7mgte issues need help doing diag

touge_monster86 · 03-02-2010, 07:04 PM

i have a 7mgte that i recently changed the head gasket on . every thing is timed right im sure because when it does start it runs clean but the problem is that it wont run . it will start up for about 5 second or less run clean then just shut off and then i have a heck of a time getting it to start again . i usually have to have some one mess with the cps and feather the gas to get it to fire up . i am stumped the fuel pump works i got good spark, the efi relay get's really hot some times, and as far as i can tell i got pressure in the line up to the fuel rail.
i have no idea 7mgte is new to me so if any one could give me some assistance i would really appreciate it

cre · 03-03-2010, 02:08 AM

Checked for loose grounds? Any diagnostic codes? You didn't try to clean the AFM did you?

To ensure it's not the fuel pump's power, jumper FP and B+ in the diagnostic box and then try to start... if it runs then then you need to diagnose the fuel pump's circuit. This won't tell you if the fuel pump is too weak though, for that you need a gauge; Even a weak fuel pump could give enough fuel pressure for a car to idle.

touge_monster86 · 03-03-2010, 09:02 PM

I will check for grounds, I did not clean the afm and I have no codes .
And wich pins in the diag box exactly do I bridge ?

Thanks for any help

cre · 03-04-2010, 01:57 AM

Quote:

Originally Posted by touge_monster86

wich pins in the diag box exactly do I bridge ?

Quote:

Originally Posted by cre

jumper FP and B+ in the diagnostic box

There's a diagram inside the lid of the diagnostic box showing which pin is which.

touge_monster86 · 03-07-2010, 09:33 PM

no luck man nothing changed. its like the injectors are not working

cre · 03-07-2010, 09:51 PM

Well, if you're sure it's fuel get a gauge on the fuel rail and get an actual pressure reading. If pressure is good check on the grounds which bolt to the side of the intake plenum again; pull them and scrub them and the manifold where they mount with sandpaper or a wire brush.

Oh, sorry, when you asked which pins I thought you were asking about jumping the fuel pump... To check codes see here: http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx

Is the injector resistor pack on the driver's side wheel well plugged in? Test it for 12v+ at the black wire with the orange stripe with the ignition in the ON position.

MA70-3.0GT · 03-08-2010, 05:51 PM

Just a thought, with the FP bridge in place & ign. on can you hear the fuel pump running & the regulator on the fuel rail blowing off excess (hissing sound)?

If not then the pump or it's wiring are an issue. You said the pump relay gets really hot, I'm not sure how hot but if it's overheating then it could either be the pump drawing excess current or a dodgy relay, the results of the wire bridge would suggest which.

touge_monster86 · 03-08-2010, 10:27 PM

when i bridge the fp it still comes on and i do here the hissing sound. i made sure that the resister box is grounded to the chassis properly and checked to see if its plugged in. still same result . i also checked to see if the cold start injector " the one under the intake manifold i think that's the name for it not sure" had pressure and it dose . i checked the ground from the ecu to the manifold as well and it is clean and in a good spot. i do have one question i exstended it and had to solder to make the ecu grounds long that would not affect its abbility to creat a stable ground would it ?

i also tested the resistor's B wire with O stripe and i did not get 12v+ i got 11.09V+

whats that about?

MA70-3.0GT · 03-08-2010, 11:43 PM

Ok im posting from a mobile now so cant check back over the thread, from what you say im not sure its even fuel now. Have you got any codes at all?
Didnt you say you had to play with the cps and throtle to get it running? It shouldnt need any throttle at all to start hot or cold, im wondering if the timing really is right. Its easy for it to skip round when you fit the cps.
First thing is codes tho, theres gotta be something there?

touge_monster86 · 03-09-2010, 12:35 AM

i lined the marks on the cam gears to the marks on the metal plate and had the crank mark set to zero. also have the cps with the drill mark lined up to the notch . i think that is right but it could be wrong. the only issue with the hole engine code is that its actually a 7mgte i swapped into an ae86 so im not sure if the code will show up on the cluster or not . and even if it did would the engine actually have to turn over and run in order for it to throw a code .

man i racking my brain. it ran great right before i changed the head gasket

03-02-2010, 07:04 PM	#1
touge_monster86 Stock Join Date: Mar 2010 Location: huntington beach Posts: 11	7mgte issues need help doing diag i have a 7mgte that i recently changed the head gasket on . every thing is timed right im sure because when it does start it runs clean but the problem is that it wont run . it will start up for about 5 second or less run clean then just shut off and then i have a heck of a time getting it to start again . i usually have to have some one mess with the cps and feather the gas to get it to fire up . i am stumped the fuel pump works i got good spark, the efi relay get's really hot some times, and as far as i can tell i got pressure in the line up to the fuel rail. i have no idea 7mgte is new to me so if any one could give me some assistance i would really appreciate it

03-03-2010, 02:08 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Checked for loose grounds? Any diagnostic codes? You didn't try to clean the AFM did you? To ensure it's not the fuel pump's power, jumper FP and B+ in the diagnostic box and then try to start... if it runs then then you need to diagnose the fuel pump's circuit. This won't tell you if the fuel pump is too weak though, for that you need a gauge; Even a weak fuel pump could give enough fuel pressure for a car to idle. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

03-03-2010, 09:02 PM	#3
touge_monster86 Stock Join Date: Mar 2010 Location: huntington beach Posts: 11	Diag I will check for grounds, I did not clean the afm and I have no codes . And wich pins in the diag box exactly do I bridge ? Thanks for any help

03-07-2010, 09:33 PM	#5
touge_monster86 Stock Join Date: Mar 2010 Location: huntington beach Posts: 11	diag no luck man nothing changed. its like the injectors are not working

03-07-2010, 09:51 PM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Well, if you're sure it's fuel get a gauge on the fuel rail and get an actual pressure reading. If pressure is good check on the grounds which bolt to the side of the intake plenum again; pull them and scrub them and the manifold where they mount with sandpaper or a wire brush. Oh, sorry, when you asked which pins I thought you were asking about jumping the fuel pump... To check codes see here: http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx Is the injector resistor pack on the driver's side wheel well plugged in? Test it for 12v+ at the black wire with the orange stripe with the ignition in the ON position. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

03-08-2010, 05:51 PM	#7
MA70-3.0GT 12psi boost Join Date: Oct 2009 Location: Crewe, England Posts: 356	Just a thought, with the FP bridge in place & ign. on can you hear the fuel pump running & the regulator on the fuel rail blowing off excess (hissing sound)? If not then the pump or it's wiring are an issue. You said the pump relay gets really hot, I'm not sure how hot but if it's overheating then it could either be the pump drawing excess current or a dodgy relay, the results of the wire bridge would suggest which. __________________ '89 MA70 Supra GT aero 3.0turbo JDM, Rebuilt motor, K&N intake, 3" stainless turbo-back. New turbo and braided line kit... '89 Honda NC27 400, NC23 cams, open pipe, PC36a shock & possibly Showa USD forks... '83 Yamaha 29R XJ750E-II, number 69 off the line, only runner in the country? Original except Koni shocks '95 Honda PC26 CB500R, Winter hack, hateful, trying to sell it I'm not paranoid, they really ARE after me!!!

03-08-2010, 10:27 PM	#8
touge_monster86 Stock Join Date: Mar 2010 Location: huntington beach Posts: 11	when i bridge the fp it still comes on and i do here the hissing sound. i made sure that the resister box is grounded to the chassis properly and checked to see if its plugged in. still same result . i also checked to see if the cold start injector " the one under the intake manifold i think that's the name for it not sure" had pressure and it dose . i checked the ground from the ecu to the manifold as well and it is clean and in a good spot. i do have one question i exstended it and had to solder to make the ecu grounds long that would not affect its abbility to creat a stable ground would it ? i also tested the resistor's B wire with O stripe and i did not get 12v+ i got 11.09V+ whats that about? Last edited by touge_monster86; 03-08-2010 at 11:26 PM.

03-08-2010, 11:43 PM	#9
MA70-3.0GT 12psi boost Join Date: Oct 2009 Location: Crewe, England Posts: 356	Ok im posting from a mobile now so cant check back over the thread, from what you say im not sure its even fuel now. Have you got any codes at all? Didnt you say you had to play with the cps and throtle to get it running? It shouldnt need any throttle at all to start hot or cold, im wondering if the timing really is right. Its easy for it to skip round when you fit the cps. First thing is codes tho, theres gotta be something there? __________________ '89 MA70 Supra GT aero 3.0turbo JDM, Rebuilt motor, K&N intake, 3" stainless turbo-back. New turbo and braided line kit... '89 Honda NC27 400, NC23 cams, open pipe, PC36a shock & possibly Showa USD forks... '83 Yamaha 29R XJ750E-II, number 69 off the line, only runner in the country? Original except Koni shocks '95 Honda PC26 CB500R, Winter hack, hateful, trying to sell it I'm not paranoid, they really ARE after me!!!

03-09-2010, 12:35 AM	#10
touge_monster86 Stock Join Date: Mar 2010 Location: huntington beach Posts: 11	i lined the marks on the cam gears to the marks on the metal plate and had the crank mark set to zero. also have the cps with the drill mark lined up to the notch . i think that is right but it could be wrong. the only issue with the hole engine code is that its actually a 7mgte i swapped into an ae86 so im not sure if the code will show up on the cluster or not . and even if it did would the engine actually have to turn over and run in order for it to throw a code . man i racking my brain. it ran great right before i changed the head gasket

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