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Login to post Forums » Grassroots Motorsports » No engine braking=bad ___ ?

Nov. 16, 2009 1:35 p.m. cghstang Reader

The car is a '98 Escort ZX-2 with the 2.0 zetec engine and manual transmission.

Symptoms include:

Revs don't drop significantly when shifting between gears.

Coasting in gear (throttle closed) provides near zero engine braking. It's almost like there's cruise control.

I was getting a high idle after extended highway stints as well.

The clutch pedal had been engaging just off the floor but I adjusted it to get engagement more or less in the middle of its travel.

The car idles fine and returns to a normal idle when put in neutral.

It does require a bit of force to select first and reverse, but the car is new to me so it may just be more than I'm used to.

From what I can figure I'm either dealing with something in the transmission/clutch (throw out, pilot, or input shaft bearing?) or some kind of vacuum leak/idle air control issue.

Please enlighten me with your wondrous GRM knowledge and opinions.
Nov. 16, 2009 2:09 p.m. Autolex HalfDork

cghstang wrote: From what I can figure I'm either dealing with something in the transmission/clutch (throw out, pilot, or input shaft bearing?) or some kind of vacuum leak/idle air control issue.

Probably both.

My guess is heat induced vacuum leak... (TB/IM Gaskets?) It's probably separate from the clutch issue... check the Slave cylinder, and the master... make sure they aren't leaking...
Nov. 16, 2009 2:17 p.m. tuna55 Reader

I will say only that that transmission is an evil, vile thing. I cannot say what is causing it though, but it isn't normal.
Nov. 16, 2009 2:32 p.m. Strizzo SuperDork

i've had a few throwouts take a crap before, sounds a lot like what you're experiencing. transmission will go into all gears just fine with engine off, but running the engine and it doesn't want to find first or reverse. the 2nd and up synchros can stop the dragging clutch though.

the high idle/no engine braking is probably another issue though. could have contributed to the early demise of your throwout, though.
Nov. 16, 2009 2:33 p.m. patgizz Dork

my truck had similar symptoms. no rpm drop between shifts, no engine braking, etc...

the throttle body gasket was blown out.
Nov. 16, 2009 2:44 p.m. cghstang Reader

In reply to patgizz:

I hope it's as simple as a throttle body gasket. I'd really rather not pull the transmission.
Nov. 16, 2009 5:38 p.m. cghstang Reader

I'm starting to lean heavily towards there being two distinct issues

When coasting in neutral, foot off of the clutch, the rpm only drops to around 1500. This has me thinking vacuum leak or whatever.

When coasting in neutral and then pushing on the clutch and moving the lever into the appropriate gear for the speed at which I'm coasting, the rpms increase to approximately the correct rate for the given road speed and gear selected. This has me thinking something with the clutch

I don't get any funny noises that I can hear when engaging or disengaging the clutch under any conditions, but they could be covered up by the slightly loud and rattly exhaust.
Nov. 16, 2009 7:18 p.m. fifty Reader

Vacuum leak: get a spray bottle of water . Idle the engine in neutral - spray water at any suspicious points of vacuum leak - if the RPMs drop or the engine stumbles, that's your problem.
Nov. 17, 2009 7:25 a.m. cghstang Reader

I tried looking for vacuum leaks with an unlit propane torch last night with no success.

Any thoughts on the clutch/transmission side of things?
Nov. 17, 2009 7:32 a.m. corsepervita New Reader

The shifting issue you are experiencing could very well be the linkage wearing out. Those bushings are notorious for getting a little bit of slack in them and then it has a horrific time in 1st/3rd/reverse when going in.

If you climb under and have the car in 1st or 3rd gear, and can grab the linkage and twist it back and forth with your bare hands with not much effort them you've got bushings wearing out in the linkage which will give the same symptoms as bent forks/crap synchros, etc. Go with ES Stabilizer bushings for the shifter, replace the end linkage bushings with OEM ford ones, OR alternatively, evenly space the end linkage with steel washers (EVENLY space them) for a permanent fix ;)

Also keep in mind, the ZX2 likes it if you go into 1st at an absolute CRAWL on those transmissions. It doesn't like to go into 1st early, if you do, it will be grabby, difficult. And the way reverse is positioned, the easiest thing you can do to get into it is clutch once, move the shifter over to the right, clutch out, clutch back in and then put it in reverse from the shifter's position. 9/10 that'll remedy the stubborn behavior (mind you you're moving the shifter over, not actually putting into reverse).

As to the RPMS, as everyone else here has suggested you have a vacuum leak.

If you need any ES Stabilizer bushings let me know, i've got an extra set laying around that i'm not going to use that you can have.
Nov. 17, 2009 7:37 a.m. cghstang Reader

I'm not as concerned about the difficulty going in to gear, it really isn't bad and supposedly already has ES bushings in the linkage.

I need help with this:

When coasting in neutral and then pushing on the clutch and moving the lever into the appropriate gear for the speed at which I'm coasting, the rpms increase to approximately the correct rate for the given road speed and gear selected.
Nov. 17, 2009 7:41 a.m. corsepervita New Reader

Oh i see what you mean... as in you push in the clutch, put it in neutral. Put it into the gear you need to be in, and the rpms match the gear to the road speed (even though your foot is still pressed down on the clutch).

That almost sounds like you've got a clutch master cyl that's letting in air since the clutch would partially be slipping and hence adjusting to the given rpms so it's never 100% open from what it sounds like?.

Assuming you've adjusted that already for the slack on it to it's max, and it's still doing it, that is a possibility. Either that or you could have internal clutch issues. Have you tried bleeding the slave first and eliminating the possibility of it being air inside?

If this is still not what you mean then my apologies for my misunderstanding.
Nov. 17, 2009 10:37 a.m. iceracer HalfDork

Bleed the clutch slave cylinder. May be a bad slave or master cyl. leaking by. Easy way to test. Holding the pedal down, put it in 1st gear with the engine running. See if the car tries to move after a minute or so.
Nov. 17, 2009 4:48 p.m. cghstang Reader

In reply to iceracer:

I tried the slave cylinder test you described and nothing out of the ordinary happened.

Today when I was driving it wasn't doing the "revs go up when in gear but foot on clutch" thing.

I'm going to bleed the slave cylinder and keep looking for vacuum leaks.
Nov. 18, 2009 7:23 p.m. Autolex HalfDork

Try this test:

go to a place where you can get the car up to 40-60 mph safely...

get the car up to 40-60 mph...

push clutch in...

coast down to zero...

If the car loses rpms (motor starts at 2k, slowly goes to 1k) with speed, it's something in the clutch system (TOB, slave cylinder, something)

Do the same thing once more, but instead of just pushing the clutch in and holding it, take it out of gear and let go of the clutch...

report back here with the results.
Nov. 18, 2009 8:32 p.m. cghstang Reader

In reply to Autolex:

I'll try that tomorrow if I can. Getting up to speed isn't a problem but coasting down to zero might annoy anybody behind me
Nov. 18, 2009 9:22 p.m. Entropyman New Reader

This sounds similar to the idle problem I had earlier this year. You could try backing off the idle stop screw, it has moved in the past and might have moved again (I didn't locktite it or anything). As far as the clutch goes the only thing that hasn't been replaced in that system is the brake master cylinder (the fluid supply for the clutch hydraulic system). I don't know if a leak in that will allow air in to the clutch system though. Sorry for the issues .
Nov. 19, 2009 9:49 a.m. iceracer HalfDork

Do you have cruise control ? any CEL's Clean the IAC. Check the voltage on the TPS. Do what autolex said. Obviously you will want to do it where there is little or no traffic.
Nov. 19, 2009 10:04 a.m. iceracer HalfDork

I just reread your original post. First, you say the idle remains high after highway stints. Then, Car idles fine. Which would indicate possibly a sticky IAC or the throttle cable,which gets a lot of heat from the engine. For the clutch. The engagement/disengagement height should be app. 59mm from the floor board. Free play should be 5-13 mm and pedal height should be 212-217 mm from the firewall. I mention the clutch measurements as I have found them to be critical in proper clutch operation.
Nov. 19, 2009 1:28 p.m. hrdlydangerous New Reader

From what I recall from my days working for Ford these engines used a mechanism to keep the idle up when changing gears to enable smoother shifts. You may be chasing something that was built into the car and isn't working quite how it should anymore.
Jan. 14, 2010 6:47 a.m. cghstang Reader

Iceracer hit it. I'd been driving around the issues for a while, bled the slave, then new slave. That fixed the clutch engagement point issues.

Last night I unplugged the IAC and now the revs drop like a rock between shifts. I'll give it a good cleaning and hope it returns to normal operation.

The zx2 will be making its rallycross debut this weekend. Hopefully it holds up well.
Jan. 14, 2010 11:18 a.m. Morbid Reader

In reply to tuna55:

Agreed. The only thing worse is it's automatic counterpart.

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