Hard starting, need help - Club Lexus Forums

Log In 

Hard starting, need help

Reply
 
 
 
Thread Tools Search this Thread
Old 07-06-09, 08:24 PM   #1
Och
Lexus Fanatic
Thread Starter
iTrader: (3)
 
Och's Avatar
 
Join Date: Feb 2003
Location: NY
Posts: 10,871
Default Hard starting, need help

In the recent couple of weeks my 01 GS430 developed a problem starting up. I need to crank it for a long time before it finally fires up, and sometimes it will only fire up on the second try. After it starts, it seems to lag a before reaching around 2500 RPMs, and then takes off like a bat.

Replaced spark plugs over the weekend with no result. Everything in the car is maintained well, new fuel filter, timing belt/water pump were recently replaced,
throttle body cleaned, new o2 sensors, new MAF, etc.

What can it be? There are no codes whatsoever. Could it be the fuel pump? And if its the fuel pump, would it be likely for the car to start hard but run well at higher RPM range?
Och is offline   Reply With Quote
Old 07-06-09, 08:28 PM   #2
Och
Lexus Fanatic
Thread Starter
iTrader: (3)
 
Och's Avatar
 
Join Date: Feb 2003
Location: NY
Posts: 10,871
Default

Oh yeah, another thing... lately it seems my fuel mileage took a huge crap, the car noticeably wastes more fuel than ever before.
Och is offline   Reply With Quote
Old 07-07-09, 06:02 AM   #3
DASHOCKER
Lexus Fanatic
iTrader: (2)
 
DASHOCKER's Avatar
 
Join Date: Jul 2004
Location: NYC
Posts: 12,182
Default

Long cranking is a sign of a bad fuel pump.. Was your old fuel pump bad? They seldom need replacing unless you encounter the symptoms you mentioned in your original post. I am still on my original fuel pump with 106k on the clock.
DASHOCKER is offline   Reply With Quote
Old 07-07-09, 07:30 AM   #4
McKrevice
Lexus Test Driver
iTrader: (1)
 
McKrevice's Avatar
 
Join Date: Feb 2008
Location: The State of Hockey
Posts: 900
Default

I'd say pump like mentioned. When you turn the key, pressure builds up, but the pump appears to be losing pressure causing it to crank and crank. Not sure if our cars have a fuel pressure regulator, but if so, that might also be the issue.
McKrevice is offline   Reply With Quote
Old 07-08-09, 12:49 AM   #5
Och
Lexus Fanatic
Thread Starter
iTrader: (3)
 
Och's Avatar
 
Join Date: Feb 2003
Location: NY
Posts: 10,871
Default

Hey guys, before I drop money down on a new pump, is there a way to test it to know for sure? Like testing the fuel pressure?
Och is offline   Reply With Quote
Old 07-08-09, 01:30 AM   #6
denut-L
Lexus Test Driver
iTrader: (11)
 
denut-L's Avatar
 
Join Date: Mar 2008
Location: mN
Posts: 1,266
Default

My brother had the same problem but he has a camry and we put in some fuel injector cleaner and problem solved.

No hesitation at low rpm's and start up's

GL
denut-L is offline   Reply With Quote
Old 07-08-09, 12:21 PM   #7
GS4_Fiend
Lexus Fanatic
iTrader: (22)
 
GS4_Fiend's Avatar
 
Join Date: Aug 2008
Location: CA
Posts: 6,665
Default

You would need a fuel pressure gauge. The pump is probably weak. Also make sure there are no vacuum leaks.
GS4_Fiend is offline   Reply With Quote
Old 07-09-09, 03:59 PM   #8
jhill20
Lead Lap
iTrader: (1)
 
jhill20's Avatar
 
Join Date: May 2009
Location: AZ
Posts: 657
Default

First of all Bad fuel pumps are not common with toyota/lexus. That being said, it does "sound" like a fuel delivery issue.

You will need a fuel pressure gauge, with most likely a certain fitting to access the fuel line, not remembering off the top of my head if it has an access port or not.
jhill20 is offline   Reply With Quote
Old 07-09-09, 04:09 PM   #9
GS4_Fiend
Lexus Fanatic
iTrader: (22)
 
GS4_Fiend's Avatar
 
Join Date: Aug 2008
Location: CA
Posts: 6,665
Default

It's lacking in spark or fuel... Or even BOTH. (CKP)
GS4_Fiend is offline   Reply With Quote
Old 07-16-09, 05:31 PM   #10
knotsofast
Driver School Candidate
 
Join Date: Nov 2007
Location: TX
Posts: 2
Default Try some fuel system cleaner

I had similar symptoms, so I decided to run through a tank with fuel system cleaner. It's gotten better but not completely gone. I am now on the second tank w/cleaner; hope it clears up.
knotsofast is offline   Reply With Quote
Old 07-16-09, 06:14 PM   #11
skperformance
Lexus Champion
iTrader: (6)
 
Join Date: Nov 2002
Location: Mississauga,Ontario,Canada
Posts: 3,488
Default

At first it sounds like a pump but if it goes away at higher RPM then it is not since that is the reverse of the problem it causes since it starves the engine as it increase in demand .

I would lean to a vac leak or maf issue first.

Throttle body cleaning and seafoam are good cheap starts before replacing anything to get a base line.
skperformance is offline   Reply With Quote
Old 07-19-09, 08:41 PM   #12
Och
Lexus Fanatic
Thread Starter
iTrader: (3)
 
Och's Avatar
 
Join Date: Feb 2003
Location: NY
Posts: 10,871
Default

Well, I'll be taking the car to a professional hopefully tomorrow. I tried new maf, and bought two new coils, which I kept swapping in until I got though all eight. No improvement so far.

I think its probably fuel pump/pressure regulator/fuel dampener issue, or maybe even injectors issue. I'll update on the progress.

P.S.

This is the first real issue this car has had in its 115k miles.
Och is offline   Reply With Quote
Old 07-20-09, 09:54 PM   #13
Och
Lexus Fanatic
Thread Starter
iTrader: (3)
 
Och's Avatar
 
Join Date: Feb 2003
Location: NY
Posts: 10,871
Default

So now I pretty much know for sure the fuel pressure is too low. Theres a fuel hose going up to the engine, and compared to the same hose in my friends GS430, it feels 50% less pressurised, both when the car is on or off. I wonder now if thats the fuel pump or leaky injectors.
Och is offline   Reply With Quote
Old 07-24-09, 10:50 AM   #14
knotsofast
Driver School Candidate
 
Join Date: Nov 2007
Location: TX
Posts: 2
Default

Well w/mine, I found the previous owner replaced the vac hose on the PCV valve with plain rubber. Over time, line was collapsing from the suction. I swapped out with vac line; starting is back to normal.
knotsofast is offline   Reply With Quote
Old 07-24-09, 11:21 AM   #15
BLAZE
Lexus Test Driver
iTrader: (2)
 
BLAZE's Avatar
 
Join Date: Mar 2005
Location: fl
Posts: 1,109
Default

Check the battery, when was the last time you replaced it ? These cars run pretty f,cked up with a dying battery.
BLAZE is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Cold start issue williamb82 GS - 1st Gen (1993-1997) 31 12-10-15 05:30 AM
SC400 new fuel pump, ECU bypass, stranded again bigwhite Performance & Maintenance 27 10-12-14 09:26 AM
Gas Tank Pressure needed?!? sc400aaron Performance & Maintenance 5 07-23-14 01:23 PM
Fuel Problem Help Please!! sc400aaron Performance & Maintenance 2 07-06-14 10:48 PM
92 Es300 Wont Start, Wiring? Jekruger72 ES - 1st to 4th Gen (1990-2006) 3 01-31-11 12:17 AM


Tags
430, bad, diagram, fuel, gs, gs300, gs430, hard, lexus, lx450, part, pump, rough, seat, signs, start, starting

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -7. The time now is 09:31 PM.


Copyright © 2000-2016 Internet Brands, Inc. All Rights Reserved