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94 Olds 88 Royale 3.8L

I recently installed new plugs and wires and a new camshaft sensor as well. Car ran great for about 4,000 miles and now this:

Check engine light flashes sometimes while running (idling or in drive). Car will begin to misfire (jerk around, shudder, skip). Occasionally, when releasing from the brake at a stoplight, it seems as though car is in second/third gear. I almost have to step all the way down on the gas pedal to begin to move.. As car begins to accelerate faster, it then kicks into gear. It shudders when this happens as well. On cold starts, car will crank over and start fine, but then after 1-3 seconds of running, will stall out (I try tapping on the gas once it cranks over to try to keep it running, but 9 out of 10 times that has no effect). Usually takes 3-4 starts before it stays running. Once engine is warm, car starts and runs without stalling. Car surges when stopped at a red light sometimes. Once check engine light is on, I can usually turn the car off and then back on, and the light will no longer be on… don’t think that’s normal for it to turn off that easily. When on the freeway, sometimes it seems as though the car won’t shift in to overdrive. It stays in third gear, at about 45 mph, and the engine revs up for about 1-2 seconds and then settles and then revs for about 1-2 seconds, and then settles, and so on (all this happens while my foot is in the same spot on the gas pedal). If I press down on the gas real hard (floor it), car will increase in speed and shift in to overdrive and steadily cruise at 70 mph or so.

These are all the DTCs that it's thrown:

P0342 Cam Sensor Circuit
P1406 EGR Pintle Position Circuit
P1630 Battery volts out of range
P1565 Cruise Control Servo Position
P0171 Fuel Trim Lean

I don't have a muffler on the car, just the catalytic converter and pipe, so maybe that has something to do with the P0171 code?

But with everything else, I don't know where to start. Could it possibly be a bad ICM? Bad fuel injector(s)? Someone help me! (or I might start bashing my head against the wall)
 

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i dont know if the fueling on that car is based on the cam sensor or not, but assuming it is, it could be causing the misfire and the lean code could be because the injectors aren't firing


also could be the ICM which the Cam position sensor runs thru

i would check that ICM first, advance will test them for free, but i dont know if they can check to see if the ICM is firing the injectors

you might have 2 or 3 separate problems, if the battery volts out of range code shows after it's cleared you could have a bad alternator or battery, the egr system could also be causing the misfire and lean code if jammed open, and the cruise i wouldn't bother with...
 

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Ohm out the coils, friend had a similar situation, was a bad coil. When a coil is bad, it takes out 2 cyls.

The high voltage windings should all be smililar and IIRC around 10K ohms. The primary side is harder to measure, but should be very low, probably under 1k ohms. But all should be really close to each other.

The Ig Module (ICCM) could be it, but don't rush into replacing or throwing parts at the car.

Fuel trims are NOT the issue, just a result of the problem.

If ok, then ohm out the injectors, they should all range 12-16 ohms. If one is off, usually they fail lower and get worse, the PCM will at some point shut down the injector to protect the driver transistor. Usually around 10 ohms or so.

Pull the battery for 30 min or so (or the PCM fuses, there should be 2 in most cases), then drive it and see what codes come back. OBD1 sets codes fairly quickly.
 

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Finally, I figured it out! I hooked up a scanner to my OBD2 plug under my dash and brought up some live data. TPS mV, o2S mV, etc. I scrolled down a little more to battery volts to find out that they were constantly at about 16, spiking up to 19 and 20 every 10 seconds or so. I had one of my buddies test the alternator and battery at the same time with a DVM. Normal readings with that. 13.4 volts or so. I thought, hmmmmm, that's funny. Maybe the computer is all screwed up. So I went over to the junkyard and stole one of those puppies from a 95 Buick Century, same ID and PROM. Plugged that bad boy in and damn, car runs like new again. Cruise control works, no stalling, sputtering or anything like that. I did happen to ohm out the injectors afterwards for the hell of it and all were good. Thanks for the help guys and hopefully this might help you out one day.
 

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Sounds like the old PCM was not reading the battery voltages correctly, or the circuit that reads them was going bad.
Either way glad you got it figured out.
 

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Very First time that I have had some one report a truly failed PCM. Hope I do not have to see one on our 95 transport 3.8L or my 2000 grand prix. Both of these vehicles have more than a few whiskers...
The ICCM (ignition control module) seems more likely to fail, along with crank sensor after time. A very bright engineer on the automotive forum for Transports cautions about changing these two modules out after 10 years or so. Not fun to have a failure on some lonesome country road...cheers
 

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Finally, I figured it out! I hooked up a scanner to my OBD2 plug under my dash and brought up some live data. TPS mV, o2S mV, etc. I scrolled down a little more to battery volts to find out that they were constantly at about 16, spiking up to 19 and 20 every 10 seconds or so. I had one of my buddies test the alternator and battery at the same time with a DVM. Normal readings with that. 13.4 volts or so. I thought, hmmmmm, that's funny. Maybe the computer is all screwed up. So I went over to the junkyard and stole one of those puppies from a 95 Buick Century, same ID and PROM. Plugged that bad boy in and damn, car runs like new again. Cruise control works, no stalling, sputtering or anything like that. I did happen to ohm out the injectors afterwards for the hell of it and all were good. Thanks for the help guys and hopefully this might help you out one day.
If you still have your old pcm, take it apart a little to look at the solder joints especially for the connector. Do any of them look like dry solder joints? Most electronic failures I've seen are due to bad solder joints.
 

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pcm

For reference, anyone with similar problems should drop down the PCM and do the tap test, that is, smack it sharply by hand and look for running engine to cut out. Common ocurrance thru the 80's and early 90's.
 

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To figure out the cause, the car will need to be taken to Vehicle maintenance or a store that has an OBD2 readers, or for 1995 and previously designs, an OBD1 readers, While a readers will not provide you with the miracle reply, it provides you with a value that becomes smaller down the issue area. Or you can buy a mobile pc known as a Analysis Code Reader that will do the same thing and may be more cost-effective. Connect the specialist into the OBDII slot in the car. You'll find the slot under the rush to the right of the rim line. Many automatic provide shops will loan you the analyze model at no cost or will run the analyze for you.



__________________________
1996-1997 Oldsmobile Bravada
Oldsmobile Parts
 

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We have found obd1 or 2 "READERS" to get people further away from the real propblems because they do not properly or completely define problems and use a different definition than a DIAGNOSTIC SCAN TOOL like a tech1/2 or Snap on MT2500/SOLICE/MODIS. These show real time live data and use the same definitions as factory flow charts for diagnostics. SO........good luck with thoses "readers".
 

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I'm with Jake as in only a short time I have found how useless a code reader is compared to something like mechanics use.
So krislou you may want to do a little more homework before trying to help another, I'm not trying to be mean, just honest.

If I went to a mechanic with a problem, and they pulled out one of the little Actron scan tools like auto parts stores have, I'd laugh in their face and go find a real mechanic.
 

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94 Olds 88 Royale 3.8L

I recently installed new plugs and wires and a new camshaft sensor as well. Car ran great for about 4,000 miles and now this:

Check engine light flashes sometimes while running (idling or in drive). Car will begin to misfire (jerk around, shudder, skip). Occasionally, when releasing from the brake at a stoplight, it seems as though car is in second/third gear. I almost have to step all the way down on the gas pedal to begin to move.. As car begins to accelerate faster, it then kicks into gear. It shudders when this happens as well. On cold starts, car will crank over and start fine, but then after 1-3 seconds of running, will stall out (I try tapping on the gas once it cranks over to try to keep it running, but 9 out of 10 times that has no effect). Usually takes 3-4 starts before it stays running. Once engine is warm, car starts and runs without stalling. Car surges when stopped at a red light sometimes. Once check engine light is on, I can usually turn the car off and then back on, and the light will no longer be on… don’t think that’s normal for it to turn off that easily. When on the freeway, sometimes it seems as though the car won’t shift in to overdrive. It stays in third gear, at about 45 mph, and the engine revs up for about 1-2 seconds and then settles and then revs for about 1-2 seconds, and then settles, and so on (all this happens while my foot is in the same spot on the gas pedal). If I press down on the gas real hard (floor it), car will increase in speed and shift in to overdrive and steadily cruise at 70 mph or so.

These are all the DTCs that it's thrown:

P0342 Cam Sensor Circuit
P1406 EGR Pintle Position Circuit
P1630 Battery volts out of range
P1565 Cruise Control Servo Position
P0171 Fuel Trim Lean

I don't have a muffler on the car, just the catalytic converter and pipe, so maybe that has something to do with the P0171 code?

But with everything else, I don't know where to start. Could it possibly be a bad ICM? Bad fuel injector(s)? Someone help me! (or I might start bashing my head against the wall)
 

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I had very similar problems with missfiring a couple years ago with my 1995 Royale, especially going up steep hills. It would start jerking and jumping. I thought it was the A/T but it was a bad coil pack. I changed all 3 packs within a year and no more jerking climbing hills.
 

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Thanks for trying to help, but 9 years later they may not even have the car anymore.
But maybe this could help somebody else in the future.
 
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