Jump to content

Engine Idle Problems


tr0ub1es0me

Recommended Posts

Hi. This has probably been covered several times by others, but I wanted to make a new thread specific to mine as the exact details may help narrow down the list of possible problems.

 

I have a 1997 Ford Escort Ghia X 1.8L Zetec SEFi which has developed idling problems.

 

The problem began after a previous problem was rectified. Initially I was having trouble with the car misfiring on rare occassions coupled with the car pulling back momentarily under acceleration, after it had been serviced. For a while this was only happening once on very rare and isolated occasions, but eventually it became more frequent until it was happening constantly and the car lost a lot of power altogether. It turned out that there was a 'bad' spark plug used when these were replaced during the service.

 

I have no idea if it would bear any relevance to the problem I'm having now; but after the spark plug was replaced these problems had gone. However, there was a new idling problem. When first starting up and the engine was cold the engine would do one of two things:

 

i) Idle normally at around 1000rpm but after pressing the accelerator (in or out of gear) and then releasing it (or coming out of gear, or holding the clutch) the engine speed would drop down to around 500rpm or lower; before either stalling if it dropped low enough (below 500rpm), or rise back up to 1000rpm or over. The engine would then either rest back at around 1000rpm and usually stay there, or it would oscillate between around 500rpm-1500rpm constantly and usually keep doing that up until pressing the accelerator again.

 

ii) Go straight into oscillating between around 500rpm-1500rpm, usually up until pressing the accelerator again - after which it could do just the same again, or the above instead.

 

After the engine had warmed a bit (literally within one minute of driving), the engine speed would not drop low enough to stall any more. It would also usually not oscillate any more, but simply drop to no less than 500rpm and then return to an idle of 1000rpm and stay there.

 

It was not a major problem like this and meant I just had to keep a bit of gas on where possible when coming to a stop or coming out of gear after first starting up. Especially if starting up from cold and going shortly into slow-moving traffic, reversing from a parking place, stopping at a junction, or any time I would have to come to a stop within the first minute of starting up - in order to prevent the car from stalling.

 

It had been like this for a while but more recently it had seemed to develop into sometimes still oscillating between 500rpm-1500rpm instead of idling when coming to a stop, even after substantial driving. A quick press of the accelerator would usually get it to idle properly again afterwards. It would still almost never drop low enough to stall except within the first minute of starting up from cold.

 

However, it seems to have developed further now where there is some further problems:

 

- Instead of just oscillating between 500rpm-1500rpm it will more often jump up to around 2000rpm and idle there instead, both when first starting up from cold, or after/during any amount of driving.

 

- When pressing the clutch pedal to change gear when driving the engine speed will often jump up instead of going down. If below 2000rpm before pressing the clutch it will usually jump up to around there when the clutch pedal is pressed. If around 2000rpm-3000rpm before the clutch pedal is pressed it will still usually jump up a bit. If much past 3000rpm it will usually behave normally when the clutch pedal is pressed.

 

- When releasing the gas pedal altogether when driving the engine speed will not usually drop below 2000rpm meaning the speed won't steadily drop off past a certain point.

 

These new problems have made the ride a bit jumpy at times, especially when driving at a speed where the revs are around the 2000rpm mark as releasing the gas can make the car hold back or pull forward a tad momentarily. It also means that when changing gear when the revs were below 3000rpm the car surges momentarily as the revs have jumped up a bit when the clutch is pressed further rather than starting to drop off, and going when going back into gear it is as if the gas pedal was being pressed at the same time...

 

The only other symptom I could mention but again may have no relevance is that the needle on the speedometer has a tendency to randomly but constantly and eraticly jump and oscillate around the actual speed you are doing +/- 5mph each way for a long time when you first start driving but eventually does settle down and act normally. This may have no relevance unless there is an electrical fault causing the engine speed problems which may also be related to what the speedo is doing. The issue with the speedo needle has been there since I got the car though - half a year before the car was serviced and the problems in this post occured.

 

I have tried replaced the Mass Air Flow Sensor with an identical and working one from my 1.7 Ford Puma and this made no difference, hopefully ruling that out. Other than that I know there is quite a lot of possible causes. :( But any help or advice taking into account the full details of the problem would be greatly appreciated.

Link to comment
Share on other sites

Osilating rev problem on mine was traced to the crank case one way oil breather valve (on front of engine block behind exhaust manifold being knackered easy test is to take pipe off that goes to it and block it with your thumb. Soon as I did this the idle speed went straight to 950 smooth. Permanent fix was to block off the manifold connection where this pipe originally joined and then put an oil breather tank connected to the front breather box.
Link to comment
Share on other sites

Managed to get the ICV off. Was a b*tch to get to, but I managed it with persistence - and didn't even get a cut or graze. Gave it a clean in petrol as per the guide linked, and was partially optimistic. It wasn't that bad inside, with loads of gunk or anything, but it did clean up pretty nice inside and take off the layer of black deposit. Managed to get it back on, which was probably more awkward but I still managed to do it quicker than how long it took getting it off, in the end.

 

But...... to my disappointment it has not cured the problem. The engine still seems to like hanging at around 2000 rpm.

 

So, that was a day well spent... lol ?(

 

Just to make note: I wasn't sure if the ICV was something that had been tried already when a family friend who is a mechanic by trade had the car. But judging by the fact that it was not clean inside - I'm guessing not. I don't know what else he HAD tried but he had said that the next thing would be the ECU or wiring loom. :(

 

 

I haven't tried the pipe which goes to the one way oil breather valve. I guess I can give that a go next.

Link to comment
Share on other sites

Just tried disconnecting the battery for half hour as suggested on fordescortclub.co.uk, so the ECU can reset itself rather than still thinking there is a fault with the ICV...

 

Wasn't overconfident but I reconnected the battery, started her up, and lo and behold, the problem seems to have gone! Took it for a slow drive around the block and everything seemed back to normal. Gonna take it for a drive tonight rather than the Puma when I pick up the other half from work, to see if it really has been rectified, but hopefully it's all good now. Thanks very much for the help given here. Will report back if the problem has not actually gone.

Link to comment
Share on other sites

Bit odd, have you had a flat battery recently or disconnected the battery for ages?

 

I had a similar problem on my old escort when the ECU was reset whilst doing pro longed electrical work, when I reconnected it back up I went for and drive straight away, idling was fk'd until I reset the ECU again and let the car idle for 10 minutes before going for a gentle drive.

 

Not to sure why an ECU would work it's way out like that for no reason.

Link to comment
Share on other sites

I don't think the battery had been disconnected any time during or after the car was serviced and I had the initial problems because of the bad spark plug. I'm not 100% sure but I'm saying this because when my stereo is disconnected from the constant power supply I lose the radio stations and other settings on it. I don't remember having to reset anything on it, which is why I don't think the battery had been disconnected at all.
Link to comment
Share on other sites

  • 3 years later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...