Need help with intermittent stalling/long crank time to start

Okay, so my riv is finally driving and running around and all is good....so long as it gets going. It has a really long crank time to get started but it always starts. I usually crank for a second or two and if I don;t hear anything good I stop, wait a second, and then crank again and ti fires right up. Now once it has fired up, it idles rough for a minute or so. I know that I do need a new O2 sensor and this is on the way from rock auto. The O2 sensor reads fine at higher RPMs (above 1500 or so) but is slow to respond below 1500. I also have random stalling when decelerating off of a freeway and if I park it in my driveway and give it a quick punch up to 3.5k rpms and just let it drop it *sometimes* stalls. Other times it catches itself and chugs for a second or two. I also notice a very slight stutter when cruising and engine speed is below 2k rpm. It also has a bit of a hesitation when I go to do a freeway pass but this is going away as I get the injectors cleaned both through the professional treatment and the techron added to the tank. Neither method works "instantly" but the 3M stuff knocked away the heavy stuff and the techron should slowly clean up some more as I drive. The supercharger needs a new coupler but that's not my issue here.

What I HAVE DONE so far
-Brand new plugs (Autolite 104) and wires (AC Delco OE replacements)
-Brand new fuel pump and filter
-Injectors were cleaned with 3M fuel injector cleaner and were done the proper way (fuel pump relay removed, engine ran using only the cleaner)
-Coils were inspected and they spark straight and true
-Battery is strong and in great condition
-Vacuum lines were replaced with fresh hoses (cut to length hose but still, it's new )
-Gas tank still has 14 gallons of 93 octane fuel I got from a quality Shell station (one of my dad's co workers is convinced it's crap gas...I have to restrain myself from smacking him)

Engine Codes
-Quad Driver 4 error

What MIGHT be the culprit
-O2 sensor
- Crankshaft position sensor
- Ignition switch
- Fuel pressure regulator
-Boost Control Solenoid? (I know mine has 255k miles on it so maybe....)

I gathered my culprit list based on what I've seen on the car and what I've seen on the forums. Help me narrow this list down!

My first guess was fuel pump, after reading that you replaced that already my second guess would be the crank sensor. Have you noticed if its harder to start when the engine is warmed up compared to when its cold?

My next best guess is to clean your MAF sensor (use MAF cleaner, NOT Carb cleaner!!!!!)

Actually yeah it starts up decently in fhe morning but if it sits for too long in the middle of the day it takes a while...

deekster_caddy wrote:

My next best guess is to clean your MAF sensor (use MAF cleaner, NOT Carb cleaner!!!!!)

LOL!!!!

themanwithsauce wrote:

Actually yeah it starts up decently in fhe morning but if it sits for too long in the middle of the day it takes a while...

That really sounds like a crank sensor, theyre cheap and easy to do. It wouldnt hurt to clean the MAF, but cold start=ok/ warm start= longer crank, says crank sensor to me.

This would be easier to troubleshoot with a tech II (dealer scan tool)

- use the tool to command on the fuel pump and read fuel pressure/listen to pump performance
- also use the tool to read output of crank sensor while cranking the engine. If you have no signal it will be **obvious**
- I second what Tyler says about the crank sensor, they usually fail "bad warm"
- I do not understand how you know the O2 sensor is slow
- Have you taken the throttle body off and cleaned the S/C side of it? If not, probably a number of your issues will be resolved if you do that. At 255 K miles the inside of the SC inlet will be pretty tarry. Also your IAC may be sticking from the crud. If you want to do this, get a replacement TB base gasket (a FelPro would be fine) then remove the TB, then remove the MAF sensor and clean it with MAF cleaner only; then remove the IAC and Clean it with TB cleaner. You may want to get TB cleaner in a can and a pie plate, clean the TB in the pie plate with the cleaner; small brush (discarded toothbrush) will help with the cleaning. You may want the service manual for detailed instructions on R&R the parts.

Albertj

Okay I did my trans filter and cleaned the maf and throttle body last night. Nothing improved but my maf was not getting a good voltage reading before and it is now. My idle air was reading high before the cleaning but went down afterwards.

Albertj - I know the o2 is slow to eespond because I saw the response measurements on a scan tool. Actually it outright died last night and would fluctuate between open and closed loops at idle or under light acceleration. I was told its graph should look similar to a heartbeat but mine had flatlined

I think I'm going to wait until that comes in and gets replaced before doing anything else sijce it seemed pretty bad last night.

themanwithsauce wrote:

Okay I did my trans filter and cleaned the maf and throttle body last night. Nothing improved but my maf was not getting a good voltage reading before and it is now. My idle air was reading high before the cleaning but went down afterwards.

Albertj - I know the o2 is slow to respond because I saw the response measurements on a scan tool. Actually it outright died last night and would fluctuate between open and closed loops at idle or under light acceleration. I was told its graph should look similar to a heartbeat but mine had flatlined

I think I'm going to wait until that comes in and gets replaced before doing anything else since it seemed pretty bad last night.

I get it.

If your wallet can stand it while you are in there replace both the upstream and downstream O2 sensors; with the price of gas as it is if you drive a lot you'll get your $$$ back soon enough. The downstream sensor does not work very hard but when it is out of spec it costs you gas mileage I am told.

When you cleaned the throttle body were you able to get the IAC cleaned out too? I ended up replacing mine because I could not get all the tar out from behind that &$^#*@ spring. Also did you notice in the factory manual it says to reset the pintle before reinstalling? I did not see that one coming but apparently when you disconnect the battery for a while, on startup the PCM runs a reset sequence. Worked like a charm for me. I wrote about it in (of all places) the radiator replacement thread (I overhauled the throttle body while I was in working on the radiator).

And about that throttle body, any problems getting the gasket? The local dealer did not have them, but funny thing one of the local parts stores had a bunch (and that's where the dealer is getting them from according to the dealer's counterman).

Thanks for the details and I hope the new O2 sensor gets you out of this rut.

Albertj

albertj wrote:

[
If your wallet can stand it while you are in there replace both the upstream and downstream O2 sensors; with the price of gas as it is if you drive a lot you'll get your $$$ back soon enough. The downstream sensor does not work very hard but when it is out of spec it costs you gas mileage I am told.

(this won't apply as he has the 95, and only one o2 sensor. )

Quote :

The downstream sensor does not work very hard but when it is out of spec it costs you gas mileage I am told.

Is this only the case with Series I SC? I thought the 2nd O2 was more for monitoring the cat converter.

I was gonna say....I'm pretty close to 100% sure there wasn't a second one...I also left the throttle body and iac in the intake when I cleaned them since the iac might need adjusting and I have a suspicion that it is possible there is another problem besides o2 that will present itself after the replacement. I figure only one repair at a time for this since it still runs fine.

AA wrote:

Quote :

The downstream sensor does not work very hard but when it is out of spec it costs you gas mileage I am told.

Is this only the case with Series I SC? I thought the 2nd O2 was more for monitoring the cat converter.

There was a hole drilled into my catalytic converter and it wasnt throwing a code. If there is a sensor, it must not do much.

AA wrote:

Quote :

The downstream sensor does not work very hard but when it is out of spec it costs you gas mileage I am told.

Is this only the case with Series I SC? I thought the 2nd O2 was more for monitoring the cat converter.

Just because I was told does not mean I was told the truth. I've been wrong more than once, and my admissions of error are not hard to find on this site.


Albertj

I wasn't questioning the fact, I was asking if the fact might apply to engines other than Series I SC.

Its not remotely a fact with the Series I SC. There is only one o2 sensor.

..unless you are meaning that it might apply to those with 2 o2 sensors... but not be remotely related to the 95 SC

Karma wrote:

Its not remotely a fact with the Series I SC. There is only one o2 sensor.

..unless you are meaning that it might apply to those with 2 o2 sensors... but not be remotely related to the 95 SC

I was mistaken.

Other than that, let's see what themanwithsauce posts as an update. He's got a scanner, and he is learning his way around the Riv fairly quickly. Finding the O2 dead was a very good catch.

I am "wait and see" right now but my hunch is he's got to catch up on maintenance that we kinda know about but is not in the book. For instance, the bit about pulling the TB and cleaning the backside. I don't think anyone believes how cruddy those rascals get unless they've pulled one themselves. And the IAC. I am not sure what codes indicate a weak IAC. The thing I learned that's pretty funny, I think, is when the IAC isn't working right the car at first runs better albeit fuel consumption goes up a little. And there is *nothing* in the owner or service manuals about a maintenance interval for the TB and IAC specifically -- and although you *could* argue that those cleanings are supposed to be done in the periodic maintenance that is sold as "throttle body service" or some such it's most often that the car is connected to a BG or other machine -- which **does not* clean the MAF or IAC....

I am kinda beginning to wonder if the omission of certain items from maintenance schedules is intentional.

Albertj


Albertj

I dont know about maintenance omissions but some recalls and their fixes are to guarantee cars into the maintenance bays.

Well my dad pulled off a pulley getting at what he thought was a water pump gasket leak (was coolant bypass hose leak...) and when he out the oulley back on it squeaked a bit...so he solves this by spraying my pulleys down with brake cleaner, wd 40, and windex.....which makes the noise a lot worse. So now I've got to get him to tell me exactly what he did and fix that hefore I get around to the throttle body. He gave me the weirdest look when I yelled at him for using windex on pulleys....

Unless your dad is a certafied mechanic, youre usually better off trying things yourself, youll take a lot more time because youll care a lot more.
In the long run, it usually pays off with less/no parts broke.

Well the pulley squeal issue was that my worn belt for the supercharger started cracking and drying out when my dad sprayed a bunch of solvent on it (who knew plastics don't like solvents?). A new belt fixed the squeaking.

The O2 is on its way and actually after the new belt and 18 gallons of injector cleaner gas the sputtering and a few other issues died down a lot. There's still an awfully long crank time before starting but I'm going to do the O2 first and see what it says. After getting the new belt the SES light stopped coming on....I got about 2 hours of some of the best motoring in my life when I put on the fresh belt and went cruising and racing around at sunset

themanwithsauce wrote:

Well the pulley squeal issue was that my worn belt for the supercharger started cracking and drying out when my dad sprayed a bunch of solvent on it (who knew plastics don't like solvents?). A new belt fixed the squeaking.

The O2 is on its way and actually after the new belt and 18 gallons of injector cleaner gas the sputtering and a few other issues died down a lot. There's still an awfully long crank time before starting but I'm going to do the O2 first and see what it says. After getting the new belt the SES light stopped coming on....I got about 2 hours of some of the best motoring in my life when I put on the fresh belt and went cruising and racing around at sunset

sounds promising!

If you read some of the old posts on this site I think you'll find that squeaking pullies are not trivial. If yours start squeaking again, time to replace. Some pullies don't squeak as a warning but they start to go out of alignment; watch out for that too.

Albertj

O2 sensor came in the mail on saturday but I didn;t notice it until this evening (oops....) I'll put it in tomorrow and update on the effect.

Well I replaced the 02 sensor....not much changed. It was the correct denso sensor and everything. It does idle better but for the most part I still have long crank times and random misfires. I am going to try the CPS next.

What all do I have to do to get to the position sensor? I heard it takes removijg the harmonic balancer.

Yap,remove the HB. and it's right there. Three inch long 1/4 x 20 bolts are needed with the puller. the kits out there don't come with that size.home depot or lowes has them. it helps to remove the upper engine mount on the 95,makes removal a little easier,although you can still wedge it out if you don't.I've done it this way, and its only a little more of a PIA.

themanwithsauce wrote:

Well I replaced the 02 sensor....not much changed. It was the correct denso sensor and everything. It does idle better but for the most part I still have long crank times and random misfires. I am going to try the CPS next.

What all do I have to do to get to the position sensor? I heard it takes removijg the harmonic balancer.

...be sure to carefully check the wiring going to the CKP. I wonder if you have an intermittent open at a crimp to a terminal in the connector(s).

Okay....I'm completely stumped now. The car idles and revs GREAT! New MAF + new O2 + new spark plugs/wires = great running engine with no engine light.

So my stalling issue went away completely....And the long crank time has persistently stayed. I even reset the computer after the MAF just to make sure the engine relearned correctly.

Interestingly enough....I let this one girl I'm friends with borrow my car a few times and she says it starts right up every time. I witnessed her miracle starting in person so apparently its intermittent but I think my car has a gender bias now