8.1 Gi-c sluggish hole shot and sputter at wot

[AsLan7]

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That’s a bummer rd. Internet garage mechanic diagnosing can be a tough road. We can’t hear or see what you are experiencing. Being in the boat with a technician who can read codes and diagnose pump pressure, fuel injectors, plug firing , etc. with a laptop is priceless. Many times without doing that it can lead you down rabbit holes. Don’t ask me how I know after replacing a number three coil pack which was the culprit of our rough running engine. I should have just had the laptop hooked up from the getgo.

The good thing is you have fresh fuel and filters. Don’t let it get you down. You may want to get your name on the technician waiting list in the meantime.


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[rabiddawg]

I went back and got the pressure test kit and sure enough the low pump was not building pressure. I’ve tried hot wiring it and still no pressure

Now the test port valve is leaking

I’ve had it.

[AsLan7]

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Keep your head up buddy. You’ll get her fixed one way or another.
Or with this sellers market you could probably make money on her...even with a bad pump.

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[rabiddawg]

I really think previous owner never ran it after he changed the pump assembly. He is going to see if he can find who or where and when he bought it. I’m hoping it may have a warranty.

[Big Block Power]

Ya. It’s the nature of forums. Folks get on the train and off the train at different stops. Don’t take it personally.
I think the majority of CChat threads show some type of resolution. I definitely know they show some type of derailment.

More of the latter. I'm glad I was never involved in those threads

This is why I purchased software and cable for my engine. I haven't had to use it but if I need it I have it. But hey my hour meter is now accurate to the ecu

[rabiddawg]

Does the low pressure pump run continuously? Or does it cycle as needed.

Now I’m wondering if the adapter in the test kit damaged the schrader valve. It’s leaking now and my valve stem tool won’t mate up to it. The whole shit show is coming out tomorrow.

Now I’m venting. It’s so freaking hot in south Louisiana right now. Miserable to work in or out of the shop. Plus it’s up n down a 6’ ladder every time you get in or out the boat. I just need to get this thing running right; then I can do the little things as I go.

Thank you all for your help and patience! I’m going visit with John Jameson now

[Big Block Power]

I might be getting on my boat tomorrow late afternoon. I'm not sure on the operation as Mine runs so I haven't had to dive into it. But I want to hear if it's whinning. When I pulled it out last time I used it I thought I heard something. I hope I didn't hear it but it got ran longer than it normally does around my lakes here. Yes it sounds like your tool messed up the Schrader valve. You can remove it maybe and bring it to a Napa and match it up.

[rabiddawg]

After messing with it some more I’m convinced the low pressure pump is bad. I can not get pressure from it again.

So the question becomes. Oem or another aftermarket?

The on on here now is not oem. It was purchased off amazon 4/19 and I am convinced the previous owner never used the boat after he installed it.

Anyone have experience good or bad with them?

[Big Block Power]

Yt used a China one and it worked. How long don't know he sold the boat. But I believe that boat is still going 2 years later? If it's my own and plan on keeping it I'm going oem.

[rabiddawg]

Here we go, gonna take it back out to False River this afternoon. I figure it either runs the same or better.

I ordered new low and high pressure pumps and regulator from man cave mechanic.

While waiting I removed all the paint from inside the assembly.

Yesterday I reassembled it and installed in the boat. I cycled the key with only the low pump wired to verify it was running. After several cycles I heard it load up like it finally had pressure. I then plugged up the high pressure pump and cycled it 4 or 5 times.

I then cranked the engine. I was surprised it took several tries for it run. It ran rough like on only 4 cylinders rough but eventually it smoothed out. I thought cycling the pumps would have avoided the rough start.

[rabiddawg]

If this doesn’t fix the issue, I have a Chevy mechanic with scanner and gauges ready to go run it on the river next week. I will turn it over to him.

[Big Block Power]

Sounds like your ok. Mine was like that after Changing the fuel filter.

[akorcovelos]

Smart move replacing it all, heard good things about Man Cave around here.

[rabiddawg]

Epic failure!

It runs worse now than before. Will not even get on plane.

Gonna call my mechanic

Making lemonade! The family and friends are enjoying a swim and beverages within sight of the landing

[AsLan7]

Epic failure!

It runs worse now than before. Will not even get on plane.

Gonna call my mechanic

Making lemonade! The family and friends are enjoying a swim and beverages within sight of the landing

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Again, sorry to hear that rd. Keep us posted after the diagnosis by the engine technician. There is a reason they get paid the marine rates they fetch....(and they're still underpaid IMHO) .

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