olin305

Whenever I start my car up, regardless of how long it was before it was last started, it always seems to take at least 10 seconds of continuous cranking for it to finally start up. I never try to start for longer than about 10 seconds, but I have noticed that on my second attempt it usually starts up right away. Also, once in a blue moon (this only happens once every couple of weeks) it'll start up a little bit more quickly, then die again if I don't give it some gas.

I'm thinking it's probably the fuel pump, I've only had the car for about a month and a half, so so far the only thing I've done to the fuel system is replace the fuel pump relay.

bitchin_buick

Fuel filter? Only had the car 1.5 months.... Chance to replace plugs, wires, dist.cap, rotor? Good luck!

ericjon262

also, when you start the car, do you let the fuel pump prime first, or just immediately start the car?

olin305

I let it prime for a few seconds before attempting to crank it

Jono4820

iTrader: (1)

Had the exact same problem with my 91 RS. I replaced fuel pump and no longer have the issue. I you were to check you Fuel pressure it is probably too low.

olin305

How exactly do I check the pressure on it?

Jono4820

iTrader: (1)

Put a 'tee' inline on the supply line from the gas tank (not the return line) and measure pressure there. The tee has what looks like a tire valve stem where the fuel pressure gauge screws in. I put my tee right in the rubber fuel hose next to the washer tank under the hood.

olin305

Sounds good, I'll have to get the tee line first, however I did check my ECM, because my check engine light was on, and it gave me a code 54, which confirms it as a fuel pump problem, because I've already replaced the relay for it. Do you know off hand where the best/cheapest place to actually get an OEM fuel pump would be? Thanks a lot again.

RBob

iTrader: (1)

The ECM isn't checking the fuel pressure, it is checking the voltage to the pump. This is usually caused by a bad relay. Which you have already replaced. Are the wires going to the relay socket OK? Contacts OK? Correct relay (the others are fan & A/C)? Many times the wire insulation at the socket starts to crumble and/or the contact corrode.

The reason that the car is starting after a long crank time is the fuel pump oil pressure switch. The engine starts to build oil pressure (from the cranking), this switch closes and powers the pump directly.

There is also a small transistor in the ECM that tends to go bad. This too will cause the fuel pump relay to not pull in at key-on. Although it is easy to replace the transistor with a common part. There are pictures and the transistor type posted on the DFI & ECM board.

RBob.

Motopsyco

any update on this? mine takes awhile too, was thinking prolly fuel pump, but now i guess it could be other issues according to this thread. although mine doesnt die afterward and runs quite well, just takes about 10 seconds to start.

olin305

Haha sorry it's taken me awhile to update this, I've been meaning to go my local parts store to get a new oil pressure switch, but there was one thing that I forgot to mention before.

Before I replaced the fuel pump relay, I kept hearing this buzzing noise coming from underneath the car when the engine was off, when I was at my mechanics place one day I asked him about it, and he unplugged the relay and the buzzing stopped, so I got a new relay, and that fixed the buzzing, I was just wondering if maybe the trouble starting had to do anything with the fuel pump still running when the car was off, because I don't know if that screwed it up at all or anything, but I know it didn't do it any good.

Edit: My car stays running after it starts up too, there's only been once or twice where the engine speed started to drop, other than that once it's running, it's stays that way. It actually runs great, starting it is the only problem.

1988-305-tbi

a few years back i decide to pressure wash my enginebay... bad idea, i started having the same problem, replaced the relay, but it turned out to be a short in the ecm, i went out got a new ecm from the junkyard and no more problems,

when you put the key in the ignition , before you start cranking it, but while it's turned to the on/run position listen for the fuel pump buzz, the ecm should run the fuel pump prime for 2 seconds then stop, if you aren't hearing any noise from the pump, you have a short some where in the relay system/ ecm



my pump would sometimes run after the motor was shut off aswell, and i had to manually unplug the replay to stop it

olin305

I think that might be it, because I listen for it to buzz, but it doesn't, ah crap... now I get to search for a short circuit... and it's freezing outside.... but I think I remember the previous owner saying something about having replaced the ecm, or something to do with the computer. I'll have to call him and ask, I'll update again when I find out more.

1988-305-tbi

it was hard finding the right ecm at the junkyard, i eneded up buying one on ebay for $39, swapped in my prom and it started right up on the first try and hasn't acted up since.

olin305

Is there any way to actually physically tell by looking at the ecm whether it's bad or not?

Cflick

If you see burnt parts, it's bad.
If you don't see burnt parts, you don't know anything. Could be either good or bad.

1988-305-tbi

what he said, i took mine apart looked at every thing, no burn parts or broken connections that i could see, but still bad

olin305

This is the closest one I could find here, came from a car with the same engine, only difference is that car had an auto transmission, mines manual. Would I still be able to use it?

Cflick

Put your chip in it, and you should be good to go !

Motopsyco

just wondering if you bought that ecm and if it worked for you, I havent gotten anywere on mine yet, and curious before I blow the money on a new ecm, I dont recall hearing my fuel pump buzzing when i turn on the key either, also I didnt think it wat the pump, but now I am thinking that after i turn off the car and get outI hear a loud buzz for a second or so, maybe the pump, I was thinking the power hatch pulldown, but when i was fixing that I had it all unpluged and I still heard the loud buzz. Think that might be the pump?

olin305

I haven't gotten the new ECM yet, I'm too poor lol. But as for the buzzing, that sounds just like what happened to me before I replaced my fuel pump relay. Try unplugging the relay while the cars off and while it's buzzing. If it stops, then it's for sure your fuel pump. I bought a new relay for it at the parts store for like $35, and that fixed the buzzing after it was turned off. Still have a problem with it not starting up right away though.

Jono4820

iTrader: (1)

What is your fuel pressure??

olin305

As of right now I'm not sure, I can't really get under the car to check it out as there's about a foot of snow on the ground. But I think it's about where it should be, because once the car actually starts, it runs great, never stalls or anything.

Motopsyco

thanx for the info, I'll check that out, I got kinda the same situation right now as far as almost a foot of snow, so I cant do much with the car right now, plus my battery is dead now too.

Cflick

Stick you ear very near the tank, and have someone turn the key on. Not start, just on. You should hear the pump start to prime the system.
Alternatively, jumper-clip battery to fuel pump power wire, then start the vehicle. If you have a fuel pump priming problem, the time it'll take you to get from the clip lead to the key will prime the system, so the vehicle should start almost immediately. ( this will also eliminate the pump and the wiring to the point you connect the clip lead, preferably right at the pump relay, both sides to check the relay itself )