I'm in need of some diagnosis help here... I've searched and never found anything that was exactly similar to what I'm experiencing or had an actual resolution. So, here are the details:
Make: 1999 LC
Mileage: 185k
Location: Colorado, ~6000ft (in case altitude may be a factor)
Problem: Having issues with starting. It will turn over, but won't start on the first try. Usually it will start on the second try, but often requires a tap of the gas pedal while cranking it. Sometimes it will take many more tries to get it started with repeated cranking. Once started, it's a little weak for a few seconds, and revving it up to a few thousand rpms seems to get it going strong again. Under normal driving conditions once it's started, there are not any issues that I'm aware of.
Other notes: I've had the LC for about 2 years now, and it has had this problem since I got it. However, it has been getting much worse lately. It used to happen once every now and then, but now it seems to happen nearly every day / week. It happens much much more frequently if there is 1/4 tank of gas or less, and it also seems to occur more when the weather is very hot. Ex, yesterday it was 97 F outside and it struggled to start each time I started it up, but this morning it was closer to 65 F and it did just fine even with less than 1/4 tank.
What I've tried: I got a scanner and looked for codes - no results. I changed the spark plugs about 8k ago for regular maintenance - no effect on the problem. I've tried running premium grade fuel instead of regular - no changes. I cleaned the MAF sensor and looked at the throttle body (didn't clean it as I ran out of time and it didn't seem that dirty) - no results. I checked for disconnected/loose vacuum lines in the engine bay and found one broken port for a vacuum line on the left side of the engine (the name of it escapes me right now), so I epoxied the broken port back together and secured the loose line back on - this improved the idle a bit but did not change the starting problem.
What I need: General ideas, relevant experience with the same issue, things to check for. I know there are other things to look into, like the fuel delivery system and others. I've always suspected the fuel pump, but haven't changed it since it's a somewhat pricey part and I don't have the know how to definitively target that as the cause of the problem. Any and all help is appreciated!
Make: 1999 LC
Mileage: 185k
Location: Colorado, ~6000ft (in case altitude may be a factor)
Problem: Having issues with starting. It will turn over, but won't start on the first try. Usually it will start on the second try, but often requires a tap of the gas pedal while cranking it. Sometimes it will take many more tries to get it started with repeated cranking. Once started, it's a little weak for a few seconds, and revving it up to a few thousand rpms seems to get it going strong again. Under normal driving conditions once it's started, there are not any issues that I'm aware of.
Other notes: I've had the LC for about 2 years now, and it has had this problem since I got it. However, it has been getting much worse lately. It used to happen once every now and then, but now it seems to happen nearly every day / week. It happens much much more frequently if there is 1/4 tank of gas or less, and it also seems to occur more when the weather is very hot. Ex, yesterday it was 97 F outside and it struggled to start each time I started it up, but this morning it was closer to 65 F and it did just fine even with less than 1/4 tank.
What I've tried: I got a scanner and looked for codes - no results. I changed the spark plugs about 8k ago for regular maintenance - no effect on the problem. I've tried running premium grade fuel instead of regular - no changes. I cleaned the MAF sensor and looked at the throttle body (didn't clean it as I ran out of time and it didn't seem that dirty) - no results. I checked for disconnected/loose vacuum lines in the engine bay and found one broken port for a vacuum line on the left side of the engine (the name of it escapes me right now), so I epoxied the broken port back together and secured the loose line back on - this improved the idle a bit but did not change the starting problem.
What I need: General ideas, relevant experience with the same issue, things to check for. I know there are other things to look into, like the fuel delivery system and others. I've always suspected the fuel pump, but haven't changed it since it's a somewhat pricey part and I don't have the know how to definitively target that as the cause of the problem. Any and all help is appreciated!
