Think you're good at wiring?

[JakeP]

Started out as this thread: http://www.r3vlimited.com/board/showthread.php?t=186664

Now I jumped power to the coil, giving me spark and fuel to the rail, but it won't start.

I tested the injector plugs and have power to both sides of each injector pigtail (WHICH IS VERY STRANGE).

Any ideas?

[StereoInstaller1]

Jake, I will spend some time with the ETM tonight.

You have downloaded a copy, right?

[JakeP]

Don't think so. Is ETM an electronic troubleshooting manual?

[JakeP]

Oh, and my friend (lbmotoring) just convinced me to pull the dash to look for severed wires or an alarm. All wires look good and no visible alarm...

[Adrian_Visser]

If you have positively confirmed that it has spark at the plugs, the fuel injectors are spraying fuel and the battery is sufficiently charged to turn the engine over fast enough the only other thing that would cause it not to start would be cam timing i.e. a broken timing belt or a timing belt that has skipped a tooth.

EDIT: Just read the other thread and I have no idea what is wrong with this car. I think there are more symptoms there than spark and fuel present and no start though.

[JakeP]

I know it has fuel at the rail, but not at the injectors. Also tried a new fuel regulator. How would I check for fuel at the injector?

[Adrian_Visser]

I know it has fuel at the rail, but not at the injectors. Also tried a new fuel regulator. How would I check for fuel at the injector?

Well instead of actually pulling the fuel rail (PITA) you could just pull an injector connector and check for +12 on one terminal with the key in the run pos. and pulsating ground on the other when the engine is turning over.

What Davesmed is saying about the ignition switch and main relay wiring is what I would be following up on if I were you.

[JakeP]

Well, both terminals have 12v, when only 1 should.

main relay is getting power now, and I put in a new ignition switch from a working car.

[jlevie]

Pin 27 of the DME is the START input to the DME. If it doesn't get power the DME won't run (and the main relay won't close and the injectors won't have power). The first task should have been to determine why pin 27 doesn't go to battery voltage when the key is turned to run/start. Jumping power to the coil should make pin27 go hot, but if the problem is in the engine harness...

Since the injectors are simple solenoids, if there is power on one side, you'll see power on the other side except when the DME grounds the injectors to fire them.

[JakeP]

Pin 27 of the DME is the START input to the DME. If it doesn't get power the DME won't run (and the main relay won't close and the injectors won't have power). The first task should have been to determine why pin 27 doesn't go to battery voltage when the key is turned to run/start. Jumping power to the coil should make pin27 go hot, but if the problem is in the engine harness...

Agreed. But every wire in the engine bay came out of a running car, because mine had damaged wiring. Possibly a connector unplugged on the dash side of the firewall?

Since the injectors are simple solenoids, if there is power on one side, you'll see power on the other side except when the DME grounds the injectors to fire them.

Even when I unplug the connector and check? Sorry, I don't get wiring 100%.

[accident]

your car pisses me off jake lol

basically what he's saying is that both sides of the injector plug will have power until the DME grounds one. in theory the power should pulse while you crank the motor.


jim: we jumped the coil from the jump block near the under hood battery tray. this caused 27 to go hot and of course the main relay closes. the unfortunately, it seems the car isnt building fuel pressure. if i pull the DME and crank it over for a bit, then plug the DME back in, it starts, but dies almost immediately after. we tried changing the FPR and fuel filter, but still have the same issue. i'm wondering if it's a pump problem or there's a pressure leak in one of the lines

[Adrian_Visser]

your car pisses me off jake lol

basically what he's saying is that both sides of the injector plug will have power until the DME grounds one. in theory the power should pulse while you crank the motor.


jim: we jumped the coil from the jump block near the under hood battery tray. this caused 27 to go hot and of course the main relay closes. the unfortunately, it seems the car isnt building fuel pressure. if i pull the DME and crank it over for a bit, then plug the DME back in, it starts, but dies almost immediately after. we tried changing the FPR and fuel filter, but still have the same issue. i'm wondering if it's a pump problem or there's a pressure leak in one of the lines

Jim's right, on second thought you would need to disconnect all the connectors at once or the splices would feed both sides of the injectors at once.

An even easier way to check if the injectors were getting power and ground to fire would be to check the c191 connector under the intake manifold. Pin 5 should have power with the key in run pos. coming from the main relay, pins 6 and 7 should be pulsating ground for injectors 1,3,5 and 2,4,6 respectively whe the engine is cranking.

[jlevie]

your car pisses me off jake lol

basically what he's saying is that both sides of the injector plug will have power until the DME grounds one. in theory the power should pulse while you crank the motor.

The injectors are wired as two banks of three. One side of all of the injectors is connected to power. The other side of each bank of three is common and grounded by the DME to fire those injectors. If you problem one connector with a meter, the common side will show 12v because other injectors are connected.

jim: we jumped the coil from the jump block near the under hood battery tray. this caused 27 to go hot and of course the main relay closes. the unfortunately, it seems the car isnt building fuel pressure. if i pull the DME and crank it over for a bit, then plug the DME back in, it starts, but dies almost immediately after. we tried changing the FPR and fuel filter, but still have the same issue. i'm wondering if it's a pump problem or there's a pressure leak in one of the lines

The very first thing to do at this point is to check the rail pressure (with a gauge) when cranking the engine. If the pressure is low, jumper the fuel pump relay socket and see if that brings up the pressure.

[JakeP]

An even easier way to check if the injectors were getting power and ground to fire would be to check the c191 connector under the intake manifold. Pin 5 should have power with the key in run pos. coming from the main relay, pins 6 and 7 should be pulsating ground for injectors 1,3,5 and 2,4,6 respectively whe the engine is cranking.

Ok, I'll check that.

The very first thing to do at this point is to check the rail pressure (with a gauge) when cranking the engine. If the pressure is low, jumper the fuel pump relay socket and see if that brings up the pressure.

Sounds good. I can jump the relay and I could also just cap off the return line (if thats an OK thing to do...)

You guys know anywhere that loans out fuel pressure gauges?

[lateracer]

You guys know anywhere that loans out fuel pressure gauges?

Summit has a liquid filled gauge for $18 with a 1/8 NPT fitting and because they're in Socal it'll be there next day if you're in Riverside. I have one permanently installed in my track car, but you could T into your factory lines pretty easily in the engine bay. Really cheap way to know how your fuel system is doing. Helped me figure out I had a bad in-tank pump.