Hard start issue when warm (1 Viewer)

[lwarden]

I've done some searching and think I have things narrowed down to a fuel pump, but wanted to check to see if I'm on the right track

1999 LC with 250K on the clock. Car starts fine when cold, but when warm it take a while to start. It will start eventually, but sometimes take 5 seconds or so.

I thought it might be a leaky injector, but now I'm thinking fuel pump. I pulled off the fuel line leading from the fuel filter to the fuel rail and was surprised to see very little fuel come out. Then I put a pressure gauge on it and cranked the engine. The pressure came up very slowly to 40 PSI then went up to 80. Once I let the key off it went back down to 10 PSI almost immediately. I was expecting to see the pressure stay up so expect it's the pump.

Does this sound like the right diagnosis? Fuel filter has never been replaced so that will be done too, but I don't see that being the problem since the pressure does not hold and there isn't any issue with the performance once the car starts.

Appreciate your input.

 

[abuck99]

You're prob on the right track. FP are 200-250k mile life span.

If you have the FSM in .pdf form, you can search the DI section (diagnostics) use the search tool to enter some key words like; "starting", "difficult to start" etc and browse the various hits you get. You can see 4 results for the search I did. Keep electing "next" to see the next association. Then go to the section it suggests: DI-336, DI-350. If you have access to tech stream you can run some diagnostics as well to help narrow in.

Like this:

 

[OEMGUY0720]

Fuel pump it is. While you’re at it do the fuel filter as well so your fuel delivery system pre-injectors are ruled out to be brand new and in perfect working condition.

 

[lwarden]

Replaced the fuel pump and that seemed to have fixed it. Also replaced the fuel filter and FPR just for good measure. Hopefully good now for another couple hundred miles.
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