engine is slugish after tune up

[redneckjeeper94]

i have a 94 cherokee with a 6 inch lift on 33 inch tires my cherokee used to be very peppy even with the lift and tires and i took it in for a tune up about a month ago and after driving it for a while the motor seems really slugish like it lost a lot of power. I suspected that they used cheap plugs and wires so i got bosch platinum stuff and cleaned my k&n and no difference.. wut could be other things that might make my engine slugish after a tune up?

 

[Mercenary]

Perhaps the engine is now lost its timing. I would suggest checking the timing with a timing light to see if it remains in spec. If that is not the problem then I suggest popping off the cap and checking for carbon build up. Also, pop out a plug to see if they are fouled at all.

 

[BCParker]

Who did the tune-up, what plugs did they use, what wires did they use, did they get the firing order correct, are the wires routed so that they cross as little as possible and always at a 90 degree angle, did they use dielectric grease, did they overtighten the plugs, is the rotor pressed down all the way on its little mounting stud?

many things to go wrong, it's a simple job but it can get screwed up.

if the ignition system checks out ok you might just have a new problem.

maybe a vacuum line was knocked loose.


just a few ideas

-B

 

[FUNKYTEE5]

Make sure the plug wires are routed correctly, check all of the vaccuum lines especially the one to the MAP sensor. Check your fuel pressure. Did they pull the distributor out for some reason? If so It may be indexed incorrectly. Just keep narrowing variables until you find the problem. It's highly doubtful that plugs or wires themselves would cause such an issue.

 

[redneckjeeper94]

they used cheap plugs and wires and i replaced them with bosch platinum stuff ill check fireing order but they will have to do timing i dont know nothin about doing all that

 

[brent]

the computer takes care of the timing, you can't adjust it, neither can they unless they flash or reprogram your ecu.

 

[BCParker]

they used cheap plugs and wires and i replaced them with bosch platinum stuff ill check fireing order but they will have to do timing i dont know nothin about doing all that

Many people on this site despise the bosch platinums. personally, my bosch single platinums lasted ~80k mi with no problems, though I have heard many people have had rough idle, loss of gas mileage, etc from using fancy plugs.

were the "cheap" ones by any chance regular copper champions? part number 412?- those are OE plugs and shouldn't be causing a problem.

 

[redneckjeeper94]

they were autolites, i havent noticed a difference between the bosch and autolite though