MuGGzyx

When I was having the "classic" stutter/hesitation about 6 months ago I did everything I could find, including everything in the "definitive hesitation" thread here and it ended up being a bad injector.

My car ran like a top for the last several months. but recently I had my CEL come on, then go off a couple times, usually days apart, the car was running fine so I just chose to ignore it (crossing my fingers).
A couple days ago when I was driving to work I noticed it start to have a rough idle, but it was cyclical, like a "pulse". Like smooth idle for 2 seconds then 1 second of rough shakiness then back to smooth. Most obvious when at a stop idling but still noticeable when at in town traffic speeds.

I went to the parts shop and borrowed their code puller and got a "DTC13 RPM Above 100".
Online the OBD1 code 13 is "RPM Signal".

Since I have cleaned, tested, and replaced almost everything "common" for this issue, I run B12 chemtool through it about every 5-6th tank so I doubt I have another bad injector, the shop said the rest were well within spec when they replaced the one bad one. Plus the timing belt was done like 5k miles ago so I doubt it has to do with that.


So I am looking at the Cam/Crank Sensors. These look like they are a nightmare to replace.

I know there is a right and left Cam Sensor up near the lifters on each side, but where is the Crank Sensor?

I found a thread that suggested an "Engine Speed Sensor" as a possible culprit for this, where is that?

MuGGzyx

Took it to the shop, they diagnosed both cam sensors as bad. Charged me $700 in parts and labor to replace both and car still ran like crap. They said it was bad plugs as the 2 they pulled during trouble shooting were very worn. I went and got new plugs and replaced and problem is exactly the same.

The car FEELS like it is missing or something. the idle at a dead stop seems very low compared to what it used to be, like below 500RPM and just kind of "puffing" as it sits.
When I really put my foot into it it goes and sounds normal but if I slow to cruising speed and just give it enough gas to keep up with the flow of traffic it feels very choppy. So basically unless I am going like hell and coming up behind people fast it runs poorly.

I replaced caps and rotors less than 6 months ago, all the normal offenders have been checked/cleaned/replaced except the plug cables. So it looks like I am going to go get a new set of cables and see if that helps, I hope it does because I can't afford to just keep throwing money at this thing.

sc4doubleO

Code 13 is cam position sensor. They rarely go bad the issue is that the wires get chewed up by either the timing belt or accessories belt.

Code 13 will also come up if your timing belt has skipped. Happened to me, its easy to adjust it back but time consuming.

Also next time a shop tells you any type of sensor is bad because of CEL ask them to actually test the sensor itself. Parts are expensive.

xxtoobsxx

iTrader: (4)

Timing belt jumped...happened to me twice on both sc400's I have ever owned. Get it squared away and you'll be good. Then ask the shop for your money back.