12 votes
Accepted

Strange noise from timing belt area

I don't know if I deserve all this credit. My idea was sound, but my measurements were pretty bad so my numbers are way off. If you try this, use the more precise software that Robert S. Barnes ended ...
Zach Mierzejewski's user avatar
7 votes

What does a good injector spray pattern look like for a four hole injector?

Basically, the spray pattern should be conical and even, without streaming, dripping, or uneven spray occurring. This ensures the fuel is atomizing as much as possible. Here is a granular image which ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
6 votes
Accepted

Excessive Coolant Expansion: Part 3

My guess is bad radiator cap. The cap has two sealing systems. One that holds high pressure (13 to 15 psi). Water at 13 psi doesn't boil until 245 Deg F it so. The other sealing system is the overflow ...
zipzit's user avatar
  • 6,539
5 votes
Accepted

The Testing Procedure for the Mazda 626 Alternator in the WSM is Unclear

You'd backprobe the S and L terminals with the connector plugged in. So attach one end to a ground point and the other to the S or L terminal. Basically the S terminal is the Field terminal. The S ...
Ben's user avatar
  • 10.7k
4 votes
Accepted

Can't get a fuel pressure reading

So I went out today and ran the fuel pump for a few seconds with the return line clamped off and saw that the amperage draw went up to 5.85 amps and the sound of flowing fuel stopped. At first I just ...
Robert S. Barnes's user avatar
3 votes

Strange noise from timing belt area

This is a bit of a shot in the dark, but I'm going to point my finger at the tensioner spring. To me, the sound in the video is very... dull. Kind of thudy for lack of a better term. It sound like one ...
kyle_engineer's user avatar
3 votes

Strange noise from timing belt area

well you either have bad bearings in your tensioner or a really fast telegraph operator in there. Change out that tensioner and its springs which is what should almost always be done when changing ...
Cc Dd's user avatar
  • 2,879
3 votes
Accepted

Do I have a fuel pressure or injector problem, or am I just chasing ghosts?

Realistically I'd redo your test using a little more accurate of a timing sequence. Two things to really make it more accurate: Use some sort of stopwatch (apps for cell phones are free). Doing so ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
2 votes

Do fuel pressure regulators allow some fuel to flow even when not turned on?

In most cars, the fuel system should hold the pressure for quite a while. You shouldn't see a significant drop in fuel pressure after engine/pump shut off. What you are probably experiencing here is ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
2 votes
Accepted

How Long to Power the Injectors for a Fuel Pump Volume Test?

According to agcoauto.com the length of time that you are supposed to let the fuel flow is 15 seconds. In that period of time, you should have collected at least 1 pint of fuel. However, you should ...
procrastilater's user avatar
2 votes
Accepted

Why would a brand new water pump make noise?

Water pump noise is not common but does happen. Steady tone noise is more common such as groans or squeals. Rhythmic noise is less common. There are three rotating parts in a typical engine water ...
Fred Wilson's user avatar
  • 11.6k
2 votes

Should the EGR be activated at idle?

At idle, your EGR valve should be closed (read: not activated), allowing no exhaust gas to get into the intake air. At idle, any exhaust blended in with the fresh air might indeed cause your engine to ...
zebonaut's user avatar
  • 171
2 votes

Why are there separate Fuel Pressure Regulator and Maximum Fuel Pressure Tests?

There are two values for the pressure since the maximum pressure is achieved at low or zero flow when the engine is not running and the other when the engine is consuming fuel. It is possible that the ...
Solar Mike's user avatar
  • 34.6k
1 vote
Accepted

Why are my injectors different colors when they all have the same flow rate?

So I e-mailed Rockauto about the injector color issue and this is what they said: Hello, All of the information we have on the products we sell is listed on our website. Please see our Help ...
Robert S. Barnes's user avatar
1 vote

Mazda 626 (1986) not starting

It does sound pretty likely to be the battery, if the alternator wasn't working it wouldn't run once you removed the jumper cables. Firstly, before you start troubleshooting make sure you haven't left ...
GdD's user avatar
  • 16.9k
1 vote

98 Mazda 626 GF 2L ATX zero ignition timing at idle?

So there are a few things that need answering here: Why the car has a rough idle Why your fuel trims are so negative Why your timing is retarded The rough idle question is the most difficult, so I'...
Robert S. Barnes's user avatar
1 vote

Mazda 626 99 overheating when on and not moving

If the car is overheating only when sitting still, it's most likely the cooling fan not working. When you're moving, air is flowing though the radiator, but when you're not, you need the fan to push ...
cscracker's user avatar
  • 307
1 vote

Mazda 626 99 overheating when on and not moving

The water pump's impeller fins are corroded and worn down. Blockages in the radiator. Feel the surface of the radiator for cold spots.
Carguy's user avatar
  • 1,957
1 vote

Rough idle only under load

My 98 Rav 4 would do basically the same thing. Mine turn out to egr valve not closing and opening right. Took it apart cleaned cleaned it good in side and out put it back on no more ideling down under ...
william reeder's user avatar
1 vote

Knock on 2000 Mazda 626 after replacing the alternator

Any play in the tension of your belt or loose pulley bearings can cause odd noises. Sometimes shops replace the internals of the alternator and rebuild it. If not done properly they can make all kinds ...
cloudnyn3's user avatar
  • 3,333
1 vote

Knock on 2000 Mazda 626 after replacing the alternator

Make sure your alternator and belt are properly tightened. A loose belt can make all kinds of noises, but mostly a loose alternator, under tension form the belt, will be spinning on an angle, and that'...
tlhIngan's user avatar
  • 12.2k
1 vote
Accepted

Cranks, but No Spark and Can't Connect to the ECU

So basically, the problem was shorted out wires in the Cobra alarm system which were causing the alarm system to randomly disconnect the ECU, fuel pump, etc: I'm not going to copy the full answer ...
Robert S. Barnes's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible