Crank position sensor or wiring...?

isaac313 · #1 01-28-2016, 12:26 PM

Y trucks rpm gauge bounces all over the place. So obviously the crank sensor or the wiring going to it is bad. The engine runs rough because of this. Where is the wire? I'm having a hard time finding it. It is a very old rusty truck so I wouldn't be surprised about the wiring.

Logan03CO · #2 01-28-2016, 12:48 PM

Quote:

Originally Posted by isaac313

Y trucks rpm gauge bounces all over the place. So obviously the crank sensor or the wiring going to it is bad. The engine runs rough because of this. Where is the wire? I'm having a hard time finding it. It is a very old rusty truck so I wouldn't be surprised about the wiring.

What type of truck do you have?

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isaac313 · #3 02-19-2016, 07:29 PM

Sorry I didn't get a notification for reply. But I changed the cps and it starts slowly an runs rough but mostly consistent. I think it's a shorted battery throttle sensor or spark plug. Hat do you guys think. It has a bad misfire. Sorry about signature.

1991 ranger 5 speed 2.3l 2wd

isaac313 · #4 02-19-2016, 10:37 PM

I've replaced the four intake side plugs. I found one that the electrode was totally shorted. So it ran a little better after that. It still starts up pretty quickly but runs rough. Since I damaged a plug wire. I'm planning on buying a set tomorrow and putting new wires in.

tomw0 · #5 02-20-2016, 07:36 AM

You might want to pay more attention to the exhaust side plugs. They do all the work getting the engine running, while the intake side plugs are used more sparingly to handle emissions control things. If exhaust side plugs / wires are bad, you'll be a lot more likely to have misfire.
tom

isaac313 · #6 02-22-2016, 02:28 PM

See I thought it was the other way around. That's very good to know. I'll have to screw with those more now.

So the exhaust side are the main plugs and the intake are the supplemental huh...?

isaac313 · #7 02-22-2016, 11:31 PM

I put in new exhaust side plugs and it runs better, but still has a fairly frequent misfire and barely enough power to move down the driveway. Doesn't seem to stall in neutral anymore but I think the idle screw is turned up too far.

tomw0 · #8 02-23-2016, 08:52 AM

Check for vacuum leaks in the hoses and intake manifold. If you have a MAP sensor, it can cause a really bad idle if it fails.
If you have little power, it can be caused by ignition timing, lack of fuel, poor mechanical condition, plugged exhaust or converter, cam timing, and so on. A bad EGR can cause an engine to run poorly. What is it actually doing? Misfire? Shake? Smooth, but powerless? Low speed problem? High speed?
Make sure there are not stored codes in the EEC-IV system. Some trucks do not have a warning light, and can have codes without you knowing.
tom

isaac313 · #9 02-23-2016, 12:31 PM

I removed the convertor to make sure it wasn't plugged. Is there a recommended vacuum test? When I pull one of the vacuum lines off while running it starts to stumble a little bit and I can hear the whistle of the suction. Here is the map sensor located? I tested my tps yesterday and it appears to work fine. I've sprayed the MAF with MAF spray cleaner. And if I take the intake off the throttle body while running it starts to idle roughly. Put it back on so MAF is working. And it's better.

Not enough power for driving, has intermittent misfire.

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I did check the codes. One was fuel pump circuit fault, which I then repaired. The other was a power steering something or other. Nothing about the engine.

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On my ranger would there be a cam position sensor? I can't remember the details on the years for those.

tomw0 · #10 02-24-2016, 06:37 AM

Not enough power for driving could be caused by low fuel pressure or lack of fuel volume delivery. Check the pressure with the regulator vacuum line connected, then with the vacuum line disconnected, engine running at idle. The pressure should jump with the vacuum line off, end plugged by a fingertip.
You can check volume using a gauge with a deverter valve to make the fuel flow into a container. Engine at idle, divert the flow into a container for XX time. Stop. Measure fuel, do math, calculate volume delivered for a minute/hour your choice, and see if that is enough. If low, suspect pump or filter or pickup sock. Some Rangers had two pumps, one lifting fuel at low, 3-5psi, from the tank, sending it to the high pressure pump mounted on the frame near under the cab, and developing over 50psi. I think regulated to the 40-ish psi range, jumping when the vacuum line is disconnected.
If the volume is limited, and pressure is decent, might want to replace the fuel filter.
tom

isaac313 · #11 02-25-2016, 11:14 AM

Where do you check fuel pressure? Is there a Schrader valve somewhere?

isaac313 · #12 02-26-2016, 10:19 PM

I checked the mounting screws on the ICM to make sure it was getting ground and it looked iffy so I ran a wire and it seems to have improved, but the engine still runs unusually. It'll run smoothly on all 4 for about 10 seconds, ten it'll stumble and misfire, then it'll repeat the cycle.

isaac313 · #13 02-28-2016, 06:23 PM

Ok, I checked my timing belt and it was off about 5 teeth....!!!!!! I put it to the correct position and now it runs much much better. Still sputters and backfires every now and then, but it's much much better. I looked at my new CPS I installed and it is rubbing the crank pulley on the inside and it is really damaging the sensor. So I'm going to see if I can get a refund on that sensor that doesn't fit correctly and find an oem sensor. I thought that was OEM but definitely doesn't fit like oem so I'll see about that.

isaac313 · #14 03-02-2016, 12:23 AM

The cps still seems to function so it'll stay for now, but I found the O2 sensor connector was rubbing the exhaust and it melted the side of it. The connector was totally trashed. I got it apart with some pliers but they'll all need to be individually spliced. Which isn't a big deal. Will these trucks even start without the O2 sensors plugged in? I don't think with the condition of the connector that the sensor was at full functionality anyway. Which may be one of my main issues. Because it seems to run rich quite a lot of the time. In fact it flooded out pretty badly the other day.........