It only starts long enough to die - PLEASE help

I've got a 95 wagon. I DROVE the car to where it sits and it ran fine. I recently swapped rear ends in the car, and when the ass was up and the nose wasn't - I hit the key to start the car. It started but immediately died. I could give it throttle and it would sputter a bit, but then die within seconds.

Figuring it may just be low on fuel, I poured in 5 gallons of gas, and it didn't help.

I then jacked up the front of the car to level it out, which also didn't help. It started long enough for me to run to the front of the engine and give it huffs of carb cleaner, and only stayed running as long as I keep doing that.

I then checked the fuel pressure and it was low and inconsistant. It was about 32 at startup, then bobbled around the 20's depending on how much throttle I was giving it.

So I just finished installing a new fuel filter on the rail and a new fuel pump with sock inside the tank. I was SURE this was it, but as soon as I hit the key - it only started long enough to die again - and it still only stays running if I let it huff carb cleaner.

I'm going to change fuel rails tomorrow with one that I'm sure is good - which will give me a different fuel pressure regulator, but I'm not sure that's going to help either.

So for real, if the car DRIVES to a spot then quits running - and you know it's got to be fuel related - and you install a new pump and filters - what the hell else COULD it be?

I need this car back on the road ASAP - so any and all help is greatly appreciated.


Thanks in advance,

John

sounds like the vats might be shutting it off,..?? you use a different key?

if you hot wire the fuel pump will it stay running? got a noid light? do the injectors shut off?
if the ecm doesn't see oil pressure (4 psi) after so many secs,., it'll shut off too,.
check you didn't wreck the ground for the fuel pump,.

nick

Sounds to me when you were jacking up the car you crushed a metal fuel line!Go back to your jacking points and
closely examine all the metal lines for damage.I dont know if there are any lines running close to your rear upper
and lower control arm mounting points but look in those areas too.
Take Care and No Smoking Under the Car
Jim aka Flasheroo

Hey Nick you want to bet a cold 6 pack of LaBatts blue on who might be right?I took a couple of girlfreinds to Niagra
Falls for a vacation and fell in love with LaBatts blue beer.Oh and I took the girls at seperate times not together.
First time we stayed above the falls and that was a blast when they opened up the barriers above the falls for the
weekend crowd.
Went back to lovely Quebec on my bike one summer in July and damn near froze my big butt off.I found out that
there was a difference between US bound Labatts and the in country kind.No hangover with the in country beer
and always had a headache with the US bought stuff.I guess drinking half a case at a time might have had some
effect but who knows.Dont drink at all now but I wouldnt mind a cold LaBatt blue now considering my level of PAIN
right now.
Wanna Bet Nick?
Jim

phantom 309 wrote:

sounds like the vats might be shutting it off,..?? you use a different key?

if you hot wire the fuel pump will it stay running? got a noid light? do the injectors shut off?
if the ecm doesn't see oil pressure (4 psi) after so many secs,., it'll shut off too,.

nick

Thanks for the suggestions.

I only have the one ignition key, I don't have a clue about the injectors, and I never tried to hotwire either pump. Being that they both act the same way, I can't imagine that I replaced an old bad pump with an identically bad new one.

If it were any of those things, how would it still stay running if I kept huffing carb cleaner down the throttle body? Maybe I'm off, but I figured that you only need fuel, air, and fire, - and you're clearly getting air - that if you have to give it a fuel source to keep running - that would by default rule IN "fuel supply" as the problem.

Also Jim - thanks too - but I actually drove the car after the rear end swap - but it was only long enough to blow a brake line, which is actually why I had the rear end in the air. I'm positive that I didn't crush any fuel lines.

Pinched fuel line/return line? Vapor canister clogged? Vacuum at the regulator?

Bewber wrote:

phantom 309 wrote:

sounds like the vats might be shutting it off,..?? you use a different key?

if you hot wire the fuel pump will it stay running? got a noid light? do the injectors shut off?
if the ecm doesn't see oil pressure (4 psi) after so many secs,., it'll shut off too,.

nick

Thanks for the suggestions.

I don't have a clue about the injectors,
, how would it still stay running if I kept huffing carb cleaner down the throttle body?
that if you have to give it a fuel source to keep running - that would by default rule IN "fuel supply" as the problem..

yes default, in supply, as the problem,. so as was listed above,. HOT WIRE the fuel pump,.which will give a known source of NON switched fuel supply,. VERIFYING you have fuel pressure at the schrader valve,.
IF the ECM decides for whatever reason to TURN OFF THE INJECTORS,.(but not the spark, foo) it will be a DEFAULT: IN SUPPLY problem,. CAPISCE??
you can have all the fuel supply and pressure in the world but if the ecm doesn't fire the injectors it ain't gonna run,.(until you introduce another fuel source,.)
vats, or oil pressure. My guess,.

Nick
JMHO
YRMV
NWEOI
PDCC

Nick

Flasher, blue sucks, end of discussion,. i can drink corona extra all day without any headache,.

1. Where would be the lest destructive place for one to hotwire the fuel pump?

2. So if the pump is running, hotwired, and it still dies a fuel death - we know it's computer related? What the heck would it up and decide to do that for? How do we make it behave?

This may sound like a stupid question, and maybe you covered this....but, have you checked the fuel pressure since installing the new pump? I've had 9c1's in the past where I've installed new fuel pumps, and had immediate issues. For example, you could hear the new pump kick on with the key as it's supposed to, but low pressure. Come to find out, the internal hose that goes from the pump to the sending unit had a split in it, basically causing a fuel leak inside the tank.

I used a borrowed pressure tester before, but I did make sure to closely inspect that hose when I had it out, and there were no leaks. It was actually holding fuel until I unsnapped the clips and released the pressure.

John,

Check your grounds really well. My VATS acted up. I first replaced my starter (would not fire) and then jumpered a wire around the vats..... IT RAN!!! I took the car up to NY for business. I went through the whole procedure do disable them (with the help of 200OZ) and THEN we found the broken grounds. It is disabled for another day!!!

Broken grounds can cause a lot of screwy problems and an easy fix. The three or four grounds at the back of the coil were bad on mine. With a rust car you may want to check all of them.

Tim

Easiest place to hot wire the fuel pump is at the connector harness coming off the tank underneath the car in the left rear corner, under the taillight. Grab a spare battery. I have one with screw-on Marine terminals so that I can add wire leads for just such a purpose.



I'm with Nick on this one, that you have a fuel problem, Witness the fact that as long as you spray starting fluid in it, it runs. As a 95, Do you have an LT1? If so the 32 lbs of pressure mentioned is no where near enough, It should be up around 42-44 lbs at 'Key on while dead headed at the regulator. Either you have a blockage as mentioned by others, or consider a split in the tank supply hose. I bet more of a split. Could even be a ruptured diaphragm in the regulator.


When you were in the tank, did you use the thin un-reinforced hose from a pump kit? I've had that crap split out twice on Shammoo, literally within miles of putting it in. Best is about 14" on reinforced hose instead. There has already been a few threads on this forum about it. Do yourself a favor, if you need to go in the tank again, ( and it sounds like you will be) buy a transmission drain plug, and install it. It will help tremendously the NEXT time you need to get in there.


When you jump the pump. listen closely , is the pump bogging down as it dead heads against the regulator in the rail, or does it sound like it's free flowing. Listen for splashing in the tank. (split hose)

Thanks guys.

Tim, I already have cleaned up all the coil grounds and even swapped in an MSD coil, so those are all clean as a whistle.

Dave, When I was working on the tank, I made SURE to closely inspect the hose. It was flexable, and in great shape. I know there weren't any splits or leaks because the hose visibly had fuel in it until I disconnected it from the pump.

Really, a tranny drain plug on the bottom of your gas tank? Sounds genius.

I finally got smart after about the third time I had to drop the tank.

John for the small effort it would take. LISTEN to what's going on in your tank. As you turn tjhe key on, you'll hear the hear the highest pitch , then bog down somewhat as it goes against the regulator.You should hear the hum of the motor BUT NO SPLASHING. Since this is such a simple preliminary test, I'd urge you to do so. If for nothing else, it will help you eliminate a cause, and move on to the next step.

I kid you not that I had a hose split after less than four miles of running. I'll never use the supplied rubber loop hose again! I'd hate to see you spend precious hours tracking down issues when it turns out to be that dumb ass crap piece of hose!


Best wishes on your success, Dave

Ok, so there's no audible splashing at the tank. I swapped fuel rails & pressure regulators - no change. I even changed computers - again, no change.

But I hooked a hotwire to the fuel pump and started it and it kept on running - and I could rev it up at will and even sustain elevated RPMs.

Now to figure out WHY it won't stay running, and Nick thinks VATS or oil pressure.

I thought the VATS would keep it from even letting the starter turn over - which was also Tim's problem too. No?

The oil is full and clean too.

When I had VATS issues, the starter would not turn over at all. Also, the "pass key fault" light on the dash would either blink, or stay on.

Yea, I don't have that.

And another datapoint to log is that it ran GREAT with the jumper wire to the fuel pump, then I unhooked it and it ran great again without it, then the third time wasn't a charm - now it's back to the original problem.

Can anybody make any sense of that?

Check your voltage at the hot wire on the connector near the pump. Check your fuel pump ground. Near the driver's tail light, I think...

Maybe you have a week wire in the sending unit??

I,m curioso as to how you actually physically hot wired the pump?? 1 wire or two??

if you spliced into the hot wire only and it ran,. then i,d mebbe guess the fuel pump relay might be pooched,..

Bewber wrote:

Yea, I don't have that.

And another datapoint to log is that it ran GREAT with the jumper wire to the fuel pump, then I unhooked it and it ran great again without it, then the third time wasn't a charm - now it's back to the original problem.

Can anybody make any sense of that?

Really sounds like a wonky oil pressure switch. It gets by-passed momentarily when you turn on the key to prime the system (thus your start) then waits till it sees pressure before it turns the pump back on. Could be the oil pressure switch is not turning on soon enough (higher pressure). The initial start is not long enough to build up pressure but removing the jumper after a start and your all right.

Don't know about all the cars but both my 91s and the 94 Caddy (and a bunch we tried at Freds at WF 08 to get gas for the demo derby) had a pig tail coming out of the harness on the passenger side firewall that allows you to jumper the FP direct to the battery. All it does is energize the relay. If this jumper works then the relay is good. If not, then its the oil pressure switch.

Bill

I used that red wire that GM provided - hanging loose right on the passenger fenderwell under the hood. Jumped a wire from that baby over to the hot terminal and the pump kicked on, then the car started right up and behaved as it should.

phastlt1 wrote:

This may sound like a stupid question, and maybe you covered this....but, have you checked the fuel pressure since installing the new pump? I've had 9c1's in the past where I've installed new fuel pumps, and had immediate issues. For example, you could hear the new pump kick on with the key as it's supposed to, but low pressure. Come to find out, the internal hose that goes from the pump to the sending unit had a split in it, basically causing a fuel leak inside the tank.

happened to me twice in about 4 months. but that's not what's going on here....

Sorry John, nothing constructive to add here except you'll have to eliminate each of the points that bring voltage to the pump

Good point, when you hot wired, did you bypass the relay?[

For some reason (incompetance) I JUST saw Bill's suggestions and that may be it.

Dave, by hotwired, I just used the factory supplied red wire that's on the passenger side. As such, I have no idea what relation that wire has to any relays.

Bewber wrote:

For some reason (incompetance) I JUST saw Bill's suggestions and that may be it.

Dave, by hotwired, I just used the factory supplied red wire that's on the passenger side. As such, I have no idea what relation that wire has to any relays.

This?

convert2diesel wrote:

Really sounds like a wonky oil pressure switch. It gets by-passed momentarily when you turn on the key to prime the system (thus your start) then waits till it sees pressure before it turns the pump back on. Could be the oil pressure switch is not turning on soon enough (higher pressure). The initial start is not long enough to build up pressure but removing the jumper after a start and your all right.

Don't know about all the cars but both my 91s and the 94 Caddy (and a bunch we tried at Freds at WF 08 to get gas for the demo derby) had a pig tail coming out of the harness on the passenger side firewall that allows you to jumper the FP direct to the battery. All it does is energize the relay. If this jumper works then the relay is good. If not, then its the oil pressure switch.

Is complete BS.

Once again...

GM built a backup into the fuel pump circuit: If the fuel pump relay should fail, once oil pressure builds, the relay is bypassed by the oil pressure switch to permit the car to start anyway. If there is no oil pressure and the relay is good, the fuel pump will still be energized.

The bypass red wire directly energizes the NO (87a) relay contacts. As long as the contacts aren't burned away, The relay solenoid can be complete junk and the fuel pump will still run.

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Wiring Diagrams -

Engine Wiring, 3 of 3 - '94/'95

- J

Well, between buying new parts and with having a parts car here to borrow parts from - so far I've replaced:

NEW:
Fuel Filter
Fuel Pump

SWAPPED IN:
Fuel Rail including Fuel Pressure Regulator
PCM
Oil Pressure Switch
Fuel Pump Relay

I also removed the drives side cargo area and inspected the ground wire there - and the whole thing looked MINT. There was no indications of trauma or drama.

And again, the only time it's run the way it's supposed to is when I've ran a hot wire from the battery to the GM supplied fuel pump hotwire wire. When doing this - it idled great, I could rap it up, I held it at like 3000rpm for about 5 seconds, it returned to idle when I let off the gas, sustained idle for about 10 more seconds, and I revved it a few more times, then shut it off.

Maybe I'm off my rocker, but with it running great with a different ELECTRICAL input indicates to me that it's not a "mechanical" problem, like a leaky tube, or pressure loss, or a bad mechanical part. It also tells me that my assessment of the ground wire at the back of the car is also good.

I'm about "-->this<--" close to finding a wire that's hot with the friggin key on and running it to the hotwire spot, and getting on with fixing the OTHER problems with the car that require it to be running.

Seriously, how can all of THOSE parts be good, and the damn thing STILL won't stay running. Like I said, it starts, then wants to die unless I repeatedly blip the throttle - but even then it only lets me blip it so many times until death catches up to it.

Ok, so I cleaned the grounds and it still did it even with the hotwired deal hooked up, so I left the pump running and looked around the back end and - you guessed it - there was a small fuel leak.

So I don't know if that's my only problem, but it's an obvious one that I need to fix before I can even think about anything else.

I stand corrected, rather rudely but corrected none the less. Problem with assuming the circuit was wired the same as some older GMs.

"If there is no oil pressure and the relay is good, the fuel pump will still be energized."

Unless your cars are wired differently then the 94 Caddy, then it appears that the PCM only energizes the relay during the start sequence. After pressure builds, power to the pump goes directly through the oil pressure switch to the pump.

From what I can see, the PCM has no idea if the pressure switch is active or not. Control of the fuel pump would be turned over to the pressure switch after start up. Otherwise, the pump would run continuously as long as the key was on, regardless of oil pressure. Sort of defeats the safety aspect of this circuit.

From John's last post it appears that we were all wrong so this discussion is purely academic. If there is a fuel leak then possibly it is a fuel pressure thing. After repairing the leak, and if it still does it thing, then pull the plug on your oil pressure switch and cross out the orange and grey wire. That should feed power directly to the fuel pump.

Bill

Bewber wrote:

Ok, so I cleaned the grounds and it still did it even with the hotwired deal hooked up, so I left the pump running and looked around the back end and - you guessed it - there was a small fuel leak.

So I don't know if that's my only problem, but it's an obvious one that I need to fix before I can even think about anything else.

I like a man that owns up to his mistakes,. shows good character,.
hows it coming now?

nick

Well the female ends of the quick connect fittings were so rusted that they weren't even hooked up correctly anymore - so I got the stuff to repair the plastic lines and retrofit new quick-connect ends onto them, but I now see that I also need new male ends at the module. They too were rusted badly and aren't reusable.

So while I know that the module is wagon specific, I doubt very much that the cover is, so the goal for this morning is to take mine to the yard and match it up to a functioning one, even if it's out of a sedan.

Evening Bewber Just curious about whether or not you got the car fixed and if so what was the eventual problem?
Thanks and take care
Jim Gordon

Awe geeze. A couple days ago I had the tank in and out 2-3 times, and the sending unit out of the tank each time and kept learning a new way for pressurized fuel to leak.

So before the night was over, I set up the latest fix so that all I'd have to do is install it and plug in the lines. So today, I go out there and position the tank up on a footstool to where I can hook up all the lines, etc - but it's still low enough to where I can see everything. So I hook it all up - climb out - add some gas - open the door - reach in - hit the key and boom, NOTHIN.

I'd left the key in the ON position two days ago and the battery was DEAD dead. After a couple hours on the charger, I hotwired the pump for a couple seconds and didn't find any leaks - so I'm optimistic about things working to get it running - but the jury is stilll out until the battery fully charges.

Thanks for askin bud. I'll let you guys know when I'm all for sure.

I feel your tank dropping pain my brutha..... I used a piece of plywood and the hydralic floor jack so I could raise/lower the tank in needed increments....

good luck

So did you put a drain in the tank last time it was out?

So this morning I went out there and hit the key and it was STILL dead dead - because when I needed an outlet for the welder - I had unplugged the battery charger that had only been plugged in for about 10 minutes.

Dave, no. I'm still not as smart as you. Not real sure I'm gaining on it either, but please don't hesitate to keep checking.

So here's another tip for you John....


PLUG THE FREAKING CHARGER BACK IN!

And, after you figure out the electricity, pick up one of these:

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Everyone that has a few cars really needs some sort of booster pack. I use mine all the time.

so does it work now?

Negatory - I've been building big signs.

Bewber wrote:

Negatory - I've been building big signs.

the ones that blow down??

did you fix the wagon yet? if so what was it??

nick

Yep, the ones that blow down - and STILL no time to look at the wagon again yet.

Wow Bewber sorry to hear about the sign and was really hoping that you fixed your wagon and
had some good news for all of us.Best of luck to you on fixing your sign and your wagon.
Take Care
Jim Gordon aka Flasheroo

Thanks Jim.

But there's been other fun stuff too - like that pacemaker I was all worried about my dad getting..... it quit working. They said that it happens like once or MAYBE twice per 200 people so they went in last week and did it all again - installing a new one.

And before he even left the hospital they could tell that THAT one was also not working. They said it was something about the leads coming unplugged - so he has an appointment on Monday with a new Dr to schedule a THIRD pacemaker surgery within a 6 week timeframe.

Oh yea too - U of M also denied my readmission to the nursing program. This means that I spent over a year and a half and THOUSANDS of dollars while unemployed just to head down a dead end road. I'm taking their hint and not going into nursing anymore.

So while I truely join you all in hoping that it runs again very soon, I also hope you guys can see just how insignificant that stupid wagon is in my life at the moment.


I'll get it going again. Probably. Eventually.

Bewber wrote:

Thanks Jim.

But there's been other fun stuff too - like that pacemaker I was all worried about my dad getting..... it quit working. They said that it happens like once or MAYBE twice per 200 people so they went in last week and did it all again - installing a new one.

And before he even left the hospital they could tell that THAT one was also not working. They said it was something about the leads coming unplugged - so he has an appointment on Monday with a new Dr to schedule a THIRD pacemaker surgery within a 6 week timeframe.

Oh yea too - U of M also denied my readmission to the nursing program. This means that I spent over a year and a half and THOUSANDS of dollars while unemployed just to head down a dead end road. I'm taking their hint and not going into nursing anymore.

So while I truely join you all in hoping that it runs again very soon, I also hope you guys can see just how insignificant that stupid wagon is in my life at the moment.


I'll get it going again. Probably. Eventually.

yes john we can see,.we ask because we care,.
Hope you can mange all your lifes challanges ok,.good luck to you and yours,.

nick

Amen Brother.. We'll all wish the best fro your dad.

Thanks guys. We'll be allright.

Apparently at some point of chasing down actual fuel related issues, and checking the schrader valve to make sure I still had pressure, etc - whoever was working on my car stopped putting home plate back on. They also left the MAF plugged in.

The result was that once my actual fuel pressure issues were resolved, it still acted the same way because of the air intake being only HALF hooked up. Anyway, the fuel system is back together and the tank is back in the car and it seems to run just fine so far.

So now that it'll stay running, I get to go back to working on locating that horrible screeching sound that was coming from the drivetrain.

I know the score is only "one down & ? to go", but it's a gorgeous day outside and I'm gonna celebrate whatever victories I can.

Thanks for all the support guys - and if you ever need someone to tell you to plug home plate back in, don't hesitate to call Crovo. He's really good at it!

What amazing timing of things having issues with this car.

The problem that kept the car from running as soon as I had a legitimate fuel issue turned out to be air related.

And the horrible screeching sound that came from the car - but didn't show up until I swapped rear ends and repaired a brake line turns out to be a front wheel bearing.

Hopefully a little TLC and some grease and I can at least get all for corners on the ground tomorrow for the first time in months.

ROFLMAO! Ok, now that's funny.