96 mx3 with 1.8- stock. Strange behavior, need help

[tehbrookzorz]

The codes, if saved, should be flashing when the key is in the on position, without starting the engine.

If you've disconnected the battery for more than a few seconds recently, since the problem has been occurring, you may have reset the codes in the computer. If this is the case, pull the jumper out and start the car, letting it run until it stalls out again. This should set the code, and then you can turn the car off, re-install the jumper and check for codes with the key just in the on position.

My guess is you'll have some combination of codes 2, 3 and 4.
If so, and only if so, this may be your golden ticket: http://www.mx-3.com/phpbb2/viewtopic.php?t=26506

If you do this mod, make sure to disable the distributor's internal ignition module by disconnecting the grounding strap inside as described. Many people overlook this. I've tried the mod and missed that step, which is why it didn't work for me. I'm sure it would work otherwise, assuming the ignition module is your problem. If it is the coil, there is a way of wiring in an external coil.

[Davidgolf321]

Still can't get codes to read via CEL, am having car towed to Garage tomorrow to hook up to computer. Just a thought- would a bad fuel pump cause this problem, or a leaking head gasket?
Any suggestions appreciated at this point, from now on its going to cost my son some coin.
Thanks

[Davidgolf321]

Update: car is at garage, and codes still can't be read (see previous post)- CEL flashes when engine is running but stays on solid when diagnostic connector jumpered between TEN and ground. What does this mean? I read some where it is a "Hard failure"- does anyone know what that is? Does it meant the ECU is bad? Is there any other way to get codes? Have proved fuel system is okay, and can't find any air or vacuum leakes- does this leave distributor and will the HEI modification cure this problem?
Could EGR system be the problem- how do you prove it? Where is a good source for a distributor for reasonable cost- any recomendations?
Thanks

[lowridah313]

I had the same problem it turned out to be my EGR solenoids which are located on the intake manifold. I just went to the wreakers and got them off a probe gt, bracket, hoses, and connecters are all plug and play.

[Davidgolf321]

Thanks, I will check it out.
Are there any other possibilities? Any guesses why the CEL won't give up codes. Questions keep building up.
I was told I could use a disty from a Probe v6 for this (1996 K 8)- any one know if this is practical?
Thanks for the help so far, please continue.
David

[lowridah313]

Your best bet is to try and find a mechanic with the proper scan tool. I know it was hard around my area, but i found one. Or you can bite the bullet and take it to a Mazda dealer, but thats gonna be expensive.

[max kl]

This is my first post and it concerns a problem that is, at least for me, difficult to describe and find the cause of. I bought a stock 1996 mx3 , 1.8l 5-speed for my son in July this year and until two weeks ago it ran great. Then, when on a short errand, the engine lost power and the rpms started surging. He pulled over and put it in neutral and the revs swung between 300 and 3000 with no power . He was able to limp home and parked the car for a few days until I could look at it. I started it and it started fine but revs would not settle down- going from 300 to 3000, sounding very rough at low revs and normal at the peak, then when the engine started to warm up the revs stabilized at about 1,000 rpm and stayed there until I touched the gas and then it lost power, and the revs started to swing all over the place again. Thinking it could be a fuel supply problem, I replaced the fuel filter (and thermostate while everything was out of the way) but no joy same problem. I have no local Mazda dealer and people I have spoken to have named everything from vacuum leaks, to EGR valves to fuel pump to distributer as cause. I need help and am not a mechanic, so have any of the members of this group experienced these symptoms or heard of them and can anyone suggest a cure?

if i look at just the simptoms it is narrowed down to
egr stuck open
distrubtor
ecm dead

the added info about the cel light makes me lean twards ecm
BUT if this is realy a 96 not a late 95 than it should have a diagnosic connector inside the car. and any cheap obd2 scanner will talk to it

if it is a 96 tan the egr is still suspect
distrubtor is the same from 95 n up probe & mx6
the 94 n up v6 uses a diffrent igniton and will act diffrently than most members have seen.

1st try unpluging vac line at egr if i still has surging idle than try connecting a vac line to egr and to a vac source [like a hand vac pump or intake mant vac ] and see it idle gets worst.
when vac is applyed to the egr with engine idling it should run rough and surge. so if idle stayes the same it would be worth removing the egr and bench testing it.
also while egr is off car start it up an see if it runns better.

if egr proves to be a waist of time than get a used dis & ecm. plug & play
hope for best

1 mor thing try unpluging the iac under the throttle body it may idle to low but if surging goes away it mat bee easyer to find problem

lastly make shure the power break vac supply hose is not cracked

[Davidgolf321]

Still trying to find solution. As I said the garage has it and cannot get codes either- the car was sold as a 96 but I have been told 96's have computer plug in under dash so this car is probably a late 95 model, as sticker on door says 96. What parts, like a distributor, ECU, EGR, etc will fit my car- so I know what to look for when part shopping. Also is there a parts list some where on this site or on line for these cars?
Thanks all the help it IS REALLY appreciated.
David

[Davidgolf321]

Finally some good news- the car has an OBDII connector, on the passenger side of the car interior, near the ECU. Got code now - P1345, which the reader says is No Cam sensor (there is no listing for a Mazda MX3 1.8 liter in this code reader's library as it is U.S. based, but another Mazda's shows P1345). I think this is the same as a 2 or 3 in theo non-OBDII system. Does any one have the OBDII codes for 1996 MX3 ?Please point me to them. Will ignition module modification fix this or is a new distributor needed?
The numbers on my distributor are: KF34
T0T57271
A search on Ebay and through King Distributors says this is the same one as is on 95 to 97 Ford Probe 2.5 v6. IS this correct? Is it best and easiest fix to replace distributor?
Thanks

[max kl]

distrubtor is the same from 95 n up probe & mx6

i will look at my shop for p1345 and c if hei will work.

but ecm gets the cam and crank signal first then tells igniter to fire so it your cam signal is dead than you dis is junk. i will look at my shop for p1345 and see if it is relivent.

[Davidgolf321]

Thanks for all your help guys, finally put new distributor in and engine runs great!
just a quick question- to read engine codes on a 96 mx 3, do you need a OBDII reader or should the CEL flash? The CEL does not flash on this car- is there a trick I am missing?
Again, thanks - we're on the road again.

[Tempus]

If you have the OBD-II connector, you need the reader for that.

this is a good thing, the newer diagnostics are MUCH better at spotting the actual problem in many cases. The paper-clip trick is for cars with the first generation OnBoardDiagnostics.