Hitting The Gas...doesn't Budge & Fighting To Stay Crunk

[shatcher80]

I have a 1991 Lexus LS400 V8 and it has been running like a champ. Two days ago I went to get some gas 93 as usually and out of nowhere I could not get the car to accelerate. It had to be pushed up my driveway. My husband changed the spark plugs and wires thinking this would help but it didn't. Checked the fuel pump and changed the fuel pump relay 12V. The car cranks but still will not budge when we hit the gas and it seems as if it is struggling to stay crunk. Removed the MAF, to check out the throttle...the first valve is open and the second one is closed but when I hit the gas pedal the first valve doesn't respond. We are at a lost on what to do next. Not sure which route we should take...please HELP!!!!

[curiousB]

I have a 1991 Lexus LS400 V8 and it has been running like a champ. Two days ago I went to get some gas 93 as usually and out of nowhere I could not get the car to accelerate. It had to be pushed up my driveway. My husband changed the spark plugs and wires thinking this would help but it didn't. Checked the fuel pump and changed the fuel pump relay 12V. The car cranks but still will not budge when we hit the gas and it seems as if it is struggling to stay crunk. Removed the MAF, to check out the throttle...the first valve is open and the second one is closed but when I hit the gas pedal the first valve doesn't respond. We are at a lost on what to do next. Not sure which route we should take...please HELP!!!!

Well the obvious thing to try is to see if your gas was OK. Maybe add some additive like HEET in case there is some water in the fuel. Other than this you need to narrow done if it is fuel or spark related. Pull a plug wire and hold close to block and while cranking see if a spark arcs to the block. Maybe better put on of the old spark plugs on a spark wire and ground it to block and see if it is sparking while cranking. If it is sparking I'd check on fuel pump, relays, wiring. If no spark then you need to check coils, wiring, crank position sensor, ecu, ignition switch, fuses, ....

and if you can suggest it subtly have your husband recheck the plug wiring order. I wouldn't have done that as a first order of business but now that he has its possible he's compounded things by reversing a couple of wires...

[landar]

New one on me....

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Main Entry: crunk

Pronunciation: \ˈkrəŋk\

Function: noun

Etymology: crunk, word of fluctuating meaning used during the 1990s in lyrics of the rap groups OutKast and Lil Jon & The East Side Boyz

Date: 2000

: a style of Southern rap music featuring repetitive chants and rapid dance rhythms

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So, the engine cranks and starts but it barely crunks (idles)?

[AzHotLS]

good one landar, I thought about making some wise aker remark but laid off.

I must be getting old

[shatcher80]

New one on me....

//***********************************

Main Entry: crunk

Pronunciation: \ˈkrəŋk\

Function: noun

Etymology: crunk, word of fluctuating meaning used during the 1990s in lyrics of the rap groups OutKast and Lil Jon & The East Side Boyz

Date: 2000

: a style of Southern rap music featuring repetitive chants and rapid dance rhythms

//**************************************

So, the engine cranks and starts but it barely crunks (idles)?

[shatcher80]

New one on me....

//***********************************

Main Entry: crunk

Pronunciation: \ˈkrəŋk\

Function: noun

Etymology: crunk, word of fluctuating meaning used during the 1990s in lyrics of the rap groups OutKast and Lil Jon & The East Side Boyz

Date: 2000

: a style of Southern rap music featuring repetitive chants and rapid dance rhythms

//**************************************

So, the engine cranks and starts but it barely crunks (idles)?

[shatcher80]

Very funny. Anyway, the throttle body has been cleaned and the engine sounds great but still struggling to stay idle :o , do I need a new TPS because the check engine light, trac light, and trac off light are coming on and staying on now.

[1990LS400]

Very funny. Anyway, the throttle body has been cleaned and the engine sounds great but still struggling to stay idle :o , do I need a new TPS because the check engine light, trac light, and trac off light are coming on and staying on now.

Have you checked for diagnostic codes? http://www.lexls.com/tutorials/intro/codereading.html

[landar]

Very funny. Anyway, the throttle body has been cleaned and the engine sounds great but still struggling to stay idle :o , do I need a new TPS because the check engine light, trac light, and trac off light are coming on and staying on now.

Sorry, not trying to be funny but just trying to understand the issues. You know, from your latest description, it almost sounds (and I know this does not seem to fit) like a battery that is on the way out. Or an alternator. I have heard of them causing these kinds of symptoms in a Lexus. Just curious, how old is the battery in your car?

As Jim mentioned, it would be good to get a reading of the engine codes.

[curiousB]

Very funny. Anyway, the throttle body has been cleaned and the engine sounds great but still struggling to stay idle :o , do I need a new TPS because the check engine light, trac light, and trac off light are coming on and staying on now.

I'm having troubling following this. Symptoms as reported:

1) car runs great

2) add gas

3) Won't start at all

4) Change plugs and plug wires

5) car still won't start

6) clean throttle body and car runs beautifully just doesn't idle smoothly

what was done to go from not starting to running smoothly except for idle as the steps above wouldn't have cured that.

Anyway if your only symptom is now erratic idle I'd suggest cleaning the IACV. It may be dirty or sticky leading to poor idle. I doubt TPS has anything to do with erratic idle.

[shatcher80]

Very funny. Anyway, the throttle body has been cleaned and the engine sounds great but still struggling to stay idle :o , do I need a new TPS because the check engine light, trac light, and trac off light are coming on and staying on now.

Have you checked for diagnostic codes? http://www.lexls.com/tutorials/intro/codereading.html

Unfortunately, one of our friends has an OBDII instead of the OBDI so he wasn't able to read it, but if I could I would drive it to Autozone since they do diagnostics for free but the car continues to shut off.

[AzHotLS]

Unfortunately' date=' one of our friends has an OBDII instead of the OBDI so he wasn't able to read it,[/quote']Right, you can't read OBDI codes with a OBDII reader. Read the tutorial closer, you use the short piece of wire and count the blinks to determine the code.

[shatcher80]

Unfortunately' date=' one of our friends has an OBDII instead of the OBDI so he wasn't able to read it,[/quote']Right, you can't read OBDI codes with a OBDII reader. Read the tutorial closer, you use the short piece of wire and count the blinks to determine the code.

Ok, the TPS had nothing to do with it. I replaced it and the car is still doing the same thing but I finally read the diagnostic codes and I am getting:

24 Intake air temp. sensor signal

31 Air flow meter signal

What does this mean? Where are these sensors located? What can I do to the fix problems?

[VBdenny]

crunk huh? sounds like you got a bad load of fuel, unless you believe in coincidences

[shatcher80]

I have replaced the MAF according to a diagnostic the old one was only providing 5V when it should be 12V. The mechanic was going to charge me $300 for the MAF and $50 for the labor. Of course I went to ebay and got the part for $59.99 and my husband put it on. The car starts and idles and 1000 rpm but after about five minutes just shuts off. Plus I still can't accelerate on the gas. The car goes in gear but shuts off as soon as I hit the gas. I'm not sure what else to do. Any suggestions?

[landar]

I have replaced the MAF according to a diagnostic the old one was only providing 5V when it should be 12V. The mechanic was going to charge me $300 for the MAF and $50 for the labor. Of course I went to ebay and got the part for $59.99 and my husband put it on. The car starts and idles and 1000 rpm but after about five minutes just shuts off. Plus I still can't accelerate on the gas. The car goes in gear but shuts off as soon as I hit the gas. I'm not sure what else to do. Any suggestions?

Check the fuel pressure at the rail The theory is that you got a bad(dirty) tank of gas and perhaps the filter plugged(have you replaced the fuel filter?). Try a little experiment. With the engine running and in park, spray some starter fluid into the air intake just as you are putting the car in gear. If the engine stays crunk, you may have a fuel starvation issue. If not, you may have an ignition issue.

[shatcher80]

I have replaced the MAF according to a diagnostic the old one was only providing 5V when it should be 12V. The mechanic was going to charge me $300 for the MAF and $50 for the labor. Of course I went to ebay and got the part for $59.99 and my husband put it on. The car starts and idles and 1000 rpm but after about five minutes just shuts off. Plus I still can't accelerate on the gas. The car goes in gear but shuts off as soon as I hit the gas. I'm not sure what else to do. Any suggestions?

Check the fuel pressure at the rail The theory is that you got a bad(dirty) tank of gas and perhaps the filter plugged(have you replaced the fuel filter?). Try a little experiment. With the engine running and in park, spray some starter fluid into the air intake just as you are putting the car in gear. If the engine stays crunk, you may have a fuel starvation issue. If not, you may have an ignition issue.

I think it is fuel starvation. How can I check the fuel pressure? What is the reading suppose to be if I get someone else to check it? So far I have had bad experiences with mechanics.

[landar]

Take a look at this thread for a fuel gauge -> http://us.lexusownersclub.com/forums/index.php?showtopic=65270&st=0&p=413824&hl=fuel%20pressure&fromsearch=1entry413824

[shatcher80]

It was the "FUEL PUMP" after all. My fuel pump was 19 years old and once I replaced it the car runs fine but I noticed that it is idle slightly high. I'm hoping to adjust the TPS and that will fix the problem.

[curiousB]

I'm hoping to adjust the TPS and that will fix the problem.

I wouldnt do this. Idle speed is under ECU control. The IACV valve is modulated (opened and closed) to achieve the desired idle RPM. This is a closed loop system unlike the old days of carburators (open loop).

Erratic idle can be due to dirty throttle body and or dirty or sticking IACV. I'd start by cleaning those up first if you are sure idle RPM is incorrect. Its good maintyenance to clean those periodically anyway so your time won't be in vain.

[VBdenny]

Sh...., well stuff you don't want in gas. Fuel filter is probably clogged and as it runs or has a demand, it shuts down. Might not be right but it would be the very first thing I checked.