Misfire without CEL possible?

[Archo]

03 Tahoe 5.3 has a rough idle, not too bad but enough to notice. Take it to a shop and they say it threw no codes but there is a misfire in a few cylinders on one side. Also told me that this could cause the slight bump or movement I feel in the tranny at times. Lastly he told me that there is a service bulletin that was out for this and this could possibly fix the problem I'm having. After reading through many threads I'm lost and seeking input. Thanks guys, he charging 275 for this update as well...

 

[blackdiamond]

Start with fuel pressure. 55- 62 while running. ck regulator on fuel rail... make sure there is no fuel in the vac line.. or if its wet inside of there, should be bone dry. that would cause that condition with no cel. then go for ignition problems.

 

[Archo]

Start with fuel pressure. 55- 62 while running. ck regulator on fuel rail... make sure there is no fuel in the vac line.. or if its wet inside of there, should be bone dry. that would cause that condition with no cel. then go for ignition problems.

Could this senario possibly affect the tranny as well? Also since I am not familiar with doing these thing I am going to send it to a mechanic and let them know this info.

 

[blackdiamond]

Its very possible. I would have to crack the fsm open to see exactely what sensors affect tranny performance but there is a couple.

 

[Archo]

Ok cool, that determines a lot like if I should go ahead and purchase this truck. Thanks! Also I'm located in the Philadelphia area if anyone has any good mechanic references

 

[blackdiamond]

no i have some family in jersey but thats it. good luck

 

[Archo]

In the meantime you think plugs and wires would.have any effect if I change those?

 

[blackdiamond]

pull and inspect condition of plugs. then if you can ohm out the wires. if not and you wanna spend a little money do plugs and wires

 

[Archo]

Also what I am.trying to determined is if.this problem is worth letting this car go. What do you think?

 

[blackdiamond]

depends on mileage and condition id say, but problem should be an easy fix

 

[Archo]

164k and condition is very good....

 

[blackdiamond]

make the seller fix the problem. then buy it