Help! Supra doesn't run right

Abe's 1987

Abe's 1987

Member
Sep 5, 2017
253
10
18
Houston,TX
Ok got the ecu in today. Will install it tomorrow and let you guys know what happens. If no change I already ordered the banjo tap for the fuel pressure and will buy the pressure gauge once I get the banjo tap.
 
Abe's 1987

Abe's 1987

Member
Sep 5, 2017
253
10
18
Houston,TX
Ok connected the other ecu I got, didn't make a difference. Test fuel pump, it is kicking on. Double checked timing all good, but I don't see how with the high idle the timing would be correct. Will check fuel pressure once I get the tools to do so. Going to check the tps adjustment again later. I will need to replace the coil pack harness as mine has been hacked up, change the EGR Vacuum Modulator as the one on mine is from the 7mge.
 
Piratetip

Piratetip

Far From Maddening Crowds
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Dec 30, 2005
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Somehow I still think there is a large/medium air leak somewhere...

It sounds like its not measuring the correct amount of air that is actually going into the engine.

In the past I have forgot to connect some air / vacuum lines, the car ran like shit until I remembered what was messed up.
 
3p141592654

3p141592654

90T
Oct 11, 2005
3,816
16
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Thousand Oaks, CA
I'm betting fuel issue, but to rule out the pirate air, take some hose clamp pliers and pinch off the IACV hose (assuming its not rock hard). The car should stall with the hose squeezed shut if there is no pirate air. His AFM numbers looked ballpark, which is why I'm betting against pirate air.
 
Piratetip

Piratetip

Far From Maddening Crowds
Staff member
Super Moderator
Dec 30, 2005
1,177
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MKE, WI
Yeah engines are pretty basic; fuel, air, spark.

Something is off!
Just need to figure out what. :D

Could be right on the fuel, hopefully he can figure it out soon.
 
Abe's 1987

Abe's 1987

Member
Sep 5, 2017
253
10
18
Houston,TX
Yes the engine stalls when I pinch the iacv hose. I found out my egr vsv is all jammed up with no air passing through, will get another one. The fpr vsv is good. There is vacuum to the fpr. Checked tps adjustment, it's good. I also think my iacv is bad as well. I took it apart and found corrosion internally and cleaned it up. Also did the test to see if it opens and shuts but it doesnt. It was stuck in the open position but i manually put it in the closed position when i had it apart.
 
3p141592654

3p141592654

90T
Oct 11, 2005
3,816
16
38
Thousand Oaks, CA
Good, unlikely its a vac leak then.

Seems like you may be dealing with multiple issues on this car.

If the IACV doesn't click and is not seized, then most likely a wiring issue. Check continuity from ECU to the IACV per the TSRM. But this is not the cause of your rough running engine.

Fuel issues won't set any codes for the most part, so I'd focus on that. The $20 HF pressure gauge kit probably leaves something to be desired, but is likely good enough for basic testing and checking for blockages.
 
Abe's 1987

Abe's 1987

Member
Sep 5, 2017
253
10
18
Houston,TX
20171030_133430.jpg
Ok I found out the downpipe has the port for an external wastegate vented to the atmosphere. Don't know if that can cause issues.

20171030_133542.jpg
This is how the previous owner has the 7mge egr vacuum modulator hooked up to the 7mgte. Will be getting the 7mgte one soon.

A few pics of the roughness of the engine as well
20171030_133004.jpg

20171030_133014.jpg

20171030_132952.jpg

And once I get all the tools I need, I'll let you guys know the numbers I get from the fuel test.
 
3p141592654

3p141592654

90T
Oct 11, 2005
3,816
16
38
Thousand Oaks, CA
You might want to disconnect and plug the vac line to the EGR modulator, to make sure the EGR is not being activated. It shouldn't because the VSV is supposed to prevent any vacuum reaching the EGR system except under cruise, but who knows what other stuff is messed up with that setup.
 
Abe's 1987

Abe's 1987

Member
Sep 5, 2017
253
10
18
Houston,TX
Well I'm ordering a egr vsv and modulator from a member here so I will have the right parts in. Also getting a coil harness to replace my hacked up harness. Will double check my iacv before I put the order it from the member. I'm trying to make sure the supra is running and running right before I think about upgrading.
 
Abe's 1987

Abe's 1987

Member
Sep 5, 2017
253
10
18
Houston,TX
And as you can see in the pics someone hacked up the frame the headlight bolts on to on the passenger side. The guy I bought it from said the guy before him did it. I will get the car running then fix that later.
 
Abe's 1987

Abe's 1987

Member
Sep 5, 2017
253
10
18
Houston,TX
Yey major updates today. Decided to pull codes again with the other ecu which it is throwing error codes finally. So with engine off it putting out error code 12. With engine running it's throwing error codes 12 and 51. I had to put a .90 mm filler gauge between the throttle plate and screw as the iacv is not opening and the engine wasn't getting air so it wouldn't stay on. So based on what I'm seeing I'm having tps, iacv, and timing issues. Will order the iacv and fix idle then fix timing. Hopefully this works. But thing I noticed is the check engine light is still not on!
 
3p141592654

3p141592654

90T
Oct 11, 2005
3,816
16
38
Thousand Oaks, CA
You will get code 51 from having the throttle valve wedged open with the feeler gauge. It also comes on if the AC switch is on.

Code 12 indicates a Cam position sensor problem. But the car will not run without the CPS signals so it could indicate some intermittent flaky wiring near the CPS. Those wires and connectors are often in bad condition from the heat on that side of the engine. The light is not on because it takes two drive cycles to set these codes and I believe you are resetting the ECU between starts.

I'd still focus on the fuel pressure and get that checked out.
 
Abe's 1987

Abe's 1987

Member
Sep 5, 2017
253
10
18
Houston,TX
Ok will do the fuel test once I get the tools. Waiting for actron to ship out the banjo bolt tap and am going to pick up the fuel gauge this Thursday.

I have been leaving the battery plugged in now so have not been resetting the ecu, and can't really do an official drive cycle until I get it running right but I can run it at idle though.

Could the cps needing to be adjusted have anything to do with code 12? I went ahead and hooked up the timing light as it was idling at 900 rpms but it wasn't at 10 BTDC it was to the right past 0 BTDC.
 
3p141592654

3p141592654

90T
Oct 11, 2005
3,816
16
38
Thousand Oaks, CA
NO, code 12 only sets when the car is cranking and does not get any timing pulses from the CPS.

Did you check the timing with TE1 grounded in the diag box? If yes, then timing is off. But, it could be the pulley has slipped on the harmonic balancer. So stick a chopstick in sparkplug hole for cylinder #1 and verify that TDC matches the mark on the pulley. Might also want to verify the cams are aligned as well if you have time.
 
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