greetings all,

yesterday, i had a difficult time starting the 88 vette. it cranked fine but, no start. i could not dig out a fp gauge as i was going to church services. however, i have had this problem some time before. (the car was stone cold).

the car would crank over as normal but, no start. the fuel filter has been replaced a little while ago as were the plugs, cap , rotor, ignition module, coil, fp relay, and fuel pump a week ago. oil has been changed, gas in the tank, recent seafoam application, tps is set ok, tb appears clean, timing at 7*.

i was limited with the time i had. i reached and felt the fp relay click when i turned the key and checked it's connections, both were ok (*see addition comments below). when i had the pump assembly out, i check all the connections for rust, etc, and that was fine also.

i started to drag the battery down a bit so, i put on a 200 amp starter/charger unit and after a few revolutions, the car started up w/o incident. when this happened months ago, i was able to get a fp gauge on the rail and it read ZERO. in any case, i have to fool the ecm into thinking that the car is flooded by holding the gas pedal to the floor even when i have fuel pressure for a "faster start". i have swapped out the ecm with no differences (no vac leaks either).

it seems that when i whack the car with additional high current, she will start. i am unsure where to check next as this sounds more like a bad connection then a bad part although, i will NOT rule out a bad part. it is like the additional current is "making" the bad connection. i also had checked for broken/frayed, loose, etc, wires and found none. all accessible connections are clean and shiny.

i am aware of the cold start injector (9th) in my car and have no idea if it is working properly, or at all. i am aware that the fp relay gets energized for 2 seconds to prime the fuel rail which, i can hear and feel the relay "kick in" and as far as last time (months ago) goes, there was NO priming of the fuel rail and car wouldn't start until i whacked it with the additional current (as above).

two weeks ago, when my fp failed, i routinely checked all the fuses and all were fine. this car from "day-1" has never started on the first revolution. i have done the injector leak down test ands it is w/in limits.

could there be a faulty check valve somewhere in the fuel system sticking open/closed and not allowing the fuel to get to the rail or to build pressure in the rail?

each time regardless if the key turning is 5 seconds apart, i turn the key, should the fp relay click to prime the pump for 2 seconds? if so, mine didn't do this "each time" as there appears to be a bit of a delay for the fp relay to "re-click", if that makes sense. i too am also aware the the oil pressure switch takes over at 4lbs.

this is a long post but, it is meant to puke up as much relevant info for a more thorough diagnosis. any help or thoughts would be appreciated.

 

Sounds like the fuel pump relay is doing what it's supposed to do. I forgot whether you OHMed the injectors, but that would be the first place I would check, or re-check. What you're doing by holding the pedal down is puting it into clear flood mode. I'd also check the connections on the starter..even though it's a b*#ch. But I really think you have an injector problem.

 

........thanks for the reply. fp and relay have already been replaced. as far as the injectors, it is that i am getting (as in the last episode a few months back) no fuel pressure so, the injectors don't figure into the "no fuel pressure on the rail" issue.

i also realize as stated in my post, that the flooring the pedal during cranking is to fool the ecm into flood mode and adding more air, less fuel to the fuel mixture for start.

however, that doesn't address the apparent "no pressure at the rail" issue either, or that i have had to put on a starter/charger and then crank to get the car to fire. the car cranks relatively at the same speed with and w/o the charger connected but, when the car acts like this, only seems to start with the added "boost" so-to-speak".

the injectors may have something to do with "hard start" but, with no fuel on the rail, it doesn't matter...yet. (have not ohm-ed" the injectors yet).

i have never heard the pump "energize" and have on occasion attached a fuel pressure gauge on the rail and turned the key to "on" and there is 35-40+ lbs fuel pressure and i can hear and feel the fp relay click.

one question that was not addressed was; each and every time i turn the key to "on", should the fp relay energize (each and every time?) regardless if i turn the key on once a second?. has anyone actually tried this to see if it happens or is there a delay between each or every few key turns?

 

First of all..NO, the fuel pump relay will NOT come on if you turn the key on and off every second...YES, I did check this because of another post, I actually went out to the vette, counted the seconds. It takes at least a 5 second interval before the fuel pump relay will again actuate!

Second, I thought the fuel pressure problem was fixed with the new fuel pump on your past problem. Are you saying you're not getting fuel pressure at the rail now when the key is turned to the ON position?

There are a few things that would cause an engine to start easier with a jump, so to speak...but it sounds like the engine turns over at the same rate with or without a jump...is that correct.

 

You must pause ten seconds between key ons to make/hear the pump run. You can jumper 12 volts to terminal "G" of your ALDL to make the pump run all the time. The car will start slow with zero fuel pressure. Perhaps the extra voltage boosts the pump flow up a small amount causing the car to prime faster.

 

.......spike that football, we are on the same page! . ok, that answers the question about the fp relay and how frequent it kicks in with the key turns...THANKS!

........yes, engine cranks about the same speed with and w/o the jump.

......yes, the past pressure problem was fixed with the new pump (surprised you remember that!) when i had barely 15lbs with the old pump. however, the same problem intermittancy with the old pump (before it crapped out) and now with the new pump still ocassionally poping up like it did the other day. i have fuel pressure at the rail but, ocassionally, I DO NOT. when this happens, it will start and will have pressure on the rail with the starter-charger on the battery. this is the most perplexing part! i believe that i can go outside right now and turn the key and will have pressure, but as i stated above and though infrequent, not always.

 

.....thanks for the reply.....about two weeks ago when my pump crapped out, i did the aldl jump and got the same results BEFORE i replaced the pump.

in the past when i have had a fuel pressure gauge on the rail, the turn of the key to "on" yielded an instantaneous 35-40+ lbs on the rail pressure.

but, the problem is that what i experienced yesterday, occasionally pops up with ZERO pressure on the rail.

with the new pump, clean electrical connections, new fp relay and connections and filter, and no damaged lines,this should not be happening even intermittently.

 

Well, you can hear and feel the FP relay come on...but, can you hear the actual fuel pump running when you turn the key to ON? you may need two people for this, one to turn the key on while you're back at the tank listening. It almost seems like you're adding a voltage spike to the system to get it to start...which leads me to a bad connection somewhere in the wiring to the fuel pump. Just because you can hear or feel the FP relay click..if you will, does not mean the fuel pump is running. Just trying to help. And yes, you surprised me last time, and I think a few others.

 

.....thanks again for the response! yes, i can hear and feel the fp relay click on/in but, since i am a "one man band", can't turn key and hear pump running at the tank inlet at the same time (plus, all my neighbors are new and i don't know them).

i have checked all the associated wiring and connectors i can get to to the fuel pump and i don't see anything remarkable. **do ya think it could be a crappy ground at the plate that covers the "tank entrance"? if so, would loosening the ground and cleaning it involve anything special?...what i mean is, if i loosened the ground, would a screw/nut fall into the tank even though i am not removing the plate?

....yes, on the voltage spike. it's like a bad connection and the extra current applied will "make" the connection to "rock and roll".

.....i agree that the mere energizing of the fp relay does not stipulate fuel pump activity.

.....yes, i gratefully appreciate the help!

......now ya lost me? uh, how did i surprise anyone last time?....

 

Was the fuel pump a reman.? They can fail and still work intermitently. Wiggle the pump or bump it when the fuel pressure is reading zero with the car on, see if it will get going. Also when the pressure is zero, does running 12v to the ALDL make it run? I don't have a book here but that many help isolate what part is having trouble.

 

...thanks for the reply......"no reman" ......i have not tried to run 12vdc to the pump through the aldl as i previously mentioned. i had connected a charger (read previous) and that helped when i had no pressure. however, i will do that later regardless if i have pressure or not to see if i can hear it run at the tank. but, i think it will as i get pressure but, every so often, i don't...and that is the problem! could it be a pump ground getting bad and isn't there one on the outside of the tank access?

 

Yes a bad ground to the pump could be your problem, but I'm not sure where it attaches other than to the pump. You surprised us all when it turned out to be a weak (bad) fuel pump causing your problems last time. I've had company for 2 weeks, the last just left, but another is arriving at 4pm Seattle time, so if I get a chance after they leave I'll look up where the ground goes to.They should be gone by 5 or 6pm, it's 3 now.

 

.......thanks for the reply....for some reason i am thinking there is a bolt/screw at one of the bolts that hold the access plate to the tank although, i could be wrong.

......yea, i was surprised too about the weak pump!...but, that is what it was.....

 

BTW, I said at least 5 seconds, actually the manual does state 10 seconds. Looking quickly I see that a ground wire comes off the fuel pump circuit 150 on an 87, but need to look further to see where it goes.will get back later, another thing is if your nervous about a nut falling into the tank...get a mechanics magnet and hold it close to the nut or wrench...should keep it from going anywhere.

One other thing, when you replaced the pump, and it seems to me you only replaced the motor..did it include a new check valve and pulsator?

 

i have a magnet on a long extension however, i still am not sure if there is a "ground bolt" at the outside of the pump/tank access........the pump was all i replaced.