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1987 Buick Century No Fuel

Tiny
JHOGAN147
  • MEMBER
  • 1987 BUICK CENTURY
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 114,000 MILES
Changed fuel pump, filter, tank, relay and lines. Car just quit but will start breifly with stater fluid. Turn key relay works and can hear fuel pump. What else is there to check?
Monday, August 10th, 2009 AT 1:47 PM

14 Replies

Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Hello, engine cranking, is there an injector pulse? Did you use a gage to check for fuel pressure? Before you replaced the pump, did you check for voltage and ground at the pump, engine cranking. Right now, I just wonder if the computer is receiving an rpm signal, without that signal the injector won't pulse. Any codes?
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Monday, August 10th, 2009 AT 1:59 PM
Tiny
JHOGAN147
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I found the fuel lines leaking so when we jacked up the car everything was rotten so we replaced all lines, sending unit, tank, and pump. Ran great for a month then we parked it for about 3 months. Started it up the other day drove it all day no issue. Went to use it yesterday started with no problem. Drove it a 1/4 mile and it died a a stop sign would not start again. Cranks fine and I used starter fliud and it starts and runs until the fluid is used. Open gas cap turn key on and hear the fuel pump breifly each time I turn the key (pressurizing the system so I'm told). No fuel is coming out of the injector at all (single TBI). I find it hard to beleive its the pump I bought it from NAPA OEM Part. Where's the pressure check connetion located I guess I could try that next. Have yet to check for codes yet.
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Monday, August 10th, 2009 AT 2:23 PM
Tiny
JDL
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You can use a noid lite to see if the injector circuit is pulsing, with engine cranking. Take the connector loose from the injector, plug a noid lite into the connector. You could probably use an led testlite at the injector plug, see if the lite pulses, engine cranking.

With TBI there is no schrader valve, you tee the gage into the fuel supply line. Depending, some models it's easier to tee in at the fuel filter, filter removed.
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Monday, August 10th, 2009 AT 2:55 PM
Tiny
JHOGAN147
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OK I will try that this evening along with getting the codes. I really appreciate your help with this.
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Monday, August 10th, 2009 AT 3:14 PM
Tiny
JHOGAN147
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Got a code 34. MAF sensor and/or MAP sensor. Test procedures say start engine but no start. Can one of these prevent no fuel?
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Tuesday, September 8th, 2009 AT 10:59 AM
Tiny
JDL
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No, if you don't have an injector pulse, the problem is elsewhere.
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Tuesday, September 8th, 2009 AT 12:02 PM
Tiny
JHOGAN147
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  • 9 POSTS
OK This is what I have done so far;
I have a 700 Series TBI with a single Injector.
Did the noid light test got nothing. Disconnected the fuel line from the TBI Unit turned the key noid light came on steady and fuel shot out for about 8 seconds then stopped. Reconnected fuel lines noid light again will not flash. My Hanes book does not show this TBI Unit shows only 2 Injector Application.
The same exact TBI and motor is in a 1987-88 Fiero which I found a picture of. Did resistance check on injector as well and the reading 1.8m (range is suppose to be 1.42-1.62 so its high). So now tell me whats next I'm in too far to give up now!
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Monday, September 14th, 2009 AT 10:58 AM
Tiny
JDL
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I'm still not sure if the computer is receiving an rpm signal? The purple wire with white tracer carries rpm signal to the pcm, with out that signal, the injector won't pulse.

The connector for the wire I just mentioned, purple/white, take it loose, leave the noid lite connected to injector plug, You did check voltage at injector plug, correct, you have voltage, just no ground? Anyway, with multiwire connector loose from ignition mdule and noid lites hooked-up. Turn the key to on, no need to crank, use a testlite connected to battery voltage, tickle the terminal for purple/white wire, does the noid lite pulse?
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Monday, September 14th, 2009 AT 11:59 AM
Tiny
JHOGAN147
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Now I'm completely lost!
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Monday, September 14th, 2009 AT 12:33 PM
Tiny
JDL
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Sorry about that, I was just trying to see if the computer could react to an rpm signal. The pcm should react to the tickle by pulsing the noid lite. The purple wire with white tracer comes from the distributor or coil pack, whichever you have, to the pcm. That wire carries the rpm signal. With the test I just described, if the noid lite flashes, I think the problem is the ignition module. If it doesn't flash, check wiring circuits and pcm.
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Monday, September 14th, 2009 AT 1:11 PM
Tiny
JHOGAN147
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Not to sound dumb (please have patience cause now we are going into a new frontier with me). How can the PCM receive an RPM signal when it wont start? When I had the fuel line off and cranked it some fuel went down into the throttle body and it started right up and the noid light came on then solid as the fuel was pumping out of the line. Did'nt want to cause a fire so we shut it right off. Would crank position sensor have anything to do with it? Spoke to a guy at AZ about it as well he sold me a pressure regulator (looks like a 50cent pice with a rubber diaphram) but he also mentioned the Crank sensor. Getting so frustrated might surrender and take it to the shop which will cost me a small fortune.
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Monday, September 14th, 2009 AT 1:54 PM
Tiny
JDL
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No problem, when you tickle that terminal I was talking about, it fools the computer into thinking that is an rpm signal and the noid lite should flash.

As far as the normal rpm signal, you get that with engine cranking, it doesn't have to start. With dis ignition the rpm signal comes from the crank sensor, with a distributor, the rpm signal comes from the ignition by way of pick-up coil. Different systems may have different quirks.

I try to answer so many questions during the week, sometimes I get confused. Just talking about post count, some of the moderators and people that answer questions here, I can't hold a candle to some of those people as far as count.
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Monday, September 14th, 2009 AT 2:26 PM
Tiny
JHOGAN147
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Well I "tickled" the terminal and got nothing. Went around to the front and for some reason the cooling fan just came on all by itself. Then the check engine light came on steady and would not go out. After several minutes of profanity and tool throwing I called AZ asked the guys where I should go next and they said sounded like the ECM was shot. I checked several boneyards (was not going to pay for a new one where the price ranged from $79-$285 depending who you called). Got one for $35 (from an 1987 Celebirty) hooked it up and bingo! Started right up and runs so smooth its like brandy new!
Just wanted to get back to you and thank you very much for all your help!
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Monday, September 21st, 2009 AT 11:08 AM
Tiny
JDL
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Glad you got it going your way.
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Monday, September 21st, 2009 AT 3:57 PM

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