fuel trouble - sevenstock trip in jeopardy
09-26-02, 11:46 AM
#1
fuel trouble - sevenstock trip in jeopardy
I am having trouble getting the car started after weeks of work, if I can't get it up and running by Friday Sevenstock is out for me.. I am stumped right now and need some advice on where to look. Here are the Cliffs notes to get everyone up to speed:
Originally went in to do a turbo replacement procedure (originals had 97k and were leaking oil), I had previously had a hunting idle once in a while so I decided to remove the UIM and LIM as well to check the gaskets out and do a hose job. While doing this I figured it also made sense to take the injectors out and get them cleaned at RC, I also drilled and tapped the rails for NPT/AN fittings. Fabricated all my own SS lines and fittings, removed the pulsation dampener, mounted an Aeromotive FPR and ran all the lines through that. So I had the hose job done (99% sure I have everything in the right place, studied the diagram very closely), new turbos mounted, everything ready to go.
Here is where I ran into trouble, first pressure test I jumpered the fuel pump on and bingo.. sprung a leak on one of the rails where I had installed an NPT fitting. Removed that, tightened up the fitting, reinstalled. Pressure test #2 went ok, I adjusted it up to 38psi roughly with no detectable leaks. Reinstalled the UIM/throttle body, attempt to start the car.. no luck, just cranks over and over but would not start. I decide to pressure test again w/o the motor on, jumper the pump, pressure shoots up to 38psi quickly.. ok I think. I pull the jumper wire and now notice that the fuel pressure is slowly dropping immediately, falls back to 0psi within 10 seconds. Damn I think, it is not holding pressure somewhere.. but where? I remove the UIM again, pressure test, no external leaks anywhere. Hmm, I figure that the 850cc injectors I installed in the primary rail are not sealing and are flooding the motor. I take those back out, put the original 550cc injectors back in and decide to worry about an injector upgrade later. Pressure test #3 checks out, shoots up to 38psi.. I pull the jumper wire and the pressure stays up for much longer now.. but still falls back to 0psi within a couple of minutes. Shouldn't it stay at 20psi or so even overnight? I saw screw it and try to start it, I perform the anti-flood procedure (floor the gas before you crank it) a couple times, then try a real start. Well I got it to start, but I can't keep it running.. it sputters to life for a few seconds and just dies no matter how I modulate the gas pedal. By this point I am quite frustrated, I check the fuel pressure gauge when I get out and it is back to 0psi.. somehow the fuel pressure is not being kept up. So I am stumped, the fuel pump is a nearly new RP Denso unit, injectors have been cleaned, no external fuel leaks that I can see or smell. What could the problem be? I am beginning to point at the Aeromotive FPR unit but it checks out during testing.. I am close to my wits end after 3 weeks of work on this car. TIA, and sorry for the long post.
Matt
93 SSM
Originally went in to do a turbo replacement procedure (originals had 97k and were leaking oil), I had previously had a hunting idle once in a while so I decided to remove the UIM and LIM as well to check the gaskets out and do a hose job. While doing this I figured it also made sense to take the injectors out and get them cleaned at RC, I also drilled and tapped the rails for NPT/AN fittings. Fabricated all my own SS lines and fittings, removed the pulsation dampener, mounted an Aeromotive FPR and ran all the lines through that. So I had the hose job done (99% sure I have everything in the right place, studied the diagram very closely), new turbos mounted, everything ready to go.
Here is where I ran into trouble, first pressure test I jumpered the fuel pump on and bingo.. sprung a leak on one of the rails where I had installed an NPT fitting. Removed that, tightened up the fitting, reinstalled. Pressure test #2 went ok, I adjusted it up to 38psi roughly with no detectable leaks. Reinstalled the UIM/throttle body, attempt to start the car.. no luck, just cranks over and over but would not start. I decide to pressure test again w/o the motor on, jumper the pump, pressure shoots up to 38psi quickly.. ok I think. I pull the jumper wire and now notice that the fuel pressure is slowly dropping immediately, falls back to 0psi within 10 seconds. Damn I think, it is not holding pressure somewhere.. but where? I remove the UIM again, pressure test, no external leaks anywhere. Hmm, I figure that the 850cc injectors I installed in the primary rail are not sealing and are flooding the motor. I take those back out, put the original 550cc injectors back in and decide to worry about an injector upgrade later. Pressure test #3 checks out, shoots up to 38psi.. I pull the jumper wire and the pressure stays up for much longer now.. but still falls back to 0psi within a couple of minutes. Shouldn't it stay at 20psi or so even overnight? I saw screw it and try to start it, I perform the anti-flood procedure (floor the gas before you crank it) a couple times, then try a real start. Well I got it to start, but I can't keep it running.. it sputters to life for a few seconds and just dies no matter how I modulate the gas pedal. By this point I am quite frustrated, I check the fuel pressure gauge when I get out and it is back to 0psi.. somehow the fuel pressure is not being kept up. So I am stumped, the fuel pump is a nearly new RP Denso unit, injectors have been cleaned, no external fuel leaks that I can see or smell. What could the problem be? I am beginning to point at the Aeromotive FPR unit but it checks out during testing.. I am close to my wits end after 3 weeks of work on this car. TIA, and sorry for the long post.
Matt
93 SSM
09-26-02, 03:07 PM
#2
I thought about this more during my lunch, when I get home I am going to perform a little test to help narrow this down. I have a hunch that the fuel pressure test is checking out fine because the motor is not ingesting fuel during it, and the pressure is falling off when the pump is turned off. The pump must be working hard enough to keep the pressure up during the test, when the motor is turned on the pressure just falls off for some reason. So I am going to shove the stock FPR into the fuel lines I ran temporarily to see if it will start or not, if it does than it is the Aeromotive FPR like I am thinking it is. At this point its either that or the pump, and the pump has been working perfect for 3 months before this. If that doesn't fix it I am going to hit some golf ***** really hard at the range..
Matt
Matt
09-26-02, 03:58 PM
#4
I haven't tested the spark, but I am pretty sure its working because it actually ran for about 5 seconds before it died. I had thought of that but as far as I can tell the ignition is working, I plan on double checking that though as well.
09-26-02, 08:13 PM
#5
You should perform a pressure test of the fuel pump, i think its called a deadhead pressure test. With the wires jumped to turn on the fuel pump, pinch the return line, the pressure should shoot up to like 90-100 psi, dont pinch the line too line, just for a sec or two. The fuel might be leaking from the little o ring on the fuel pump, or the fpr might have an internal leak. Both of these have happen to me on different times. On the other hand you might also have a big vac leak from the lower intake manifold. Which would cause you car to run like ****, make sure you map sensor is hooked up. On outlet of the fuel pump, there is this little plastic thing that keeps the fuel from flowing back into the tank, if you take it off the fuel pressue will drop pretty fast after you turn off the fuel pump. Or your injectors could be leaking. Check your grounds too, righ on top of the upper intake manifold. Good luck, hope you make it to sevenstock, i'm heading down there from S.F. on Friday.
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09-27-02, 11:16 AM
#8
Well I didn't get around to testing anything out last night, I had been putting 2-3 hours into it the last 4 days prior and I just got tired of it.. sometimes you need a break. I am testing out the fpr and pump today for sure though, I am praying I don't have to remove the UIM for the third time. I did pull the plugs when I was having the trouble and fully expected to see them soaked in gas, but to my surprise they were dry as a bone and I couldn't smell any gas inside the housing. I am still putting my money on the fpr but we'll see what happens.
Matt
Matt
09-27-02, 01:20 PM
#10
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what EMS are you using? If you're using the PFC, did you remember to change the 850cc primary BACK to 550cc primary...That will cause the car to start, but won't hold idle for crap and eventually die on you....I should know...I just did this 10 minutes ago!
09-27-02, 01:27 PM
#11
fart on a friends head!!!
also check the PIM setting if you are using the power fc. i did something like this and it was on option 1 when it should have been on normal. ya know.
paul
paul
09-27-02, 06:54 PM
#14
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Matt,
Okay, go check your spark now. All the connectors connected to the coils? Is the igniter connected? Did you change the spark plugs? Try those also. I'm feeling your pain Matt...
Okay, go check your spark now. All the connectors connected to the coils? Is the igniter connected? Did you change the spark plugs? Try those also. I'm feeling your pain Matt...
09-27-02, 10:17 PM
#15
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I am in the same boat. I spent the past three days pulling all nighters to get ready for seven stock and I also cannot start the car for more than a short period of time.
I converted to full non-sequential with complete emissions. Other than the oil leak I found, the starting problem is the only real problem. When it starts, it sounds, and feels like it is running on only one rotor.
I also pulled my injectors, and cleaned them, which is the only major difference from any other time I have pulled the UIM off. I did the ATF trick thinking that I didn?t have compression, and it did start up right away, but again, very rough, and sounded like one rotor. I checked the map sensor, plugs, plug wires, coils, and fuel injector harnesses, but nothing seemed out of line. When I pulled the plugs, the front rotor was soaked, but I could not tell if it was oil or fuel because they didn?t smell. The rear rotor plugs were fine. I replaced the front rotor plugs with some clean plugs and managed to start it again a few time, each after about 10 tries with the starter, and running only for about 3 minutes with my foot on the accelerator before dying. To start it, I had to hold the accelerator wide open until it slowly caught and gradually rose in speed. It felt very unbalanced, and loud (I?m thinking the Non-seq caused the loudness). When it was running, it smoked oil out the tail pipe despite having already burnt off the ATF. I pulled the plug a total of four times and found that the fronts were again soaked. I am lost for answers. I even change my front leading spark wire, but no help. I have this vision of the oil injector spewing into the front rotor. My only other thought is that I some how seized the primary front fuel injector, and that the oil metering is simply fouling out the plugs. I will pull that next.
Anyway, if you find an answer first, let me know, and I will do likewise.
Good luck,
Micah Robles
PS ? I hope you still come to SS5 even if you don?t have a 7 to take ?I am. Come talk to me if you get there early, I will be parking all the non-rotor cars 9:30 to 10:30.
I converted to full non-sequential with complete emissions. Other than the oil leak I found, the starting problem is the only real problem. When it starts, it sounds, and feels like it is running on only one rotor.
I also pulled my injectors, and cleaned them, which is the only major difference from any other time I have pulled the UIM off. I did the ATF trick thinking that I didn?t have compression, and it did start up right away, but again, very rough, and sounded like one rotor. I checked the map sensor, plugs, plug wires, coils, and fuel injector harnesses, but nothing seemed out of line. When I pulled the plugs, the front rotor was soaked, but I could not tell if it was oil or fuel because they didn?t smell. The rear rotor plugs were fine. I replaced the front rotor plugs with some clean plugs and managed to start it again a few time, each after about 10 tries with the starter, and running only for about 3 minutes with my foot on the accelerator before dying. To start it, I had to hold the accelerator wide open until it slowly caught and gradually rose in speed. It felt very unbalanced, and loud (I?m thinking the Non-seq caused the loudness). When it was running, it smoked oil out the tail pipe despite having already burnt off the ATF. I pulled the plug a total of four times and found that the fronts were again soaked. I am lost for answers. I even change my front leading spark wire, but no help. I have this vision of the oil injector spewing into the front rotor. My only other thought is that I some how seized the primary front fuel injector, and that the oil metering is simply fouling out the plugs. I will pull that next.
Anyway, if you find an answer first, let me know, and I will do likewise.
Good luck,
Micah Robles
PS ? I hope you still come to SS5 even if you don?t have a 7 to take ?I am. Come talk to me if you get there early, I will be parking all the non-rotor cars 9:30 to 10:30.
09-30-02, 12:36 PM
#18
Nope, haven't got it running. I haven't tested the spark because yet, I am still fixated on the fuel pressure issue. I only spent about 2 hours messing around with stuff this past weekend.. but here is where I am at now.
I pulled the Aeromotive FPR and plumbed the stock FPR into the fuel lines with some creativity
. Again, no dice.. car won't start, fuel pressure still strange. So I crossed the FPR off my list at that point and moved on to testing the fuel pump. I blocked off the delivery fuel line before it got to any of the rails and plumbed in the pressure gauge, switched on the pump.. hmmm, only got up to 35psi and would not budge. Now the pressure SHOULD be shooting through the roof with the pump's delivery line blocked. I inspected all the lines under the car, near the fuel filter, and on top of the gas tank and found no leaks. So tonight I am moving on to testing the continuity and voltage that the pump is getting.
Matt
I pulled the Aeromotive FPR and plumbed the stock FPR into the fuel lines with some creativity
. Again, no dice.. car won't start, fuel pressure still strange. So I crossed the FPR off my list at that point and moved on to testing the fuel pump. I blocked off the delivery fuel line before it got to any of the rails and plumbed in the pressure gauge, switched on the pump.. hmmm, only got up to 35psi and would not budge. Now the pressure SHOULD be shooting through the roof with the pump's delivery line blocked. I inspected all the lines under the car, near the fuel filter, and on top of the gas tank and found no leaks. So tonight I am moving on to testing the continuity and voltage that the pump is getting.Matt
09-30-02, 01:16 PM
#19
And to answer Jspecracer, everything is connected as far as the coils are concerned. I am going to take your advice and test the spark though to make sure. I do feel a little unsure about the grounding points under the UIM though.. there were two spade type connectors that I disconnected when I was working previously. One of the grounds is part of the ignition coil harness, and it just bolts on under one of the nuts that hold down the coil bracket. The other one I have grounded under one of the nuts on the top of the rack, which should work because it looked to me like the whole rack was grounded. I did notice an open threaded hole on the rear side of the UIM (near the firewall) just a bit more toward the passenger side of the car.. not sure what if anything is supposed to go there.
09-30-02, 05:47 PM
#20
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Originally posted by mjw
And to answer Jspecracer, everything is connected as far as the coils are concerned. I am going to take your advice and test the spark though to make sure. I do feel a little unsure about the grounding points under the UIM though.. there were two spade type connectors that I disconnected when I was working previously. One of the grounds is part of the ignition coil harness, and it just bolts on under one of the nuts that hold down the coil bracket. The other one I have grounded under one of the nuts on the top of the rack, which should work because it looked to me like the whole rack was grounded. I did notice an open threaded hole on the rear side of the UIM (near the firewall) just a bit more toward the passenger side of the car.. not sure what if anything is supposed to go there.
And to answer Jspecracer, everything is connected as far as the coils are concerned. I am going to take your advice and test the spark though to make sure. I do feel a little unsure about the grounding points under the UIM though.. there were two spade type connectors that I disconnected when I was working previously. One of the grounds is part of the ignition coil harness, and it just bolts on under one of the nuts that hold down the coil bracket. The other one I have grounded under one of the nuts on the top of the rack, which should work because it looked to me like the whole rack was grounded. I did notice an open threaded hole on the rear side of the UIM (near the firewall) just a bit more toward the passenger side of the car.. not sure what if anything is supposed to go there.
Damn...I don't know what to tell you! Seems you've got everything right, but there's still something amiss...
Good luck with her either way!
Van
10-07-02, 12:12 PM
#21
Ok, I am digging this one up again because I have NEW information finally!! I decided to tackle this logically and eliminate certain components of the fuel system as the problem, so I started pressure testing way back at the pump in the trunk of the car.. hooked the pressure test gauge right up to the hardline outlet on top of the fuel pump. No fuel lines, injectors, filters etc. inline that could be the culprit, just me and the fuel pump.
Well it turns out the problem resides back there, blocking off the feed line only results in 32psi instead of the min. 70psi listed in the manual. So I am thinking the fuel pump is bad, but just to be sure I have Goracer stop by and I swapped out his stock fuel pump into my car, same result.. only 32psi. Hmm, so I put the pump back into his car and the thing skyrockets up to 75psi before I pull the jumper wire. Well no we know the problem is electrical somewhere.. I test out batteries. 11.8V on mine and 12.5V on his, that can't make much of a difference. I even swapped his fuel pump relay for mine with no change in the situation. I also tested my fuel pump resistor and it is within spec, .7 ohms resistance.. arrghhh!!!!!
So does anyone have a possible lead I can follow up on here?? This all stems from a turbo replacement/vacuum hose job/and cleaned up fuel system. I had all the intake manifolds off so now I am wondering if there is a screwy ground under there on the motor that could cause the pump to do this? The only thing left I can think of to try is to bypass the fuel pump resistor with a jumper wire, but I don't want to run my car like this.. the thing will flood out!
Matt
Well it turns out the problem resides back there, blocking off the feed line only results in 32psi instead of the min. 70psi listed in the manual. So I am thinking the fuel pump is bad, but just to be sure I have Goracer stop by and I swapped out his stock fuel pump into my car, same result.. only 32psi. Hmm, so I put the pump back into his car and the thing skyrockets up to 75psi before I pull the jumper wire. Well no we know the problem is electrical somewhere.. I test out batteries. 11.8V on mine and 12.5V on his, that can't make much of a difference. I even swapped his fuel pump relay for mine with no change in the situation. I also tested my fuel pump resistor and it is within spec, .7 ohms resistance.. arrghhh!!!!!
So does anyone have a possible lead I can follow up on here?? This all stems from a turbo replacement/vacuum hose job/and cleaned up fuel system. I had all the intake manifolds off so now I am wondering if there is a screwy ground under there on the motor that could cause the pump to do this? The only thing left I can think of to try is to bypass the fuel pump resistor with a jumper wire, but I don't want to run my car like this.. the thing will flood out!
Matt
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