Hello all,
This is my first post here so I'll try to be a specific as possible. I bought this car with a known problem (no compression in #4 cyl) with the thought of fixing it for my daughter to use as a commuting car for college. After removing the head, found an exhaust valve in #4 cyl with a chunck missing. Replaced the valve, lapped all remaining valves, replaced valve seals, replaced timing gears/chain/guides and reassembled engine. Intake manifold was removed in its entirety with no components being removed. New intake manifold gasket was installed before remounting to head. With engine fully assembled, oil system primed, I attempted a start. Engine stumbled to run, would not idle at all. Replaced O2 sensor and engine started up and steadily climbed to about 3000 rpm. Shut it down and attempted to find why it climbed so high and wouldn't come down. Checked the output voltage of the new O2 sensor after it cooled down and it read 0.0871 volts. The old sensor read 0.156 volts. The Haynes manual gave 0.1-0.9 as the range for the O2 sensor voltages. Stuck the old O2 back in and the engine raced to 3000 rpms again. Use my OBDII scan tool to read codes but it gave a P0340 and P0341 code which relates to a camshaft sensor. Unless it's somewhere well hidden, this engine has no camshaft sensor I could find. It does have a crankshaft sensor which I removed and tested (700-900 ohms, mine tested 781 ohms). My engine also has the air pump setup mounted atop the a/c pump. I removed the vacuum line at the manifold and inserted a golf tee to block off that circuit and was able to get the rpm down to 2000. I bought a vacuum gage to check the MAP sensor readings on the OBDII scan tool and they matched so I assume the MAP is working properly. I also picked up a code for misfires on the second and third startup. Any ideas on what could be going on? Anyone had a high revving DOHC 1.9 before that picked up camshaft codes? Does this engine actually have a camshaft sensor hidden somewhere that I might have missed? I've kind of hit a brick wall. Any help would be appreciated. Thanks.

Scott

 

I have some information that I am unable to print out unfortunatly that says to the affect that Electronic Ignition Modual supplies a signal to the PCM when it determines that cylinder #4 actually fires on the compression stroke. This has something to do with cylinders 1 and 4 fire simultaniously but are of opposite polarity.
Which makes sense if you think about it, a number of 2 cylinder engines will fire both cylinders at the same time, but one is on compression and the other is on exhaust so you need one coil for two cylinders and one trigger circuit.
Coil tower polarity is of opposite polarity as is the firing of the two cylinders. This apparently is sensed by Capacitive pick up plates located under number 1 and 4 coils. It seems if it detects opposite polarity from expectactions it pulls a cam sensor error.
O.K., I am reading and paraphrasing because it is far to difficult to print out (can't do) and copy. And I don't have a car in front of me.
However
1 cylinder 4 has a problem
2 no one solved it
3 makes sense if some one had it apart and gave up
4 hooked some wiring to ignition curcuitry up wrong
dunno, can't tell. but if you have not bought a book I suggest you do and look it up.
If you refuse to do that I'll copy it down an type it out
and HATE YOU for doing it.
And if I look up the cam sensor codes, the software defaults to a miss-fire diagnostics for the 300 series codes.

waving again

 

John,
When I bought the car, the previous owner had done no work to it. He said it lost power and he took it to a garage to check it out because it was running so rough. It was at that time they did a compression test and found no compression in #4 cyl. He parked the car at the front of his driveway for sale. When I went to pick it up it ran enough to drive up onto the trailer. When I took the head off, I was the one to find the exhaust valve missing a chunk. It wasn't burnt, the piece just broke off. I personally never saw that defect before but figured everything else seemed to be in working order less one cylinder. As far as having a manual, the Haynes <grimace> manual I do have lacks a lot of specifics for the 2000 1.9. Like all references to the EGR system are for the vacuum operated system not the solenoid version on my engine. Also, the Haynes manual has no info on testing the air pump circuit.
What manual are you getting your info from because I couldn't find any reference whatsoever concerning tower polarity or coil signals tripping camshaft codes? I don't mind picking up another manual, it's just WHAT SPECIFIC manual has the pertinent info. I picked up a Bentley manual for my VW years ago and found it superior to any VW manual I previously owned. In taking the head off, the spark plug wires were simply layed off to the side with no other wires associated with the plug wires touched. The rear wiring harness for the injectors/TPS/MAP/other sensor??/PS switch/Alt/knock sensor was layed off to the side also without any other wiring harness disconnects. The engine runs smooth but just fast. The coils could be a problem because a couple of times I noticed the engine would start to break up a little but then smooth out. It's intermittent though. One thing I have noticed is some of the electrical ground connections are pretty green with corrosion. I was wondering if the corroded connections could be setting up a make/break connection with the grounding circuit thereby forcing the electrical circuit to find new grounding paths thereby tripping the various engine codes. The high rev is still a mystery. I was thinking vacuum leak at first but after pretty much isolating the manifold and obtaining a steady 17 lbs while running at 2000 rpm, I'm not sure. I guess I could clutch the engine down to around 1000 rpm and see what the vacuum is then. I've never had a car race like this at idle. I hope this gives more of an insight as to what exactly has taken place with this car. Thanks for the response and please give me the name and publisher of the manual you extracted your info from. It sounds light years ahead of the one I'm currently using. Thanks again.

Scott

 

I actually have some software that lets me look a few things of this nature up and it quit printing out some time this spring. The problem other than something like Haynes or Chiltons is that a lot of information is abreviated in one form or another but this is not unusual, they always have been. It has always been a matter of degree. I used to buy Motors books for a long time. They dissappeared of the market it seemed some where in the 80's, at least as far as I could see. Chilton's was the equivelent and why both were available I think the only difference was the color of the cover for the most part.
I bought Chiltons until they dissappeard. Now I buy the paper back marque coverage when I need one and for the most part if I can deal with the abreviated information it works.
Haynes, Chilton and Mitchels all seem to me to be about the same. My Saturn book was purchased about the time the Saturn was which makes it 1996ish. If the 2000 car you have is new for 2000 as far as these parts go, it may not even be in a 2000 Saturn book which brings up the next question.
What year does yours cover? If it does not specifically say what year it is that may be the problem.
Dunno.
I think my Saturn book is either haynes or Mitchels. But it is going to be dated.
Like I say if you need the data I'll go through the agravation of typing it out on the forums. If your book has any indication it does not cover your year check to see if you can get one that does and
although I have not done it in a few years, the local library if you have one and it is good size genrally has a line of automotive repair books I think in Mitchels that may help.
I'll watch for an answer and deal with this tomorrow if required but as far as being able to get a copy of what I have, I doubt it, I shouldn't even have a copy.

 

Oh, on he green fuzzy connections. Years of working on computor controlled stuff says that is a no no, Generally disconnecting and reconnecting connectors is good enough to get good contacts. High quality stuff for those connectors, but I keep a tube of dialectric grease or points grease as it is sometime called to goo up connectors with when I put them back together to help from this happening again in climates where it rains more than it does here.

 

I know a leak from the PVC to the throttle body will produce about a 3K idle....

Also, issues with the ECTS will occasionally cause higher than normal idles, but it wasn't an issue prior to your repairs so it's not likely the cause.

Intake manifold gasket leak ? (no indication that the gasket was replaced) -- spray some carb cleaner or WD 40 around there and see if it affects the idle.

There is indeed no cam sensor on an s car -- like unc was paraphrasing, the DIS monitors the firing and detects misfire conditions in that way.
____
0341 is Cyl 1 not cyl 4 misfire I believe.

I would splurge for new plugs (NGKs) and wires before going off on an electrical chase. If not the wires/plugs, then we'll move on to the coil packs
____
O2 sensor -- use the Denso part -- My S Cars hate the Bosch part and run poopily.
____

 

Derf Says;
There is indeed no cam sensor on an s car -- like unc was paraphrasing, the DIS monitors the firing and detects misfire conditions in that way.
========================
O.K., that makes sense after a good nights rest. Going through the diagnostic tree my software defaults when you klick on the Cam Sensor error code to the missfire diagnostics. That makes sense if I think about it because a miss fire will trigger that code. Dang, I am thinking in circles again.
As to Spark Plugs, I have not had any problem with Champions so to my way of thinking it is pretty much personal opinion.
Other than some of the hype type plugs, name brands are all pretty much the same.
If you have an ohm meter measure the resistance of the wire and check the length. Right now I do not remember a number that is exact, but 10K ohms per foot sounds about right. That is 10,000 ohms. But what ever it is, the 4 wires should be close to the same with the longest having the highest resistance and the shortest the lowest.
Although you can be fooled, if the plugs look ok and all the same, not a problem most of the time, gap and re-install. If you are not sure error on the side of caution and get new.

 

First off, thanks for all the inputs while I chased my tail for the last 4 days. The high rev problem was, as I assumed, a massive vacuum leak. After going over the installation steps over and over, it occurred to me I couldn't remember connecting the brake booster hose. Sure enough, after crawling under the car I found the line sitting next to the intake fitting. After connecting it, on restart the car fumbled a bit so I held the idle more or less around 1000 rpm. It wanted to die off at that point. Then after about 15 seconds, the engine regained it own idle at around 1100 rpms. It idled for 2-3 minutes before I noticed it breaking up a bit so I think the spark coils might be on their last leg. the car has 207,000 and the coils look like they might be originals. I'm thinking of going with a pair of Accel coil modules. At least now the engine's not screaming. Now to replace the exhaust and brakes, then road test. Thanks again.

Scott

 

Happy Dance!

 

Hee hee hee -- It's the "little things" that trip us all up now and again. Glad you are back on the road