First, I’ll admit that my car probably has lots of issues. It’s a 98 For Escort ZX2 w/ over 150K. I was assuming that it was time for a tune up as I couldn’t remember the last one or find record of it and the car is running very rough. The clerk automatically recomended the fuel induction service also. I’ve read what it is, but what is an average cost? In addition the roughness (severe stutter) seems to get worse when I turn on the AC and my husband says possible vacuum leak. Does this make sense and is it costly?
Some more info would help. Is this roughness present only at idle or can you feel it while traveling at road speed?
Automatic or manual transmission?
Any Check Engine Light on?
At 150k miles it’s possible that the induction service MAY help if the problem is present only at an idle.
This service could run a couple of hundred dollars, and to be honest, there are a few things that should be verified before going in and spending money on this.
The use of A/C increases the load on the engine, especially noticeable in a four cylinder. So, the engine will run worse, naturally, with the A/C on. I suggest you get the tune-up done first. The difference will be more than noticeable. Then, consider any other services after the tune-up.
No check engine light. BAD at idle, not felt when accelerating. Tune up seems to be a good start and I’m gonna go for the basic. Thanks for your time!
Turn down the offer of fuel induction service. Go for the basics of tune up. This may cure what ails. The fuel induction is unlikely to help at all.
I’m going to guess at a few possibilities here. A rough idle not felt at speed, and if fuel mileage is about the same, could be caused by the idle speed being too low.
The idle speed being too low, or too rough, could be caused by a vacuum leak or an Idle Air Control valve problem. The Idle Air valve is actually a vacuum leak, although it’s a computer controlled one.
Cleaning the IAC may help or it may not.
JMHO, but if you opt for the tune-up (also a possibility) the first thing that should be done when the spark plugs are pulled is to run a compression test.
A decent shop should do this with every tune-up IMHO; and especially on a higher mileage vehicle.
If the compression is somewhat low even on one cylinder the engine will have a rough idle that no amount of tune-up parts will fix.
There are other things that could cause this but those listed should be the start; especially the compression test. There’s no sense in running up a bill if the engine has a mechanical fault, so weed that out first.