Need help with vibration in new motor!! (5th gear shimmies) PLEASE HELP!!

[skiwesser]

Okay, stock block .030 overbore, new eagle rods, forged K.B. pistons, Trick Flow #1 Cam (221/225 dur. @.050,.499/.510 lift), AFR 165's, Typhoon intake (port matched to heads),73mm C&L meter, 24# injectors, 65mm TB, 1 3/4 longtubes w/3 chamber F.M. cat-back. T-5 in good shape for now, will a tremec bolt up to a stock bellhousing?

OK, the problem is that in 5th gear (most notable, I can feel it in 4th sometimes too) at low RPM's 1500 and under if you ease into the throttle the shifter shakes to the point that I have too gear down, at first I had NGK's in it and it really shook, went to 1/8 mi. track and ran 9.01-9.06 all motor, 8.85-8.89@ near 77mph on 60 shot of gas, which only picked up 1.5-2mph trap speed, I knew somthing was wrong so I only ran a few times and on the way home it was hesitating and sputtering of fouled plugs.

Swaped to autolite 3923's and new cap and rotor and wires, and it helped a lot, now it only does it I'd say 50% of the time otherwise it's smooth as silk when I accelrate at even 1100-1200 RPM's in 5th.It goes back and forth about every time I drive it.

When it's running with no vibs it seems to have quicker throttle response & or quicker accelation. I have a crane ing. and blaster coil, but it doesn't matter if I unplug the crane box or not.

Fuel press. is at 40#, 24# injectors

ANY THOUGHTS?????

[skiwesser]

You can see the stock (most all bolt on's) motor was quicker, somthing is definenintly wrong, I'm almost sure it's ingnition related but I can't find any bad connections or lose wires.
Timing is at 15 degrees, with 93 octane and aluminum heads should I bump it up a little??

Could it be the used A9L cpu, or would it act up worse?
24# squirters are used too but they were clean and don't tick.

[Gearhead999]

How is the coil?? I'd go there first.

[skiwesser]

Coil is new ps-1 or whatever comes with HI-6 crane box, It's new, but??
Wonder what would happen if I hooked speed density CPU back up & unplugged MAF??

[skiwesser]

Okay, I've noticed a trend, in the morning it runs smooth as silk. I can let the RPM's fall to 1000 and ease into the throttle and it accelerates smoothly. In the afternoon, and typicly the rest of the day it will shake so bad in 5th at 1500 and under that I have to go to 4th, I't really feels like ingtion miss but I've changes plugs, wires, cap & rotor, I even swapped CPU's with my buddy mine ran fine in his car (I got it used) and I had same problem with his??
HELP!!!!!!

[Dark Knight]

Scan for codes? Bad 02 sensor?

[Gearhead999]

If the car runs good cold then starts the "shake" as it warms up. I would lean toward the ECT might be bad. The ECT gives the ECM input as to the engine temp. so it can richen up when the engine is cold, like a choke on a carbed engine. As the engine warms up it leans the mixture down.

Get a scanner on it and besides the codes you can monitor what the sensors are sending. It will surely "shake" if it is lean. What do the plugs look like??

[skiwesser]

I havn't put the scanner on it but no check engine light?
Plugs look good.
O2's are stock I.E. OLD and I did go to longtubes could they cause this??

[Gearhead999]

Header won't cause this. I'd put a scanner on it and read the stream to see what's going on.

[Dark Knight]

Headers wouldnt cause it.. old O2's would though. If the wires are old and cracked, did you put longer wires on? How old is old? Originals?

[skiwesser]

O2's are original, wires were long enough to reach bungs in new headers, but wouldn't check engine light come on if CPU was not getting a reading from them?
Anyway I'll check it with a scanner this week.
Thanks

[skiwesser]

Okay I got codes 91- O2 sensor low voltage/system leanor voltage out of range so I need new O2's.
But I also got code 95- Fuel pump secondary circuit fault.
What is this? Either of these could be my problem because it runs fine every day until i shut it off so I guess it's running rich as per called for by cpu when I've just started it for the day.
but what is this code 95 and how do I fix it??
HELP
THANKS
WES

[skiwesser]

New O2's didn't fix it so I guess I'll try the ECT, isn't that the sensor screwed into the intake? If I unplug it and see if it runs diffrent will that tell me if it's bad b-4 I buy a new one? I'm still looking for loose wires (grounds) and arking sparks (in the dark) but to no avail.
I am going nuts this thing runs great in the morning but I gotta drive it to the track and shut it off so I won't know what it'll really run until I fix this, it wasn't doing it b-4 the rebuild so It's gotta be somthing I can track, right?
HELP ME PLEASE

[Hozer 88GTConv]

Have you run a cylinder balance test with a Actron code scanner?
I'd do a KOER test after it is hot and exhibiting the symptoms you are describing and then follow it with a cylinder balance test.
It will identify a weak or weak cylinders and should really help you eliminate much of your troubleshooting considerations.
I'd also talk to your longtube vendor and see if they have heard of probs with 02's at those locations not providing temp readings within the range of OEM 02's. A voltage calibration may be necessary...
good luck...

[skiwesser]

Well I broke the tranny this week (3rd) so I'll have to fix that first and keep chasing this grimlin.
BTW what is a cylinder balance check?
I never heard of that.
Thanks
Wes

[v8-7]

Here is a good article on how to get codes, and some info on what tests can be run , including how to do a balance test and a description of what it is .

http://www.mustangworks.com/articles...-iv_codes.html

I'm trying to track down a code 95 as well, but I doubt that is your problem.

[skiwesser]

Well I finally got tranny in this weekend, I tried a friends distributor but still missing when hot and cycled off, and restarted.

Traced it to the #2 fuel injector, swapped in one of my old 19# ones and fixed the skipping.

Now, can I leave that 19# injector and roll with it? If not where can I buy ONE 24# injector?