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Discussion Starter #1 (Edited)
This is basically Project DC2's thread above. I'm hoping for more coverage by starting a new thread. I'm going to post the problems again and hopefully someone can help me because I'm going absolutely insane.

All of these problems are at partial throttle at most 3k rpm.

1.When you start the car, it seems fine. After 30 seconds or up and down the block, the car hesitates and studders. Feels very weak, no power. rpms go to like 580-680 at idle.

2. Even at idle the car vibrates like a v8 old school muscle car. The whole car vibrates! I don't think it's supposed to do that.

3. Spark plugs are NGK 3330's gapped to 0.028 Do you think it's the spark plugs?

4. Check engine light is on because of the O2 sensors. Does anybody have instructions on which O2 sensors to tie togther? There's 4 of them. I bought an O2 sensor Simulator off of importparts.com. Which sensor(s) do I substitute the O2 simulator for?

5. Which hotwire sensor setting for the S-AFC2? 12 or 13? Keep in mind this is a Hotwire 98 OBDII VVTI car. Are the sensors the same for TT & NA for 98's? Mkiv.com says one thing, the manual says the other.

Is it because S-AFC2 isn't adequate for my application? Would it help if I switch to E-Manage?

Sometimes you wonder if this shit is really worth it. You're in the hole so much money and everything is going to shit. I have the horsepower of a golf cart. Wish I was back in Iraq. Feel the need to pop somebody.:mad: :(

By the way feel free to respond and guess to what you guys think is wrong with the car.
 

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King of the NA-T's
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Can you tell if the car is rich or lean? I have no idea how you have the AFC set, but I would start with both HI and LO maps in the -25% range, that should be in the ballpark. I like the HI to LO crossover point at ~75%. Then just tune the HI maps on the dyno.

How much vacuum are you pulling at idle? A leak somewhere will make it run like crap, and will give you low vac readings at idle.

Try pressurizing the whole intercooler/pipe setup. You can make a adapter real easy out of a 3" piece of PVC and a cap. Thread in a shrader valve and put the whole assembly on the inlet of the turbo (take off the filter/afm/etc). Then pressurize and check for leaks in all the piping (and BOV).

Also, check a couple plugs to see what they look like, and it might not hurt to check your timing just to make sure it didn't get moved accidentally.

That all I can think of right now.
 

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King of the NA-T's
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I just re-read your post again...

Since you will be running low boost, the 3330's are a little cooler than you need, and you can also keep the gap higher ~.032". Stock TT heat range plugs with the larger gap will help idle a bit, but probably isn't your main problem.

Definitely check your ignition timing.
 

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Formerly NA-TT
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Just an add in question: If you were running rich or lean would it wreck the spark plugs?

I know a few people who went through a few sets of spark plugs before they got everything figured out and tuned.

If that is the problem then it would explain the rough n rocky engine.

--Justin

PS. Good luck.
 

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Discussion Starter #5
Thanks for the info guys. Will check on it tomorrow. See how this shit goes. You should see Phill! I'm stressing him out so much I don't think he'll ever want to do an NA-T install on a Supra again. You should see how badly my car shakes at idle. It's pretty insane. I feel like I own a domestic muscle car. Sounds like one too.
 

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Formerly NA-TT
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Yeah, I was thinking about it more... spark plugs gone to hell = shaky car because some cylinders aren't firing + little power because some cylinders aren't firing.

I would pull the plugs and make sure they are looking ok, but first do what Dave said and check all your hoses.

Don't worry, it is worth it. Sometimes I walk 20 blocks to work because my car is getting worked on or I am installing something at the time and can't drive it. It is all worth it, especially the turbo!;)

Good luck.

--Justin
 

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565rwhp Turbo Lexus
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I bet it isn't the plugs. I bet it is something loose, something simple. (I hope). Check all vacuum lines, check IP pipes, check ignition components ... normal things ...
 

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I rock like CRACK
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:stupid: I also bet it's not the plugs. I would put my money on the safc settings being wrong.
 

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SSSUPRA said:
:stupid: I also bet it's not the plugs. I would put my money on the safc settings being wrong.
i had the S-aFC on there before ti was turbo and drove it around for a while and no CEL, so i dont think its the S-AFC

imma try to tie in together the o2 snesors and put ont he simulator and try TT spark plgus
 

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Formerly NA-TT
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SSSUPRA said:
:stupid: I also bet it's not the plugs. I would put my money on the safc settings being wrong.
MickeyDago: hey, didn't you go through a few sets of spark plugs when doing your install?
fLYPInOy457: ummm yeah
MickeyDago: why was that?
fLYPInOy457: because when i first installed the set up, i put my afc way rich
fLYPInOy457: so it fouled my plugs
MickeyDago: how did you know it was the plugs and not something else?
fLYPInOy457: ummm listenin to the motor
MickeyDago: was the car really rocky?
fLYPInOy457: yeah
fLYPInOy457: sounded like an old domestic
fLYPInOy457: only 5 cylinders were firing
MickeyDago: hey, set these fools strait
 

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Formerly NA-TT
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The afc II could have been the problem; ie, the settings were too rich, but if you didn't touch anything, then maybe you are running to rich for another reason? Injectors are spraying to much, I don't know, but it sounds like the same problem as flypinoy457 had.

--Justin
 

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Formerly NA-TT
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I looked at the afc instructions on apexi's website. The afc II instructions say T7-C for 93-97 and 98-02 says to use the T10-C. Then on the USA update page for the afc-I they say use T7-A.

So which did you use, T10-C or T7-A? The shape of the ECU is different on each one, so you should be able to tell which one to use based on the shape, correct?

--Justin
 

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Formerly NA-TT
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I was thinking some more about your problem, and I need more clarification on the power.

Does the car idle rough, and have little power as you accelerate up the rpm scale? Or does the car just run rough in some rpm ranges?

If it is the latter then get the s-afc II dyno tuned. That would probably fix the problem. A/F guage may be good.

If it is the prior, and the power seems to increase, but is weak then it could be the plugs or a leak, but I don't see the leak.

I mean, if it was a leak wouldn't it be pretty obvious like the sound of an air leak, plus when you reved the car the wastegate would open higher in the rpm scale?

Let us know when you figure it out?

--Justin
 

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i did a number of things, 1st i connected the o2 sensors and installde the o2 simulator, then i blew out the coolant that was hanging aroudn teh spark plug galley, i guess takin off the intake manifold so many times got coolant everywhere, repalced with supra TT plugs gapped at .035 and now the car idles fine and runs coo. to the dyno toamrorw !
 

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So basically you don't know if it was the O2 sensor or the plugs. Damb you man! How do we know who was right? J/K. Good to see the car is running right though.

--Justin
 

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Thinking Person
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SAFC settings arent going to have that much effect on it running like that...

i had similar problems and it was because i used cheap home depot rubber hoses to put all the intercooler pipes together... i put on good silicon and tightened them up good and it ran great...

i tie my O2 sensors together at the diagnostic plug; of course i have OBDI...

for it to run that bad; something major has not been connected correctly...
 

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GOT OIL ...?
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bobmarley said:
Whats your setup? like turbo/mani and such.
i managed to find u this from his earlier posting :)

DaveH Custom Manifold+
PT51 Turbo+
38 Tial Wastegate+
Shorty Downpipe+
Wastegate Dump Pipe $1605
Veilside Ti Exhaust $1030
Apexi SAFC2 $295
6x440cc PTE Injectors $250
Copy of HKS TypeS IC $370
Walbro 255lph Pump $100
HKS SSQV BOV $212.27
Install + IC Pipes
+Oil lines + Misc $1173

Total $5035.27

enjoy
 
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