95 V6 626 Auto, runs bad after warmup

[Trigggl]

I'm hoping I don't need a MAP sensor on this thing. I bought a donated car for $1000. It is this 95 V6 626. I love the car, but I'll never buy a donated car again. Here is a list of things I've already had to get repaired to get it ready for my wife to use.

New brakes(front and back), both O2 sensors, all belts(including timing), two new tires, rack and pinion steering, wheel alignment and an oil change. In the process of changing the O2 sensors, I discovered that the front driver side frame was bent and then straightened. The driver side headlight, marker and turn signal didn't work, but after buying the parts I figured out that the light harness just needed to be plugged in. The new light fixture has a broken mounting on one side.

The car has a problem that doesn't happen till it starts warming up. It runs smooth when it's cold, but when it warmed up it would run like it was on 3 cylinders. I decided to start with the small easy things to troubleshoot it, since the engine light isn't coming on. This past weekend I changed the pcv valve, the air filter and the spark plugs(I used platinum). I couldn't afford the cap and wires yet and wanted to see if the ignition was part of the problem before spending money on it. I still can't figure out why the temp. of the engine would matter with this, but now that I think about it, it reminds me of a problem I had with wrong temp plugs on a motorcycle. The plugs helped the car a little. The car doesn't jerk while stopped anymore and idles better. It isn't missing as bad but it still is missing when it warms up. I'm hoping that a new distributer, rotor and wires is all I need.

Does anyone have any other ideas, or am I possibly on the right track?

[rjitzsu]

distributors very common problem on early 2.5L engines... especially with temp.
a $10 spark tester may save you a bundle of money though.

[Trigggl]

Originally Posted by rjitzsu

distributors very common problem on early 2.5L engines... especially with temp.
a $10 spark tester may save you a bundle of money though.

Or an inductive timing light?

If it is the distributer, would a junk yard part be an option or make sure I get a new one?

[rjitzsu]

I enjoy junk yard parts.

I would much rather get a junkyard or reman part than get an aftermarket one. I've had many many problems with aftermarket caps, rotors, distributors, and wires on mazdas... other than that, the aftermarket is fine.

anyhoo...
a timing light won't give you a great indication on how strong of a spark you're getting... plus they're a lot more expensive... but if you've already got one it'll work.

while you've got that timing light out check your timing... a weak t-belt tensioner may also cause your problem. you'd probably notice a rumble from the front cover though...

[Trigggl]

Originally Posted by rjitzsu

I enjoy junk yard parts.

I would much rather get a junkyard or reman part than get an aftermarket one. I've had many many problems with aftermarket caps, rotors, distributors, and wires on mazdas... other than that, the aftermarket is fine.

anyhoo...
a timing light won't give you a great indication on how strong of a spark you're getting... plus they're a lot more expensive... but if you've already got one it'll work.

while you've got that timing light out check your timing... a weak t-belt tensioner may also cause your problem. you'd probably notice a rumble from the front cover though...

I already have the timing light, I just need to find it. It may be in storage.

It's weird. I can drive to the store and the engine will run fine. I leave the store and try to drive home and it acts up from the get go. It also doesn't seem to want to down shift when it's running bad.

I just had all of the belts replaced by the Mazda dealer. They also had me change the O2 sensors. I'm not getting a check engine light, but I sure wish I did.

[Trigggl]

Well, we took the car to the Mazda dealer. It was starting to eat fuel like an otr(over the road) Freightliner. Of course, my daughter isn't the best at feathering a throttle. The Mazda dealer finally called us back and listed the problem as being caused by the spark plugs, wires, cap and rotor. They even said my platinums got burned out, the ones I just installed. They want a small fortune for the job, but I'll do it myself. Mazda parts are just way too expensive. I'm sorry I ever bought the car, but there appears to be an end in sight.

[kjbuente]

There is a mod that you can that will fix and help prevent this from helping again, and there are some cool effects that come with it. 1) CHEAP!!! like only $13 total I belive. 2) If you decide to do a full mod, you can get some extra HP. These distys fail because of some components being so close to the engine, they over heat and fail. This move these components away from the engine and the replacements are far more reliable!

Send a message at [email protected] if your interested. I'll send ya a link to a site that shows you how exactly how to do this step by step.

[Trigggl]

Update: Whoever had the car before, bought valve cover gaskets, but only replaced the easy one. I had to remove the intake manifold to get to the back one. Once I got the manifold off, I noticed one of those freaky plastic vacuum things bolted to the bottom had a broken nozzle, so there was a break in my vacuum line that I never would have found. It seems like someone was under there and tempering with things because there were a lot of bolts that were nearly hand tight. The valve cover was exactly tight either. I think I managed to get all the vacuum hoses reconnected in the apropriate places. There is one solinoid that I need to replace because I broke the nozzle trying to get it off. I got the one part from the junkyard for $5 and can get the other for the same price once I actually have the money. Cancelled the order for a new solinoid, since I found a number of them in the junkyard. What do the cost new? $70 and $60.

[kjbuente]

Depends on what the solinoid is. Without know, hard to tell.

[Trigggl]

Originally Posted by kjbuente

Depends on what the solinoid is. Without know, hard to tell.

It was a rhetorical question that I answered myself.