MX-3.com

I just bought a 92' MX3 GS but it has an engine problem. That doesn't bother me to much, I'm still stoked.It has the 1.8L and a manual tranny. Thing is that the car starts and runs for a little bit then shuts off. The guy I bought if from said that a mechanic told him that the oil pressure sensor was bad. I really could not find any other topic dealing with this problem. Has anyone encountered this problem before? Does this sound like a reasonable answer? Where exactly is the sensor. Ok, so next, the car is high mileage (220K miles) so I was thinking about swaping a new engine in if I can't solve the problem or once the engine goes. I don't want the fuel economy to be any lower and I don't need all of the power a KLZE offers, so what should I go for another K8 or something else. What else can be swaped in with the same efficiency? What about a 323 engine? What about a new tranny?

You cant use a 323 engine unless you replace everything in your engine bay, including transmission and axles...the easiest way is to stay with the same series engines...you have a K8, a K-Series V6, and a K-series engine is what you should stick with. The 323 uses a B-Series 4cyl engine, the same B-Series found in the Protege's, Miata's, Ford Escorts and a few others. If your Mx-3 was a 4cyl, it uses the same b-series as the listed cars, than you would have been able to swap in the 323 engine. You still can, but it's not worth the work

You don't need a 200hp KLZE, you can get a 165hp KLDE, still a 2.5L v6 but not as high-tuned as the KLZE, but still a good upgrade. Both the KLZE and KLDE are the same amount of work to install.

Honnestly, my gas milleage has improved quite a bit with the KLZE, i guess cause it's not working as hard.

If you were to swap in another k8, or go with a klde or klze just use your k8 tranny (unless u need a new one). They are all the same, just differences in gear ratios. And if you want better fuel efficiency, go with the bigger engine.

As for your car shutting off, could possibly be the distributor going bad as well which is a very common problem with these cars.

get a KL-DE from a probe or mx-6, get the ECU and VAF too and just swap it all in, youll get the same or better fuel economy and the car will be alot more fun to drive and it will most likey cost more to find a K8

How long does it take before it shuts off?

It is DEFINITELY not your oil pressure sender. I unplugged mine over a year ago when I Got my aftermarket autometer oil pressure gauge. My ECU doesnt' care that it is unplugged either.

If it shuts off as soon as you start it, it is probably a connection problem with your VAF (airflow meter). If it only shuts off after it is warmed up, it could be your coolant temperature sensor.

It could also be fouled O2 sensors if it just runs like crap an eventually dies.

Try to pull the ECU code from the diagnostic box. It should be throwing a code if it just dies like that

Also does it spudder ?
is it @ a certain RPM range?

Dont forget the all important distributer prob...where the car will just shut off for no apparant reason. (Ign module)

how is that rubber intake hose, did you check it for cracks/tears...if it lets in air it'll stall

So I got the car home yesterday. When I went ro pick the car up the guy pointed to the MAF and said that is what the mechanic said was wrong. I set up the transaction through his brother in law who told me it was the oil pressure sensor. So today I pulled off the MAF to look at it. The intake hose was reciently replaced so it is in very good condition. So can I somehow test the MAF to know if it is truly the problem? How much will a new one cost and where is a good place to get one? I am currently charging up the battery so I can try to start it.

It's actually a VAF, not a MAF.

Go to the mx-3.com homepage, and click the online manual link in the leftside column. Then go to Page F2-150. You will need a meter to measure resistance.

Thanks for that information IanL. OK well I pulled the VAF and did the tests. All of the readings that I took came back within the ranges that were indicated on that page. The only thing that I found strange was the fact that there was not any linearity between the position of the measuring core and the resistance. Is there supposed to be? Well here is what the readings were like. Closed it was 310. Upon depression the resistance occilates between the 380 and 520 depending on the distance depressed within the final 2 cm the resistance steadily falls from 420 to about 130 when it is fully closed. Is this bad? I can't open it any more I don't think. Maybe the contacts on the rheostat are dirty. You think if I clean then I could fix it? I could seperate the part mechanically and then repair it when I was done. Here I will show a graph of the resistance values that I observed.
........__ .............__........ _--_ .......................................
....../....\.........../.....\......./......\.......... __........................
-----.......\......./........\__/..........\....... /....\.......__............
...............\__/...........................\...../.......\__/.....\.........
..................................................---.................... \........
............................................................................\........
............................................................................ \.......
..............................................................................\_....
.................................................................................\

Darn I don't think the Graph will come out, Wait I know!!
I think it looks good this way. Well if the VAF is OK I guess it gave me a reason to pull an engine component to paint it. Haha. Well I think I will try to get the engine codes next. Probably should have started there.

Well, I have to say I've never had to measure mine, but I agree that the potentiometer looks dirty/worn. I'm not sure whether they are repairable.

Ok so I pulled the engine code and it came up as 10 so a broken thermistor it is. Unfortunatly that is located in the VAF which is seeled up. Now I am off to radio shack to buy a new one with a similar resistance temp relationship. I guess I can Just marry that in to the current set up and it should be right. Here is where I got my info: http://homepage.ntlworld.com/mx6-uk/malf/malfcode.htm

Well Holy Mary Mother of God, This sucks. So I put the new temperature sensor in from the Probe GT (disgusting) And then I went to fire her up. Nothing, she will not turn over. I then jumpered the terminals of the starter and she was cranking. So starter is still good. So then I deceided to pull the codes again. Now I am getting both a 10 and an 8. I checked where I did the splicing for the sensor and it was correct. What keeps the engine from cranking? Is there a system that will shut down the car if it is insulted enough. What is the deal?

NewHaven wrote: What keeps the engine from cranking?...

Not a lot. The Main Fuse (80 or 100A), the actual start switch in the ignition key unit, and the starter interlock switch on the clutch pedal (MTX) or the Inhibitor Switch in the transmission (ATX).

With Codes 8 and 10 both showing, maybe that fault is in the VAF plug/socket (airflow and temp sensors both go through it).