svx dies after running for a few mins what to try?

[green_eyed_lady]

Originally Posted by jrturbosvx

update. my svx is now fixed! thanks to the fuel pump module being unplugged in the rear trunk parcel.when i was working in the trunk the other day on the stereo system i must have unpugged it.i will be going for a long drive up to the berlin turnpike in a few mins to pick up some more parts to install on this svx before the reading meet in a few weeks.everyone will see the suprise parts im going to be installing when my car gets to reading. i want to specially thank john svxcess for all the time he spent trying to help me with this problem i had and thanks to svxfiles for the more than half-dozen phone conversations he had with me before John jumped in and tried to help (by calling Tom for more information and then relaying it to me).im running the same alt upgrade setup on this svx and its been working great.thanks guys for all your suggestions.see everyone at Reading!

Fixed it for you. John is not a mechanic -- where do you think he gets his information?

You're welcome.

[jrturbosvx]

first off i want to say that im a little shocked at the last comment in the fact that i at no time said i want to thank only john for his help in this latest problem.i called john to verify that my alt upgrade i did was wired correctly which it was.i have called ot so much i didnt want to keep tieing him up so i didnt want to call and bug him again.i was going to start a whole new thread thanking old tom for all the help and time he has given me over the last couple of months.in fact i sent ot some resistors when he told me he needed some and i sent them out and knew he would get me back in the future as i knew i wanted a modified resistor when he got them done,15 and 20 min mods like we had talked about. i also said i would bring him more before reading and come hang out and get some work done before reading and i still want to.Over the last 4 days between work and my svx its been a nightmare.havent had time time take pics of parts,cars or do much inventory before reading.my svx still needs work so i dont know if ill even be able to come to reading.sorry for the rant but when i saw that last post it ruined my day today.thanks josh

[oab_au]

Originally Posted by svxcess

Josh,

That's great news!

In the past whenever my car was working perfectly and then started acting abnormally, I would always think back to the last thing I did before the trouble started. I did not know you were in the trunk working with the stereo.

I would like to know in detail just how this fuel pump module/ fuel pressure modulator works. Could save many of us time in diagnosing problems.

This should be in the How-To documents somewhere.


See you at Reading!!

.

I would be surprised if the car ran at all with the pump modulator unplugged.

It is just a resistor that the ECU switches into the pump circuit to reduce the pumps speed when the need for fuel is low. The pressure is not changed, just the amount pumped through the engine circuit. This is to reduce the heat that the fuel picks-up from the engine.
The pump won't run with it unplugged.

PS. Trevor will be along to explain it in more detail.

Harvey.

[Trevor]

Originally Posted by oab_au

I would be suprised if the car ran at all with the pump modulator unplugged.

It is just a resistor that the ECU switches into the pump circuit to reduce the pumps speed when the need for fuel is low. The pressure is not changed, just the amount pumped through the engine circuit. This is to reduce the heat that the fuel picks-up from the engine.
The pump won't run with it unplugged.

Harvey.

It is bad news when a member asking for specific information is wrongly advised.

It is not surprising that the car ran with the modulator unplugged, if and when the circuitry is properly understood.

The fuel pump modulator is not “just a resistor that the ECU switches into the pump circuit to reduce the pumps speed when the need for fuel is low.

A completely separate resistor is permanently connected in series with the fuel pump. This resistor is bypassed to ground by the pump modulator when full fuel flow is required. In point of fact the modulator provides a means of increasing fuel flow, not reducing it.

If the fuel pump modulator is unplugged the fuel pump will continue to run. However the negative supply will be only via the resistor and this will mean that the pump will run only at a reduced speed.

Correct understanding of what is involved explains your problem and the fix.

When operating normally, the modulator is controlled via the ECU. This is enables full pump speed and fuel delivery to be selected to meet demand.

P.S. Harvey, in reply to your belated sarcastic P.S. N.B. I corrected your stupid mistakes, rather than explained.

[green_eyed_lady]

Originally Posted by jrturbosvx

first off i want to say that im a little shocked at the last comment in the fact that i at no time said i want to thank only john for his help in this latest problem.i called john to verify that my alt upgrade i did was wired correctly which it was.i have called ot so much i didnt want to keep tieing him up so i didnt want to call and bug him again.i was going to start a whole new thread thanking old tom for all the help and time he has given me over the last couple of months.in fact i sent ot some resistors when he told me he needed some and i sent them out and knew he would get me back in the future as i knew i wanted a modified resistor when he got them done,15 and 20 min mods like we had talked about. i also said i would bring him more before reading and come hang out and get some work done before reading and i still want to.Over the last 4 days between work and my svx its been a nightmare.havent had time time take pics of parts,cars or do much inventory before reading.my svx still needs work so i dont know if ill even be able to come to reading.sorry for the rant but when i saw that last post it ruined my day today.thanks josh

Josh,

Sorry to have jumped off the handle like that. It just kind of struck a familiar nerve to have other people thanked (John, Chike, et.al.) for information supplied here. Other people do the writeups (because they have more time and/or are faster typists) but Tom does the research and the work.

Didn't mean to ruin your day, but Tom spends an average of 8-10 hours per week on the phone with people walking them (and their mechanics) through procedures so they don't have to come here and pay us to do them -- everything from checking the trans fluid to a complete 4.44 and rear end swap. Let's see, at $20.00 per hour for consulting, we could just about break even if we charged for his 25+ years of Subaru and 15+ years of SVX experience. Instead, that money is going to some other mechanic and/or staying in somebody's pocket while Tom is "donating" his time and expertise.

By the way, that post was not prompted nor sanctioned by Tom. I think sometimes he wishes I would just "put a sock in it", but that's not my nature. Please don't hold it against him.

Glad you got your car running again. Hope to see you at Reading (or before!)

[SVX10]

Awesome! Glad you found it. Random electrical stuff is a PITA!

Originally Posted by jrturbosvx

update. my svx is now fixed! thanks to the fuel pump module being unplugged in the rear trunk parcel.when i was working in the trunk the other day on the stereo system i must have unpugged it.i will be going for a long drive up to the berlin turnpike in a few mins to pick up some more parts to install on this svx before the reading meet in a few weeks.everyone will see the suprise parts im going to be installing when my car gets to reading. i want to specially thank john svxcess for all the time he spent trying to help me with this problem i had.im running the same alt upgrade setup on this svx and its been working great.thanks guys for all your suggestions.see everyone at Reading!

[SoCal LS-L]

Harvey and Trevor, bst frnds 4evr

[Trevor]

Originally Posted by SoCal LS-L

Harvey and Trevor, bst frnds 4evr

Wrong advice becomes permanently recorded, and is likely to come up, when in the future someone searches for information. I do not consider this a good thing for the network and will continue to make corrections where desirable. The fact that a single member is so often to blame, is not my doing.

I say again -- I am not here to gain popularity regardless. If you do not like me, I do not give a damn. Rattle your dags.

[SoCal LS-L]

Originally Posted by Trevor

Wrong advice becomes permanently recorded, and is likely to come up, when in the future someone searches for information. I do not consider this a good thing for the network and will continue to make corrections where desirable. The fact that a single member is so often to blame, is not my doing.

I say again -- I am not here to gain popularity regardless. If you do not like me, I do not give a damn. Rattle your dags.

Who said anything about not liking you? IMO you are one of THE most knowledgeable people on here, and your skill with the different electrical/mechanical systems on the SVX is impressive. I was merely making a feeble attempt at humor regarding your feud with Harvey, it was something that I would say if two of my guys at our shop got into it.

Henceforth I did not mean for my joking about to become ill received, didnt mean anything negative by it, and if it bothers you Trevor, I wont say anything about it again.

[Trevor]

Originally Posted by SoCal LS-L

Who said anything about not liking you? IMO you are one of THE most knowledgeable people on here, and your skill with the different electrical/mechanical systems on the SVX is impressive. I was merely making a feeble attempt at humor regarding your feud with Harvey, it was something that I would say if two of my guys at our shop got into it.

Henceforth I did not mean for my joking about to become ill received, didnt mean anything negative by it, and if it bothers you Trevor, I wont say anything about it again.

Kia ora Chris,

There is a problem in the that both kwren and Harvey and some others rely completely on sarcasm when communicating with me. One starts to suspect sarcasm lurking within all posts. Little pictures can be misconstrued and are no substitute for the written word.

I am very sorry that we appear to have been out of step and thank you for explaining. Believe me, you have not had to convince me against my will. All is well that ends well. The negative has become positive.

Sincerely, Trevor.

[James Scott]

Originally Posted by Trevor

Wrong advice becomes permanently recorded, and is likely to come up, when in the future someone searches for information. I do not consider this a good thing for the network and will continue to make corrections where desirable. The fact that a single member is so often to blame, is not my doing.

I say again -- I am not here to gain popularity regardless. If you do not like me, I do not give a damn. Rattle your dags.

I can't find my Dags anywhere.. . Have you seen them. . ??

[Trevor]

Originally Posted by James Scott

I can't find my Dags anywhere.. . Have you seen them. . ??

Kia ora Jim,

Eh? Crikey, you are a bit of a dag. Hope you are not taking the piss out of me.

Not being a dodgy sort of a bloke and no piker, I included the required info within my post as I double do now. Do the hard yakka, have a gawk at the link below, Take a squiz at “R” for “Rattle your dags” and you will be home and hosed. Betcha!

Hooray, Trevor.

[green_eyed_lady]

Originally Posted by Trevor

Kia ora Jim,

Eh? Crikey, you are a bit of a dag. Hope you are not taking the piss out of me.

Not being a dodgy sort of a bloke and no piker, I included the required info within my post as I double do now. Do the hard yakka, have a gawk at the link below, Take a squiz at “R” for “Rattle your dags” and you will be home and hosed. Betcha!

Hooray, Trevor.

Trevor, you never fail to entertain us!

[svxfiles]

Originally Posted by Trevor

Kia ora Jim,

Eh? Crikey, you are a bit of a dag. Hope you are not taking the piss out of me.

Not being a dodgy sort of a bloke and no piker, I included the required info within my post as I double do now. Do the hard yakka, have a gawk at the link below, Take a squiz at “R” for “Rattle your dags” and you will be home and hosed. Betcha!

Hooray, Trevor.

Trevor,
sometimes, when you mix your meds, and you hear the dog talkin to ya,

Its just the meds.

[michael]

If I had a pacemaker I'd trust Trevor to diagnose and rebuild it! His dedication to in depth understanding is absolutely amazing, I often find myself at awe by some of the posts. Kudos for the commitment and time spent so the rest of us can read the cliff notes. I guess this a thank you post to all who spend time helping all of us to lazy to cook the books :/