev when set at 10 BTDC, but idled pretty shitty, not nearly as good as it should. I ended up with with 13-14 degrees BTDC and a decent idle. I went for my first test drive (which was sweet after 5 months of hard work and countless dollars) and things went pretty well. The engine died a few times when I would let off the gas coming up to a stop light though, so I still have some bugs to work out. I also unhooked my Apexi Neo like whitemike said (thanks for responding), but the car ran worse and would not rev at all with it unhooked. My AEM A/F gauge is jumping all over the place and sometimes is just ----- with no reading. Any ideas on why the gauge isn't working?

 

[gottadiesel]

Alright, So today I spent most of the day working on the Supra. I set my TPS according the the TSRM and immediately noticed a difference. The car would rev when set at 10 BTDC, but idled pretty shitty, not nearly as good as it should. I ended up with with 13-14 degrees BTDC and a decent idle. I went for my first test drive (which was sweet after 5 months of hard work and countless dollars) and things went pretty well. The engine died a few times when I would let off the gas coming up to a stop light though, so I still have some bugs to work out. I also unhooked my Apexi Neo like whitemike said (thanks for responding), but the car ran worse and would not rev at all with it unhooked. My AEM A/F gauge is jumping all over the place and sometimes is just ----- with no reading. Any ideas on why the gauge isn't working?

A couple of things, make sure when you disconnect the Neo that you connect the two ends together that input into the ECU for your Karmen signal. Another item on the Neo, make sure you have the latest firmware, they had a series of releases that the Karman translator did not work properly.

If you A/F gauge is new and properly mounted, I would assume it is correct, so the question is fluctuating? What conditions are you getting these fluctuations? (idle, decel, accel etc...) Also --- Means it is leaner than 18, so will not read, on the other end it will just read 10, but could be lower than 10.

My personal opinion is, until you have car running good, put cams back to Zero and timing per TRSM 10BTDC. If it will not idle properly, then look elsewhere, changing timing will only cover up the issue.
The TPS was a good place to start, will for sure make a difference.
Any Codes being thrown?
Is your BOV recirculated or does it blow to atmosphere? This will affect your AFRs between shifts or downshifting etc...
Have you used a meter to read for Vf signal to see what the ECU is trying to do for fuel (add or takeaway)
Does your Lexus AFM have the full length after-market screw in it or just factory?
What else did you do with fuel system (AFPR?, Bypass J-tube?, Fuel pump wiring mod?)

Last but not least - Say Hi to Iowa for me and stay warm - I moved back to WA 4 yrs ago after being in Chariton, IA for 10 yrs...

 

[1988MK3]

So I removed the Neo and jumped the Karman wires and the car seemed to run pretty much the same. I took another look at the TPS today and decided to readjust it. This time I got it spot on and was able to adjust the timing to 10 degrees and the engine would rev. I am still having a somewhat rough idle, and the idle doesn't seem to stay the exact same rpm all of the time. It idles between 700-900 rpm, but a few times it has idled super low and stalled. I am still have the stalling problem when I am coming up to a stop sign at speed (2-3k rpm), then I push in the clutch to brake and the car stalls.

So I checked both the AFM's I have today with an ohm meter. Based on this chart (http://oldschool.supracentral.com/htm/repair.htm#afm) both of the AFM's I have are bad. I got about 3k ohms across THA-A2 on both of them (it was chilly out today), but I couldn't get a reading on any of the other prongs (e1-vc and e1-ks). So this could definitely be my problem! What do you guys think? Anyone know what a new AFM costs new from Toyota?

gottadiesel, awesome help. Thank you. I have an Aeromotive AFPR that came with the car. It's got the 255 lph pump installed, but I don't know if it's got the fuel pump wiring mod. How do I tell? I have not done the VF test as I didn't know about it until you told me about it. I looked it up and maybe I will do it tomorrow. The car threw a code 31 today, but only for a little while, then it went away and I couldn't get it to pop back up. Things are pointing at the AFM being bad, which could be the reason the NEO isn't picking it up. I checked the Firmware on the Neo and as far as I could tell the firmware is newer than the version they were having problems with. The A/F gauge came with the car and is still jumping around at all RPM's (points at AFM being bad again). My BOV blows to the atmosphere. I kept the cams at 3 degrees advanced for today, I might try putting them to zero tomorrow as well.

I think the next thing I need is a new AFM. Before I go out and spend money on this, what do you guys think?

Thanks dudes!

 

[supraguy@aol]

I didn't see your answer about the blowoff valve- maybe I missed it?
Is it recirculated? because if it's not, that's why you're stalling out. (just as Gottadiesel inferred)

 

[1988MK3]

The bov is not recirculated. The engine dies though without boosting. I can be decelerating up to a stop sign, be calmly driving at 2,000 RPM, push in the clutch and the engine will die. Does this still point to the BOV being the problem?

 

[whitemike]

The bov is not recirculated. The engine dies though without boosting. I can be decelerating up to a stop sign, be calmly driving at 2,000 RPM, push in the clutch and the engine will die. Does this still point to the BOV being the problem?

Yes, I had the same issue before I converted to MAP. Even light accel would result in a stall when approaching a light/stop sign. I highly recommend recirculating or converting to MAP using MAFT Pro or similar.

Mike

 

[1988MK3]

What do you think about the AFM in the above reply??? I will look into the BOV. Thanks!!!!

 

[whitemike]

Well, again, I think anyone who has converted from AFM to MAP can vouch for this: If you're going to spend the money on a new AFM, just buy a MAFT-Pro. It'll do everything your Apexi does and more. Not to mention eliminating the AFM. Brand new is around $400+ sensors. It uses generic GM air temp and map sensor that can be found cheap and are very popular. I bought mine for $320 with all sensors included in the classifieds section.

That's my opinion on the matter, to me the AFM is a major pain in the ass, especially when you blow an IC pipe off on the highway!

Mike

 

[supraguy@aol]

Yeah, putting a GM maf in blowthru mode is nice, and allows you to vent the bov to atmosphere with no problems.
Hell- I have an extra GM maf that i'll sell you cheap if you decide to go this route.

 

[whitemike]

I was more talking about running in speed density mode, but, I suppose either would suffice in this situation..

 

[gottadiesel]

Well, again, I think anyone who has converted from AFM to MAP can vouch for this: If you're going to spend the money on a new AFM, just buy a MAFT-Pro. It'll do everything your Apexi does and more. Not to mention eliminating the AFM. Brand new is around $400+ sensors. It uses generic GM air temp and map sensor that can be found cheap and are very popular. I bought mine for $320 with all sensors included in the classifieds section.

That's my opinion on the matter, to me the AFM is a major pain in the ass, especially when you blow an IC pipe off on the highway!

Mike

^^^^^^^ YES YES, Everything whitemike said!!!!!!!! I had similar issues after my build, was also using the NEO (my opinion, is it is a better suited for V-techs and the like) A new AFM from Toyota is roughly $600, I found my Maft-Pro with Sensors on Ebay (had only been used for 6 months) and paid $325 for it and it is so so so much better than using a NEO on a Supra...

I know you have already spent a lot of money and time.. I was in the same position... 8 months and $8k later I fought with the AFMs for a month, bought 2 other used ones on-line etc... Once I swapped to Maft-Pro and got it tuned right... loved it ever since!!!

The installation is not difficult, the biggest thing you have to do is add a bung to your IC piping for temp sensor.

If you decided to go that route, feel free to PM me, I have freshly gotten mine done, so would be glad to help you find the right software and safe maps to start with...

Back to your question on the AFMs, I tested mine with a meter on the car (reading freq and DC) and on the bench reading resistance... they all tested ok, but all made the car run like crap (sometimes would throw a code and sometimes not) My car would either run really rich when idling, it would miss while trying to give it more than 5% throttle, it would die on occasion... pretty much un-drivable... I made no other modification other than change to maft-pro and all of those issues went away...

Good luck either way...

oh and yes to clarify I am running Speed Density also...

 

[1988MK3]

Awesome guys! Tons of useful information, I truly appreciate it. I am definitely going to look into the Maft-Pro. All I know about it basically is what you guys have told me, so I have some research to do. I'm sure I can sell my AFM and Apexi Neo setup on ebay and pretty much pay for Maft-Pro, which sounds like the way to go. I have tons of time to get this working too, since winter is coming up quick on Iowa. I can't wait to move out west and cruise the mountain roads. Gottadiesel, I will probably take you up on that PM once I get around to installing the Maft-Pro.

Thanks dudes!

 

[gottadiesel]

Awesome guys! Tons of useful information, I truly appreciate it. I am definitely going to look into the Maft-Pro. All I know about it basically is what you guys have told me, so I have some research to do. I'm sure I can sell my AFM and Apexi Neo setup on ebay and pretty much pay for Maft-Pro, which sounds like the way to go. I have tons of time to get this working too, since winter is coming up quick on Iowa. I can't wait to move out west and cruise the mountain roads. Gottadiesel, I will probably take you up on that PM once I get around to installing the Maft-Pro.

Thanks dudes!

No problem... and yes you are correct, I sold my Neo for $235 on ebay and sold my Lexus body for $55, so it was almost a wash...

 

[1988MK3]

Guys, I'm back again.

So I've got 3 different AFM Lexus sensors. They all read pretty much the same when I check them with an ohm meter across the THA-E2 Connections. The weird thing is all of the other readings across the other pins are open curcuits, I'm not getting any reading. I have referenced this website for the ohm readings (http://oldschool.supracentral.com/htm/repair.htm#afm). Could the chart on this website be wrong, or are all 3 of the AFM's bad? OR, do the Lexus AFM's read different from original Supra AFM's?

So here's whats happening: The car starts up when cold and idles decent at about 1,000 RPM. The car runs for about 1 minute and the idle goes down to 750-800 ish and the idle starts to miss. Soon after, I've got a super rich running car with black smoke coming out of the exhaust and a bad miss. The car won't idle worth a crap and I have to give it gas to keep it running. As I said before, I have adjusted the TPS correctly and timing is set at 10 Degrees.

Could I have a bad IAC or O2 Sensor? Oil could have easily gotten on the O2 sensor from the hole in the piston before I rebuilt it, could this cause it? Any Ideas at all? I was thinking the AFM was bad before, but after getting three different AFM's that all read the same, I think I may have another problem.

Thanks in advance.

 

[boostcraver]

Can't help you on the AFM's unfortunately, but as far as the IAC (ISCV), you can check that for proper operation by listening for a brief clicking noise after shutting the car off. There should be a smallish pipe that runs across the head, in front of the 3000 pipe on top of the valvecovers. One end should connect to the accordian pipe after the AFM and the other end to the IAC. It will not work properly if it isn't being fed fresh, metered air. If you want more info on the Maft-Pro, check out this thread: http://www.supramania.com/forums/showthread.php?133414-afm-delete&p=1643842#post1643842
Hope this helps you and good luck!

 

[gottadiesel]

Guys, I'm back again.

So I've got 3 different AFM Lexus sensors. They all read pretty much the same when I check them with an ohm meter across the THA-E2 Connections. The weird thing is all of the other readings across the other pins are open curcuits, I'm not getting any reading. I have referenced this website for the ohm readings (http://oldschool.supracentral.com/htm/repair.htm#afm). Could the chart on this website be wrong, or are all 3 of the AFM's bad? OR, do the Lexus AFM's read different from original Supra AFM's?

So here's whats happening: The car starts up when cold and idles decent at about 1,000 RPM. The car runs for about 1 minute and the idle goes down to 750-800 ish and the idle starts to miss. Soon after, I've got a super rich running car with black smoke coming out of the exhaust and a bad miss. The car won't idle worth a crap and I have to give it gas to keep it running. As I said before, I have adjusted the TPS correctly and timing is set at 10 Degrees.

Could I have a bad IAC or O2 Sensor? Oil could have easily gotten on the O2 sensor from the hole in the piston before I rebuilt it, could this cause it? Any Ideas at all? I was thinking the AFM was bad before, but after getting three different AFM's that all read the same, I think I may have another problem.

Thanks in advance.

Two things - There is a way to actually bench test the Idle control valve, it is in the TRSM, but in a nut shell, you use 3vdc (two standard 1.5 vdc batteries in series) then you sequence the voltage from pins 1-4 to go one way then 4-1 to go the other way... this is the way to fully test that it is fully opening and closing...

In regards to the AFM... HHmm well that is very much a similar symptom that I had, I would not say for sure that the AFM is the problem, but I went through 4 used ones... car ran like crap on all of them (only 1 threw a code) got rid of it and went with Maft-Pro and car ran great?? Anyway your next level of testing, as any of the resistance test are about useless, is to meter the voltage duty cycle and the hertz of the Karman signal from the AFM to the ECU, but to really test this signal IMO an O-scope is needed. The Lexus electronics should be identical to the Toyota one, it is one part number different, but I went through this very issue and had a couple of lengthy threads back in June/July with similar issues.

If you want to PM me, I would be glad to get you my number and you are welcome to call, as sometimes easier to help that way than typing back and forth... Not that I am any type of master, as I am far from it, but I have experienced a very similar issue recently, so I may be able to help and would be glad to do so if I can...