'92 LT1 hard starting
#1
'92 LT1 hard starting
Hello All,
I have researched most of the past topics regarding this subject... but seems mine is slightly different - here is my scenario;
[ul][*]Vehicle was running perfect 4 days ago.[*]Typically, in the morning or if it is a "cold" start, the motor would fire up immediately, idle high for a moment, then settle down to a nice idle.[*]If the vehicle was warm, it would take slightly longer to fire up, but the time was always consistent (hot or cold).[*]Now, from a cold start, it takes extended cranking (starter is fine, motor turns over as it always has - fast. New battery since about 1 month ago - old battery had a leaking side post) and then fires up. Also, fuel pressure regulator is new, replaced the old one as preventive maintenance although there was nothing wrong with it and the vehicle ran O.K. before and after the replacement.[*]After vehicle starts, it runs great, no problems, hesitations, nothing unusual.[*]Occasionally, it will fire up as normal, but most of the time now, it takes extended cranking tofire up.[*]I have not performed any diagnosis as of yet - looking for feedback first. But I have the following in mind: Fuel pump, one or more injectors took a dump, Optispark, ignition coil.[/ul]
Thanks,
Nick
Any comments?
I have researched most of the past topics regarding this subject... but seems mine is slightly different - here is my scenario;
[ul][*]Vehicle was running perfect 4 days ago.[*]Typically, in the morning or if it is a "cold" start, the motor would fire up immediately, idle high for a moment, then settle down to a nice idle.[*]If the vehicle was warm, it would take slightly longer to fire up, but the time was always consistent (hot or cold).[*]Now, from a cold start, it takes extended cranking (starter is fine, motor turns over as it always has - fast. New battery since about 1 month ago - old battery had a leaking side post) and then fires up. Also, fuel pressure regulator is new, replaced the old one as preventive maintenance although there was nothing wrong with it and the vehicle ran O.K. before and after the replacement.[*]After vehicle starts, it runs great, no problems, hesitations, nothing unusual.[*]Occasionally, it will fire up as normal, but most of the time now, it takes extended cranking tofire up.[*]I have not performed any diagnosis as of yet - looking for feedback first. But I have the following in mind: Fuel pump, one or more injectors took a dump, Optispark, ignition coil.[/ul]
Thanks,
Nick
Any comments?
#2
RE: '92 LT1 hard starting
Sounds like the fuel pump relay might be bad. Your car has a redundant voltage supply to the fuel pump, through the FP relay and through the oil pressure switch. Typically, when you have extended crank times, you are having to wait for the car to build oil pressure though the sender to engage the fuel pump switch built into the oil pressure switch. Watch your fuel pressure when cranking and you probably will see.
#3
RE: '92 LT1 hard starting
Hello All,
I started to troubleshoot the starting problem this morning... went to Advanced Discount Auto Parts to buy a fuel pressure gauge. When I came back home I swapped out the factory fuel pump relay, but it had no effect on my problem. Oh well, at least the relay will not have to be replaced again! So, I go to connect the fuel pressure gauge (had to make some room first by disconnecting a few things) and noticed that when I disconnected the fuel pressure regulator vacuum line, fuel squirted out. I new immediately that the regulator was defective, even though it was replaced 5 months ago. I called the auto parts store, from which it was purchased, and it was replaced under warranty. This particular part was a Tru-Tech PR92T (Made in the USA too). The parts guy said that he was surprised it was defective, but things like this happen. We will see. If it goes kaput again, I'll buy an original AC/Delco I imagine.
Thanks Mech for the help,
Nick
I started to troubleshoot the starting problem this morning... went to Advanced Discount Auto Parts to buy a fuel pressure gauge. When I came back home I swapped out the factory fuel pump relay, but it had no effect on my problem. Oh well, at least the relay will not have to be replaced again! So, I go to connect the fuel pressure gauge (had to make some room first by disconnecting a few things) and noticed that when I disconnected the fuel pressure regulator vacuum line, fuel squirted out. I new immediately that the regulator was defective, even though it was replaced 5 months ago. I called the auto parts store, from which it was purchased, and it was replaced under warranty. This particular part was a Tru-Tech PR92T (Made in the USA too). The parts guy said that he was surprised it was defective, but things like this happen. We will see. If it goes kaput again, I'll buy an original AC/Delco I imagine.
Thanks Mech for the help,
Nick
#4
RE: '92 LT1 hard starting
Glad you got'er fix up. I'll have to look into that on my '87.It is doing the same thing and I can't stand forit to be down. Had to wait all last weekend for tires on it. Couldn't stand it and had to break out the KX500 and abuse it for awhile. nothin' like a power rush...injoy your vette and thanks for posting your solution. Most people don't post the cures. Cheers
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