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Hard to start after replacing injectors...

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Old 05-25-2017, 04:29 PM   #41
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The FSM claims it'll drop at least 3psi for 2+ seconds on a cold start, I've never tried it for myself though.

Check out the second page of the FSM that I posted, it's got all the steps to see what the problem is. I'd only go through it after checking the wiring though since that might be your problem.
Thanks...what's the "Distributor 4-way connector"?
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Old 05-25-2017, 04:33 PM   #42
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Thanks...what's the "Distributor 4-way connector"?
It's a 4-pin wide connector. The wires come out on the back passenger side of the distributor, though I believe the wires run from there to the drivers side where you can unplug it. I've only unplugged it while removing the distributor which gave me easy access to it.

*Also glad you saw that in the FSM, I forgot to mention it in my previous post.

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Old 05-25-2017, 04:38 PM   #43
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It's a 4-pin wide connector. The wires come out on the back passenger side of the distributor, though I believe the wires run from there to the drivers side where you can unplug it. I've only unplugged it while removing the distributor which gave me easy access to it.

*Also glad you saw that in the FSM, I forgot to mention it in my previous post.
Thanks...would you have a pic of that connector? Or maybe if you know where it unplugs from? Thank you!
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Old 05-25-2017, 04:52 PM   #44
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I just drove the car so the engine is a bit too warm to stick my hands in there and play with it - but here's a photo of the wires:



You want the group of wires on the right side running parallel to the spark plug wires, you can see that there are four of them. The connector on my car is just under the distributor, but the wires are long enough that they could be anywhere behind there. I said they go to the distributor on the back of the passenger side, but it's almost exactly on the center/back of the distributor.

Here's a picture showing the connector:

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Old 05-25-2017, 04:56 PM   #45
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Also keep in mind that while it may be easy to disconnect the connector, it will require a bit of pressure to connect it back together. So if you can't get the connector out enough so you can work with it, then you may not want to attempt to disconnect it. I've done that before where I just tell myself that a long flat screw driver would work to take it apart, only to have to pull more stuff apart later so I can reconnect it.
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Old 05-25-2017, 04:57 PM   #46
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I just drove the car so the engine is a bit too warm to stick my hands in there and play with it - but here's a photo of the wires:



You want the group of wires on the right side running parallel to the spark plug wires, you can see that there are four of them. The connector on my car is just under the distributor, but the wires are long enough that they could be anywhere behind there. I said they go to the distributor on the back of the passenger side, but it's almost exactly on the center/back of the distributor.

Here's a picture showing the connector:

Okay, yea...I remember those! Thanks, I had a different one in mind. The pic helps a lot!
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Old 05-25-2017, 07:47 PM   #47
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change the fuel pump relay.
You're probably building enough oil pressure to energize the oil pressure fuel pump switch and that's what's turning on your pump
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Old 05-25-2017, 07:51 PM   #48
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change the fuel pump relay.
You're probably building enough oil pressure to energize the oil pressure fuel pump switch and that's what's turning on your pump
I thought oil pressure was a backup?
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Old 05-25-2017, 08:23 PM   #49
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I thought oil pressure was a backup?
It is a backup, but that is what coupeguy2001 is basically saying when he says it's only turning on when oil pressure is built, which would cause a hard start.

Two easy ways to test the relay though. The first is to simply listen for the fuel pump when you turn the key. If you don't hear it, the fuel pump relay could be bad. However, it could also just be a quiet fuel pump (mine has decent noise insulation). So the other way to check it is simply hook up a fuel pressure gauge and see what the pressure is when turning the key to "on". If it builds, the pump relay is fine.

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Old 06-01-2017, 08:01 PM   #50
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the system has to go thru a learn process. disconnect the battery for a short period, connect, restart the car, and let it idle for around 15 minutes. see if that helps....

hey, did you ever get the leaking valve cover issue resolved?
Following up here. Tried this, but no change. Thanks!
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Old 06-01-2017, 08:04 PM   #51
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Coolant Templates Sensor. We will need a scanner to see what the ECM sees for temperature and hit the sensor with an infrared thermometer and see if they are close.

Any chance of getting the cold start injection piece serviced?
Following up here. I replaced the Coolant Temperature Sensor, but no change. Still hard to start. Thanks!
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Old 06-01-2017, 08:12 PM   #52
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Oh, okay...that one. I put a new connector in for that one, but maybe I'll go ahead and replace the sensor as well. The word "switch" just threw me off...

What's "bin"?

Thank you.
Following up here. I replaced the Coolant Temperature Sensor, but no change, and it's still hard to start. Looks like I will be following this test procedure next...unless anyone has anything else to add. Thanks!
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Old 06-01-2017, 08:16 PM   #53
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Originally Posted by GREGGPENN View Post
I talked to KellyAnn Conway and will provide an "alternate fact"! LOL

I think it's just as possible old injectors lose resistance/flow over time.
Some will be worse than others....and will have different effect depending on whether they are the same/opposite side as the 02 sensor. Failing (coil) injectors on the same side as the O2 sensor will be adjusted for -- by increasing pulsewidth (fuel). Over time, this could make your engine run richer and richer. As you know, the richer it is, the better it'll run when COLD. That includes start-up.

When replacing the injectors...even if the ECM is disconnected, you might not regain ideal start-up if you didn't replace the CSI too. If it degraded over time...and was compensated for/by wider PW from the ECM, that may account for worse cold-starts after servicing.

Plus, I don't discount the possibility of fuel leakage as theorized above!





Be aware that disabling VATS -- in the chip -- doesn't disable the function of the key pellet. To complete the disabling process, it is suggested that you place a resistor (equivalent to the range of your key pellet) in the ignition wiring. IIRC, this procedure is described on VATSUCKS.com.
I did replace the Coolant temperature Sensor, but it's still hard to start. Just wanted to follow up. Listening to any other ideas you may have...thank you!
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Old 06-01-2017, 08:20 PM   #54
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You'll definitely be able to get it solved without touching the chip, just need to figure it out.

If the switch doesn't do it, grab a fuel pressure gauge and see if the pressure drops when attempting to start the car cold. I believe that step is in the FSM images I posted - but it is basically checking to see whether the cold start valve is injecting fuel or not. Hopefully you don't have to mess with it though.

Did you already check your wiring to ensure it's all good?
Thanks...looks like I am on to that step next. Thanks for posting that! I have the FSM, but scroll function on my PC doesn't seem to work right, and it makes finding that stuff really tough!
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Old 06-01-2017, 08:22 PM   #55
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Originally Posted by slhawkins View Post
The FSM claims it'll drop at least 3psi for 2+ seconds on a cold start, I've never tried it for myself though.

Check out the second page of the FSM that I posted, it's got all the steps to see what the problem is. I'd only go through it after checking the wiring though since that might be your problem.
Thanks...do you have any instructions on checking the wiring other than the plugged ends? You may have already included it, but the lingo and abbreviations people use on here often throw me off, so I apologize if that's the case. Thanks!
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Old 06-01-2017, 08:25 PM   #56
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Originally Posted by coupeguy2001 View Post
change the fuel pump relay.
You're probably building enough oil pressure to energize the oil pressure fuel pump switch and that's what's turning on your pump
I put a new fuel pump in a couple of years ago, but only put a few hundred miles since then. At that time, I replaced a few relays, and pretty sure that was one of them. Can you tell me where it is so I can confirm? Thanks!
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Old 06-01-2017, 08:27 PM   #57
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Originally Posted by slhawkins View Post
It is a backup, but that is what coupeguy2001 is basically saying when he says it's only turning on when oil pressure is built, which would cause a hard start.

Two easy ways to test the relay though. The first is to simply listen for the fuel pump when you turn the key. If you don't hear it, the fuel pump relay could be bad. However, it could also just be a quiet fuel pump (mine has decent noise insulation). So the other way to check it is simply hook up a fuel pressure gauge and see what the pressure is when turning the key to "on". If it builds, the pump relay is fine.
Thanks...Yea, I definitely hear the pump!
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Old 06-01-2017, 09:50 PM   #58
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Well, I went to the next step, and hooked a fuel pressure gauge up. When I turn the ignition on without cranking, the gauge goes right up to 45 psi but quickly drops down to 20 psi. I tried it again, and it did the same.

The third time I turned the ignition on, it went to 45 again. This time I cranked it for two seconds with the 4-wire distributor wires disconnected, and it dropped down to 30 psi much faster, and kept going down to 20 psi, though at a slower rate after I stopped cranking it.

Going by the FSM, it just says if it drops more than 3 psi it's okay...but does this seem normal?

Thanks!
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Old 06-01-2017, 10:13 PM   #59
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Well, I went to the next step, and hooked a fuel pressure gauge up. When I turn the ignition on without cranking, the gauge goes right up to 45 psi but quickly drops down to 20 psi. I tried it again, and it did the same.
THIS is what worries me. I had an L98 in an F-body and Y-body. None of them fell that fast in stock mode.
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Old 06-03-2017, 03:52 AM   #60
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THIS is what worries me. I had an L98 in an F-body and Y-body. None of them fell that fast in stock mode.
Got a few ideas of what might be going on here. Still troubleshooting though.
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