No injector signal

[dustin77]

need some help! A little background. car 77 celica lift back. motor 89 7mgte stock harness and ECU. Problem is I am not getting pulse to the injectors. I have voltage to the injector resistor thingy. gapped and tested resistance at the cps and that tested good. all grounds are good on the engine including the one at the coil packs. good 12v to the ecu it starts off of the cold start injector chugs then dies. I have put a noid light on the injectors so I know I am not getting any pulse. things I plan to check when I get a chance ignitor signal to the ecu, and clean and regap the cps. any thoughts would be much appreciated as I am lost and kinda going in circles!
Thanks Dustin

And the previous motor that was in it, just not enough power!

 

[Nick M]

If you pull a spark plug, you probably don't have spark either. There is no pulse to the injectors. The PCM doesn't have injector drivers like domestics do, where they often employ FET's to switch power. Toyota PCM provides the ground path, power is constant.

Without the pickup signal, the ground will not be supplied. Check to see that you have power (B+) to the injectors, and pull codes.

 

[dustin77]

ok a little update. I do have 550 injectors and the lexus afm on it part number 22204-42011 but everywhere I read said that the electronics is the same but I know that part number is different than what the 7mgte is by just the last number! I switch out that injector resistor thingy and got pulse. I have always had spark just wasnt any pulse to injectors. but all that appears to be good. put a light on it and am getting a code 32 afm failure. I did the voltage test across the afm and it is good. any help would be much appreciated.
Thanks Dustin

 

[dustin77]

ok another update. I got the HAC sensor hooked up, and now I am getting a code 41 and 51, I know I need to adjust the tps now and see if thats the culprit, or if my harness is messed up somewhere. I have redid the connector at the CPS that was brittle and frayed, so just hoping thats the only bad spot. if any body has any insight please shed it my head hurts and am done for the day!
Thanks Dustin

 

[jetjock]

...The PCM doesn't have injector drivers like domestics do, where they often employ FET's to switch power. Toyota PCM provides the ground path, power is constant....

Interesting. So what does it have? Relays? Hamsters running on little wheels? :icon_razz

 

[Nick M]

Interesting. So what does it have?

Toyota PCM provides the ground path, power is constant.

But you already knew that.

 

[jetjock]

Well, the box has to sink the injectors somehow. Point is our PCM does has drivers. It's been a long time since I was inside one so I don't remember whether they're FET, BJT, or even IGBT technology but I'm guessing MOSFET. Perhaps 3p will chime in to settle the matter.

 

[dustin77]

ok well i got the tps set and adjusted, no more codes coming up on the trouble light just a constant flash yippee! but still does not start... sprayed some starting fluid in it last night when I took the throttle bosy off to adjust the tps. put it back together this morning it fired and ran for about 15 seconds then dies. I am assuming that was the starting fluid from last night, but now I am back to it turning over and chugging then nothing. I did get a code 43 for no ignition so I put power to it and still nothing. I am hoping that is what the sta is supposed to get is 12v or is it suppose to only get 12v while it is cranking and then ground or or just not see the 12v?
Thanks Dustin

 

[Nick M]

STA is the signal to the PCM so it knows you are cranking the engine in an attempt to start. You need that because Toyota does not turn on the fuel pump in a priming fashion, again, like the others often do. When it is running, you have the airflow meter and pick up. That will not cause a stall (43) when running. How is your fuel pressure? You can jump the fuel pump in the diagnostic box FP-B+ and see if it starts. When it does, you can work on repairing the circuit.

Well, the box has to sink the injectors somehow.

Of course, but they don't switch power like others sometimes do, Toyota switches ground. That is all I said. Little squirrels....:biglaugh:

 

[dustin77]

fuel pressure is good 45psi. my fuel pump is turned on by the key not the harness. well we have got it to start and idle but once you touch the throttle it dies. and throws a code 31 afm. I tested the resistance and it was good but I also read that the test doesnt really mean anything.:cry: so i am going to be looking for another afm, unless someone has an idea on to clean it, but everywhere I was reading that cant really be done.
Thanks Dustin

 

[dustin77]

looking for a post that someone made here a while ago I cant find it! It has the part numbers for schucks or kragen's Mass air flow sensor just the electronic piece not the whole housing that they show on their website and in store if someone knows what I am talking about if you can point me in the direction that would be awesome!
Thanks Dusitn

 

[speedfreak426]

Hey this is speedfreak426 from the 1stgen Celica sites, I am sad to see that you are having all these issues trying to get this thing to fire up.

I don't know how current those pictures are that you posted, but I can see a few problems just by looking at those.

Get rid of the aftermarket BOV, it's going to only cause you issues, especially stalling. Just get a long bolt and lock it shut for now.

You have open holes inbetween the AFM and turbo, those could be causing several issues as well, but I assume you noticed and fixed that already.

I have some spare 7M electronics if you need other stuff to further diagnose the problem. Wish you lived closer so I could be a better help.

Here is how mine was set up a few years ago if that helps.

 

[dustin77]

the hole I am assuming you saw on that boot is plugged! I cleaned my maf with some electronic cleaner and threw it back in today it idles low and bounces up and down with all vacuum hoses hooked up, I pull the isc valve off of the turbo and it idles way high and still once I hold the throttle it dies if I pump it I can get it to rev a little and still want to die! But I am not getting the maf code so hopefully that cleaning will last a couple months! But I do get a 51 when I touch the throttle which I am assuming because of the starter switch hooked but would that affect the idle and throttle response or would that be a miss adjusted tps? it does smell rich while it is running. I need to get a down pipe on it so I can get the wide-band hooked up and radiator should be here Wednesday and get that on! would the temp sensor have anything to do with idle jumping also? I am at a loss and just jumping back and forth I dont know anymore and my head hurts just thinking about this thing!
Thanks Dustin