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Ecomike 09-05-2017 04:06 PM

hard starting 2001 SL1
 
Having to start it three times for it stay running. Runs fine, might even say great. use to need to wait about 10 seconds in run for dash lights to go out and computer to be ready to crank, to get a 1-2 second start up. Now it never fires the first 6 second crank. Second crank it runs, but barely for 3-4 seconds at low rpms, then dies.

Third try it runs up to 1500 rpm at first and runs fine.

No new codes yet, will check it again today. Still has the old EGR, emissions code BS that has been a pain for years, it is unrelated.

Looking for ideas, on what might cause it be hard to start but then vanish.

toggenburg 09-05-2017 05:28 PM

Re: hard starting 2001 SL1
 
Well, what is the history on plugs, wires and maintenance?

Ecomike 09-09-2017 02:30 PM

Re: hard starting 2001 SL1
 
Seems my second post got lost. Wires, plugs are all good, and recently regapped (4-6 months ago). I did the MMO-GM TSB piston ring cleaning trick recently (3-6 months ago) that solved the massive oil consumption rate that had gotten out of hand.

I checked the OBD-II codes and found a new one, and also found that 2 of the emission monitors were still not locked in. It had been ages since I cleared the p0401 code or had a dead battery (about 3-4 months ago left the head lights on).

The new code was lean code, P0171. The O2 sensor is not that old, and does not have that many miles to be bad. I suspect the blower-EGR, clogged ports, garbage system Saturn used on these, P0401 code problem, caused a fake lean code.

I cleared them and made 4 trips, so far P0401 is the only code,one I have battled for 4 years now.

P0171 has not returned, yet, and it has not yet locked in the 2A or E or EE monitors.

I have discovered that if I just let it crank an extra second, it starts properly the first try, but it use to start in 1-2 seconds, not 3 seconds.

fdryer 09-09-2017 03:25 PM

Re: hard starting 2001 SL1
 
Mileage of this car? Fuel filter replaced? Fuel pressure?

alordofchaos 09-09-2017 11:04 PM

Re: hard starting 2001 SL1
 
[QUOTE=fdryer;2254176]Fuel filter replaced? Fuel pressure?[/QUOTE]
and fuel filter brand, if replaced. Only a couple brands are known to provide the right pressure with the integrated regulator

Ecomike 09-10-2017 12:47 PM

Re: hard starting 2001 SL1
 
About 280,000 miles. New fuel system installed about 8 years ago, about 60,000 miles ago. There have been no signs of it actually running lean. Not running hot and fuel usage increased, not decreased. And lots of power at the gas pedal on demand. Runs perfectly normal at up to 80 mph, tons of power, running cool/normal. So I have no reason to suspect any fuel issues. Primary O2 sensor is only about 35,000 miles and 5 years old.

Got the P0401 and 410 codes on the last drive cycle, the ones I have been fighting for years now.

[QUOTE=fdryer;2254176]Mileage of this car? Fuel filter replaced? Fuel pressure?[/QUOTE]

Ecomike 09-13-2017 06:03 PM

Re: hard starting 2001 SL1
 
Latest update. Clearing the lean OBD code has improved the MPGs from about 22 to to about 28, and improved the starting ease. And it has not returned. Still getting the P0401 code, but not the lean code last 300 miles. I will update this as times goes by.

Ecomike 09-25-2017 09:12 PM

Re: hard starting 2001 SL1
 
Does anyone know if the fuel pump has two separate power paths in the run and start(crank) positions of the ignition switch?

billr 09-25-2017 10:18 PM

Re: hard starting 2001 SL1
 
I'm pretty sure it is a single path, a relay controlled by the PCM. The ignition switch has no direct control at all.

fdryer 09-25-2017 11:26 PM

Re: hard starting 2001 SL1
 
^ Correct. At ignition on time, engine off, the PCM program sends a two second command to the pump relay to run the pump then shuts off pumping. When the starter engages and turns over the engine, crank sensor signals are sent to the pcm to allow it to run the EFI system: turn on fuel pump, initiate the ignition system for spark and pulse injectors. The same signal from the pcm is used in two situations to power the pump relay that sends 12v power to the pump.

Ecomike 09-26-2017 10:41 AM

Re: hard starting 2001 SL1
 
Thanks for the detail, so in the PCM logic, there are two virtual paths (based on PCM input data) , but only one in the hard wiring. This rig has always (since I bought In 2008, I think, refused to start if you crank it before several of the dash monitor lights go dark. After that it use to start in 1 second. Now at random times, it varies from a clean 1-2.5 second crank to start, to three tries. The second or third try always fires up instantly!!!!! 1 in 10 starts fires up in 1-2 seconds on the first try. Runs fine, currently getting 28 mpg on mixed city/highway/drive through long wait for hamburger driving LOL. Does not seem to care if it is cold or hot starts. Cranking is great (very good battery and starter).

Thinking about sensors and contacts. Intake air temp? CPS? Time to pull out my snap on brick maybe.


[QUOTE=fdryer;2255415]^ Correct. At ignition on time, engine off, the PCM program sends a two second command to the pump relay to run the pump then shuts off pumping. When the starter engages and turns over the engine, crank sensor signals are sent to the pcm to allow it to run the EFI system: turn on fuel pump, initiate the ignition system for spark and pulse injectors. The same signal from the pcm is used in two situations to power the pump relay that sends 12v power to the pump.[/QUOTE]

Ecomike 09-26-2017 02:12 PM

Re: hard starting 2001 SL1
 
Today, with the AC running, in park or neutral the engine ran nice and quite at a rock solid steady 900 rpm. But in drive at a drive in, zero MPH, AC still on, it began cycling rpms and dropping 100 rpm (like it wanted to die maybe) to about 700 rpm and running back up to 800 rpm. But it does not do it neutral or park.

Could the post Cat O2 sensor be dying finally and doing this with no code??? The first O2 sensor, pre cat is only 2 years old.

SRGW 09-26-2017 02:42 PM

Re: hard starting 2001 SL1
 
[B][SIZE="3"]A while back I had RPM surge [100 rpm] in drive at idle and found a dirty alternator connector. I would check alternator output at battery when rpm is changing and see if it is changing. Possible weak alternator when at operating temp.

1995 SL1 231,050 Well Oiled!! ;)
1997 SL1 62,450 Just A Teenager!! ;)
CHECK YOUR OIL!! :)[/SIZE][/B]

fdryer 09-26-2017 02:44 PM

Re: hard starting 2001 SL1
 
No dual circuit for fuel pump. It's one line, one circuit, period. One signal to run the for pump whether it's for two seconds or as long as the engine turns. The PCM detects whether the crank sensor signal is being sent to the pcm or not and determines either to run the pump for two seconds or have crank sensor signals allow it to run the pump for as long as crank sensor signals are being sent to the pcm. This isn't a pump or pump signal problem.

With mileage approaching 300k and replacing pump and filter, did you check fuel pressure? Don't assume, verify it. Guessing can be an expensive way to replace parts without determine what failed. With an intermittent starting problem, fuel and spark are the two main issues that must be verified at least once when problems don't go away. Yes, fuel and spark are there because the engine runs but no one can tell you why one or both aren't giving near instant starts which we're expecting. Starting requires instant full operating pressure from the fuel pump - that's where a fuel pressure gauge is needed to see actual pressure at ignition on time just before starting. Spark needs to be verified by a starting test in the driveway to verify spark at low starting rpm. When you verify both are consistent without problems, the next step would be a compression test. Lower than normal compression is only one reason for poor startups.

Chasing the egr and secondary air pump problems may be contributing to this issue. Addressing each problem requires eliminating one problem at a time as one or several problems can contribute to startup problems.

Ecomike 09-26-2017 03:02 PM

Re: hard starting 2001 SL1
 
I should mention that my surge is not an increase in rpms, but a rough engine drop, then a smooth increase and hold at a smooth 900 rpm for 3-4 seconds, then the cycle repeats. I will check the battery and wiring/alt voltages this week.

toggenburg 09-26-2017 03:59 PM

Re: hard starting 2001 SL1
 
I'd still replace the CPS

toggenburg 09-26-2017 05:57 PM

Re: hard starting 2001 SL1
 
^^ Ugh, sigh, I posted on wrong topic again!

Ecomike 09-26-2017 08:32 PM

Re: hard starting 2001 SL1
 
P0701 Lean code came back today. Cleared the codes and the wandering rpm in drive at a stop, when away. the P0701 code returned rapidly this time. Going to run the Snap on mt-2500 scanner on it tomorrow and check for vacuum leaks and check the ground and voltage at the battery....

I forgot to mention that first starts usually run rough for 1-2 seconds before it clears up, and sometimes dies, but then starts right up and runs fine right away on the second start.

Ecomike 09-27-2017 01:23 PM

Re: hard starting 2001 SL1
 
Well this is new one. here is what happened today in order.

I used the Snap on MT-2500 scanner, STFT was a little negative, and LTFT was a little positive, not huge way off numbers. The first (pre cat) o2 sensor was switching correctly, the post cat sensor was parked at about .395V, but the emissions monitors were not locked in yet (I cleared them last time, restart the relearn....0, and the engine was running in open loop, and was running very well, no surge, BUT!!!!

When I checked the battery voltage, and then used my multi meter to verify the SnapOn reading of the battery voltage I found a wandering battery voltage, and low system voltage with all loads on, brake lights, head lights, AC and blower on Max,... etc, it was cycling to 11.9 (lowest I saw) to 13.9 volts when all the loads were on when the engine rpm fell.

As a side note, the MT-2500 has many data outputs on the saturn I have not seen before, COLL beans!!!! Future project...

So I went to AZ, to test the bat-Alt-Starter system expecting the voltage regulator/alternator to show as bad.

Silly me, the battery tested the battery was BAD!!!! Did not even suggest charging it.....I still had reservations about the Alternator VR..... and the battery was only 2 years old :eek:

Got a new free (warranty) battery from AZ!!! :yes:

So, as expected the codes got cleared again, disconnecting the battery.

But here is the crazy news!!!!!

the OBD-II code scanner showed the system switched to a green light, all sensors and emmisions monitor locked in, in a 3 minute (or less?) drive!!! WTF???? Now a happy rig running closed loop.

Even the 5 year old P0401 and P0410 codes are gone????

I must add I did check the vac lines, the PCV valve got wiggled, the CTS and AIT sensor connectors got wiggled, but I doubt that did anything.

I have no doubt this is too good to be true, so I will be monitoring it with scanners 93 rigs I have) for several days.

But in 10 years and 100,000 miles I have never seen this rig go to a closed loop green scanner (OBD-II) ready for inspection operation in less than 30 minutes of painful drive relearn process.

I have seen very odd battery behavior, but in 45 years I have never seen this version. So far the rough engine cycling with all loads on max is gone. I still need to check the peak load battery voltage, will post up when i have more data. thanks for all the feed back folks!!!

SRGW 09-27-2017 01:38 PM

Re: hard starting 2001 SL1
 
[B][SIZE="3"] I am old school always look for the obvious. Hope it doesn't return.

1995 SL1 231,050 Well Oiled!!
1997 SL1 62,450 Just A Teenager!!
CHECK YOUR OIL!! [/SIZE][/B]


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