buick wont start?

[shaun callaway]

Re: buick wont start?

hahahahahahahahahahaha



PLEASE DONT DO THIS

[squirrel]

Re: buick wont start?

On a serious note, I'd be curious to disassemble a bad pump and see what breaks. I've heard that they are cooled by the gas flowing through them and will overheat / fail if the pump is run dry or if you frequently run it low on gas.

that's the case with older cars....newer ones (late 90s?) have a reservoir around the pump that keeps it submerged all the time.

An air conditioning (R12) pressure gage can be used to check fuel pressure on some GMs

For spark test, the older GM manuals suggest cutting the ground electrode off a new spark plug, and using it to test for spark. I connect the shell of the plug to ground with a big clip lead, saves from getting zapped. If it will jump the extra long gap from the center electrode to the threads, then it has enough juice to fire the plugs.

I would not buy any new parts until you verify either spark or fuel pressure working/not working properly.

[milkovich]

Re: buick wont start?

OBDII is so cash. 8) Way easier than being smart like dieselgeek.

Assuming no go on the noid light, how would one go about determining if it's a sensor or an ECM on a 92 like that?

It'd be good info because I'm looking to pick up a 3rd gen firebird eventually and a lot of that 80's junk mystifies me.

[dieselgeek]

Re: buick wont start?

He said no spark. I am presuming he already tried actually checking for it. It's not hard, there are many ways to do it.


I'm gonna bet Cam/crank sensor. Beagle seems to think fuel pump but those aren't usually an on/off problem.


Monte, check for spark next. Don't spray chemicals or starter fluid down the intake, that's a dumbass idea and isn't going to tell you anything more than checking for spark, and it is a huge fire hazard.

[fabricatordave]

Re: buick wont start?

ok that was much better than just saying wack the gas tank.

come on now whaking on the gas tank has gotten me home before

[squirrel]

Re: buick wont start?

probably works about the same as whacking the starter with a hammer to get it going. I think it jiggles the worn out brushes just enough to get them to make contact, once it starts turning it will keep going.

[82z]

Re: buick wont start?

I have run into this problem a few times. First make sure you have sufficent fuel pressure at the rail, If you do then I would be willing to bet money that the crank sensor probbably just crapped out on you.

[SpiderGearsMan]

Re: buick wont start?

could be broken wires fronmmmm the vats lock cyl usually gives a crank no start ++++special 5tools involved 4 hours labor+150-lock cyl+new key need a vats interrigator+to get key code from chip vats cyl cannot be recoded good luck from the sick bay

[shaun callaway]

Re: buick wont start?

He said no spark. I am presuming he already tried actually checking for it. It's not hard, there are many ways to do it.


I'm gonna bet Cam/crank sensor. Beagle seems to think fuel pump but those aren't usually an on/off problem.


Monte, check for spark next. Don't spray chemicals or starter fluid down the intake, that's a dumbass idea and isn't going to tell you anything more than checking for spark, and it is a huge fire hazard.

yes

[redragtop]

Re: buick wont start?

could be broken wires fronmmmm the vats lock cyl usually gives a crank no start ++++special 5tools involved 4 hours labor+150-lock cyl+new key need a vats interrigator+to get key code from chip vats cyl cannot be recoded good luck from the sick bay

Very good idea on that GM product Simple check for ign lock problem Security light should come on steady with key on engine off (koeo) and then turn off after 5-7 seconds. If it stays on or worse(flashes), the car may think it is trying to be stolen and disable itself (can be bypassed with resistor if needed). Also verify the light does indeed work and also check engine light works.

Next step would be check for fuel pres. (gauge prefered)
Next check for spark -ST125 spark tester (or equiv) preferred or pull plug and crank while observing for spark (following std safety precautions)
You can use your test light to check injectors (carefully unplug connectors), should have 12V on one terminal-koeo- Then connect test light clamp to Bat+ and check for pulsing ground on other terminal while cranking to see if PCM is sending signal to injectors to open. If that is working correct it also verifies operation of crank sensor because PCM did see RPM signal.
If you do need new crank sensor - make sure you use gauge to set it. Too deep and it can be damaged, too far away and may not work correct.
Failure of any above tests need further looking into and more and better tools.
There are several pages of diagnostics for NO START. These few checks however cover most common problems

Side Note--Although usually go/no go, have had fuel pump run but not develop enough pres to open injectors (why you need pres reading to verify it's within spec)

[dieselgeek]

Re: buick wont start?

You can use your test light to check injectors (carefully unplug connectors), should have 12V on one terminal-koeo- Then connect test light clamp to Bat+ and check for pulsing ground on other terminal while cranking to see if PCM is sending signal to injectors to open.

are you sure about using a 12v test light, which has almost no resistance, to check for injector pulses? that's usually OK on an engine that runs low impedance injectors, but these should be high impedance. Normally, a test like that will cook an injector driver. Plus an incandescant light likely won't even light with a 5 millisecond pulse to ground... correct me if I am wrong because it sounds like you are a knowledgable tech

-scott

[SpiderGearsMan]

Re: buick wont start?

buy a cheap noid light at the parts store vats kills the fuel in the old cars

[redragtop]

Re: buick wont start?

Noid light is the prefered tool A test light can be used if need be but not as good.

Scan tool is best way to check for RPM signal if you have one available (doesn't everyone have one?)

Test light shouldn't hurt that car, but pays to check.

Also forgot to add when doing spark test, plug wire from companion cylinder (shares coil with test wire) should be grounded to engine

[dieselgeek]

Re: buick wont start?

Noid light is the prefered tool A test light can be used if need be but not as good.

Scan tool is best way to check for RPM signal if you have one available (doesn't everyone have one?)

Test light shouldn't hurt that car, but pays to check.

Also forgot to add when doing spark test, plug wire from companion cylinder (shares coil with test wire) should be grounded to engine

good stuff, thanks for helping! Welcome to the EFI nerd club too! ;)

[1988montecarloss]

Re: buick wont start?

i already tried the "hit the gas tank" trick before i asked about it here and it still didnt start.

i never actually checked to see if it was getting spark. i heard the fuel pump and was just assuming that was the missing link. ive been sick for days and its dark out now so ill check tomorrow.