Car bucking randomly HELP!

Yellow302

Member

Mar 2, 2003

789

2

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NJ

Oct 22, 2007

#1

• Oct 22, 2007

• #1

Car has started to act up lately and I don.t know why.

symptoms are bucking but no backfiring. random rpm. Seems to be fine if i free rev the car.

So far I have checked the following.

Cap- new
Rotor -new
Coil - swaped
TFI or ICM - swaped
O/2's - New (does the same when i shut them off)
Dizzy - Cleaned out with electric cleaner*** running 80% better now, still bucks though.

Things to check still:
Clean Maf
PIP sensor
Dizzy

 

Yellow302

Member

Mar 2, 2003

789

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NJ

Oct 22, 2007

#2

• Oct 22, 2007

• #2

"According to Ford, TFI failure causes the vehicle to buck, hesitate, and experience other "driveability" symptoms that provide a warning that the TFI module is about to fail."

Found this somewhere, TFI moduals are known to die after high temp exposure, my car has overheated many of times lately, could this have killed the TFI.

If so how/where can i replace it?

 

Yellow302

Member

Mar 2, 2003

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NJ

Oct 22, 2007

#3

• Oct 22, 2007

• #3

im guessing the TFI is the blaster coil, which i already swaped and still had the same issue...

 

toyman

10 Year Member

Jul 19, 2007

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79

Vernon BC

Oct 22, 2007

#4

• Oct 22, 2007

• #4

Yellow302 said:

"According to Ford, TFI failure causes the vehicle to buck, hesitate, and experience other "driveability" symptoms that provide a warning that the TFI module is about to fail."

Found this somewhere, TFI moduals are known to die after high temp exposure, my car has overheated many of times lately, could this have killed the TFI.

If so how/where can i replace it?

Click to expand...

Heat was a problem when the TFI (Thin Film Ignition) module was attached to the distributor. The TFI module is now located on the fender wall behind the air intake duct. That's not to say that isn't the problem but I would be inclined to look elsewhere. I'd first clean the MAF sensor and see if that helps. It's located in the air intake duct.

 

Yellow302

Member

Mar 2, 2003

789

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NJ

Oct 24, 2007

#5

• Oct 24, 2007

• #5

I havent cleaned the maf yet, but voltage is consistent and fuel pressure is good. My TFI or ICM was right next to my super charger which does get hot. I have replaced/relocated the unit and problem still exists.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Oct 24, 2007

#6

• Oct 24, 2007

• #6

A TFI's critical temp is ~257*F. Once they start to degrade, that temp can be greatly lower (moving a bad TFI too a cooler location might not solve your issue). Have the TFI bench tested several times at the parts store.

Pop your cap off and run a magnet around in the dizzy bowl. If you start picking up ferrous material, check the dizzy's bushing and inpect the PIP. If the bushing goes, it often takes the PIP with it. Simply having a dirty PIP can cause slight misses and bucks (almost like having timing too retarded on a carbed car). I clean the bowl out with electrical contact cleaner.

Of course, the MAF cleaning idea was excellent. Do that - it takes 5 mins and is free if you have contact cleaner (which you should). Clean the IAT while you're at it (not to fix anything but just so it's cleaned at the same time as the MAF. I do them at the same time always)

Good luck.

 

Yellow302

Member

Mar 2, 2003

789

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NJ

Oct 24, 2007

#7

• Oct 24, 2007

• #7

A guy i know said the same thing, I clean the bowl out with electrical contact cleaner.

Ill give that a shot before spending more money on parts

 

94-302-vert

Active Member

Aug 16, 2004

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NE CT

Oct 25, 2007

#8

• Oct 25, 2007

• #8

Are the plugs/wires new as well?

How about running some fuel system cleaner?

 

Yellow302

Member

Mar 2, 2003

789

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NJ

Oct 25, 2007

#9

• Oct 25, 2007

• #9

94-302-vert said:

Are the plugs/wires new as well?

How about running some fuel system cleaner?

Click to expand...

Wires are good, plugs are getting old.

I flooded and blew out the distributer with electric cleaner spray and flushed out dirt/oil/grease/old gasket peices

Car is running about 80% better but still bucks occasionaly. going to check the gap on the plugs or replace them soon.

 

Yellow302

Member

Mar 2, 2003

789

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NJ

Oct 25, 2007

#10

• Oct 25, 2007

• #10

Ok good news i guess, CE light came on when the car was bucking again. Im hoping it saves the code in the memory or something so if i hook up a scanner it can tell me what it is.

Will it save the code?

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Oct 25, 2007

#11

• Oct 25, 2007

• #11

It should as long as your battery does not get disconnected.

 

Yellow302

Member

Mar 2, 2003

789

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NJ

Oct 26, 2007

#12

• Oct 26, 2007

• #12

HISSIN50 said:

It should as long as your battery does not get disconnected.

Click to expand...

sweet ill scan it when i get home from school