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95 Taurus Injectors new and won't start

I replaced the injectors on my 95 Taurus, now it will crank but won’t start. I also replaced the EGR pressure sensor because the vacuum line connection was broken.
What could I have done wrong?

     Did it run before you replaced the injectors?

Do you have fuel pressure at the rail? Spark? You may have unplugged something for clearance and not got it back in. I would double check all the connectors.

I expect this will prove to be some electrical connector or vacuum line that wasn’t replaced correctly or something like that. Maybe a fuse got blown in the process. Are you able to determine whether or not the fuel pump is running?

One other idea: If the EGR is now fully engaged all the time, that would prevent the car from starting. The EGR isn’t supposed to fully engage except during acceleration. Is it possible you connected the EGR vacuum control to the wrong vacuum hose? Check the vacuum connections compared to the drawing (usually this appears on a sticker on the underside of the hood) of how they are supposed to be routed.

One more thing … good idea to verify the fuel pump shut off switch hasn’t turned off for some reason or the other. This is a safety device that prevents the fuel pump from running after an accident. Unlikely to be the problem, but probably worth your time to reset it. Your owner’s manual should tell you how to do this.

@LeRoy if I may ask: why did you replace the injectors?

Americar: It ran before I replaced the injectors!
George San Jose: I can hear the fuel pump running!
db4690: I replaced the injectors because I had low power!

@LeRoy FYI plugged injectors can often be restored to proper operation by connecting fuel cleaner to the fuel rail. Any competent will know what I mean, even if they’ve never done this themselves.

By the way, had someone diagnosed the injectors as being plugged?

If the injectors are not plugged up then I would suspect a misdiagnosis from the start.

LIttle info has been provided about the car but you need to determine what is missing from the cylinders; fuel or spark. Spray some carburetor cleaner into the intake and see if it will start or not; at least for a few seconds.
Provide that info and we may be able to narrow it down a bit more. This is a TFI car so those modules are always suspect.

db4690: I tried cleaning the injectors for a long time, not on the fuel rail!

@LeRoy FYI the best way to clean injectors is to hook the cleaning solution directly to the fuel rail.

Jgarewal-I may not have fuel at the rail. When I remove the fuel pressure relief valve cap, I get no fuel. All the connections are tight.
George San Hose-The vacuum lines are all connected, I clamped the ones that were a little loose. It would be difficult to connect the EGR vacuum controlto the wrong vacuum hosedue to the lengths and positions. How can I check the EGR valve for proper operation?

@LeRoy removing that cap will tell you nothing. There’s a schrader valve inside that test port. The fuel pressure gauge would depress the schrader valve.
What you can do is cycle the key, then press down the schrader valve with a small screwdriver… If no fuel squirts out, you’ve likely got not fuel pressure at the rail.

I think you need to step back and take a deep breath. This entire thing sounds like a fishing expedition.

Spray some aerosol carb cleaner into the intake to see if the engine will run for a second or two. This will at least narrow it down to lack of fuel or spark although the former could be related to the latter.

If there is no fuel pressure in that rail after doing what DB recommended then you might try this.
Look for the diagnostic connector under the hood. There should a separate plug attached to it and this wire should be tan with a green stripe. That wire is the splice from the fuel pump relay to ECM wire.
Run a jumper wire from ground somewhere to that plug. You should hear the pump run and if you have a spark the engine should run. This is for test purposes only; do NOT leave it like this.

Anyway, that’s something to consider and you might post back with any results.

@LeRoy … re: checking EGR. On my early 90’s Corolla, the way I check that the EGR operation is to start the engine and let it idle to nominal operating temp, then I apply vacuum to the EGR vacuum port and verify that this stalls or nearly stalls the engine. I do it that way on my early 70’s Ford truck too. But every car is different. The shop manual will have a procedure for checking yours I expect. In any event, a faulty EGR stuck in the engaged position could cause the car not the start. And since you replaced the EGR, you should consider this a possibility.

Another idea: I’m wondering if you could have an air bubble in the fuel rail which is preventing the fuel pressure regulator or the check valve from working properly. Does the shop manual say the fuel rail needs to be air-bled after replacing the injectors? There may be some kind of priming operation needed after depressurizing the fuel rail.

One final idea: There’s many things that can cause loss of power. Faulty injectors wouldn’t be first on the list from my perspective, unless there were other reasons to suspect the injectors. First thing I’d do if low power were a problem on my car is bring all the routine engine maintenance up to date. Next, I’d check the compression. Then I’d replace the fuel and air filter. If the power remained low still, on a 95 like you have, I’d next suspect the cat may be plugged. Hang in there, I think you’re close to a solution. Best of luck LeRoy!

@GeorgeSanJose he doesn’t have an air bubble in the fuel rail
I believe you’re overthinking it.
I’ve replaced injectors, including on Fords.
There is no "special procedure"
As far as priming goes, cycling the key a few times should allow the fuel pump to build up pressure at the rail, assuming the system is functional

Thanks @db4690 … my fuel rail experience is w/a late 70’s VW Rabbit. And no bleeding was necessary with the VW CIS FI system as I recall. I did have a problem one time after repairing this CIS system when the engine got flooded, and I couldn’t for the life of me figure out why it wouldn’t start.

Oh, maybe I’m on to something. The OP should consider whether it is possible that somewhere along the the line the engine has gotten flooded. Maybe pull out all the plugs and crank the engine for 30 seconds, then leave the plugs out overnight, and install the plugs and try again the next day. Especially true if a visual inspection of the plugs show signs of wetness at the tip.

I cleaned and applied dielectric compound to the new plug wires at both ends. I fully charged the battery. The engine starts and runs slow for three seconds. I did the KOEO test and got code 556. It says fuel pump relay primary circuit failure but that can’t be. I can hear the fuel pump run. I also got code 6636 but I don’t have a list of four digit codes so I don’t know what that means. I am not giving up on this Taurus. It is a matter of principle!

To review: I had trouble checking fuel pressure in the rail. There was a rubber washer in there but when I got that out and pressed on the schrader valve, I got gas all over. I have plenty of pressure. I replaced a lot of stuff on this engine in the past year such as the fuel filter and air filter. I lost a little honeycomb material when I replaced some exhaust parts but not much. It is not blocked.

@LeRoy perhaps it’s time to take the car to a shop and fully disclose all that’s happened and what you’ve done.