Rough start & idle, stalling

took the day off from work.. so hopefully i can get some answers from my riv today.. I will pick up fuel pressure gauge and some stuff to scrub the engine, so i can pinpoint where any leaks are,

What numbers am i looking for with this gauge?

Fuel Pressure should be 50 with the vacuum line to the FP regulator disconnected and plugged. It will vary with the vacuum line connected to the regulator.

im not really sure how to test for pressure....

ok.. i only got to do a " key on no start" test b/c my batt started ticking when try to start... anyways it shot right up to 48 on first turn then 50 on second turn of key. Im seeing good pressure at the rail, what should be my next step?

Charge battery and test fuel pressure with car running.

Sorry, yes - dave is right. Engine should be running during FP testing.

well got the batt charged  and started the car. The SES light was not on and it started right up without having to press gas pedal. Second start up i had to hold down the gas pedal to start. tested fuel pressure, 46-48 with regulator connected, 50 with it plugged. While i was doing this i heard a faint grinding noise from the back of motor. I leaned over to pinpoint the sound and put my hand onto a burning hot alternator, note car was only on for maybe 5 min. Could a failing alt throw the random misfire code? Or shut car off at highway speeds?

Quote :

Could a failing alt throw the random misfire code? Or shut car off at highway speeds?

Maybe not, but if it's that hot try to diagnose the issue further. If the alternator does need replaced, might as well get it out of the way. You'll need to eventually.

More on testing for bad alternator:

https://rivperformance.editboard.com/t7992p15-alternator-noise-mechanical-failure

any other ideas?

96rivie wrote:

well got the batt charged  and started the car. The SES light was not on and it started right up without having to press gas pedal. Second start up i had to hold down the gas pedal to start. tested fuel pressure, 46-48 with regulator connected, 50 with it plugged. While i was doing this i heard a faint grinding noise from the back of motor. I leaned over to pinpoint the sound and put my hand onto a burning hot alternator, note car was only on for maybe 5 min. Could a failing alt throw the random misfire code? Or shut car off at highway speeds?

failing alt = misfire?  maybe, if only because the sensors are voltage dependent and if the batt is discharged far enough then the sensors will fail. PCM will shut car down if enough bogus readings are noted.

K thanks

96rivie wrote:

K thanks

By the way you ought to test that battery for a dead cell.  Easy way:  charge it using a battery charger, whatever you have (hopefully bigger than tricklecharger).  After it is charged up, disconnect it and use a meter to read the voltage.  It should be something like 12.2 - 12.6 volts.  Any less and you have at least one bad/dead/crippled cell in the batt... and should then replace the battery (as well as the alternator, we already know that's an issue).

I took the batt to advanced, had them slow charge overnight and it and it only went up to 880 amps, then we quick charged it for 30 min and it went up to around 1100

96rivie wrote:

I took the batt to advanced, had them slow charge overnight and it and it only went up to 880 amps, then we quick charged it for 30 min and it went up to around 1100

That is not the answer you needed, really.  All you need to do is charge the battery then read the voltage, not the cranking amps. 

Here is why.

Each cell in the battery puts out about 1.5 to 1.7 volts.  If you are reading less than 12.2  volts or so on a "fully charged" battery then you have an electrical problem in one or more of the cells and need to replace it. What that problem might be does not really matter because you can not get the parts to repair the battery.  FYI the problem often is that car batteries are not built for deep discharge and if you do discharge one too deeply it will partially or completely short out one or more cells.   The battery will read a certain voltage with no-load depending on its construction (lead-antimony is conventional construction, the OE Delco batteries for our cars were lead-calcium and actually put out about 12.6v no load when fully charged; replacement batteries are not all lead-calcium and so may read a bit lower no-load, like 12.2v).  For those of you even more curious about batteries here is a VoTech tutorial on them from Kevin Sullivan, a professor from Skyline College (http://www.skylinecollege.edu/)  in San Bruno, CA:

http://www.autoshop101.com/trainmodules/batteries/101.html


The sensors for the cars' systems -- temperature sensors, et cetera -- could care less about what cranking amps your battery will put out.  Your sensors, however, care a lot about voltage.

The other thing you care about is if you have the OE style positive battery cable with the thermistor that reads temperature of the battery and sends a signal back to the charging system to up the charging power if the battery is cool enough. If the thermistor is not working correctly you can have undercharge or overcharge chronic problems.  So if your cable was replaced with a generic one, or if you are running the wrong type battery (should be a Group 79) it could also be a problem.

What's the story?

Its a OEM Duralast gold batt.. After about a month or so with car sitting and batt terimnals unplugged, its holding charge and it started up. Im still having the rough start issue where i have to hold down the gas pedal for it to start, and the SES light started to blink, then it stayed on steady. Car has been sitting outside uncovered just waiting to get worked on, but Im not sure where to start anymore

Not sure where to start, eh?

Might mean you are not following the recommendations you were given, so lets try this.

If your battery is good, get a good junkyard alternator and swap it in. Then...

Read the stored codes and report back to us.

After that you'll clear the stored codes and drive until you set new codes and then report back to us.

We are not perfect but we also get nothing from b-s ing you or selling you stuff. So although taking this advice is at your own risk and peril, it is not like anyone earns a commission.

okay i recently bought a used alt from pick-n-pull, took it in and had it checked... all good. Its going on now!! Will report back as soon as i can get it up to shop and have em pull the codes

96rivie wrote:

okay i recently bought a used alt from pick-n-pull, took it in and had it checked... all good. Its going on now!! Will report back as soon as i can get it up to shop and have em pull the codes

Next item:

If you are going to work on the car yourself your own code reader and/or scanner along with a service manual set are worth buying. You can get both used on eBay for short money.

Albertj

good advice... any scanner or tuner better than the other?

Hey all.
Today and yesterday I just stalled randomly without any warning signs. I'll let yesterday go because I was really low on gas so it could have been a starvation issue. But today I had more than half a tank and it just cut out while I was driving. Both times the oil and battery lights flashed. Fluids and voltage are both good (~14.3 volts when running, ~12.9 when not). The only possible thing that I believe to have caused it is a cheap crappy OBD bluetooth scanner I got. It had the same problem as my old one (flashing lights and stuttering) so I ripped it out.

What I'm thinking:
That OBD scanner
Fuel filter or pump (might both still be original)
Electrical issue (wire grounding out or something)

Take that scanner off and keep driving.....see if it happens again. I've suffered this as well. I'm not disclosing anything until we hear back from you, as it could be a couple different things.

I've heard of that happening to other cars on a cheap bluetooth OBDII scanner as well.

Abaddon wrote:

Take that scanner off and keep driving.....see if it happens again. I've suffered this as well. I'm not disclosing anything until we hear back from you, as it could be a couple different things.

That's the problem though. It has been off for about a week. I took it off the first time it happened.

So it just cuts out and stops running? No sputter, no spit, just stops like you killed the Ignition?
You're probably losing spark instantaneously. Have you tried restarting it right after without cycling the key?

Yeah pretty much. And what do you mean cycling the key? As in not turning it counterclockwise at all, just clockwise to start it? If so, that's what I did (after it was in park of course). The first time was at a stoplight and today was pulling away from a stoplight.