VX will NOT stay in Lean mode...HELP!!

[VXman]

Okay here is what is going on. When warm but before all the way warmed up it will stay and cruise in lean no problem, once warmed up you can not keep it in lean and cruise. With out pressing any more on the gas pedal it will go right into full rich, this is on flat land. Can anyone HELP ME PLEASE!!

I have already did all the cleaning of the intake and egr. I have replaced the O2 sensor with a NTK. I put new plugs, wires, cap, and rotor on. Car came with a rebuilt dizzy. I put on new timing belt and water pump. I also rebuilt the trans and counted the gears to be sure that it is a VX or CX trans.

Is there anything that I am missing? Could it be my ECU? Thank you for your help

[N2UAD]

Did you check engine compression to make sure the engine is in good shape? I don't recall the numbers but the shop manual gives the specs.
If the engine is not putting out enough power to say cruise on a flat highway at 60mph in lean burn then you step on the pedal more.

[VXman]

Ok, thanks...I will check the compression. Yeah, I have to keep my foot on the gas just to really cruise at 60-65 as soon as you let it in lean it loses speed.

Now it seems lean will work just fine at times but for the most of the time you just cant keep it in lean no matter even if you are on flat land or not.....thanks though I will try that!

[VXman]

Okay did the compression check and got 125 across the board. seems to be perfect. I just drove 170 miles 50% city and 50% country driving and I got 34 mpg

Please Help!! any ideas? what else can be causing it?

[add|ct]

Plugged cat maybe? Does it feel robbed of power when you go from moderate/medium throttle to WOT and vtec engages?

Have you adjusted the valves within spec(though not too tight?)?

You stated in the OP to have changed the plugs, but didn't specific which brand and model plug.

How are your CVs?

Any brake drag at any of the wheels or is a wheel bearing affecting the wheel/tire's ability to rotate within norms while off of the ground?

What year is your VX? Is it equipped with a 49-state Federal ECU or the CA emissions friendly ECU which doesn't allow for lean burn?

Your RPMs at 60 should be around 1,900-2,000 or so in 5th gear, if I remember correctly off hand.

Tire PSI?

[VXman]

Yeah CVs are good..i fixed them when I rebuilt the trans. along with going through and lubing and adjusting the brakes and wheel bearings are good..everything moves very freely. it will fly down a hill out of gear.

Yes, 48 state ECU. it is a 92, car was bought near Philly and came from Jersey where it was first sold. yes I am getting that RPM at 60 also more closer to 1800. I am running DENSO plugs and wires, not as good as NGK but next to it.

I don't believe that I feel any power loss and when I changed the O2 i looked down at the cat and it looked real nice and clear. But thanks for the idea and I will look more into that. I have did a quick check of the values when I did the Timing belt they seemed perfect but I am planing on doing a better check and even adjusting the exhaust values to have more clearance since Honda's are know to burn those values.

Thank you again for your help and look forward to more ideas. I am waiting to hear back from a friend that may know someone with a ECU so i can try that, also.

[add|ct]

Cool, report back and welcome to the site!

[vxdude]

I would go ahead and change those denso out for the ngk plugs, it would cost you 10$ and make sure they are gapped properly. How about your wheels/tires, are they all oem?

[VXman]

Thankx for the idea...when I changed the plugs they had autolite junk in there. When i put the Denso in there they helped a great deal towards mpg. NGK will be what I go with next time but Denso is in my option is next in line for best. I already have 50 buck in denso and Ngk is another 10 to 15 more but I dont think that is the problem. The plugs and wires only have less then 2k on them. thanks for the idea and if nothing else I will come back to that. but I think that add|ct may be on to something there with the cat.

to not let it stay in lean mode something would be holding it back. That is kinda how it feels but hard to tell since i never drove another VX before. So i hope to check the cat this week and see how that goes. Yes, the rims are OEM they do of course have 175 insteed of the OEM 165 which I hope to get when it is time for tires.

Thank you add|ct for the welcome, and thank you for all the ideas. Again look forward to more ideas on what this may be, like they say 2 minds are better then one. I will update with everything I do till this is fixed.

[theholycow]

Does it coast well in neutral?