Ran out of gas, car is barely running now!

[juniinc]

I ran out of gas today,,,very dumb. Put a gallon in, now she is barely running.

I barely drove home, idles funny, no more than 23~25 MPH.

Possible limp mode?

What happened? Any input would be appreciated

[juniinc]

Talked to my buddy technician, he thinks throttle adaption is thrown off.

I'm gonna try to reset it,,,leave the key on for a minute, turn off the key, pull it out, a few cycles.

Has anyone ran out of gas or experienced this??

[wvicary]

Never heard of it causing an issue like this before.

[juniinc]

Cel on, scanned, P1502,,,so I tried to perform the throttle adaption.

No luck, just getting frustrated. I must have tried more than 20 times, ,,,still won't rev no more than 2000rpm.

I disconnected the battery then hooked it back up,cel gone, turn the key on for 1minute,turn it off for 10sec, pull the key out,,, I know the trick is wait til U Hear the TB motor engaging then leave it for a minute. Seems like no matter how many cycles I try my TB motor is not engaging at all.

Maybe it will take 30 key cycles LOL I'll open up the engine bay, dig it a little further tomorrow.

[JFP in PA]

What year and model is the car? P1502 it a throttle jacking code on some years, and a fuel pump relay code on other years..............

[logray]

It's a 2001, ME 7.2

P1502 Throttle jacking unit, spring test

That's the third or fourth one of these in the last couple weeks!

[juniinc]

2000 986 S.

Thanks for bringing that up, I think it is the throttle unit for my car.

Fuel pump shouldn't turn on at all with a bad relay, should it?

I heard sometimes it takes more than 10~20 key cycles to get this adaption programmed. Maybe my DME needs to be re-flashed who knows!

Edited February 17, 2012 by juniinc

[logray]

Hey what's that in your profile then, it says 2001? ;)

Same DME as 2001, same code.

To reset adaption, key on engine off 1 min. Key off 10 sec. key on again, Check and erase faults with code reader (i.e. durametric).

No the fuel pump would not activate if it doesn't have power.

[JFP in PA]

2000 986 S.

Thanks for bringing that up, I think it is the throttle unit for my car.

Fuel pump shouldn't turn on at all with a bad relay, should it?

I heard sometimes it takes more than 10~20 key cycles to get this adaption programmed. Maybe my DME needs to be re-flashed who knows!

Relays sometimes fail by going intermittant (sometimes work, sometimes do not). When this happens, the fuel pressure starts jumping all over the place.

Edited February 17, 2012 by JFP in PA

[juniinc]

Relay fails as soon as I run out of gas, very rare coincidence don't u think?

unless it has something to do with low or no fuel pressure.

When I was cycling the key, as soon as I turn the key on I can hear the fuel pump come on but, doesn't CUT OFF at all?

I'm also wondering the cel code p1502 has to be cleared in order to reset this throttle adaption,,,I don't have a durametric at this point .

When u disconnect battery, I wonder if that clears fault code?

[JFP in PA]

Relay fails as soon as I run out of gas, very rare coincidence don't u think?

unless it has something to do with low or no fuel pressure.

When I was cycling the key, as soon as I turn the key on I can hear the fuel pump come on but, doesn't CUT OFF at all?

I'm also wondering the cel code p1502 has to be cleared in order to reset this throttle adaption,,,I don't have a durametric at this point .

When u disconnect battery, I wonder if that clears fault code?

Relays fail under these conditions due to the excessive load on them when the pump starts to go in and out of cavitations as the fuel runs out; so no, it is not a coincidence.

Pulling the battery cable will clear the P1502 code, as will any scanner.

[juniinc]

Thx, are there identical relays down there? If they are I will swap em around. See what happens.

[JFP in PA]

The relay is in the panel above the fuses in the left footwell, upper row, second from the left. You can pull the relay and jumper terminals 3 and 5 in the relay panel to simulate an operating relay (pump will be on all the time). The relay itself is a $10-12 item at retail, so I wouldn't put too much time into it.............

[juniinc]

Thx JFP & logray. Will update soon

Edited February 17, 2012 by juniinc

[juniinc]

Problem solved for a few minutes this morning,,, started her up rpm won't go no more than 1500 then, I turned it off, back on for 1 minute, off for 10 sec, pulled it out then she started fine everything back to normal. Took her around the block, running like a champ. Back to the garage shut her off then started ,,,problem came back & still continues.

Weird

Edited February 26, 2012 by juniinc

[AndyA6]

Uhmm, just thinking and by no means I am a tech or something......

Sediment in the tank got sucked into the fuel filter and possibly further up thus causing problems?

[phillipj]

Just goes to show NEVER run these cars out of gas. It always end up in tears... Right Loren?

Edited March 8, 2012 by phillipj

[necad]

Did you find the cure?

I did everything you did, and more. Luckily, or unluckily our winters are long, so I messed around with it all winter. Checking all the wiring, controls, etc.. Finally sent the DME unit to be checked. Will know the results in a few days.

I was just wondering what the fix is. No one I have seen on the inet has ever posted a resolution. I doubt there are thousands of these cars in garages not running. I do not have the luxury of being near a dealer or a qualified tech. Been working on my own pcars for over 12 years, but this one has me stumped.

[AndyA6]

Yeah, update?

[mikefocke]

Ever check the fuel pump which is, on some model years, cooled by the gas in the tank? I can see running dry cooking the pump. I'd be looking at a fuel pressure check assuming that one abnormality was somehow associated with the other.

[juniinc]

No cure yet,,, haven't check the fuel pump yet.

It does feel a lot like a clogged filter or perhaps my pump is toasted as mikefocke mentioned. I believe these 2000 internal fuel pumps has a sock(mesh) filter,,,hard to clog that I'm thinking.

I will check the fuel pressure asap, is there any DIY For doing this?

Also waiting to hear Necad's result, I really think this really has something to do with throttle adaption communicating DME.

Edited April 30, 2012 by juniinc

[bar10dah]

I will check the fuel pressure asap, is there any DIY For doing this?

You can start with post #19 here: http://www.renntech.org/forums/topic/32106-code-p1124-p1126-p0446/

I followed those links Logray posted, bought the right equipment, and tested my fuel pressure pretty easily. Somewhere further down those posts, I even put up links for where I bought my fuel tester (and adapter) from. Also, I believe the second link Logray posted in #19 says you can pick up an A/C tester that'll have the correct adapter for the fuel pressure tester port.