Surging
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I recently aquired a 2000 Ranger XLT 4 cyl. Within the first couple weeks the check engine light came on then the performance began faltering pretty seriously. Then without any meddling from me it began for about a week or so when the weather cooled a bit to run fine, the check engine light went off on its own. Then a couple weeks ago the light came on again and the performance went down the tubes..

The check engine light has been coming on and off, as you'd expect it is on when running bad. Sometimes it will begin running smooth then the light goes out. But for the last few days only running bad. So I've replaced the Camshaft Sensor which for the last 3 or 4 times I keep getting a code for that. I've checked what vaccum lines I can find etc. I'm at a loss at what to do next. Any ideas anyone? It is undrivable in the present condition, the rpms vary wildly at idle, it drops out at low rpm cruise speeds in any gear, when letting off the accelerator a continous clicking sound which sounds like from under the hood, which I can't check while driving of course, during the deceleration period it chugs violently.









Thanks.

 

Wow, lots of input there. I hardly know where to start!

First of all, when you get a code it doesn't always mean that that particular sensor is bad, it can also mean that there is some condition causing the sensor to trigger a fault code in the computer, or that there is a bad connection somewhere. If you keep getting a cam position sensor code and you have replaced the sensor, I'd look at the wiring or the connector to the sensor.

In your case I think I might even try unplgging the computer, check the connector for any sign of corrosion or crud on the contacts and plug it back in again. The fact that your problem seems to come and go makes me think of a bad electrical connection somewhere. There are also a couple of large plugs in the wiring harness that connect the engine harness to the chassis harness. I'd check those too.

 

Thanks, I'll check that out today, I'd read about a 'break out box' for checking the Camshaft Sensor in place while running etc, I did attempt to check the supply voltage to the sensor while it was running and got a 5.7 mostly steady supply but haven't devised a safe technique for checking the output side yet.

I'll look into the other connectors though.

Thanks for the ideas.

 

The problem with a Breakout Box for home mechanics like us is that they're very expensive, not something you can justify paying big bucks for if you don't use it all the time. I doubt you can rent one either, but I suppose it's possible.

 

I took both connectors loose and cleaned them with contact cleaner. No dice. The one under the cab did look like it had a little grime or discoloration in it...sprayed it twice. The connector on the top to the cpu was slighty sticky with a layer of dust on it, if I were to guess someone had sprayed it with wd40 or something which left a dust collecting film on it. But still not a change. The hotter it gets outside the worse it runs.

 

The temprature dropped 30 degrees overnight, today the truck runs great. One or two chugs and that was it.

I suppose I wait until the weather heats up to see what happens then.

Any ideas?

 

Only drive it in cold weather...? Sorry, I know that wasn't very helpful...!

 

My thought was to sell in cold weather.

 

Sounds like you have a bad sensor, or connector, somewhere. Try to run the diagnostics after it has warmed up and running bad. I have a breakout box, but I don't use it a lot because it is to much trouble to hook it up. I can usually locate the wire connection on the harness and using a straight pin through the wire, make a connection to test. That is usually easier than pulling the computer and hooking up the breakout box, but occassionally I can't locate the correct wire and have to use the box. If you do not have any way to check engine codes and don't have a feel for locating the electrical wires and sensors , you probably should go ahead and get some professional help.

Good luck with it.

 

Thanks for the suggestions David, a few weeks (or months) back I found the problem. I'd started another thread under the Ranger section higher up on the board. To recap I replaced several sensors, this is the first vehicle where I'd had to deal with such stuff so I was impatient etc. After eventually thinking I'd discovered the computer unit to be malfunctioning as per my tests I replaced it. No avail. Test driving it I'd smelled a slight odor of burnt plastic, the wiring kind. In a fit I pulled over and began prodding the harness itself to find it was sort of not put together very well, i.e. had been worked through before obviously. I saw a short section of grey/orange wire which had a shrunken appearance, like a few millimeters, I reached down tugged it, it snapped. It was a factory junction which had sealant over a soldier joint with shrink wrap over it, apparently the junction had been squeezed to tightly, to my mind it had always been partially severed or completely severed which would give sporadic problems. I replaced a section of the wire and it has been fine since then.

Thanks again for the suggestions.

Gary