Valve Guides worn out?

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driftingalong1

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Apr 20, 2006

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Jun 24, 2006

#1

• Jun 24, 2006

• #1

I have an 88 5.0 coupe speed density. Recently i set my timing, tps and put all new ignition on. Super coil, wires, plugs, distrobutor cap and rotor. When i pulled the plugs there was a small bit of oil around the threads and signs of burnt oil on the electrode. There is no smoke out the exhaust. When the car is cold only when u rev her up she backfires. But when im driving, it runs very strong and smooth. The plug gaps are set to the proper specification. Each time it backfires it always comes from the passanger side and its not just a little pop, its very noticible and irritating. Are my valve guides wore out? piston rings mabey? there is only 161 k on the motor and its stored away every winter. Somebody please help!!

 

fidstang

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Jul 19, 2005

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South Lansing

Jun 24, 2006

#2

• Jun 24, 2006

• #2

The only way to tell if the valve guides are worn is to have a friend follow you and watch as you get on it. When you shift a puff of blue smoke will be noticable. As for the back fire, I would get a timing light and see what it is at when cold and compare it to the warm reading. You may have to much timing advance when it's cold.

 

_jb_

New Member

Mar 4, 2004

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Michigan, Berrien County

Jun 24, 2006

#3

• Jun 24, 2006

• #3

Maybe injectors are dirty.

 

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driftingalong1

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Apr 20, 2006

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Jun 24, 2006

#4

• Jun 24, 2006

• #4

How could a dirty injector cause a backfire? i can understand if the injector is shot and just dumping fuel, but if it was dirty would it not be giving less fuel?

 

DMAN302

My mom says thanks for the pearl necklace.

Nov 8, 2003

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59

windsor, Canada

Jun 24, 2006

#5

• Jun 24, 2006

• #5

Well if she's running fine and not burning obnoxious amounts of oil then just enjoy the ride and don't give it a second thought. If your really worried do a compression test and or leak down test and install an aftermarket oil pressure gauge. At 200.000 miles mine was drinking oil had no pressure and ran like a mother till the day we pulled her out. Sounds to me like a good ole tune up is in order.

 

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driftingalong1

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Apr 20, 2006

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Jun 24, 2006

#6

• Jun 24, 2006

• #6

I have tuned her up. set the timing, TPS, new plugs, cap and rotor, coil. I get good oil pressure too shes not burning madd amounts of oil either. Do you have ne other ideas or suggestions of the problem? thanx for your time!!

 

DMAN302

My mom says thanks for the pearl necklace.

Nov 8, 2003

2,120

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59

windsor, Canada

Jun 24, 2006

#7

• Jun 24, 2006

• #7

pull the codes by using either a code reader or use the search feature on the site to see alt methods to pull codes..from there you can get a starting point by eliminating the obvious. Backfire could be a bad gap on a plug and when cold could be an issue..I run stock ignition and .054 gap.

 

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driftingalong1

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Apr 20, 2006

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Jun 24, 2006

#8

• Jun 24, 2006

• #8

Brand new NGK G power plugs are in and gapped to .054, so thats not the problem. thanx

 

DMAN302

My mom says thanks for the pearl necklace.

Nov 8, 2003

2,120

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59

windsor, Canada

Jun 24, 2006

#9

• Jun 24, 2006

• #9

sorry never liked anything but autolights in a ford..just my .02

 

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Daggar

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Jul 19, 2004

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Jun 24, 2006

#10

• Jun 24, 2006

• #10

To answer your question above:

A dirty injector can cause backfire if the spray pattern it not atomized well enough that the combustion mixture's burn is not complete by the time the intake valve opens. The better the atomization of the fuel the more predictable and more complete the fuel burns during a single stroke of the engine.

Things that I might check or do in addition to what's been mentioned above:

Check voltage going into the coil it should read 12+ volts regardless if rpm
Advance timing in 2* increments and take note of any changes
Close plug gap in .020 increments and note any changes
Disconnect and plug vacuum source going to fuel regulator and rev to recreate condition
Replace cap and rotor with old pieces (if new) or inspect rotor and cap contact condition (if old pieces)
Check condition of plug and coil wires and ensure they're clean
Run engine at night and look for any sign of arcing
Check charging voltage from alternator (should be 14+ Volts regardless of engine RPM above idle)

 

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driftingalong1

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Apr 20, 2006

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Jun 25, 2006

#11

• Jun 25, 2006

• #11

I first had a set of bosch platinum +4's in her and ran like junk so i took em back and exchanged for the NGK's seems to be a bit better but still getting a big backfire on cold revs

 

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driftingalong1

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Apr 20, 2006

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Jun 25, 2006

#12

• Jun 25, 2006

• #12

Daggar said:

To answer your question above:

A dirty injector can cause backfire if the spray pattern it not atomized well enough that the combustion mixture's burn is not complete by the time the intake valve opens. The better the atomization of the fuel the more predictable and more complete the fuel burns during a single stroke of the engine.

Click to expand...

Thanks alot for the information now it sounds like i might be getting sumwhere. tommorow morning ill pull the injectors check em out and clean em up and try again!

 

DMAN302

My mom says thanks for the pearl necklace.

Nov 8, 2003

2,120

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59

windsor, Canada

Jun 25, 2006

#13

• Jun 25, 2006

• #13

you won't be able to physically see or clean the injectors when you remove them..you should be looking to pull the codes..the car might very well want to TELL you what the problem is.

 

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driftingalong1

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Apr 20, 2006

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Jun 25, 2006

#14

• Jun 25, 2006

• #14

how do you suggest i pull the codes?

 

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Daggar

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Jul 19, 2004

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Jun 25, 2006

#15

• Jun 25, 2006

• #15

Wallmart code reader $30. Beats the Volt meter method hands down IMO.

 

DMAN302

My mom says thanks for the pearl necklace.

Nov 8, 2003

2,120

2

59

windsor, Canada

Jun 25, 2006

#16

• Jun 25, 2006

• #16

30 bucks that could save you hours and lots of cash...far too often we throw money at problems.

 

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driftingalong1

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Apr 20, 2006

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Jun 25, 2006

#17

• Jun 25, 2006

• #17

alright ill have to try that one out and see if any codes come up. Thanz alot for the help tonight everyone!! Talk to yall lata!