OK, so, all the crap that I've been through to get this '94 to run for my little brother and it keeps punching me in the gut... After I got the OMP replaced, the OMP lines replaced (not the nice braided steel lines, trying to get things to run right so my little bro can decide what direction he wants to take the car), figured out that the ECM crapped out (replaced it with a used one that I found on Ebay), I found a broken nipple on the turbo control solenoid and the check valve on the vacuum line that goes up to the pressure chamber on top. I put the car back together and it ran pretty good like that, had a high idle and a bit of a skip at an idle, but all in all, it ran good (compared to the way it ran in limp home mode). So, I get replacement check valves from a guy on Ebay that was recommended on this site. I also found a replacement solenoid on Ebay. I get the stuff and went to replace the two things. I get a bunch of broken vacuum lines in the process and the double throttle solenoid valve and the charge control solenoid valve both broke. I get a bunch of vacuum line from NAPA and two more solenoid valves from Ebay. I get it all back together, get it started up, no check engine light or anything. But, for some reason, the engine dies if I give it too much throttle. It's weird, everything is plugged in, the bad vacuum lines have been replaced, I can't figure out what's wrong... Any suggestions? Also, do all of the solenoid valves operate the same? They have the same driving voltage? They are in the same postion? I'm about at the end of my rope, and my little brother is going to be back from Iraq in about 2 weeks. I need any help that I can get...

 

1. check the vac hose routing to make sure its correct. 2. Ebay - check valves - used, correct parts - make sure. 3. Solenoid from ebay - new used, right part for your year? 4. Check the LIM gasket and get the engine smoke tested for vac leaks.

 

1) I agree. 2) if they are Dale Clark's check valves, good, just make sure they're pointing the same way. 3) Mazda solenoids are pretty universal - if it looks like the same solenoid (minus any stickers or paint dots) it probably is the same solenoid. Also, all solenoids run on the same input voltage - if one is not receiving the same voltage than you have an electrical issue to troubleshoot.

Unfortunately you might be fighting an insidious wiring harness problem. It can cause random and frustrating symptoms. Things like working in the rats nest and changing metering lines can crack the wires of a brittle harness - I know from painful experience. If you can swing the cash and your engine harness is brittle, consider changing it at the next reasonable opportunity.

Dave

 

I agree with Item no.1

 

1) I used the stock vacuum routing diagram to double check where all the lines were going (was considering trying to use the "simplified vacuum routing diagram", but I didn't give it a good look over yet to see what's involved). 2) The check valves are Dale Clark's, they are new, and they work fine, I installed them in the same direction that the originals were in, and then use the vacuum diagram to verify that they were correct. 3) The solenoids aren't year correct, but they appear to be the same from the outside, so I was hoping that they operated the same.

The old brittle wiring harness worries me the most. Can it be changed with out removing the engine? About how much do they cost? Where do you guys usually get them from?

The weird thing is that it seems like the ignition cuts out if there is too much throttle input. And considering the condition of the vacuum lines and other plastic parts under the hood...

Thanks for your input, anything else that you can think of that I can try, don't hesitate to tell me.