Weird vibration from 3200 to 3700

[88-378]

Weird vibration from 3200 to 3700 - bad wires!!!

Like the title says. it is smooth to 3200 and smooth after 3700 Has anyone had a problem similar to this? I can pretty much rule out the drivetrain and suspension.

why would it only do it for 500rpm's?

I think it is a miss..ignition system?

what do you think? I am putting the car up next weekend to check out everything anyway. (my car is basically brand new front to back. it is fresh off a complete resto minus paint) I am almost finished with breaking the clutch in. could it possibly be the clutch not broken in yet?

 

[Mustang5L5]

I had the same thing happen. Since I did a 5-spd swap at the same time this happened, I assumed it was a balance issue.

Drove for a year living with it. Happened to check codes one day and did a cylinder balance test and discovered cylinder #4 was dead. To make a long story short, the injector was completely dead. I drove around for over a year on 7 cylinders and didn't even realize it.

 

[Noobz347]

Does it vibrate only while under power or does it also do it when coasting?

 

[88-378]

it does it a little while coasting. not as bad as when I am on the gas.

It doesn't shake the car either. so it's not that viloant of a vinration, but is noticeable.

 

[88-378]

I had the same thing happen. Since I did a 5-spd swap at the same time this happened, I assumed it was a balance issue.

Drove for a year living with it. Happened to check codes one day and did a cylinder balance test and discovered cylinder #4 was dead. To make a long story short, the injector was completely dead. I drove around for over a year on 7 cylinders and didn't even realize it.

I guess I will be testing a few things. I plan on putting new plugs in, so I will see what that tells me.

 

[BlackGT89]

If it's related to engine RPM maybe your harmonic balancer is starting to go ?

 

[Mustang5L5]

Do a cylinder balance test as part of checking the engine running codes. It will tell you if you have a misfire

 

[88-378]

I have a code reader and a book. I also need to get it back down to Atlanta Chassis dyno. I need it checked.

hold up. I think i have a bad wire. So i guess i have been running on 7 cylinders....LOL

 

[88-378]

Well, well, well.

Had a bad wire. Just ordered a new set.

 

[BlackGT89]

Glad you found it !

 

[88-378]

thanks. just hope i didn't damage anything. rings, piston, valves, etc...

A good friend and shop owner was messing with me telling me I need to re-ring that cylinder.... then he started laughing. He said it should be fine...

 

[Mustang5L5]

Glad you found it. You probably weren't 100% dead onthat cylinder, so i wouldn't worry.

When i put a new injector in, felt like i gained 50HP.

 

[88-378]

Glad you found it. You probably weren't 100% dead onthat cylinder, so i wouldn't worry.

When i put a new injector in, felt like i gained 50HP.

You did! If i take my 405 at the crank, divide it by 8 and you get 50hp! LOL

It was probably my fault when i repaired a wire. Their must have been another small cut in it somewhere. I have a new set of FRPP wires coming. Plus i was getting crazy readings from my ohm meter.

Went to black wires for a more sinister look!

 

[88-378]

New wires in. ran codes and a balance test.

All is good.