97 Lesabre Hard Starting


Smith1000
06-16-2008, 06:11 PM
I have a 97 with just under 200,000 miles on it. Recently, it has been hard to start in the morning. It usually fires the first time, but immediately dies. Sometimes I have to crank on it and press the gas pedal slightly. It will then start and run fine/normal. It runs great otherwise.

No codes have set due to this problem. The fuel pump has never been replaced. It seems fuel related. Are there any other potential items to check? Could it be the fuel pressure regulator valve? Thanks.

maxwedge
06-16-2008, 07:43 PM
I'd check fuel pressure at start up, key on make sure it primes to 41-47 psi. Also how recent is the fuel filter, get past this and next step is a scan to look at the temp sensor input.

happydog500
06-16-2008, 07:56 PM
I had, not the same problem, but one simular. It ended up being my fuel pump. maxwege is right. You need to check the fuel pressure.
Chris.

Smith1000
06-17-2008, 09:17 PM
Thanks. I'll check the fuel pressure this weekend. This afternoon, it started fine. The fuel pump must be getting somewhat weak by now.

happydog500
06-18-2008, 06:58 PM
Several people told me fuel pumps eather work or they don't. I found that was not true. On mine, after I replaced the fuel pump, I could tell it had been getting weak as time went on.
Wow! what a difference it made! I could do nice burnouts again with it.

Chris.

Smith1000
06-21-2008, 09:54 AM
I checked the fuel pressure this morning. It initially reads 50 at start up. When running, it reads 43-44. The fuel pressure is great. There are no codes. It still was hard to start this morning. Had to press into the gas pedal. In the afternoons, it is not hard to start. I'll check the temp input sensor next.

maxwedge
06-21-2008, 03:16 PM
Look for raw fuel in the hose at the FP pressure regulator.

Smith1000
06-21-2008, 04:08 PM
No raw fuel at the fuel pressure regulator hose. Just checked it. It was difficult to start, even though the temp is over 80 this afternoon. Had to press into the pedal. I haven't checked the resistance of the temp sensor yet.

Smith1000
06-21-2008, 06:58 PM
Is there only one temp sensor? I believe there is and it has 3 wires. The engine temp reads fine, but possibly one of the other leads may have a problem. Might try cleaning the iac and passages also.

maxwedge
06-21-2008, 07:07 PM
A scan will answer that question as you will get a live sensor reading, a leaking injector is another problem, check how fast the FP drops after shutoff

Smith1000
06-21-2008, 08:05 PM
Now that you mentioned it, FP is dropping fast after shut off. I noticed that this morning. I would bet it's a leaking injector over the temp sensor. I would expect a code if the temp sensor was acting up.

Smith1000
06-22-2008, 07:42 AM
Temp sensor is okay. Also, I cleaned the end of the idle air control valve and the interior passage where the tip seats. I added some injector cleaner to the fuel as well.

Jrs3800
06-22-2008, 11:50 AM
Ok... For the L36 Series II, the fuel pressure spec is 48-55 Psi( You will idle a little lower than 48 )...

But if the system is bleeding off pressure quickly, then the regulator may be bad and bypassing the pressure back tot he tank, or the Check ball in the pump may not be seating properly causing a leak down issue...

Next time you jump in the car, cycle the ignition a few times to build pressure and see if that helps the car start quicker

Smith1000
06-22-2008, 09:17 PM
Cycled it and it started right up, so it's the pressure bleeding off for one reason or another. It doesn't smell flooded after starting. Must be the check valve or the pressure regulator. There is no raw gas in the line though. Thanks.

Jrs3800
06-23-2008, 11:06 AM
Call your dealership and see if there is a recall campaign that covers the 97 LeSabre... A lot of these cars actually had to have the Fuel pressure regulator replaced due to the regulator leaking, also I believe that GM reflashed the PCM to help avoid any backfires through the intake...

Could be a replacement Fuel Pressure Regulator for you if GM covers the LeSabre under this...

happydog500
06-23-2008, 06:02 PM
My dealership once told me you can't flash a PCM. They acted like they had never heard of such a thing.
Thats the kind of stuff I'm up against in my town.

Chris.

Jrs3800
06-23-2008, 06:13 PM
Thats a pretty screwed up town... And they either didn't want to do it, or didn't know how...

My Buddy was tinkering with a 93 Bonneville SSEi Supercharged at one point.. Car is long gone... But here is my point...

He rewired the car to accept the 1997 OBDII PCM, and this would be the same as the 1997 Buick PCM... My Buddy and another one of the Guys did a lot of tuning with that PCM trying to get all of the tables right... So they flashed it, and changed it... Updated and flashed again...

In the Future we will be updating my 1995 Bonneville to the OBD2 system... And this is simply due to the tuneability standpoint...

I hate dealerships like that

Smith1000
06-24-2008, 08:02 PM
Since I have been running the fuel injector cleaner through in the gas, it has been starting great every time. Maybe it broke loose some crud in the check valve. Thanks.

HotZ28
06-24-2008, 08:43 PM
:dunno: My dealership once told me you can't flash a PCM. They acted like they had never heard of such a thing.
Thats the kind of stuff I'm up against in my town.

Chris. :wtf:

BTW, I hope I never drive my PA through "Wenatchee" and have a PCM go out! :rofl::rofl::rofl: I do not understand how anyone could work at a GM dealership and make a comment like that! Is this the same Dealer that told you that you only need 4-qts of fluid with a trans filter change on a 97 LeSabre? Maybe the guy who owns the trans shop (for 20-years) that told you the same thing, worked for this Dealer at one time? :dunno:

Remember, if you ask 10-people the same question and you get 10 different answers, it could be that no one is right. Now, if 8 people out of 10 tell you the same thing, you probably have the right answer! :iceslolan

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