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F-Body Road Racing and Autocross Forums > Community > General Discussion
Honda93
In the last week or so, it cranks for 2-3 seconds before starting whereas it used to start immediately. I installed a new starter 6 months ago as you all may recall. I also installed a K&N fuel filter 10 month ago. No issues until last week.

Research online and on FRRAX is pointing to a fuel pump or fuel pressure regulator. Or the battery. Or the spark plugs.

Car runs super fine once started and starts right up once it has been running. If it sits 6+ hours, it'll revert to needing extra time.

Suggestions?
trackbird
If you turn the key on (but don't try to start it), do you hear the fuel pump prime for 2 seconds? If so, it's not a fuel pump relay. If not, it likely is a fuel pump relay. The oil pressure switch has an over ride that turns on the fuel pump when it "sees" oil pressure. It's a backup in case the relay goes bad.
GCrites80s
Does the car have a distributor, Opti-Spark or coil packs?
Honda93
QUOTE (trackbird @ Sep 1 2017, 08:40 PM) *
If you turn the key on (but don't try to start it), do you hear the fuel pump prime for 2 seconds? If so, it's not a fuel pump relay. If not, it likely is a fuel pump relay. The oil pressure switch has an over ride that turns on the fuel pump when it "sees" oil pressure. It's a backup in case the relay goes bad.


Yes. I do hear the fuel pump prime.
Honda93
QUOTE (GCrites80s @ Sep 1 2017, 09:41 PM) *
Does the car have a distributor, Opti-Spark or coil packs?


Sorry! It's a 2001 Z28, so coil packs.
CrashTestDummy
That's a tell tale for a fuel pump. Get a gauge on it and see what the pressure is on the day's first key-on.
Honda93
QUOTE (CrashTestDummy @ Sep 2 2017, 10:28 AM) *
That's a tell tale for a fuel pump. Get a gauge on it and see what the pressure is on the day's first key-on.


Damn. They're a bitch to change, right?

Guess this is a good time to learn about the "trap door" approach, yes?

If this turns out to be the case, isn't this the suggested upgrade?

http://www.ws6project.com/user_stor/catalo...-fit-fuel-pump/
Honda93
Or... Is OEM the way to go since the original lasted 15 years?

http://www.rockauto.com/en/moreinfo.php?pk...954&jsn=459
Honda93
Going to have to put a gauge on it. It started right up on two occasions this morning (Sunday) after sitting since Thursday night.

Then, after letting it sit, I turned the key to position 2 (just before start), heard the fuel pump prime, and then put a large rag in front of the Schrader valve and pushed it in... A few drops dribbled out. If it had 40+ psi in there it would have sprayed or "burst" into the rag more than just a few lazy drips.

<sigh> Not looking forward to the job or having to buy the pump because I have a feeling you're all going to say it's the pump/regulator which is all integrated into that single unit.
CrashTestDummy
That's why the gauges. It's looking like a pump, but you want to make sure.

Yes, they SUCK! Had to do the pump on the SS TWICE, when I discovered the pump assembly was wired wrong. Had to replace te entire tank assembly on the SVO after it sat in a body shop for more than a year, so yes, I feel your pain.
mikedamageinc
Do you get any stumble on WOT runs in the upper RPM? Mine was doing that plus the slow start like you mentioned. I did a walbro 255 with racetronix kit and trap door method and it was fairly easy and economical compared to OEM and dropping the tank.

In the mean time, you can turn the key to on for a couple seconds and then crank it, that should help it start quicker.
GCrites80s
QUOTE (Honda93 @ Sep 2 2017, 01:36 PM) *
QUOTE (CrashTestDummy @ Sep 2 2017, 10:28 AM) *
That's a tell tale for a fuel pump. Get a gauge on it and see what the pressure is on the day's first key-on.


Damn. They're a bitch to change, right?

Guess this is a good time to learn about the "trap door" approach, yes?

If this turns out to be the case, isn't this the suggested upgrade?

http://www.ws6project.com/user_stor/catalo...-fit-fuel-pump/


Trap door is fine for racecar, but on cars that will see street use the value of (or at least the demand for) the car can be significantly reduced by cutting the hole.
Honda93
QUOTE (mikedamageinc @ Sep 4 2017, 12:28 PM) *
Do you get any stumble on WOT runs in the upper RPM? Mine was doing that plus the slow start like you mentioned. I did a walbro 255 with racetronix kit and trap door method and it was fairly easy and economical compared to OEM and dropping the tank.

In the mean time, you can turn the key to on for a couple seconds and then crank it, that should help it start quicker.


None that I notice. Pulls strong.

Also, the last two days (3 starts in all) it fired right up.

So, this is the Racetronix part?

https://www.texas-speed.com/p-2361-racetron...p-assembly.aspx

Will I still need to get the Wallbro 255 separately or will the Racetronix do it all? I plan on keeping the motor stock.
Honda93
QUOTE (GCrites80s @ Sep 4 2017, 10:06 PM) *
Trap door is fine for racecar, but on cars that will see street use the value of (or at least the demand for) the car can be significantly reduced by cutting the hole.


I think an autocrosser would buy it if I were to sell it someday. The previous (original) owner told me at least a dozen times that it had an "autocross patina" to it. It's no show car.
Shortcutsleeping
The two times I've encountered this on third gens it has been the fuel pressure regulator. My assumption is it is bleeding off pressure.

After the initial start of the day it would then start fine. Swapped FPR then it would fire up clean in the AM.

Just my .02

Costas
cars and such...
mikedamageinc
QUOTE (Honda93 @ Sep 4 2017, 10:27 PM) *
QUOTE (mikedamageinc @ Sep 4 2017, 12:28 PM) *
Do you get any stumble on WOT runs in the upper RPM? Mine was doing that plus the slow start like you mentioned. I did a walbro 255 with racetronix kit and trap door method and it was fairly easy and economical compared to OEM and dropping the tank.

In the mean time, you can turn the key to on for a couple seconds and then crank it, that should help it start quicker.


None that I notice. Pulls strong.

Also, the last two days (3 starts in all) it fired right up.

So, this is the Racetronix part?

https://www.texas-speed.com/p-2361-racetron...p-assembly.aspx

Will I still need to get the Wallbro 255 separately or will the Racetronix do it all? I plan on keeping the motor stock.


That looks like everything you need, I got mine at ws6store though, as long as it's not just the regulator like mentioned above. Mine was going bad for a long time, which is why I probably got the missing and it wasn't severe, just felt like a slight miss close to 6k like it needed a tune up or something.
JimMueller
I installed a Racetronix 255LPH pump and hotwire kit back in 2010. I hope you don't need to contact them for support as they are not the friendliest folks for diagnosis. They'll just tell you to RTFM, including their installation docs and all the GM documentation on their website. Be careful putting the float arm back in if you're concerned about an accurate fuel level gauge. I've also intentionally chosen not to use the trap door because it's a street car.
Honda93
QUOTE (mikedamageinc @ Sep 5 2017, 09:43 AM) *
That looks like everything you need, I got mine at ws6store though, as long as it's not just the regulator like mentioned above. Mine was going bad for a long time, which is why I probably got the missing and it wasn't severe, just felt like a slight miss close to 6k like it needed a tune up or something.


Isn't the regulator in the fuel tank on the pump assembly on the 1999-2002 cars? Or an I mistaking it for something else?
Honda93
QUOTE (JimMueller @ Sep 5 2017, 12:17 PM) *
I've also intentionally chosen not to use the trap door because it's a street car.


Solely for resale purposes? Was it aesthetics? Water intrusion? Chassis rigidity?
Mojave
I cut the trap door on my last street car, and was very happy I did.
mikedamageinc
Resale value would be my only concern and even that didn't bother me. Just be careful to not cut any lines, follow the write up on ls1tech. I used a piece of sheet metal as a cover with a bunch of screws and rtv to seal it.
slowTA
I see it this way, to do a trap door I would want to drop the tank first so I don't damage anything while cutting. So if the tank is out already, may as well do the pump with it out. Then... Since you don't plan on modifying the car to the point you'll need a higher volume pump it would just be for maintenance reasons... Which hopefully wouldn't be for another 10 years? So you get my point there!

On the flip side, a trap door should get hidden under the carpet pretty well, so it wouldn't come up during resale unless the buyer asks.
Honda93
QUOTE (slowTA @ Sep 5 2017, 07:30 PM) *
I see it this way, to do a trap door I would want to drop the tank first so I don't damage anything while cutting. So if the tank is out already, may as well do the pump with it out. Then... Since you don't plan on modifying the car to the point you'll need a higher volume pump it would just be for maintenance reasons... Which hopefully wouldn't be for another 10 years? So you get my point there!

On the flip side, a trap door should get hidden under the carpet pretty well, so it wouldn't come up during resale unless the buyer asks.


It makes sense, no doubt. I dunno. I still think it's stupid they left no access for such a thing. How much time do people estimate it taking to get the tank out the non-hatch way?
CrashTestDummy
That would have cost GM an additional $0.25 PER car!!! =8-0

They would have gone bankrupt!!


Oh, wait.

I think there's someone who makes nice door panels for that job at leas n a 3rd Gen, isn't there? But yeah, drop the tank anyway, to do the pump replacement job and panel cutting, if necessary. But don't just throw parts t it. Put a gauge on it to see what your initial key-on reassure is, and what the leak down rate is.
slowTA
Dropping the tank isn't the worst job ever assuming you get the car high enough off the ground. You pretty much have to pull the rear end, I've done it while keeping the control arms and torque arm connected but it made maneuvering the tank a royal pain. With the torque arm pulled from the transmission and the control arms straight down you should have enough room to manage the tank easily. Don't forget to loosen the brake hard line from the body so it drops enough.

I'm horrible at guestimating time, so 4 hours is a very rough estimate.

Also, if you have the plastic has tank the regulator is in the tank instead of on the fuel rail.
CrashTestDummy
QUOTE (slowTA @ Sep 6 2017, 06:38 AM) *
<SNIP>

I'm horrible at guestimating time, so 4 hours is a very rough estimate.

<SNIP>


So it would take me 8 hours. dry.gif
Mojave
QUOTE (slowTA @ Sep 5 2017, 06:30 PM) *
I see it this way, to do a trap door I would want to drop the tank first so I don't damage anything while cutting. So if the tank is out already, may as well do the pump with it out. Then... Since you don't plan on modifying the car to the point you'll need a higher volume pump it would just be for maintenance reasons... Which hopefully wouldn't be for another 10 years? So you get my point there!

On the flip side, a trap door should get hidden under the carpet pretty well, so it wouldn't come up during resale unless the buyer asks.


Drop the tank to cut the trap door? I cut mine without dropping anything, worked great, no issues.
slowTA
What did you use to cut the hole? Did you find a guide online as to where the hole needs to be?
Mojave
QUOTE (slowTA @ Sep 6 2017, 04:33 PM) *
What did you use to cut the hole? Did you find a guide online as to where the hole needs to be?


I used either a manly Dremel or a like a 3" cutoff wheel, it has been years now. I'm sure I looked on LS1Tech for the hole location. The final hole wasn't perfectly where I would have put it but it was good enough to get the assembly out.
GCrites80s
In the mid-90s my neighbor had an '87 TA. He went to screw a speaker box into the cargo area and then gas started running out from underneath the car. It wasn't his favorite day.
trackbird
QUOTE (JimMueller @ Sep 5 2017, 12:17 PM) *
I installed a Racetronix 255LPH pump and hotwire kit back in 2010. I hope you don't need to contact them for support as they are not the friendliest folks for diagnosis. They'll just tell you to RTFM, including their installation docs and all the GM documentation on their website. Be careful putting the float arm back in if you're concerned about an accurate fuel level gauge. I've also intentionally chosen not to use the trap door because it's a street car.



That's an understatement. They are a complete bag of dicks to deal with. I ordered something on black friday and about 30 minutes later I got an email with a black friday coupon code (unrelated to my order). I emailed them and said "I got the coupon at 8pm....after I placed the order....can I have you adjust the price to the sale price". They refused to do it. On top of that they weren't much help when I had support questions and referred me to their forum for answers. I've pretty much vowed to never buy anything from them ever again.

The "question" I had was that my new fuel pump wouldn't work. So I got to install one in my 1991 Corvette a couple times. Ultimately, I received a wiring harness and pump that weren't wired the same (the pump was running backwards...no fuel pressure). It all came from Racetronix.

They make nice stuff, but hope you never need to ask them anything about it.
CrashTestDummy
QUOTE (JimMueller @ Sep 5 2017, 11:17 AM) *
I installed a Racetronix 255LPH pump and hotwire kit back in 2010. I hope you don't need to contact them for support as they are not the friendliest folks for diagnosis. They'll just tell you to RTFM, including their installation docs and all the GM documentation on their website. Be careful putting the float arm back in if you're concerned about an accurate fuel level gauge. I've also intentionally chosen not to use the trap door because it's a street car.

Fukwits! Yeah, they suck! Got their 'kit' as an upgrade when I had to replace the pump in our 95 SS. Dropped the tank, replaced the pump assembly, reinstalled the tank, put about 5 gal. Of fuel in, because I was certain that this pump that everyone swears about would fix our problem, only to have the car NOT start, even though I could hear it spin up on key on. Put a pressure gauge on it, and wasn't getting any pressure. Dropped everything back out, this time with 40# of fuel in the tank, only to discover, after emailing them about my issue, and getting no response, that they had fscking wired the pump backward.

I let them know what I discovered, and they were like 'yeah, that happens.'. Azzholes! That was after running their 'kit' in our 95 Caprice, only to have the relay out at the tank end fail on my wife on her way to work.... Twice! I rerouted the harness around that relay, and the car runs fine to this day.

I'm done with those assclowns!!

But I'm not bitter! 2thumbs.gif
Honda93
If I didn't want to go Racetronix, which of the OEM-style units would you recommend? Delco only?
Honda93
UPDATE

I put a fuel pressure gauge on it and turned the key to the #2 position (just before start). The gauge immediately went up to 53 psi and then began to bleed down almost immediately through the 40's into the 30's and then into the 20's.

I took it off at that point because I thought the system was supposed to hold pressure for quite some time.

Regulator?
GCrites80s
It could also be an injector (or more than one) not closing all the way.
CrashTestDummy
QUOTE (GCrites80s @ Sep 7 2017, 07:49 PM) *
It could also be an injector (or more than one) not closing all the way.

Yes, it is supposed to hold pressure for a while. Much more than 10 PSI per minute, and i'd start looking at failed equipment

Hmmm, would a plug show a leaking injector(s), or would you have to pull them before starting to see who is wet?

Another thing to check: pull the vacuum hose off the regulator to make sure the diaphragm isn't blown. Although on a LS engine, one would expect all sorts of CELs, not so much on a LT* system.
trackbird
QUOTE (slowTA @ Sep 6 2017, 05:33 PM) *
What did you use to cut the hole? Did you find a guide online as to where the hole needs to be?


I'm not defending cutting the hole, I understand why it's done and on a race car...I might do it. However, here's how I'd do it (and I own that exact brand and model). What's funny, mine said it cut 12 or 14 gauge (and it has). This one says 18. I bought this one because it was far cheaper than the Milwaukee and it cut heavier metal (at least that's what the rating said). It likely won't hang low enough to catch a fuel line as you shear the hole open.

http://www.homedepot.com/p/Kawasaki-Sheet-...40358/203125925
CrashTestDummy
You'll probably need a good hole saw so you can cut a starting hole/corners. Oh, and you'll want to practice on some metal before you start on your car. These things take a certain amount of control, and can start 'walking' if you're not careful.
GCrites80s
QUOTE (CrashTestDummy @ Sep 7 2017, 10:40 PM) *
QUOTE (GCrites80s @ Sep 7 2017, 07:49 PM) *
It could also be an injector (or more than one) not closing all the way.

Yes, it is supposed to hold pressure for a while. Much more than 10 PSI per minute, and i'd start looking at failed equipment

Hmmm, would a plug show a leaking injector(s), or would you have to pull them before starting to see who is wet?

Another thing to check: pull the vacuum hose off the regulator to make sure the diaphragm isn't blown. Although on a LS engine, one would expect all sorts of CELs, not so much on a LT* system.



I'd say pulling the plug before starting is probably better. A cylinder that is rich all the time would turn dark brown or black but one that is only extra rich for 2-3 revolutions might not. But the plug could wet foul then turn brown from the cylinder being dead. As a 2-stroke guy I have killed a ton of plugs and many weren't discolored much at all.
GCrites80s
But argh, we're talking about pulling 4th gen plugs which is about as fun as dropping the axle to replace the tank.
trackbird
QUOTE (GCrites80s @ Sep 8 2017, 10:48 AM) *
But argh, we're talking about pulling 4th gen plugs which is about as fun as dropping the axle to replace the tank.


I can do 4th gen (non EGR cars) plugs in about 45 minutes...give or take.

The trick is to take one of these:

http://www.sears.com/gearwrench-3-4-in-ful.../p-00947896000P

and apply it to the wrench flats on one of these:

http://www.sears.com/craftsman-4-pc-spark-.../p-00934504000P


I just reach back and put the socket on the plug (after pulling the plug wire, of course) and then slide the wrench in place and loosen the plugs. When I'm done, I take the new plugs and work back to front and start them by hand, drop the socket on and wind them down hand tight, snug with the flexible box end ratcheting wrench.

The rear passengers side plug still has to be done from the bottom...I think. (I can't remember if I got that one or not).
GCrites80s
^EGR is pretty messy on an LS1.
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