I have spark, and the fuel pump comes on. Why won't the injecters fire?

[rhamlinii]

Help, I have spark. I know the fuel pump comes on because I have a rewired 255 hp fuel pump. The 2 fuel pressure guages tell me that i'm getting 40 worth of fuel to start the car. My 750cc injecters will not fire for NO REASON at all. I can take any dsm apart and put it back together, but I suck at electrical wiring diagrams. Can someone please help me and tell me what to check and how to check it. I would hook a voltometer to the positive side of the injecter, but how would I know what to look for? That would show that if it's getting power and maybe the problum would lie in the injecters. I just put a new wiring harness in from a running car, so i'm lost. Please help me, i'm also using dsmlink. Once again, i'm getting spark. I know the fuel is coming to the injecters, I just cant get them to fire. PLEASE HELP ME ANYONE.

I'm also taking the car apart and putting it back to 14b power.

 

[boostnhard]

Bro if i was you i would check my Hayne's or whatever manual, to make sure about resistance, continuity, so on and so on.

 

[luv2rallye]

Did you check if you have to replace the injector ballast resistors with different ones for 750's? A voltmeter won't help much as you'll read +12V on both sides to ground (if you don't you have a problem). One side always has 12V and the other side gets pulled to 0V by the ECU but only for a ms so it will still read 12V since the pulse is so short. A noid light on the ECU side would give you visual indication however. Or turning the CAS by hand (with key on) should fire them one at a time.

 

[rhamlinii]

Did you check if you have to replace the injector ballast resistors with different ones for 750's? A voltmeter won't help much as you'll read +12V on both sides to ground (if you don't you have a problem). One side always has 12V and the other side gets pulled to 0V by the ECU but only for a ms so it will still read 12V since the pulse is so short. A noid light on the ECU side would give you visual indication however. Or turning the CAS by hand (with key on) should fire them one at a time.

Yes, I understand what you are saying. It's just that if I get the correct amount of spark, shouldn't I get the injececters firing too. I know the CAS has to work because i'm getting spark, or are the two seperate?

 

[luv2rallye]

Separate signals from CAS see here: http://www.dsmtuners.com/forums/showthread.php?t=238267#post50470620

 

[Ajax]

If you use I believe a 470 Ohm resistor and a LED and stick that in the injector plug it should light up everytime it fires.

 

[poonman]

ajax do you know what color codes that resistor is off hand and which type of Ma Led to use, that makes me want to make a lil project.

 

[Ajax]

I will have to look when I get home, work till seven then I will get you the info.

 

[toyotaturbo]

Help, I have spark. I know the fuel pump comes on because I have a rewired 255 hp fuel pump. The 2 fuel pressure guages tell me that i'm getting 40 worth of fuel to start the car. My 750cc injecters will not fire for NO REASON at all. I can take any dsm apart and put it back together, but I suck at electrical wiring diagrams. Can someone please help me and tell me what to check and how to check it. I would hook a voltometer to the positive side of the injecter, but how would I know what to look for? That would show that if it's getting power and maybe the problum would lie in the injecters. I just put a new wiring harness in from a running car, so i'm lost. Please help me, i'm also using dsmlink. Once again, i'm getting spark. I know the fuel is coming to the injecters, I just cant get them to fire. PLEASE HELP ME ANYONE.

I'm also taking the car apart and putting it back to 14b power.

We had this happen once on a 1G and it turned out to be the ECU. It was getting fuel, but the injector signal was getting lost somewhere. Check and see if all of your injectors are turned on. I know with DSMLink you can turn off individual fuel injectors. Also, check your cam angle sensor, that's a culprit sometimes as well.

 

[Ajax]

Well went home for lunch cant seem to find it but I know it was a 470 Ohm resistor 1/4 W is fine with a 20Ma LED. Remember it only works one way so if its not going turn it around.

 

[rhamlinii]

We had this happen once on a 1G and it turned out to be the ECU. It was getting fuel, but the injector signal was getting lost somewhere. Check and see if all of your injectors are turned on. I know with DSMLink you can turn off individual fuel injectors. Also, check your cam angle sensor, that's a culprit sometimes as well.

yeah thats what everyone keeps telling me, the sad part is i have dsmlink in there.

 

[poonman]

Well went home for lunch cant seem to find it but I know it was a 470 Ohm resistor 1/4 W is fine with a 20Ma LED. Remember it only works one way so if its not going turn it around.

Thnx bro, ima do a lil project with 4 LEDs just for fun and make my own test box, a plug in and look for the bag voltage type thing.

 

[rhamlinii]

Thnx bro, ima do a lil project with 4 LEDs just for fun and make my own test box, a plug in and look for the bag voltage type thing.

I found out the problum, the dsm link chip was loose. I re-socketed it and tighened the screw that holds it in. I now have no problums, so it actually was the ecu for everyone that was interested. I had to but another ecu and it started right up, so i opened my current ecu and it looked fine. I then felt around and could tell how lose the eprom was. So as I said, I got the screw driver and crossed my fingers. Thank god it worked.