QuestionQUESTION: Hello, I have had a 1990 1.6L Mazda Miata for a number of years. Recently it started hesitating and being very sluggish at take off, but after it would get up to a certain speed, like 35 mph and over it seemed to run fine. The hesitation/sluggishness was also amplified when it was going up hill, and would be lucky if it would reach 5 to 10 mph within 5 minutes.
I replaced the spark plugs and wires myself, and the plugs were fouled with oil, I also replaced the gasket that goes around the plugs. But the hesitation/sluggishness at take off remained.
I replaced the PVC valve, air filter and fuel filter, but nothing seems to have worked.
I did take it to two local shops, the first shop informed me that it was a timing belt issue and that they were unable to work on it. The second shop that I took it told me that the timing was fine, and it was another problem, but they were not able to determine what it was.
At that point I have taken it to a dealer, whom informed me that the problem was with the air intake and it would be a $750 job to fix the problem. Well I just got off the phone with the dealership, and they are telling that replacing the air intake system has NOT fixed the problem, and I am still responsible for the $750 repair bill.
Before I authorize the dealer to attempt anything else, I was hoping that you might be able to provide me with some insight. Thank you.
ANSWER: the dealer should of checked for a vacuum leak first and cleaned or replaced the mass air flow sensor. if you timing is fine those are the key areas to look. you seem to have covered everything else. also have you ever had your idle speed adjusted sometimes that's a reason for hesitation.
alot for shops take people for a ride if they don't know much about cars. a suggestion to you if you fit that profile is go to your local parts store and buy the repair manual for your car and read it front to back. alot of it my seem like it's written in a fogein lanuage to you but it will help you get to know you car alittle better and posibly aid you in fixing it yourself. i suggest michele or haynes there two of the best.
---------- FOLLOW-UP ----------
QUESTION: Thank you very much for your fast reply, and suggestions. Actually when I purchased the spark plugs, wires, PVC valve, and other parts I also purchased a Haynes manual. I couldn't figure out what it was from the manual, so I tried a couple of different shops, and finally had to take it to the dealer.
One shop informed me that it was a problem with the distributor cap, and I informed them that I would be picking my car up and not to touch it, since the 1990 Miata doesn't have a distributor cap. I at least knew that much.
Thank you again for your helpful suggestions.
Answerit's under trobleshooting in the front of the manual
(engine stumbles on acceleration)
-spark plugs fouled
-fuel injection system faulty
-clogged fuel filter
-incorrect ignition timing
-air intake leak
now i'm not to furmiler with you modle but it's the same problem i had with my 626 and it was do to a vacuum leak in the air intake box and a couple faulty surge valves
you replaced the plugs fuel filter had the timing checked
question did you gap your plugs to spec or just put them in from the box?
and my other question to you is what type of gas do you
use some of the mazda's require premium if you've never ran premium try running a tank of it with injector cleaner before spending any money having the fuel system looked at.
with the price of gas going down so much in the last month you won't even notice the cost:) i'm sure it'll still be cheaper then the crazy 135 a litre we were paying not even 3 months ago :)
hope that's of some further help good luck.
