VX cruising RPM increasing?!

[4bfox]

Back to the well of knowledge again. My `92 VX is acting weird, after I thought I got the idling fixed, sometimes it warm idles around 1500 RPM, sometimes it idles at 600 RPM. Then last week I noticed another strange phenomena...at cruising speed (65-70 for me) it WAS running around 1600-1800 RPM. Then for a couple of days it ran at 2400-2500 RPM. And my FE sucks, down to 35-38MPG.

Any ideas?

Thanks in advance!

[JanGeo]

maybe your tach is acting up ?

[Sigifrith]

Were the headlights on? Heater etc?

[kamesama980]

oh comeon guyes...

I assume you have an automatic, check your trans fluid. it's probably low causing the trans is probably slipping like mad and will burn out in no time flat. Remember, check it warm, with the engine running, and not in park. or you'll get a false reading (unless honda had a check procedure that actually was easy back then but I doubt it)

[TomO]

Kamesama980 - Sorry, but all VX's were 5 speeds

4bfox - sounds like your clutch is slipping. I would've agreed with the tach screwing up (I've seen it personally on a Honda before) but since your FE is hurting, something is causing your clutch to slip. Could be the rear main seal leaking oil onto the flywheel, could be a failing pressure plate, could be garbage in the clutch line preventing the fluid from traveling back to the reservoir. I would start with inspecting the flywheel by removing the flywheel cover at the bottom front (engine side) of the trans and see what you can see. Then flush out all the brake fluid in the clutch line/reservoir and replace with new and inspect for leaks. If all those check out good, it might be time to replace the clutch.

[Ryland]

If in a given gear the engine speed, and wheel speed no longer match, then either your gauges are giving a fales reading, or your clutch is slipping, to check the clutch without getting under the car, go down the highway in 5th gear and either watch the tac or have a passenger watch it for you, the speedo and tac should move in sink with each other, try lightly pressing on the clutch, and on the gas to get the clutch to slip, then while stilll pressing on the gas let off the clutch, the rpms should drop as the clutch makes a firm connection, you should also make note of at what point the clutch starts to dissengage, if it's as soon as you even touch the pedal, then its out of adjustment, a repare manual will tell you step by step how to fix this.

[VetteOwner]

theres also you can try, be going liek less than 10mph slowlyy press the brake while giving it gas. if the engine stalls out and the rpm's steadily decrease before it stalls then the clutch isnt slipping, if the rpm's go up while pressing brakes but speed stays same or goes down, its slipping.

[broadwayline]

Prolly the tach, my VX tach is very inaccurate, some days it reads properly, some days it says my rpm is 600 lower than normal.

[4bfox]

Yes, it's a 5 sp manual trans. May be the clutch cylinder....last time I was under the dash, there was evidence of fluid leakage....maybe air in the line?

[kamesama980]

^ could be. BUT keep in mind the fail-state of the clutch is engaged. You have to work to disengage it. That means if your hydraulics are failing, you'll have problems disengaging the clutch, NOT clutch slippage. only exception is if you have an internal slave cylinder (to the bellhousing) and it's leaking fluid on the clutch disk.

As for the slippage in general... either the tach is off or the clutch is sliping. Usually it doesn't slip during straight line cruising but during acceleration when there's more torque going through it. You're gonna have to bite the bullet and use some gas here. get into 1st gear and do what's mentioned above. get the engine up to about 2k rpm or more (more=better for the test) and push the gas and brake together.... hard. You want to be pushing the gas as hard as you can while using the brake to not accelerate. If the RPMS spike disproportionately to your speed, the clutch is slipping.

Similar, faster, but more violent test involves being stopped (with some space around you) put it in 5th and drop the clutch with the gas floored and engine near redline (yea, gotta do it fast...gas, rev, clutch in a second or 2). If the engine stalls quickly, the clutch is good. if the RPMS slow down then stall over a second or more, the clutch isn't so good but works. If it takes a little while to stall it or it doesn't stall, the clutch oughta be replaced or upgraded.

[landspeed]

If the clutch is slipping, then you can make it last for ages if you need to, just by matching engine speeds before using the clutch (except for 1st gear from a standing start, of course), and by using less power so it doesn't slip. Once it begins slipping, it heats up and the slip continues, so you have to ease off the pedal.

My original Bluebird had a slipping clutch, for about 2 years, but once it started, it never got any worse, due to my change in driving style :)

The danger of prolonging the lifespan of a worn clutch is that you can damage the flywheel, especially if the clutch fails suddenly at the end.

[4bfox]

Yesterday I had to do a 180 on the highway (my wife forgot something), and noticed when I goosed it pretty good to get up to cruising speed, the tach jumped about 500 RPM for just a second. So it may be the clutch....anyway I've got a guy that's going to look at the brakes next week, will have him check the clutch out as well.

[Biffmeistro]

Yeah... Definitely the clutch slipping then. If you floor it with the clutch engaged and the RPM goes up when the speed doesn't... Bad clutch.