Built engine installed but not running right. Need guru's help! *HD Video*

MarkIII4Me

Project OVERKILL!!!
Apr 10, 2005
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Charleston, SC
So it fires right up, but idles like a diesel truck and hesitates like crazy if I give it gas. The timing is probably off. I set the CPS per TSRM but can't keep the engine idleing long enough to set timing with timing light. The a/f is 14.7 at startup and drop to around 13.5 once operating temp is reached. However when I give it gas and actually start building any positive pressure (maybe 1psi), it goes crazy lean. If I don't give any gas, the engine dies after about a minute. Fires right back up and does the same thing. Once warmed up, it'll die right away unless I give it gas. Oil pressure is good and I'm pulling around 21psi of negative pressure at idle, which is surprising since the engine is supposed to have raised cams.

My engine management is not ideal for the simple fact that I am trying to use a 2jz tps on a 7M ecu with piggybacks. Some members have said it would work as long as I set the tps below idle point. I get an idle signal, but the car still won't idle properly. I am unsure if it's the tps or not. The hesitation when giving it gas is most likely from the tps though. I read in a very old SF post that the 2jz TPS puts out the wrong resistance for our injectors, but that doesn't make any sense to me. I am using a JDM 7mgte ECU (I'm running no EGR), HKS VPC and SAFC2. I've never used a SAFC before and performed the initial setup but did not adjust any of the fuel points yet as I feel this is not necessary at this point. I moved the idle knob on the VPC from 12oclock all the way to 6oclock, yet my AF's did not change at all. I would think they would go crazy rich. Is my VPC defective perhaps?

I knew I was way over my head here with this project. But after years of giving the vehicle to idiot mechanics (who destroyed my ride) and not having qualified SM members in my area to help out, it was either part out the thing or do it myself. I chose the latter and ended up here. I figure going standalone makes sense at this point, but there are several reasons I don't feel like taking this route. First off, I'm not jumping at spending $1800 on an AEM and pulling my current piggybacks. Secondly, I want to be sure there aren't any other issues that I have overlooked that are causing my engine's problems.

I can rotate the 1jz tb's butterfly and use a 7m tps, but it'll be tough to weld in a lip to keep the butterfly sealed at idle, and it'll also be a performance hit due to the reduce diameter and turbulence caused by the lip. There's always the option of ditching the 1jz throttle body and using a 7M TPS, but that would require mechanical mods like moving the Tial BOV to the intake pipe, creating a flange for a different throttle body, fabbing a new throttle cable and bracket, and changing the IC pipe going to the TB due to the angle change. With winter coming and me not having a garage anymore, all of this is quite difficult. Not to mention, I like the aesthetics of my current setup and putting a 7m or Q45 throttlebody on my manifold will look like ass imo.

I'm not surprised that I'm having these problems as I built my entire setup on the idea that I could get the 2jz tps to work. I may have been wrong. Has this ever been done before? If not, can a TPS have it's tolerances modified? I'd be willing to spend quite a bit of $$$ to get my current setup working the way it sits. I've had issues in the past, but currently there are no leaks and I'm throwing no codes. Can anyone help me get this baby running???





If there's someone qualified in my area to work on this problem please let me know. I'm at my wits end here. And by qualified I mean that they are familiar with this engine and it's electronics. Not someone who wants to play around with an expensive toy. As that's what I've been doing up until this point.
 
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GrimJack

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Dec 31, 1969
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Wait... I'm confused. Perhaps you could explain the system you have put together a little more?

7M-GTE longblock, right? 2J TPS? Whyfor? And a 1J butterfly? Again, what's the reasoning here? What else is different?
 

toyotanos

What will we break today?
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Nov 29, 2008
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Looks like he's adapted a 1/2JZ intake manifold to his 7M. edit: and is using its original tps, not the 7M one

Questions for OP:
1- is the TPS adjusted as close to the 7M's original setup as can be had? (follow the 7M repair manual and see if the signals match up. If not then you need to do the tps swap)
2- is your fuel pressure 20psi at idle? That's what it looked like in the video...way too low.
3- Have you tried running the car with OEM electronics in place? (might be a good way to eliminate piggybacks)
4- Is your timing adjusted correctly?

I know you don't like the idea, but having an AEM (or other standalone) you wouldn't be dealing with compatibility issues like this. Not beating up on you, just saying that sometimes the grass is indeed greener on the other side. srsly, I <3 my AEM :p
 

92TealSupra

Supramania's Parts Man
Sep 2, 2008
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I try to get the 7M electronics back on.. or find a TPS that will work for these specs. Making a sort of Frankenstein parts build on this may not be the optimal way to go right now..
 

IBoughtASupra

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Mar 10, 2009
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Sell the piggybacks and look for a AEM V1. You will be very happy. It will eliminate all the issues you are having right now. It is a pretty penny to spend to get one but you will solve a lot of issues you are currently having.
 

MarkIII4Me

Project OVERKILL!!!
Apr 10, 2005
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Charleston, SC
Really not trying to go standalone, but I understand that I may have to at this point. Does the AEM V2 have any benefits over the V1?
 

IBoughtASupra

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Mar 10, 2009
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You could get a V1. Give them a call and see if they have any advice. If they don't want to do a V2, then a V1 will be your option or ProEFI. You can run it off a 48 ECU and make your own harness. It is cheaper.

ProEFI 48
Plug and Pin Kit
Buy the wires and make your own harness.
You can even go 1ZZ coils to eliminate the igniter. It is very simple. One power, one ground and a ground trigger. These coils come off the Corolla and can be found really cheap.

The TPS will work, you can run a GM 3Bar sensor, Stock JZ IAT Sensor works, that you can get aftermarket for 80-90 bucks, coils would be 120 and then the 48 EMS, plug and pin kit along with different color of wires.

It will be cheaper and you will have a new harness. There are a few members here that can help you through PM's and there pretty cool people.
 

MarkIII4Me

Project OVERKILL!!!
Apr 10, 2005
1,249
1
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Charleston, SC
IBoughtASupra, does the ProEFI or AEM have support for the factory IACV?

Mike, any idea why I'm experiencing these issues? Once again, not trying to go standalone unless I have to.
 

MarkIII4Me

Project OVERKILL!!!
Apr 10, 2005
1,249
1
38
Charleston, SC
toyotanos;1779453 said:
Questions for OP:

1- is the TPS adjusted as close to the 7M's original setup as can be had? (follow the 7M repair manual and see if the signals match up. If not then you need to do the tps swap)

Did not adjust the tps per tsrm since the tolerances are close, but not exact. I set the TPS to where the ECU received an idle signal (IDL grounded to E2), right around .49v)


toyotanos;1779453 said:
2- is your fuel pressure 20psi at idle? That's what it looked like in the video...way too low.

During the video it was at 22psi, I've had it as high as 28psi, but it doesn't seem to make any difference at all. Stuttery idle and A/F remain pretty much the same.


toyotanos;1779453 said:
3- Have you tried running the car with OEM electronics in place? (might be a good way to eliminate piggybacks)

When I lost my garage I lost damn near all my extra parts (long story), so not really an option right now. Can't use a OEM TPS on a 1JZ throttle body anyway due to the butterfly opening in the opposite direction. If I rewired it in and set it correctly it would at least help solve the idle issue. But I don't have a OEM TPS anymore.


toyotanos;1779453 said:
4- Is your timing adjusted correctly?

As mentioned in my post, I set the CPS per TSRM but can't set the timing to 10 deg above TDC since the engine won't idle long enough. I need a damn helper. lol



Something to add:
I did read somewhere that the 87-88 and 89-92 Supra use different O2 sensors. The one I'm using may have come off of an 87-88, I honestly can't remember. My ECU and harness is 90-92. Do the 2 different sensors use the same plug? Because it fit my harness just fine. Perhaps this could be the culprit?
 

IBoughtASupra

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Mar 10, 2009
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I doubt it is but it's worth a shot. I have unplugged the O2 numerous times when the engine was running and it changed nothing about the idle.
 

MarkIII4Me

Project OVERKILL!!!
Apr 10, 2005
1,249
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Charleston, SC
That's what I figured. My AF's are stable at idle as well. Plus wouldn't the wrong O2 throw a code? I'm actually surprised that if the 1jz TPS was not compatible, it would throw a code as well, but I have no ECU codes.
 

MarkIII4Me

Project OVERKILL!!!
Apr 10, 2005
1,249
1
38
Charleston, SC
So what is making it sound like a diesel engine? Does timing being off make an engine sound like that? Or is it something internal like the cams? I don't hear any knocking, pinging or tapping so I assume it's mechanically fine. When I had the valve covers and oil pan off it was spotless inside.