dslreports logo
site
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
3961
share rss forum feed


lostinms
Moo

join:2001-11-29
Grenada, MS

Car running rough

My 86 mazda has started to run pretty rough. It acts like its missing. I checked the Coil and it appeared to be bad as he was putting out a orange spark instead of a blue one so I replace it.

The Plugs and wires have been recently replaced before this happen and it was running pretty good then. There is some but not alot of loss of power. My MPG had really took a dip too. I am leaning towards ignition issue that I have not found yet but not sure.

I do have a exhaust leak some where on the manifold would it cause it to run rough?

Right now my car sound like a Volkswagen bug the air-cooled version.

Any help would be appreciated.



Juggernaut
Irreverent or irrelevant?
Premium
join:2006-09-05
Kelowna, BC
kudos:2

Have you checked the plugs? That can give you a very good clue.



Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium,VIP
join:2001-04-19
1970 442 W30
kudos:18

1 recommendation

reply to lostinms

An exhaust leak can burn valves just like a vacuum leak can and either will cause a very rough idle. Time to look at the plugs and run a compression test and also repair all leaks found.
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?


PrntRhd
Premium
join:2004-11-03
Fairfield, CA
Reviews:
·Comcast
reply to lostinms

"I do have a exhaust leak some where on the manifold would it cause it to run rough?"

If the O2 sensor has the wrong reading it can affect the fuel mixture going to the engine. Usually it will cause a Check Engine indication.
A clogged catalyst will also cause the wheezing you are describing.



lostinms
Moo

join:2001-11-29
Grenada, MS
reply to lostinms

Unfortunately this car does not have a check engine light wish it did sometimes.

Yeah I really don't want any burnt valves its hard enough to get parts for the old car. My wifes grandmother had regular check ups on the the car before I got it and i have been doing my best to keep her running. Was planing on looking and the Plugs and find that exhaust leak if the weather will warm up. Wish I had a enclosed garage.



Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium,VIP
join:2001-04-19
1970 442 W30
kudos:18

said by lostinms:

Unfortunately this car does not have a check engine light wish it did sometimes.

You don't need a CEL. The car is actually easier to work on without having the added complexity. You still have the basics to deal with on any vehicle before you look at the CEL and the attached computer.
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?

Bob4
Account deleted

join:2012-07-22
New Jersey
Reviews:
·Optimum Online
reply to lostinms

Just because the spark plugs are new doesn't mean one didn't go bad. I had a spark plug die at 12,000 miles in a brand new car.

If it runs rough at idle, disconnect the plugs one at a time and see if any do not have a detrimental effect. That may help narrow-down the problem.

For that matter, make sure the spark plugs aren't loose.



Cho Baka
Premium,MVM
join:2000-11-23
there
kudos:2
Reviews:
·TekSavvy DSL
·Cogeco Cable
reply to lostinms

In addition to the spark plug suggestions made by others,

What wires did you put on?
Name brand or value brand?

I have only found NGK or OE Mazda wires to be any good.

If you have a compression gauge, why not do a compression test while the plugs are out. If possible please attach a clear photo of the business end of the plugs.

Does the car use any oil? If it has been using oil for a while, then I would be more than a little concerned that you have a compression issue - this is an OLD car.
--
The talented hawk speaks French.



Sr Tech
Premium
join:2003-01-19
Valhalla, NY
kudos:1
reply to lostinms

You mention plugs and wires, what about cap and rotor? I cannot believe well maybe a car from '86 made it this far with original dist cap.

What is the actual make and model of the vehicle?


Bob4
Account deleted

join:2012-07-22
New Jersey

said by Sr Tech:

what about cap and rotor?

It probably has points, too. Were they replaced recently?


lostinms
Moo

join:2001-11-29
Grenada, MS
reply to lostinms

Just fyi this car does not have points. It is fuel injected plus it has a computer in it. The Cap and rotor has been replaced just I don't know when. My wife's grandmother really took care of the car and had it serviced by the book.

It had sat for a while cause she was getting to that age where she did not need to drive so I she gave it to me.

i have found the exhaust leak and it appears the manifold gasket had gone bad so I am waiting for one to get in from the parts house and that won't be till Thursday. Gota love the holidays.

The car in question is a 1986 Mazda 626 non turbo with stick shift. It is the last year that model was made in Japan and shipped to the US. '87 and on was made in the US.

The reason why I change plugs and wires, the wire leading form the coil to the distributor had gone bad. The Plugs I didn't like what they had in there which was Bosch so I put NGK's back in it when I did the car ran like a champ. Like she was brand new. It won't be till after Thursday that I will update do to having to wait on a part.

Its getting harder and harder to find parts for it in stock with out having to order it.


Bob4
Account deleted

join:2012-07-22
New Jersey

Granny had a stick-shift? I'm impressed!



Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium,VIP
join:2001-04-19
1970 442 W30
kudos:18

said by Bob4:

Granny had a stick-shift? I'm impressed!

My Grandmother learned to drive on a farm using a Ford F100 pickup with three on the tree at age 14. That was several decades ago though.
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?


lostinms
Moo

join:2001-11-29
Grenada, MS
reply to Bob4

if it was automatic it would not be running today. From what I am told the automatic versions would die around 60k miles.



Sr Tech
Premium
join:2003-01-19
Valhalla, NY
kudos:1

I have worked on many of these cars in the past and have seen many things go wrong with them. After rereading your original post, have you tried doing a compression check, or cylinder leak test make sure head gasket and valves are ok? Has the timing chain ever been replaced or checked? Car this old could be anything, even a possibly a cat starting to go bad.



lostinms
Moo

join:2001-11-29
Grenada, MS

1 edit

yes the timing belt has been replaced. Found the old one in the trunk and it had look pretty good. After I get the exhuast manifold gasket replace and that won't happen till the stupid part gets in on Thursday. I could go to one of the dealers in town to see if they have the part but they love to charge you a arm , leg and kidney for their parts.

Oh and Merry Xmas.



Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium,VIP
join:2001-04-19
1970 442 W30
kudos:18
reply to Sr Tech

said by Sr Tech:

I have worked on many of these cars in the past and have seen many things go wrong with them. After rereading your original post, have you tried doing a compression check, or cylinder leak test make sure head gasket and valves are ok? Has the timing chain ever been replaced or checked? Car this old could be anything, even a possibly a cat starting to go bad.

Many, many Years ago a friend bought an old 626 with the 4 cylinder and it ran very badly (like a dead cylinder so he got it cheap). The only thing wrong was I found the rotor button had burned a hole through the top near the center electrode and it was carbon tracking the spark to the distributor shaft instead of the plugs. A new rotor button for 2 bucks made it return to firing on all 4 cylinders like new. That was it and he drove it hard for the next 4 or 5 more years. I think he paid under $400 for it.
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?
Expand your moderator at work