93 MX-3 V6 hesitation issue(edited 7/15/12)

[Jazzylay20]

My book says I should U've that gps too but I check the bin and mine all match engine and everything. The books probably wrong

[kyser182]

So i got the new alternator in today
Fired him up and he ran pretty good. Probably the best since ive owned him.
Still hesitates if i stomp the gas under 4k RPM but i expected that, still need to replace at least 1 of the o2 sensors and would love to replace my TPS

few quick question tho.
1. VRIS solenoids. any mazda/ford V6 from the 90s pretty much going to have those?
2. anyone use the 1wire o2 sensors with any success? what about using a 2 wire universal o2 sensor that could help against any grounding issues?

[davmac]

Hesitation is most likely ignition related, but if the car idles poorly it could also be related to air (intake or vacuum leak). Back to basics: Check intake connections and vacuum hoses for leaks and make sure properly connected. How old are your plug wires, plugs, distributor cap and rotor? Ignition tune up including quality wires solves many problems. Our cars are notorious for distributor issues, but most of the time a distributor failure is coil or ignitor fails = car does not start. It is relatively rare that the distributor fails slowly.

Adjusting TPS: The procedure is found in the service manual starting at this page. Mazda 626, MX6 and Ford Probe all used the K series engine so sensors are interchangeable.

My guess is the TPS you have is good and needs adjustment. The best way to set is with ohm meter and feeler gauge per the manual. On your multimeter you can use the ohm setting to test continuity. Mulimeter will read ol = open loop.

Fresh O2 sensors will help improve gas mileage but have little impact on rough idle or hesitation issues. Get the universal 4 wire Denso O2 sensors from Rockauto or similar place. They are OEM and relatively cheap.

[kyser182]

The car idles fine. except sometimes after driving around awhile, when i come to a stop, the RPM wont come down to its normal 700Ish RPM location and will stay up around 1200-1400RPM. doesnt seem to be effecting anything, just something that happens at random.

This weekend my hope is to remove and replace whatever sparkplugs need to be replaced and do the same with wires. im working on a budget so im not going to go nuts on some spendy wires lol.

Ill test the TPS at that time as well and try to do some adjusting keep you guys updated

i really appreciate all your help so far =D

[kyser182]

So I got a wild hair up my arse and began going over the wiring of my car.
after tracing things out I found the wiring on the o2 sensor next to the radiator to be totally f***ing wrong lol.
Went to autozone and bought some crimp and heat shrink wire connectors and rewired it all properly. Started up the car and went out for a 30 mile drive though all kinds of driving. Highway/stop and go etc

For all intensive purposes the hesitation is gone. I can now punch it from idle to 6k and it runs steady and strong!!! Im so excited! Car hasn't driven this well since I bought it. Im still going to replace the plugs anyway.

So no CEL in 30 miles I will update soon if I get any codes.

[gerald_23]

So the problem was the o2 sensor wiring?

[Daninski]

So the problem was the o2 sensor wiring?

You are one dense MoFoer, but I mean that in a nice way. Isn't that what he just posted (retorical). Hey great find, glad you fixed it. Man I'm an azz.

[kyser182]

70 miles since "the fix" and all seems very well. No CEL yet.
I think VRIS Solenoid #2 may still not be working. I had that code before the fix.
after 5500ish rpm the UMFFTH of the engine slows.

Hopefully this weekend I will do the plugs and log more miles.

Now that the car runs so much better I have to relearn how to drive it hahaha

You guys have been so much help and I really appreciate all your input. Hopefully I can meet some of the local guys around Portland in the future.

[gerald_23]

So the problem was the o2 sensor wiring?

You are one dense MoFoer, but I mean that in a nice way. Isn't that what he just posted (retorical). Hey great find, glad you fixed it. Man I'm an azz.

LOL yeah but it was deserved. I just wanted to make sure there was nothing else to it. I have checked my o2 wiring and i still have the problem. my power(white/red) wire goes to the blue o2 sensor, and the other to the white. both black wires go to the heater wires for the o2 sensor. I lost on what to do next

[Jazzylay20]

ok guys i'm back. So my k8 is being a pain like usual. the problem im having is when i start it up its rough then drive it cold and she runs like a champ, but as soon as it gets the the cold line it sounds like it has a constant small backfire, instead of a tune noise ot the exhaust it sounds like a muscle car. hope that makes sense. i know that one or two of the lifters are slowly going out but its made the clicking since i got it 6 months ago. idk if thats a hesitation or something else. please help.. btw no cel...

[cWs306]

so when you fire it up at first when its cold it runs rough? but then if you just drive it cold, it runs like a top and has no issues untill it warms up?(not always good to drive cold btw..imo) maybe a 02 sensor? or maybe fouling spark plugs, rotor or cap or disty? trial and error lol.

[JeremyP]

I had a similar problem. It ended up being the small disk that's sandwiched in behind the distributor cap but before the block. I believe their is a plug that comes up to the top of the ditsy. Wish I could be more specific but it was a little while ago. I couldn't even drive my car. When I got on the gas it would sound like it was randomly hitting on cylinders with no order. Was out of commission for like 2 months trying different things.

[Jazzylay20]

Runs a lil hard when idling no matter if its warm or cold when it drives cold it runs well but when its warm it runs funny. It kinda put puts but only if i hit the gas

[cWs306]

yah check your 02 sensors and ignition system components. Spark plugs, spark plug wires, cap, rotor, coil, disty. maybe your coil is on its way out. known issue.

[Jazzylay20]

I had a similar problem. It ended up being the small disk that's sandwiched in behind the distributor cap but before the block. I believe their is a plug that comes up to the top of the ditsy. Wish I could be more specific but it was a little while ago. I couldn't even drive my car. When I got on the gas it would sound like it was randomly hitting on cylinders with no order. Was out of commission for like 2 months trying different things.

are you talking about the inside of the dist? or Are you talking about the wire that goes from the dist to some electrical thing(aka the coil)