Fuel Injector Problems

[jdhughes17]

Thanks for the heads up.

But the fuel pump isn't the problem right now. The reason it won't start is because the fuel injectors aren't woking.

[76was124]

Okay, so to summarize where you are at:
1. Engine cranks, but will only start and run while there is starter fluid in the intake ( so ignition works)
2. Fuel pump is running and you confirmed fuel is making it to cold start and main injectors.
3. No electrical signal to cold start or main injector coils.
4. You verified clean ground wires on intake housing and exhaust cam box.

One thing still not clear to me is if you have 12volts at the injectors?

The 12 volts should be on one of the injector wires with the the ignition switch on. ( I believe in the accessory position (other forum help on this?), but for sure while cranking) . The other wire connects through the ECU pulsing to ground to fire the injector. Do you have the 12 volts at the Injector? With the ignition switch on, connect one lead of your Noid light to one of the injector pins the other lead to chasis ground. Does it light up? If not, try connecting one lead to the other injector wire and the second lead to chasis ground. Still not lit? Then you have a blown fuse or other open wire from the +12V to the injectors.

Wiring diagrams courtesy Brad Artigue are available at: http://www.artigue.com/fiat/

[jdhughes17]

76was124: We did what you said with the noid light, and it lit up. Then we measured the current going to the injector, and found that there are 12.27 volts going to it. So that's fine. But it still won't start.

Also, we rolled the car into the garage, but now when I turn the ignition, the starter will make a loud click. Half the time the engine will turn, and half the time it won't. That's a new problem.

[jdhughes17]

There Should also be a third ground wire on the passenger side firewall wall connected to the back of the exhaust cam box. Make sure these connections are there and clean.

We cannot find any wire coming off the back of the exhaust cam box. Can you post a picture of where it should be, or where it IS on your car? Thanks.

[bradartigue]

Thanks for the heads up.

But the fuel pump isn't the problem right now. The reason it won't start is because the fuel injectors aren't woking.

Allow me a moment: Don't reply like an alfabb.com member, if you know what the problem is then don't ask for help. Of course the problem isn't the fuel pump. But the problem is power - and the thing that controls fuel pump power has been bypassed, presumably because it doesn't work. While many people diagnose from the point of failure (the injector) I'd prefer to understand the problem (in your case, at least one root cause is someone messed with how the thing works). Which leads me to believe there is at least one cause and potentially many problems. Therefore when someone says they can run the fuel pump without cranking the motor then I say you have a molested fuel injection system. Which makes diagnosis more difficult.

I can tell you one thing: it is NOT the injectors themselves. If all four of your plugs are bone dry - if you aren't spraying fuel - then don't diagnose the injectors, it is a waste of time. Sure all four could be plugged, but I don't know anyone who has ever actually seen this condition.

- confirm that you have power to the ECU in the first place. we already know someone messed with your dual relay (i know, you know everything, but FI systems that have been messed with usually have some weird stuff going on with power in general). Find the fuses, test the dual relay, figure out of you have power in the right places. So far you don't have the injector pulse, so you don't have power in the right places, meaning something is keeping your ECU from providing the pulse.

- ignition coil has a brown/white lead to the ECU #1 pin that must be connected and have continuity.

- the fuel injection system is grounded to the plenum. there are two black wires that ground to the bolts holding the plenum lid down.

- the engine grounds are critical. you should have large grounds from the transmission bellhousing to the body, from the coil mounting stud to an engine mount bolt, and from the exhaust cam box rear cap to the firewall. Run another from a plenum bolt to the firewall. You can't have too many grounds.

- the battery leads and ground are critical. Check them, clean them.

[76was124]

76was124: We did what you said with the noid light, and it lit up. Then we measured the current going to the injector, and found that there are 12.27 volts going to it. So that's fine. But it still won't start.

Also, we rolled the car into the garage, but now when I turn the ignition, the starter will make a loud click. Half the time the engine will turn, and half the time it won't. That's a new problem.

Regarding the ground on the exhaust cam box...I would just add one, and attach it to the firewall. I can't look at mine right now, but I think it was on a ring terminal mounted under a screw head maybe on the back cover on the cambox. If the ring terminal is there and no wire, I would clean it up and crimp or solder a new wire to the ring terminal and ground it to the firewall near the coolant reservoir. If the ring terminal is gone, it's hard to get to that screw, so find another place easier to attach to the cam box...(just don't loosen any screws holding the cambox to the head). You could even use a temporary alligator clamp just to see if missing that wire makes a difference.

Regarding cranking..that could be related if you have an intermittent ignition switch. Or could be a weak battery. As Brad said in his last post...the car wiring has likely been changed, so it's hard to know what you have there now. I would follow his advise and check the wiring to the ECU. Looks like you have the 12 v at the injectors, so you are not getting the injector pulse connections to ground. That comes through the ECU, which as mentioned needs a pulse from the ignition as well as other signals to function. Including I think some through the dual relay.

Hope that helps?

[jdhughes17]

76was124: Checking the current at the wires under the glove box, the large brown wire has 12 volts, the pink/black wire has 12 volts, and the red/black wire has nothing. If I go to the steering column side, where it comes from the ignition, then the red/black wire has 12 volts. When I checked the red/black from the steering column side to the glove box side, there is no continuity.

[spider2081]

76was124: We did what you said with the noid light, and it lit up.

If that is the case the noid light is lighting up doesn't that mean you are getting both the voltage from the fuel injection dual relay and the momentary ground signal from the computer. I thought the noid light lighting told you the injector was getting eveery thing it needs to open and allow fuel to pass.

Am I missing something???

[klweimer]

THE place to start when sorting out these issues is the Fiat Fuel Injection Diagnosis and Maintenance Manual. If you PM me with your address, I'll send you my copy to use. It isn't perfect, but as good as it gets to solve these issues. One item of note - You can reverse the plugs on the double relay and then nothing works...

[bradartigue]

76was124: We did what you said with the noid light, and it lit up.

If that is the case the noid light is lighting up doesn't that mean you are getting both the voltage from the fuel injection dual relay and the momentary ground signal from the computer. I thought the noid light lighting told you the injector was getting eveery thing it needs to open and allow fuel to pass.

Am I missing something???

If you test the injector connector with a noid/test lamp you should get a flickering light when running the starter. If you don't then the next step (which is test 13 on page 9 of the diagnostic manual) is to connect a test light to terminals 88z and 85 of the dual relay, then diagnose further.

Absolutely get the fuel injection step-by-step diagnostics guide. I can send you a download link for it if you don't have it.

[alan5252]

In regards to the fuel pump problem you should also check where the wiring enters the engine compartment from under the dash from the ECU. When i had problems and nothing was testing correctly, i finally found that the wiring was so brittle it has broken the shielding on the wires which shorted and caused back feeds so nothing worked.
In regards to you're starter problem, Check the ground in the trunk from the battery and the ground from the engine to frame. After a long battle with an intermittent starter and replacing the solenoid, i finally replaced the drive. In checking the drive, the gear should be able to turn one way but not the other. Mine would not turn forward or backward so at times i am guessing that the drive would not mesh with the flywheel and then it would just click. One click with every try of ignition crank. This solved my starter problems and it was a strange one! Good Luck

[DieselSpider]

Thanks for the heads up.

But the fuel pump isn't the problem right now. The reason it won't start is because the fuel injectors aren't woking.

Is the fuel pressure to spec? If the fuel pressure is low due to a weak pump or fouled pressure regulator you can still have a no start issue although the rest of the system is working. On a gasoline system I believe its supposed to be somewhere between 50 and 70 psi. I have been dealing with the mechanical diesel fuel injection mostly now so I am a bit rusty on the electrically operated gasoline systems.

[jdhughes17]

I have new fuel problem regarding the injector system. I have a leak right where the rubber tubing connects to the fuel rail. I have not been able to figure out what kind of a connection is here. It feels as if the hose slips over a sleeve, but there is no clamp holding the rubber hose on. I suspect that there is a retention ring or something under the flange, but without removing the rail (which I do not want to do), I cannot see. Any help would be appreciated.

[lglade]

I pulled my fuel rail to do this same repair and it was really no big deal...besides it gave me a chance to replace those tired old injector seals.

The fuel hoses from the rail to the injectors slip over a hose barb on the rail. And the little "bells" (clamps) slip over the end of the hoses to keep them restrained to the rail/injector. Midwest Bayless has a kit for replacing all of the high pressure fuel lines. The stock diameter fuel line (7.5mm) lets you reuse the bells to keep the original look. And if you reuse them then you can just omit using the hose clamps included in the kit. A heat gun makes it really simple to install the new hoses.

http://www.midwest-bayless.com/Fiat-124 ... 80-on.aspx

Removing the old fuel lines to the rail is a little tricky (mostly to avoid cutting yourself) as you have to use an Exacto knife to get under the flange of the bell, and then you cut the fuel hose length-wise to release it from the hose barb.

Lastly, if you have found a leak then you should look to replace *all* of your fuel lines, including the low pressure lines from the tank to the fuel pump. I found cracks in my fuel lines (in the engine compartment AND under the car), and I'm really glad to have made repairs before a disaster happened.

[Zaffer]

It seems as though I am having the same issue at the same time. I am running another post, but will follow this one as well. I, also, am having an issue with the main injectors not firing, however my CSI is still working, so it will run for a few seconds due to the injector spraying some fuel when cold.

Brad, would you be able to post a link to the FI manual? I don't yet have this, but would love to in order to narrow down my issue.

If I resolve the issue first, I will post what I found with my car both here and on my thread, http://www.fiatspider.com/f15/viewtopic.php?t=28125