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
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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.

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

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

diag
 

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

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.

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.

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?

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?

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 :mad:

The check engine light is easy to wire up. One side of the lamp goes to a 12v source (the 7.5A Gauge fuse in the stock setup) and the other to the pin labelled "W" at the ECU (see the EFI section of the TSRM for the pinout).

Some codes will set without the engine running... it's always worth checking.

hooked up engine light got nothing . i also decided to test the injector resistor box on the passenger side and power at the ecu and its good . but i check for power at the afm and there was none and i am also wondering if there should be power going to the injectors with the key on the on position

would a faulty tps have anything to do with this ?

No the TPS is only a trim sensor... the car can be driven without it, throttle response and idle just suck and it'll like to stall if the IDL switch is damage or the TPS is actually disconnected.

Yes, the injectors will have power with the ignition in the ON position... they won't have a ground as that's supplied by the ECU.

Engine light??? You replaced the check engine light or what? Pull the glove box out and test the ECU for +12v at Batt, B+ and B1+. I can't provide a pinout as you haven't filled out your profile or mentioned in this thread what year your car is... but those are the pins you need to check. Batt should always have power and +B and +B1 are both ignition switched.

the car is an 85 corolla but the motor is from a 91 supera.

ok checked the b+ and b1+ and they both have power . now i said before that the injectors did not have power going to then well i had a the wrong year ecu on it and now they have power. so i have spark, power to injectors , power to the ecu, power and all functional resistors but still same result no start!!

i updated my profile

Have you actually measured the fuel pressure yet? Are you sure the CPS is clocked right and not 180 degrees off? Have you inspected the CPS to ensure that the pickups are properly gapped? You're running all the 7M-GTE's electronics and engine harness correct?

FIXED IT!!!! lol

im dumb when i wired the igniter to the coil packs i miss matched a wire. and this yellow wire that goes to the egniter was barely attached to the plug lol

im an idiot .

so it start and runs pritty damn good but it has a tuff time starting and when i push the throttle it bogs a bit on the way up . i would say that it smooths out and climes nice and strong after about 3,000 rpm.

its almost as if it has a bad cold start or and its getting a bad o2 reading on eccelaration .......idk . would it have anything to do with the fact that its running of the manifold and down pipe ?

you have any idias ?

Since it can now run longer than 5 seconds, before anything else I'd check your ignition timing. You're almost guaranteed to be off a little, and that could be what's causing the hard start and boggy acceleration (it only takes being a couple of degrees off to run like crap)

I checked the timing a few times allready thinking it was that to begin with. It's dialed in. Once it warms up it runs to smooth for it to be out of calabration . I can check it again but I'm possitive that every thing is were it should be in reagards to timing