Hello,
I have a 93 mx3 gs that does not like to start up well. It cranks longer than normal and tries to start only to catch and run like it has bad valve seals(no smoke). I pulled the plugs,(no sign of oil usage) replaced them and in the process i found the last plug on the front bank to be fuel soaked. (the one closest to the regulator.) Assuming i found the root of my evil I tested the pressure in the fuel system (diag connector jumped) and got 43psi. The spec is 30-38psi. The rest of the system checked good, except maybe the distributor(fuel Rail) leak down. Dont have a spec for that but pressure started bleeding off in 10min. So maybe leaky injector or bad regulator causing a intial start/rich condition?
Condition of the plugs showed signs of possible A/F ratio problems, but all the plugs on the above mentioned bank were clean. No codes. O2 sensor readings good.
I have 18years exp in auto repair so believe me when i say that the basics have been covered. That said every car and system has it own quirks that only DIY'ers seem to know about. My reference sources have not been much help with this.
I dont want to throw parts at this so im posting to see if anyone has come across this already, before i buy injectors and a regulator. Im leaning towards leaky injector, but have not been able to find a cost effective set to replace them. I do not have a way of doing a injector balance test. That tool broke long ago. It could still be the 5psi difference in the rail. My rear valve cover gasket needs to be replaced so that would be a good time to put injectors in.
So if anyone knows anything please feel free to reply.
Thanks DHAuto

 

I believe you can get injectors professionally cleaned, then buy new seals and your regulator. Phone around a few places.
While your there, clean your EGR, change your PCV valve, clean throttle body and MAF.
All new gaskets.

 

Hi, thanks for the reply
Professional cleaning is a option IF an injector is the problem. However, i would like to find the problem. As i said i dont want to throw a lot of parts at this issue. Doing a bunch of stuff at once may not show me exactly what was wrong. Half the benefit to having problems is the knowledge gained from the repair. While all the jobs you mentioned will go a long way to helping the engine to run efficiently it may not fix the issue. A PR, Inj, alone are not that inexpensive not to mention supplies,nickle and dime parts and pieces, as well as out of service time.

 

DH: May I toss around some ideas:
you could move the questionable injector to another cylinder and see if the problem moves along with it. If so: bingo!

Consider a complete engine cleaning on the cheap:

The Lacquer Thinner (NOT PAINT THINNER!) cleans more than the catalytic converter. the whole fuel system including the injectors get a good cleaning with this method.

 

Hi, thanks for the reply.
I have considered moving the injector, but was hoping for someone with a similar issue. I have already tested the cat for a clog and I'm good there. The last tank of fuel was spiked with Lucas fuel cleaner(Double Dose).
No change with the issue. Using lacquer thinner is not necessarily bad unless the injector is plastic. Whether it just the pellet or pellet and body, lacquer thinner may eat it away as well as ethanol or certain other alcohol type additives can do over time. That could be why it leaks now; past owners fuel buying habits. If thats the issue i do not want to make it worse. At the same time it is definitely and idea to keep in mind, at least the problem would show more. I may have to just replace the tool to do the balance test.
Thanks Again keep the ideas coming.

 

There is another one:

 

Pull the fuel rail and zip tie the injectors to the rail and then turn the key on to prime them them and wait to see if one is leaking out. This will save u from replacing them if not needed and if one is leaking then u dont have to replace all of them.

 

Hi, tanprotege
That vid is good, ill have to try that if it turns out the injector is leaking. The lacquer thinner is $23 bones a gallon; An expensive maybe. I checked on the injector seals to try the other posters idea. At $6 bones an injector to reseal them thats not much cheaper. It seems everyone is leaning towards the injectors leaking. I,m still not sure the reg might not be the issue. Or both. Well it seems im going to have to dive into this a little further to try and verify the issue.
Thanks to everyone who replied, i will keep rechecking for ideas or new info as well as post any progress.

DHAuto

 

If I were the religious type I would pray for you.

Wait! I'll tell my wife....

 

SERIOUSLY, TOO EXPENSIVE
WHY DON'T YOU SEAL IT WITH GLUE, A PIECE OF RUBBER, OR MAYBE A BANANA, YOU KNOW THE SAME ONE PEOPLE PUT IN TRANSMISSIONS.
You sound like a used car sales place (DH Auto!?).