Injectors not firing. HELP!!! After BHG job

flyjum

New Member
Oct 5, 2006
75
0
0
Mesa AZ
I replaced my head gasket, did all everything, hooked up wires grounds...we checked every ground, every fuse.

the cold start injector fires and sputter starts then dies.

so the injectors are not firing...

We voltage tested the CHARGE fuse in the engine bay. This is the strange part. When testing only one side of the fuse connection it has 12v with ignition ON. But when i complete the circuit and connect to both sides of the fuse, the voltage on both drops to 0.70v

i already tried replacing the injectors and replaced them back with the old. didnt affect anything,

help please
 

cuel

Supramania Contributor
Jan 8, 2007
1,536
0
0
Baytown, Texas
Is the 7.5amp "charge" fuse on the pre 89 the same as the 7.5amp "ign" fuse in the TSRM?
http://cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=D&P=6

Sounds like a short somewhere? I don't have a meter here at home to test mine with. Maybe a burned out charge warning bulb? What happens if you unplug the alternator? Not the power wire, but the 3(I think) wire connector from the harness? I think that's what that fuse is for, but I don't have a pre 89 wiring diagram here to look at.
 

flyjum

New Member
Oct 5, 2006
75
0
0
Mesa AZ
Got spark how many grounds are there on the Inatke Manifold will check 12v again. No CELS showed up yet
 

jetjock

creepy-ass cracka
Jul 11, 2005
9,439
0
0
Redacted per Title 18 USC Section 798
Shouldn't be a factor. I'd normally suggest the igniter isn't sending back IGf but if that were the case he should have a code 14. If it were me I'd be looking at the power side of the injection circuit.

Course, we only have his word the injectors aren't firing. I see no proper diagnostic method in the post that proves it. For all I know they are and it's something else.
 

cuel

Supramania Contributor
Jan 8, 2007
1,536
0
0
Baytown, Texas
You can get a universal noid light at a local parts store pretty cheap. Handy to have if you want to check for injector pulse.
 

p5150

ASE and FAA A&P Certified
Mar 31, 2005
1,176
0
36
Central Idaho
You never said if you had 12v going to your injectors. There should be a constant 12v on one of your injector pins.

I dont think its a ground issue - it sounds to me like you dont have the 12v going to your injectors.

We voltage tested the CHARGE fuse in the engine bay. This is the strange part. When testing only one side of the fuse connection it has 12v with ignition ON. But when i complete the circuit and connect to both sides of the fuse, the voltage on both drops to 0.70v

Also sounds like you arent using a mulitmeter correctly - your description sounds like you connected the fuse terminals and then measured the voltage across the terminals?

Take off an injector clip and measure the voltage on the pins with the key on and tell us what you find.
 

cuel

Supramania Contributor
Jan 8, 2007
1,536
0
0
Baytown, Texas
Cool, thanks for the link. You always come up with the coolest tools :)

That would make testing relays a lot easier. I've tried a couple different probes like that for injection and spark off the tool truck, but never had good luck with them. They would get to much interference, and not get an accurate reading. I actually have a noid light kit, with different size lights for different makes and models that I like. Plug them right in to the harness, and they read accurately.
What I really need to do is get a scope to go with my scanner. They even offer free courses when I buy it to teach me how to use it correctly. It would make testing everything electrical much easier, especially as advanced as cars are becoming today. Sometimes I really miss the beautiful simplicity of a carbureted v-8....
 

flyjum

New Member
Oct 5, 2006
75
0
0
Mesa AZ
please stay ON TOPIC. You guys can chat about tools anywhere on here, but i need this fixed asap before i leave the country.

it has SPARK
the injectors for 100% sure are NOT fireing
the injectors ALL have contact 12 v
checked all grounds
car runs when gasoline is put in throttle body

We voltage tested the CHARGE fuse in the engine bay. This is the strange part. When testing only one side of the fuse connection it has 12v with ignition ON. But when i complete the circuit and connect to both sides of the fuse, the voltage on both drops to 0.70v

WHATS THE PROBLEM PLEASE
 

jetjock

creepy-ass cracka
Jul 11, 2005
9,439
0
0
Redacted per Title 18 USC Section 798
flyjum said:
WHATS THE PROBLEM PLEASE

Based on your comments about the charge fuse (it can't be involved btw ) the problem is you have what appears to be a relatively simple electrical issue (although I'm doubting it) combined with no idea how to do electrical troubleshooting. My guess is unless you take it to someone who knows what they're doing you're in for more frustration. Lacking that motivation there's always this:

http://tinyurl.com/yqqpay

And you still haven't told us how you know the injectors aren't firing....
 

flyjum

New Member
Oct 5, 2006
75
0
0
Mesa AZ
after sitting for almost a year we decided to yank the engine.

We tried and we failed. turned out to be a nightmare. many wires were fried together and the ecu itself had burn mark across much of the board. The only thing i can think of is a hardcore lighting strike hit the car while in storage and grounded through the positive which was hanging on the ground.

we had operating voltage at the ecu but when it went to fire the injectors the amperage would level of at like .4amp at 7 volts to all 3 powers

cold start was still working
ignition was fine...
but most ecu circut was fried
 

teedoff00

14 psi boost
Dec 5, 2007
297
0
16
Selah, WA
I thought I was having the same problem with my injectors not firing and they weren't. My problem turned out to be a kinked line near the fuel tank, which resulted in poor pressure. My cold start injector had a bit of pressure as well from cranking so much. So in short check all the stupid little things first, could be your problem. Have you checked your EFI main relay? You can check for pressure like JJ suggested here:
"Pretty tough to test a "fuel pressure" regulator without using a "fuel pressure" gauge,

If all you want to do is see if there's sufficient pressure in the rail to run the engine simply pop off the cover on the pulsation damper and look at the screw. For the future an easy way to gain access for pressure measurement is to drill and tap the top of the CSI bolt for 1/8 NPT..."
So after you have tested your system out mechanically and made sure the Fuel pump works, and your Fuel Pulsation damper, and your fuel pressure regulator. As well as checked all lines and the filter. Then move on to testing it out electrically.
Good Luck, hopes this helps!
 

88suprajosh

New Member
Jul 17, 2008
12
0
0
Naptown
The car will start then die....My car did the same damn thing found out it was a circuit open relay. When you turn over the car it bypasses this relay to get fuel to the cold start injector but after engine starts it then quickly fades out. The circuit open relay is suppose to come on to turn on the fuel pump to continue operation on the engine. its behind the passenger kick panel and is marked circuit open. This is very common on all toyotas when they sit.
 

cuel

Supramania Contributor
Jan 8, 2007
1,536
0
0
Baytown, Texas
flyjum;1109109 said:
after sitting for almost a year we decided to yank the engine.

We tried and we failed. turned out to be a nightmare. many wires were fried together and the ecu itself had burn mark across much of the board. The only thing i can think of is a hardcore lighting strike hit the car while in storage and grounded through the positive which was hanging on the ground.

we had operating voltage at the ecu but when it went to fire the injectors the amperage would level of at like .4amp at 7 volts to all 3 powers

cold start was still working
ignition was fine...
but most ecu circut was fried

You definitely need to fix the harness before you put in another ecu. What year, and standard or auto? I have a spare ecu for an 87 standard ge.