Mazda MX-6 Forum banner

Help With 93 2G That Won't Start

4K views 11 replies 3 participants last post by  Feeeetask! 
#1 ·
I have a 93 MX6 LS V6 that had been running really rough the last few weeks. The idle was wandering all over the place and the engine would miss or cut out a lot as I drove it. Last night it stalled out and now it will not start at all. It cranks fine just but no fire.

I replaced the TPS about 2 years ago. I pulled codes from it today and get 9 (coolant temp sensor), 12 (TPS), 16 (EGR valve position sensor) and 26 (Solenoid valve purge control). Any ideas what the likely culprit is? Could the TPS have gone bad again that quickly? I suspect it might be the EGR valve but I can't even find it. Looks like it might be the thing buried way under the throttle body but it sure doesn't look to have the same connectors or anything like in the Haynes book.
 
#4 ·
Have you checked for fuel pressure and spark? Mechanical timing may be harder but if the other things check put it's helpful to know
 
#5 ·
Sorry for the late reply but I haven't been able to work on the car due to work. I am replacing everything that I got a code on from the computer. I know this might not clear up the issue but it needed to be done anyway. I've replaced the Coolant Temp Sensor and the TPS.

I am in the process of replacing the EGR valve but that is one hard mother to get to. I have gotten it out and it was toast. Really nasty and the hoses leading to it had water in them. Not sure why that would be. It's not coolant but clear water. I am waiting on new hoses to install the new EGR valve.

In the mean time I have checked the EGR boost solenoid, it's fine, and replaced the lines leading to it. I pulled the VRIS (I think) solenoids off the top of the engine and they are fine. I ran some new hose around there too. I had a code for the Solenoid Purge Valve which is on that bracket too. It is broken and I am waiting on a replacement to be delivered for that too.

I have a new fuel filter in hand and will change that tomorrow and check for fuel flow. Any tips on that process?

When I get the engine a little more put back together I will test for spark.
 
#6 ·
I am in the process of replacing the EGR valve but that is one hard mother to get to. I have gotten it out and it was toast. Really nasty and the hoses leading to it had water in them. Not sure why that would be. It's not coolant but clear water. I am waiting on new hoses to install the new EGR valve.
I must correct myself and say that I realize now that these hoses are water hoses. Did not realize they were cooling the EGR valve but I guess they are! So that explains the water in there.
 
#7 ·
OK I have replaced everything I had codes on the OBD for and it still won't start. I have also checked and replaced the fuel filter. I pulled the hose up by the injectors on top of the engine and it was full of fuel and under pressure. :surprise: So I assume I am getting fuel flow. Is there a way to make sure the injectors are actually working?

I have also checked the coil. I read 1.8 ohms on the primary and 15K ohms on the secondary. I do get a spark but it looks weak to me. Any way to tell further if this could be the cause of not starting?

Also checked all of the fuses under hood and in the foot well all are fine.
 
#11 ·
You can rent a compression gauge from any auto parts store. You would need to check mechanical timing by putting the car at TDC for cyl 1 and verifying the timing marks are lined up.
 
#12 ·
OK since it drives me nuts that nobody will close out these question threads with the solutions I will post mine here. Car is now running, it was the distributor that was at fault. I did a spark test and it did have spark BUT the thing to note is the spark was not a "Bright blue" powerful spark, it was dull and pinkish. So don't be fooled by the fact that you have a spark the disty might still be toast. BTW disty's at Autozone $330 on ebay $85. I bought lots of parts off ebay this time. No they don't have the warranty or service life but quite frankly this car has numbered days left. Here is everything I did. This cleared all my codes and fixed the car. Car is a 1993 MX-6 LS V6 2.5L.

1. Replaced EGR Valve and hoses. Threw a code, it was toast and expensive $230.
2. Tested all vacuum solenoids. Fine except for the Purge solenoid located on the bracket with the VRIS solenoids.
3. Replaced faulty Purge Solenoid Cheap on ebay.
4. Replaced 90% of the vacuum lines
5. Replaced Coolant Temp Sensor (twice because I broke the first one off in the head and had to extract it)
6. Replaced upper intake hose. Cheap on ebay.
7. Replaced Throttle Position Sensor. Set according to the shop manual with a feeler gauge and a continuity tester. Setting it by back probing for voltage with T pins is the wrong way.
8. Checked the ECU harness for ground connection. Fine
9. Checked fuel pump. Fine
10. Replaced fuel filter. Easiest to remove driver side front tire and plastic shield then pull the filter out of the bottom.
11. Replaced distributor, rotor, cap, wires and plugs
12. Checked engine compression. Fine but 5 & 2 a bit low.
13. Set timing by rotating engine to TDC and checking cam positions. Take off passenger side front wheel and there is a bung there that leads to the crankshaft pulley. You just need a 5" extension and a 21mm socket to rotate the engine.
14. Set final timing with timing light.

-END-
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top