55mikey55

iTrader: (1)

there's not really anything to illustrate. the factory switch is just like the tpi switch, just with another wire for the sender. if it's worth a shot, i'll wire in the tpi switch tomorrow, and see what happens. but i jumped those two wires close to the relay, and the pump ran constantly. even when the truck was off and the key out.

55mikey55

iTrader: (1)

this is what happened today (if it helps any)



oh, when i was looking at it, i realized that the tpi switch's colors are backwards... would this make the pump cut off when the oil pressure is reached?

Maverick H1L

iTrader: (8)

The thing with the fuel pump is this. The ECM is SUPPOSED to control the fuel pump under normal circumstances. If the ECM system fails, there will be a code 54 (once you get the engine running... this happens when the engine has enough run time), and the crank times will be extended because the engine is waiting for the oil pressure switch to close, due to having enough oil pressure, to run the fuel pump. If the pump runs for 2 seconds when you first turn the key on without cranking the engine, then the relay system is working.

Unplug the fuel pump relay and crank the engine. If the engine won't start, the oil pressure switch is bad and you need a new one. It's either that or the fuel pump isn't generating enough pressure to keep up with the loss of pressure by the fuel injectors. If and when the oil pressure gauge registers oil pressure, you should be able to hear the fuel pump running until the pressure drops off below 15 PSI.

When you pressure tested the fuel system, did the fuel pressure drop when the engine was started or without? If the pressure dropped without the engine running, you have other issues you need to look into and you'll need 2 pairs of locking pliers with something to pad the jaws.

55mikey55

iTrader: (1)

ok. when the fuel pump relay is unplugged, it runs fine with CEL code 42 and 54
i tried to repeat the condition, but to no avail, now the truck is back to it's old tricks. the truck ran fine when i unplugged the relay, but then when i was checking, i unplugged the oil pressure switch. i had about 30 seconds of glory until i touched the gas pedal.

Maverick H1L

iTrader: (8)

Code 54 is the fuel pump circuit fault I mentioned before, probably because the relay has been removed.

Code 42 is an EST fault. There should have been a tan/black wire with a single connector in line with the harness somewhere near the heater fan assembly. Did you cut or remove this connector? The code 42 appears when this tan/black wire is open (disconnected or cut). This is also how you set the base ignition timing, by disconnecting this connector.

55mikey55

iTrader: (1)

yeah, i'm trying to set the timing, but it won't run long enough.

55mikey55

iTrader: (1)

should i just lock it down? or what should the base timing be? can i just set it to 0* and hook the connector back up?

Maverick H1L

iTrader: (8)

Okay, you can plug the fuel pump relay back in. How does the fuel pressure act? Does it remain steady when the engine isn't running or does it drop?

The base timing should be set to around 12* BTDC, IIRC.

55mikey55

iTrader: (1)

it's steady before startup. i haven't put the gauge back on since putting the high pressure clamps back on...
do you have some kind of chat? or a phone #?

Maverick H1L

iTrader: (8)

My AIM sn is maverich1l... Sorry, no cell phone.

55mikey55

iTrader: (1)

i'm s10guru on aim

55mikey55

iTrader: (1)

yo! i have an all new problem... the pump won't prime when i turn the key on. the pump waits until i crank the motor, leave it in run, then primes... i'm lost...

Maverick H1L

iTrader: (8)

Do you have factory radiator fan or MAF relays? Swap the fuel pump relay out with one of those and see if that does it. The relay could have died.

55mikey55

iTrader: (1)

when i snatched the relay bracket off of the 88 iroc, it had 2 late style relays and one early style...
the early style relay is the F/P relay...

just found this...

55mikey55

iTrader: (1)

possible FPR... ima try pinching the return hose shut tomorrow and see if it fixes it. $69 will make the wifey alot happier than $160...

Maverick H1L

iTrader: (8)

The relay isn't that expensive at the parts store. Also, I don't think the FPR will solve your problem if you still haven't gotten the right fuel pump... I doubt the FPR can lose pressure THAT quick with the engine trying to run. Especially because the system holds pressure when the engine stalls (FPR leak usually means that the pressure will continue to drop when the engine dies and the pump stops but will usually hold pressure while running due to injectors pulsing).

55mikey55

iTrader: (1)

i'm going to get the FPR and fuel pump from TPIS when our taxes come back in... so i guess we'll have to wait and see...

55mikey55

iTrader: (1)

so, in my late night brilliance (lol) i have it figured out... follow along and tell me if this makes sense...when wiring my body harness, i had 2 wires going into the cab, both by my diagrams were ignition wires. one goes to the alternator, while the other goes to the ECM. if i have these two wires backwards, that would explain why the ecm gets enough power to run the fuel pump once, but then after the truck is running, cut power to the fuel pump. earlier today, i cranked the engine, then just for kicks, cut the ign off, then back on. VOILA, pressure built back up to 45, and the truck revved back up. the alternator was killing the pump once it built power.... worth a shot tomorrow? ima try it

Maverick H1L

iTrader: (8)

Okay. Let's go through this again.

1. The engine starts but dies because a lack of fuel pressure kills it.
2. Fuel pump relay works long enough to prime the fuel system.
3. Fuel pressure drops slowly as engine runs, until it reaches about 22 PSI, where the engine dies.
4. Fuel pressure rises back to about 45 PSI and holds when the engine dies.
5. Fuel pump continues to run on the oil pressure switch when fuel pump relay is disconnected/removed.

So, we know these things:
1. Fuel pump pumps enough fuel to fuel rail to pressurize system.
2. ECM wiring is correct.
3. Fuel pump relay wiring is good. Relay may not be, however.
4. Oil pressure sender/switch and associated wiring is good.
5. Alternator wiring is good.
You haven't tested the radiator fan yet, so we don't know if that's good or not.

From the above we can deduce:
Fuel pump pumps fuel, enough to initially pressurize the fuel system. However, SOMETHING is holding the fuel pump back from producing enough flow to keep the system pressurized where it should be. The wiring is correct, so the problem lies in either the fuel lines or the fuel pump.

Remember: You wired the ignition wires up so that the wire running to the ECM also runs a couple of low-current relays, as opposed to the fuel pump, injectors and coolant fan directly. The wires running to both the fan, the fuel pump, AND the fuel injectors SHOULD be coming straight from the battery. So, when the ignition is shut off, the relays should be as well, cutting power to all of the above (except the fuel pump, which will continue to have power if there is enough oil pressure until the pressure drops).

55mikey55

iTrader: (1)

right. all of these are right, and wired to run from battery power, so when i turn the ignition on, a big CLICK comes from the engine bay. all the relays are working... FPR and f/p are coming from TPiS and are scheduled for delivery on the 16th. f*in tuesday cuz a ups shipping error. but we'll see what happens when they get here. if all else fails, i'll get another fuel pump to let the computer think it's running one, put a strainer on it and throw it in the tank, but simultaneously, i'll put in a switched fuel pump in the original position that actually pumps the fuel. that way the computer still gets a fuel pump reference signal, the high/low voltage monitoring, and the real fuel pump can be switched so when i turn the ign on and the switch on, i control pump run time. whatcha think?
(of course this is only if the tpis pump doesn't work or get the same no start condition...)

BTW when i ordered the pump, the dude told me that it sounded like the pump i got was for a tbi...
i ORDERED a tpi pump though... >>>this one<<<

Maverick H1L

iTrader: (8)

You have the fuel pump installed in the tank, right?

Make sure everything on the sending unit is connected up nice and tight and properly, and that there aren't any wiring problems at the tank.

For the backup situation, you could just run the pump off of the oil pressure switch instead of having it use the relay as well. That's a safety issue anyways... The OPS is designed to cut off the fuel pump in the event oil pressure is lost (say, an accident where the front of the vehicle ends up stopping the crank in some way) to prevent fuel from spraying all over the place and possibly causing a fire. As long as the ECM sees a voltage signal coming out of the relay (you could possibly cut the wire to the fuel pump wiring from the relay if you want), you won't have a code, so you won't need to screw with a second pump.

55mikey55

iTrader: (1)

yeah the pump is in tank.
by process of elimination....

1. fuel pump
2. FP relay
3. oil pressure sender(even though it it just out of the box)

BTW the intake is coming off tomorrow to get polished, so i won't be bored until 2sday. plus, i'll be able to get to the FPR when it comes

could my problem be the oil pump? i didn't change it when i put bearings in it...

but if i jump the sender, then it would run, so prolly no, right?

Maverick H1L

iTrader: (8)

Fuel pump relay is good, as the pump DOES run with the computer controlling it.
Oil pressure switch is good, as the pump DOES run as the engine is cranked.
On your list, this leaves the fuel pump. It's possible you got the wrong pump, especially with Chinese junk. Hit up a junkyard and see if you can't get the right one just for testing until you can get a new one (might even try for the whole sending unit so you can just drop it in and go). There is a slight chance you can get a new fuel pump from a junkyard (replaced one in a Dodge Daytona V6 with one from a junkyard and somehow got a newer one from the yard). Not to say you will, but it's possible.

55mikey55

iTrader: (1)

you don't have measurements on a sending unit for a camaro do you? height and width? width should be the same...my buddy said to go get one for an s10 with fuel injection... like a 99-00 with a cpi v6 (vortec)

55mikey55

iTrader: (1)

BTW does that AFR check work with tune ports too? like checking the o2 with an ohmmeter while the engine is running for peak HP(to get the closest to a stoch. air/fuel ratio)?

Maverick H1L

iTrader: (8)

I personally don't, as I'm one of the lucky ones who haven't had to replace the blasted thing yet. It may require a little more than half a tank of gas in your fuel tank, since I believe that the F-body fuel tank is shorter in height than yours.

55mikey55

iTrader: (1)

started work on the lower manifold...this polishing deal is gonna take a LOONG time... i may end up painting the bottom black, and just polishing the runners and the plenum...that way i might be done by the time UPS arrives...

55mikey55

iTrader: (1)

got the plenum polished... FINALLY.


final product...



i'll have installed pics tomorrow hopefully...

55mikey55

iTrader: (1)

got my fuel pump and regulator in today, at 7:00. if i wasn't so happy it got there, i would've cussed the driver out. seeing as how the truck got loaded this morning at 7:30(am). i broke my t40 torquing the runners down, so i gotta go pick one up tomorrow... but i'll have some info on it tomorrow... if this pump won't do it(being rated to flow enough fuel for a 400hp TPI) then i wired it up wrong or something... i got the regulator installed, and can't wait to crank this bitch up....

Maverick H1L

iTrader: (8)

Let me guess, the parts were shipped via FedEx and you live in a rural area? I hate the way FedEx does that. Last March, I had to replace my radiator, and it was shipped via FedEx. The part was in my local hub at 7:00 or something AM, and the hub is literally 20 minutes down the Thruway from me. I had the car apart ALL day, and didn't get the radiator until 5:00, when we were going out to dinner. The worst part? I had to be out at 6:00 the next morning for work. I was burning mad... And I used to work for FedEx...

55mikey55

iTrader: (1)

ok...new problem... i lifted the fuel pump out just enough to see what was going on whenever the pump primes... it never gets the chance to build enough pressur because while the pump is running, the reg. i guess is sending it right back to the tank... help! how does this work? the more i turn the screw down, the less fuel it gets? or is it backwards...

Maverick H1L

iTrader: (8)

The system is supposed to work that way, especially with a high flow pump. It may not take the full 2 seconds to pressurize the fuel system. The regulator is actually on the OUT side of the fuel rail, and controls the fuel pressure by regulating how much is sent back to the tank, if any, once the system is at full pressure, whatever that may be. As is my understanding, tightening the bolt or what have you on the top of the regulator increases the fuel pressure in the rail, but you may want to check the paperwork to make sure.

Also check the connection of the fuel pump to the outlet pipe in the sending unit. If the connecting pipe is cracked, as can happen, fuel pressure won't build up.

five7kid

iTrader: (14)

That may be what's happening, not the reg returning fuel back to the tank.

55mikey55

iTrader: (1)

ok. there are no cracks, and no leaks. i traced all of the fuel lines from the pump (set to one side but still submerged in fuel) all the way to the rail. the regulator is hooked up, and no leaks there. when i hook up my gauge, it shows the pressure building to 38-40lbs, then bleeding back off. i'm just about ready to set this bitch on fire and call the ins. company

55mikey55

iTrader: (1)

ok let me get yall up to speed... this weekend while i was waiting on ups... i took my intake off and polished the plenum, and put ALL new gaskets on the top end... when i took the distributor out, it turned the oil pump some kinda crazy funky way and i had to re-set the timing all over again...now that my old reference points are gone, it's being a bitch again... i'm doing everything like i used to, but for some reason, it just wants to denotate (not detonate) and not crank... (it's making funny noises instead of starting up...) i know that if it backfires through the TB then i need to retard it, but when i do, then it just spins fast. i checked the spark again, and all i haven't done is check the injectors...again...but i'm worried about the fuel pressure. it's ac ting like it's not getting enough fuel to fire.... but when i add ether, it wants to fire out of the TB.

tomorrow- i'm gonna take the valve cover off, make sure i get the right exact 0*TDC, then try to get it to run. when i get it to run, whenever that may be, i'll put the gun on it really quick and set it to 6*BTDC and hook up the base timing connector. then , we shall see if the fuel pump was my problem. BTW, my idle screw is all effed up. i have no clue how far back it needs to be to maintain idle, and i don't wanna scare the old folks around here when it fires up...lol

BTW the fan DOES NOT RUN under diagnostics check. i put a test light on it today, and nothing. idk if that's the only difference in my 88 and yours, or if the wiring is all wrong...i'm thinking about getting a painless harness when i start my new job just for peace of mind and knowing that everything is wired correctly.

the last thig(when it rains, it pours...) i think my starter is going or my battery charger is going. i put it on a 2a trickle charge and i'll go mess with it in the morning, but for now, i'm just gonna walk away from it...

Maverick H1L

iTrader: (8)

FYI, next time you go to remove the dizzy, make 2 marks on the base plate with a marker or whatever you have that will write on it. First, mark the place where the rotor is pointing while installed. Second, pull the dizzy, and mark the place where the rotor is pointing the instant it comes loose from the camshaft and oil pump drive, should be back to the left.

BTW, anyone watching this have a pic of a fuel sending unit assembly so he can see where the connecting hose/pipe cracks occasionally when the pump is replaced?

55mikey55

iTrader: (1)

55mikey55

iTrader: (1)

ok, so in setting the timing, if i'm getting deep sounds out of the manifolds, do i need to turn the dizzy clock. or counter clock? sounds like it's firing on the exhaust stroke...

Maverick H1L

iTrader: (8)

For the dizzy, clockwise is retarding the timing, and CCW is advancing... If the coil is firing closer to the exhaust stroke than the intake, you need to advance the timing a bit.

88gta3508

you really have a problem the FP.. should not drop at all.. even after you turn off the ignition.. you should have about 40# for at least 20 - 40 min.
you have a blockage,, FPR is leaking check the diaphragm. or your pump from china can not produce the required volume and pressure !!!!

five7kid

iTrader: (14)

Sounds to me like the distributor is in 180 degrees off. Happens to the best of us.

Or, the pump outlet line is cracked/leaking, which could look like the return when you're operating the pump with the pick-up lifted up a little and you're peeping through a crack.

55mikey55

iTrader: (1)

ok, well the timing is fixed. now back to the fuel pressure
it looks to me like the pump is pushing the same amt of fuel out of the return line... like the regulator is letting too much fuel by...

five7kid

iTrader: (14)

When the engine isn't running, the regulator will be returning all of the pump flow back to the tank.

55mikey55

iTrader: (1)

ok. engine starts, then fuel pump quits. oil pressure switch is brand new, i have a flow chart for the fuel pump, so i'm gonna work with it a little bit...

the regulator wasn't putting enough rail pressure up, right now i have it at 46 lbs and it stays steady for about 7-8 minutes

55mikey55

iTrader: (1)

ok, well the ecm isn't sending a signal to the relay to prime, nor is it sending a signal to run the pump while the engine is running... do i need to check the power while the engine is being cranked? the pump primes after the computer sees the engine stop cranking... and primes for 2 seconds

five7kid

iTrader: (14)

The "signal" is to ground the relay magnetic circuit.

55mikey55

iTrader: (1)

i'm gonna go buy a switch and a relay and put a fuel pump switch in the truck...then see what happens...

55mikey55

iTrader: (1)

ok, i'm running strong now, with no codes

next stop exhaust shop

55mikey55

iTrader: (1)

i noticed that my sender is not reading above 15 lbs when the engine is started... i'll look into it tomorrow, but the engine isn't knocking of rattling or making any noise whatsoever so the engine has oil pressure... but i don't know the way to go about checking the gauge to see if maybe it's wired wrong...plus my multimeter got wet and refuses to work now

55mikey55

iTrader: (1)

ok well, it's running great now (from what i can tell...) i've got the coolant lines hooked up and now i am waiting on the exhaust shop monday... then it's to the DMV to get re registered...yippee! lol

can you set the TPS by ear? like i said, my multimeter crapped out on me, so i can't set it... i'll hook up the tach over the weekend, so i know where i'm idling, and then we'll see what's going on...
base idle for a 5-speed is what? 700? i'll have to unhook the wire and set the timing and base idle, then set the TPS by response... that'll work, right? help me out fellas