I love my 7m, but.....

SupraBro

SupraBro

New Member
Jan 23, 2009
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Brentwood, Tennessee, United States
hey guys, my name is brandon and i have a couple of questions. I have a 1988 supra 7mgte. Bought the car with a bhg so i got a built 7m to replace it. It was just a head and block with wiesco pistons, hks mhg, arp studs and headwork. So i swaped everything over to the new motor about a year and a half ago. So hear are my questions. This problem has been going on since day one. Its the well known HOT START problem. This problem has made me replace every dam sensor on my motor with a brand new one, not like its a bad thing, but the problem is still there. When i put the motor in i grabbed a brand new engine harness from toyota to save any problems that might occur. So that being said this is the list of stuff i have replaced with new ones NOT USED.

TPS AJUSTED PER TSRM
IACV
COILPACKS WITH GREAT GROUND
GAUGE TEMP SENSOR
ECM TEMP SENSOR
NEW ALT WITH A BIG 3 UPGRADE

So there is one thing that i noticed today that could be the problem but i don't know. I have the stock FPR and i noticed that it has a hole on top of it. I thought there was supposed to be a small screw there in place for a factory adjustment. So i did a hot start today and it started missing and i took a small strait angle pick tool and pressed a tad bit and the car started to smooth out then went back to missing again. Could this be the problem?? Is there supposed to be a screw there?? Any help on this problem would be great. I have searched and searched about this problem for about a year now and making a thread is my last hope.


Second problem with my poopra. I feel like i have a boost leak problem. So i have been blaming it on those old factory soft pipes. So i ordered a kick ass FMIC kit from aaron at drifmotion to try and get rid of this problem. The top pipe keeps the stock bov i am using but i do have a extra top pipe with a knock off hks bov. I just did not want to install it yet until i get a real bov. So lastnight i installed the whole kit and it seemed like it got rid of the problem. The car felt way stronger and spooled much quicker. So i decided to put my manual boost controller on it today to try and get 10psi out of her. Well it does not seem to like it after 8psi. It falls on its face, but you can hear my stock ct-26 pushing harder. The old problems are coming back with less power. So i double and triple checked the hardpipes for any problems and everything seems great. Could it be my stock bov leaking

Here is my 88 supra

p1788147_1.jpg


p1788147_2.jpg



Any help would be great and sorry if my spelling is not the greatest.
 
planemos

planemos

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Apr 22, 2011
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With all of the things you have done to your motor, I would say you know more than me hahha. But if I was to tell you what to do I would say do some fuel mods like injectors fpregulator pump. And better yet get a wideband/gauge to moniter the air/fuel ratio.
 
mecevans

mecevans

Supramania Contributor
Jan 18, 2009
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M-bay, cali
The fpr is in the front. The thing in the back is the pulsation dampner.

Hot starts could be caused by cold start time switch, improper vacuum lines, faulty vsv's, or lack of residual fuel pressure.

For lack of power past 8psi could be spark blowout or detonation. Get some fresh brk7e's and gap them on the tight side. Use 91 octane fuel. Check timing while your at it.
 
SupraBro

SupraBro

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Jan 23, 2009
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Brentwood, Tennessee, United States
Ok, so i just searched what the pulsation dampner does. It smooths the pulsation of the closing injectors. So there for it should not matter for the problem that i am having. Tomorrow i will look into the cold start timer switch and check the injector. Then i will check my gab on my ngk's
 
SupraBro

SupraBro

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Jan 23, 2009
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Brentwood, Tennessee, United States
The cold start time switch is ohm right per tsrm. So i am thinking that the hot start problem could be caused by the cold start injector sticking open. The car cranks great on a cold morning. Can these injector's be flow tested and cleaned like a normal injector?
 
radiod

radiod

Supramania Contributor
Dec 13, 2007
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Abbotsford, BC
^ This. It's designed to bump up the fuel pressure to push through in case it's warm enough that the fuel is turning to vapor.
 
GrimJack

GrimJack

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Dec 31, 1969
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idriders.com
That *might* be the plug, but I don't think so. The VSV is nearer to the front of the engine.

Can you post some pics of the front of the fuel rail where the fuel pressure regulator is? Trace the vacuum signal line on the FPR, tell us where it's going. It should be going to a VSV - a vacuum switch - and I suspect it will be plumbed directly into your intake manifold instead.

Another step to try... when it is hot and should be showing the symptoms you describe, pop the hood and remove the vacuum line to the FPR before you try to start it. If it runs properly, chances are this is the problem.
 
SupraBro

SupraBro

New Member
Jan 23, 2009
274
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Brentwood, Tennessee, United States
GrimJack;1788284 said:
That *might* be the plug, but I don't think so. The VSV is nearer to the front of the engine.

Can you post some pics of the front of the fuel rail where the fuel pressure regulator is? Trace the vacuum signal line on the FPR, tell us where it's going. It should be going to a VSV - a vacuum switch - and I suspect it will be plumbed directly into your intake manifold instead.

Another step to try... when it is hot and should be showing the symptoms you describe, pop the hood and remove the vacuum line to the FPR before you try to start it. If it runs properly, chances are this is the problem.
Click to expand...


Thanks for the help! I will try this today and i will get some more pics up.
 
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