Idle Problems!

I just went through the nightmare of having too much voltage, bad alternator, buying a new computer and waiting a week for my car! After all that, My car still goes into a low idle and boggs down sometimes when I start it. I have cleaned the intake, replaced all the sensors, checked all the wiring, replaced the fuel filter, ran the codes and still nothing. The car will run fine when given gas and put in gear but WTF! Can anyone tell me what this might be? Thank you in advance!

Make sure the MAF sensor is clean and check all over for vacuum leaks.

Spark plugs?

Think I fixed it with coolant temp sensor

rivparadise wrote:

Think I fixed it with coolant temp sensor

I get it - ct sensor "lied to" the PCM basically saying the car was already warm... how'd you figure that one out?

Oddly enough, this strange looking man at carquest with a handlebar mustache asked me if I knew everything that governed the idle. He ran through all the list of repairs I have done and then came to the Coolant Temp Sensor. 15.99 and ten minutes later my idle is fine. I'm a little weary to start celebrating yet but so far so good!

Every once in a while those fellas at the store have some good advice. I wish that would have come to me in a dream or something before I spent $450 on stuff I didn't need. Oh well, Got a new Alternator, Computer and Diagnostic readout! Woo Hoo!

rivparadise wrote:

Oddly enough, this strange looking man at carquest with a handlebar mustache asked me if I knew everything that governed the idle. He ran through all the list of repairs I have done and then came to the Coolant Temp Sensor. 15.99 and ten minutes later my idle is fine. I'm a little weary to start celebrating yet but so far so good!

Yes I've received a good bit of help that way, actually mostly at the local farm store (used to be Central Tractor) concerning home and land maintenance. For instance, I needed to learn about wiring for homes and outbuildings, got pointed to "Wiring Simplified" - isbn 0-9603294-6-3 - studying that book enabled me to install, change and maintain wiring that meets code... up to and including service entrances. (it's big brother Practical Electrical Wiring also includes light commercial and light industrial installations). Almost 20 years ago someone at a local hardware store talked me through determining how deep to bury fence posts (the answer is deep) and why (avoid frost heave).

This site serves a similar purpose, for riviera owners, but I did not have Mr Handlebar's context, if I woulda I'd of shared. Congrats and happy driving. And thanks for sharing your answer.

Albertj

Still getting slight cutting out and jerking. It starts when I'm on the highway at cruising speeds. Will do it in all gears and idle. It seems less since I changed the plugs and wires but still doing it. Sometimes once a week other times every day. HELP! I'm losing my confidence in the old girl but still love her!
Please help me

rivparadise wrote:

Still getting slight cutting out and jerking. It starts when I'm on the highway at cruising speeds. Will do it in all gears and idle. It seems less since I changed the plugs and wires but still doing it. Sometimes once a week other times every day. HELP! I'm losing my confidence in the old girl but still love her!
Please help me

It's time to check the wiring harness at the firewall connector. Not all Rivs have this problem but in many the wires break at the terminal crimps with age, sometimes even under the insulation. There was a good thread about this, a person with problems similar to yours did not believe the bit about the wiring harness - we went back and forth on it for days it seemed - but when it turned out that was the problem took **really** nice pics of the repair and posted them. I can't find it, searched on stall* AND firewall. Maybe AA remembers it and will post/

Point is I think we've seen this before. It's neither common nor unique.

Albertj

Thanks Albert for all your help. When the weather gets a little better, I will start to track down the harness to the firewall. I am planning on removing the dash and interior this winter while I have another car on the road. The green hornet! My moms old 1997 cutlass! If anyone else has some suggestions please chime in as well!

Took her over to the speed shop in town. Costly but worth having them look at it. Also ordering the FSM sometime today or tmrw!

rivparadise wrote:

Took her over to the speed shop in town. Costly but worth having them look at it. Also ordering the FSM sometime today or tmrw!

may not catch the firewall connector wiring problem. What happens is the wires fatigue and break off inside the insulation. More than one list member has purchased a nice Riv for short money because that wiring issue frustrated the PO.

Albertj

If they cant find it I will have the FSM soon and begin to chase it down! New tester and cold garage to start the process! Thank you again! Will keep this updated.

rivparadise wrote:

If they cant find it I will have the FSM soon and begin to chase it down! New tester and cold garage to start the process! Thank you again! Will keep this updated.

you can take the chill off the garage with an electric heater, or by driving the car to warm it up then pull in the garage.

if your garage is weatherstripped you probably won't need to heat it per se unless it's below say 20F outside.

just sayin'

Albertj

Have to run a generator for electric. 10 foot swinging doors that are about 100 years old with lots of leaks! Not your typical garage. I'm hoping it's something very simple. I'm due for a break with this car! No worries though. I feel like I have an army to fight these problems with this site. Thanks!

rivparadise wrote:

Have to run a generator for electric. 10 foot swinging doors that are about 100 years old with lots of leaks! Not your typical garage. I'm hoping it's something very simple. I'm due for a break with this car! No worries though. I feel like I have an army to fight these problems with this site. Thanks!

You are in the Buffalo/Niagara Falls area - you might be able to get brush-style weatherstrip by the foot to slow up the drafts by those doors for short money from an industrial MRO (maintenance, repair,operations) supply house. Just saying. One example is http://www.almostairtight.com/ and another is http://www.memtechbrush.com/ - I am not recommending or warning you away from them, but just in case you're unfamiliar, or for others who read this after you do, you can have a look at their sites and you'll see what I'm talking about. You should be able to get an equivalent product, industrial size, from a local-to-you MRO house without much hassle. Good luck with the wrenching.

Thanks! Speed shop said they know for sure its not the tranny but want to be sure it's the coil packs. When I fried my first alternator the car ran a few times with over 18 volts pumping through the system. Looking back, I can say this started right around that time! I think that would blow those coil packs!

They can measure the primary and secondary resistance of the coils on the pack and compare to new/known good ones. When they are going they drift out of spec - not sure but my guess is that it's as the insulation inside breaks down.

Let us know. This is "one for the books." By the way did you or anyone else figure out why your alt failed?

Albertj

When this started, the low idle popped low voltage codes. Got it checked and they said alt. was bad. That is when I dropped the lead wire and had a small fireworks show! It took me a few days to realize I fried the new alternator. Second one blew when I drove home with a dead battery!

QUESTION HOW DID YOU HAVE TOO MUCH VOLTAGE???

Bad Alt. Blown diode inside of it.

OMG! I feel like my problems are just starting compared to what you are going through. I have replaced my neutral safety switch, battery and I'm getting a new alternator today. My car has been in limp mode off and on for about a month. First it was "starting problems" - If I stopped at a store on my way home from work it may not start again for about 30 minutes; Then the transmission went into fail safe (limp home) mode; Scans had us check the battery which was hot and looked like it was about to explode which prompted checking the alternator which is overchargin the battery - too much voltage. I will shoot my car and put it out of my misery before I start buying batteries and alternators on a weekly basis! I love her - I really do, but dang what a nightmare!
It's kinda like the chicken and the egg. Did the alternator just go bad, or did something else cause it to go bad and kill the batterry, etc., etc.???? Any body have any other ideas?

Deep cleansing breaths! Start by reading over as many threads as possible to holster as much info as you can. Its like going back to school with these cars and trust me, I have lost patience as well. As stated before, I fried my NEW ALTERNATOR by forgetting to unhook the battery and letting the lead wire drop on the supercharger. It sparked pretty good but never thought I cooked the alternator.I cooked my second NEW ALTERNATOR by running the car with a dead battery! Your electrical systems have limp modes to prevent worse damage. If your alternator is bad then too much voltage can harm more stuff. In my experience, shut her down, replace alternator, check battery and go from there. I have a bunch of friends that are mechanics who are a treasure of help but this site kicks ass for getting to the heart of the matter, Riviera Specific. There are a lot of challenging, thought provoking, time consuming and not what you wanted to hear solutions. Keep us informed.

katrinasriviera wrote:

OMG! I feel like my problems are just starting compared to what you are going through. I have replaced my neutral safety switch, battery and I'm getting a new alternator today. My car has been in limp mode off and on for about a month. First it was "starting problems" - If I stopped at a store on my way home from work it may not start again for about 30 minutes; Then the transmission went into fail safe (limp home) mode; Scans had us check the battery which was hot and looked like it was about to explode which prompted checking the alternator which is overchargin the battery - too much voltage. I will shoot my car and put it out of my misery before I start buying batteries and alternators on a weekly basis! I love her - I really do, but dang what a nightmare!
It's kinda like the chicken and the egg. Did the alternator just go bad, or did something else cause it to go bad and kill the batterry, etc., etc.???? Any body have any other ideas?

Get a factory manual set off eBay.

Check to make sure your positive battery cable is correct. If it is a plain cable (does not have fusible link, thermistor) then it is not the right cable.