help riviera acting up

first i was driving to work thursday moring and it started stuttering and then died had 2/3 tank of gas. busy at work so i had towed to garage they said i had a bad fuel pump so 600 dollars later they said it was fixed. picked up car and drove 2 miles to work no problem. end of day i leave work cap off gas because garage only put some of my gas back in. hit the interstate about 60mph starts stuttering again. get off next exit stuttering now at 45 and then dies on me again and wont crank again same symptoms as thursday. sits over night next morning i go and it cranks right away and i head back to same garage and in 2min its stuttering but limps back to garage and dies on me as i pull in to garage. any ideas guys incase this mechanic is out of it, i will give him benifit of one mistake or bad part he's a former gm and buick ase certified mec

first off,they should have tested the car. second,open up the fuel tank acces panel in the tunk and make sure there is a new pump in there. third,did they change the filter? did they check fuel pressure? did they check for clogged injectors. fourth,burn the f.....n place down

they tested the car and told me fuel pump was bad, yes new filter with pump the rest i dont know probably wont hear back from garage till monday. told the guy he already tapped me out there is no more money for him to get he gave me a one year warrenty on parts and labor

matches are cheap

tell them to replace the crank sensor!!!!!!

There are some problems.

For this diagnosis although he's a former GM mechanic, if he does not have a Tech II and know how to use it, there might be no way to diagnose the problem.

Your problem *sounds* like a bad crank sensor. You probably did have a weak fuel pump (the GM in tank pumps are notoriously weak, when they fail you need to put in a good one, a Carter or a Bosch (new or used) or else you are most likely sunk-o). But the crank sensor - the problem is it's about the only failure you cannot actually diagnose because to the Tech II it will look like someone simply shut the engine off, nothing is wrong. It could also maybe be the ignitions witch, but you need an aftermarket alarm test kit to check that one, its a set of LEDs and IIRC its one led that's lit if the injectors have power and the other if the ignition module has power. These are both difficult diagnoses. Ig switches usually go after several years if your riv has never had the ig switch replaced it's not a bad idea for PM if you have the $$.

As for that crank sensor - Basically if you have a GM car that stutters and dies when warm and the Tech II shows nothing is wrong -- then the first thing you consider to do is replace the crank sensor. It is behind the flywheel on the 3800 engine. You need a special puller, or else you often rip the flywheel rubber while pulling it, and need to replace it too.

When you replace the crank sensor DO NOT put in a lowpriced one - put in a Delphi or OE ACDelco (not the Delco value priced line, not a Standard or other line). The lowpriced ones do work but don't work very long due to differences in the encapsulation of the sensor's electronics I am told.

if crank sensor goes bad it wont crank at all though will it, mine cranks after sitting but goes to stuttering and jerking in a few min of driving

The engine will crank with a bad crank sensor, but will not run b/c the computer does not know the engine is turning...

deekster_caddy wrote:

The engine will crank with a bad crank sensor, but will not run b/c the computer does not know the engine is turning...

...and since it does not know the engine is turning, it turns off the fuel pump. To many mechanics this will look like a bad fuel pump. "Oh your engine stops running because the fuel pump quits for no real reason" they say -- but they never hook up a Tech II to see if the crank sensor signal stopped out for no reason or because the crank sensor quit sending data... and they don't know enough about this specific engine computer's operating strategy to guess that the crank sensor might be a problem... and when you challenge you on it they look at you like you just grew horns and "pull rank" - after all they are the mechanic and you are not... Many perfectly good Rivs get dismantled due to this quirk, it frustrates owners and mechanics alike.

The only way to test for this that I know of is to pull the crank sensor and connect an ohmmeter to the leads to check for continuity (it has high resistance but you do get some current flow) then immerse it in boiling hot water or blow on it with a heat gun (200 to 250 F oughta do it). If it opens up (it should not) you know it's bad.

What is happening is that when the crank sensor is warm, or is vibrated, the little connections between the terminals and the electronics in the sensor open. When the sensor cools back down, the contacts usually close. it is not unusual for these sensors to give up after 80-120 thou miles. If you get a good quality replacement cranks sensor, that sensor may not quit again ever.

There is a remote chance your problem is actually the ignition switch (NOT the lock, the electrical switch that installs behind the lock).

Thanks for completing my thought Albert! Excellent and thorough advice as always!

deekster_caddy wrote:

Thanks for completing my thought Albert! Excellent and thorough advice as always!

we could/should produce a radio show addressing roadworthiness, maintenance and upkeep, troubleshooting, and "tuning." If we can find some way to make it pay.

If I can throw in my two cents - about 2 months ago, I had very similar symptoms and all indicators pointed towards crank sensor but it turned out to be the MAF sensor (which was my second guess).
While this doesn't explain the bad fuel pump or lack of power to the fuel pump, every other symptom you described especially the cool down time and it started no problem was the same.

playa wrote:

If I can throw in my two cents - about 2 months ago, I had very similar symptoms and all indicators pointed towards crank sensor but it turned out to be the MAF sensor (which was my second guess).
While this doesn't explain the bad fuel pump or lack of power to the fuel pump, every other symptom you described especially the cool down time and it started no problem was the same.

Sometime what happens is multiple components fail more or less simultaneously because they reach the end of their engineered lifetime.

sorry guys been busy, update mechanic has had my car for a week he showed me his gm ase cert. i trust guy. he told me my car has broke his spirit and ego at this point he is not charging me anymore labor just parts. he originally changed fuel pump. now has changed crank sensor and pcm he thought he had it fixed and he test drove it one more time before i picked it up and again it left him on the side of the road same situation. he said injectors are not pulsing right. he said he now is going to re check ignition control module and spark plugs and wires. he claims to him this is personal now lol. it not mechanic so i could have misqouted some of this thanks for any more help u guys can give me

sure its personal. its now a matter of pride.I guess your pride wont take a hit,just your wallet.hey,as long as he fixes her huh?
when he finds the culprit he shouldnt charge you for all the replaced/good parts. nothing bolsters pride like benevolence

well im in 200 dollars for a re manufatured pcm and a crank sensor, the only reason i havent freaked and went off over parts that havent fixed is because the car was poorly maintained before i got it. almost at 200,000 mile never had crank sensor changed so im getting some parts that are living on borrowed time, without the labor to put them in.

mechanic still working on car still same problem any more advice guys
not charging me for labor

you should recap what's been replace and what's stil wrong...

I am thinking wiring harness connector at the firewall, broken wire in one or more corners.

Ok update, they test drove it all day yesterday after replacing the ignition control module and said they have fixed it no more problems they charged me for parts only but have changed pcm, crank sensor and ignition control module I'm out 480 for parts does this sound right and they claim the pcm shortest in turn messing up my crank sensor and ignition control module does this sound right not a pro at this

sounds plausible, and they ended up replacing a group of parts that were probably near the end of their engineered life. it's running, right? call it a lesson learned.

there is a possibility that cleaning the ICM would have fixed it - but I don't get the impression you were doing any of this work yourself. The issue actually will be, going forward, that the riv will become crushingly expensive unless you are wrenching on it yourself.

Ok guys I appreciate the help. Got another problem and would rather I fix the take back to garage. In mornings when I crank it up it runs about 1000rpm steady as I drive to work the rpms jump up when I put it in park at work (7 miles) it jumps to 2500rpms I cut it off and re crank fire back to 1000 rpms steady please help I'm going broke LOL

Sounds like you need to adjust your idle maybe.

amaidendevil wrote:

Ok guys I appreciate the help. Got another problem and would rather I fix the take back to garage. In mornings when I crank it up it runs about 1000rpm steady as I drive to work the rpms jump up when I put it in park at work (7 miles) it jumps to 2500rpms I cut it off and re crank fire back to 1000 rpms steady please help I'm going broke LOL

Did you touch the throttle body or Idle Air Control (IAC)?

the garage did work dont know i have been reading i think maybe its iac napa had one for 29.99 i believe my father in law said i could clean it with throttle body cleaner but it seems to happen in morning in afternoon on way home no problem, two mornings in a row had this problem but i can fix things when i have to and im tired of paying garage. also no check engine lights come on when this happens and i can shut it off and goes back to 1000 rpms. car has been poor maintance i bought for 1000 dollars and now trying to fix so any help i would appreciate i have read and used this site for great info thanks

recap of work done new fuel pump, refurb cpu, new crank sensor and new ignition control module