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HELP!! AARRGH


j_train5344

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Alright guys, got the 93 cutlass vert as some of you may have seen. Got 107k miles on her and ran tip top...except I had white smoke from under the throttle body and had timing belt fragments all over behind the covers. 

I changed the timing belt per Memphis man's how-to video and it worked like a charm. Thanks for that! My initial startup following was lackluster thanks to a dead battery but it did run although briefly. Pulled the battery to charge and a 1 1/2 wks later (northern Indiana weather, ugh) changed the uim, lim, and valve cover gaskets. Also did plugs and wires. Thermostat too. Might as well right?? Reinstalled battery. 

Crank no start!!

Fuel pump has prime. Fuel check valve gives a spray followed by burbles of fuel. Cam flats are down at tdc on the front bank. Pulled the valve cover to confirm. Didn't check the rear because I don't want to undue/redo the upper if I don't have to. Also, nothing moved when doing the timing belt. Plug wires are seated properly with locking clicks at all plugs/coils. Attached is the diagram used. 

She sputters intermittently like she wants to start. I need help!!!

Screenshot_20240324-205634.png

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What is the fuel pressure at prime?  When cranking?  How old is the fuel filter?  Is there gas in the tank?

What is the cranking compression pressure of all six cylinders?

How old are the spark plugs and plug wires?  Are the plugs fouled from excess cranking?  Will the ignition coils reliably fire a spark-tester calibrated for HEI?

Connect a scan tool, verify ALL sensors and ALL computer outputs.  Do you have an RPM signal when cranking?

Edited by Schurkey
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27 minutes ago, Schurkey said:

What is the fuel pressure at prime?  When cranking?  How old is the fuel filter?  Is there gas in the tank?

What is the cranking compression pressure of all six cylinders?

How old are the spark plugs and plug wires?  Are the plugs fouled from excess cranking?  Will the ignition coils reliably fire a spark-tester calibrated for HEI?

Connect a scan tool, verify ALL sensors and ALL computer outputs.  Do you have an RPM signal when cranking?

Umm...I have no idea is the answer to almost all your questions. I don't have any of the tools required to test anything you're asking. The plugs and wires were new until today. I put the wires back in that id replaced and the car fired up briefly before dying again without restarting. You can tell it's trying but no luck. I know there's gas in the tank for sure. The fuel filter matches the rest of the underbody in color...dusted. I'd suspect it's oe. If you're asking if the RPM needle flutters when trying to start, I don't know that either. My eyes been on the battery gauge watching it drop slowly with each attempt. I know none of this is probably going to help, but again, the car ran tip top before I opened her up. 

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15 hours ago, j_train5344 said:

Umm...I have no idea is the answer to almost all your questions. I don't have any of the tools required to test anything you're asking.

If you aren't willing to obtain proper tools, you need to have someone else work on your vehicle.  Fuel pressure testing can be done with tools borrowed from the "Loaner Tool" section of an auto parts store.  I use O'Reillys and sometimes Autozone, but they're not the only ones with a Loaner-Tool program.

The fuel filter matches the rest of the underbody in color...dusted. I'd suspect it's oe.

Start there.  30 years is an entirely unreasonable service life for a fuel filter.

If you're asking if the RPM needle flutters when trying to start, I don't know that either.

I don't care about the tach, although that's a better indicator than nothing.  I want to know if the computer is getting an RPM signal, and you'll need a scan tool to find that out.

My eyes been on the battery gauge watching it drop slowly with each attempt.

Put a charger on the battery.  A fully-charged battery should show 12.6--12.8 volts depending on it's construction AFTER it's  been disconnected from the charger for an hour.

 

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You don't "need" a scantool, necessarily, Its a 93' its not that smart in the first place.

Qucik and dirty oldschool should get you pointed in the direction. These methods served me well for years. I'm saying this as someone who owns all the diagnostic equipment at this point in my life.

Are the plugs fuel fouled? if they are that's a problem, New or not if they are soaked in gasoline they won't do much, pull it out if its wet and smells like gas then yeah

Do you have injector pulse? One bad injector can bring the other 5 down with it. Its not uncommon for them to fail as the cars get older and older.

To check it, pull the cover off the fuel rail, unplug an injector any injector. get yourself a 194 lamp unfold the leads and stuff them in the injector harness, does it flash while cranking? if it does plug the injector back in and move to another of the front 3 and repeat, this will rule out the one you just disconnected as being bad

Make sure the battery is up to the task, the ECM won't run under ~9v or so. 

is the tachometer needle moving when you're cranking if not its an indication that the crank sensor could be bad

Check fuel pressure, put a small flat blade screwdriver to the schrader valve on the fuel rail, do you get a forceful ejection of gasoline with the depression while the key is on? its probably ok 

pull the vacuum line off the fuel pressure regulator, does fuel come out of it? if so thats a problem. if you happen to have a small hand vacuum pump pull a vacuum on the regulator if it won't hold any vacuum, thats also a problem

Next lets get into the weeds a bit more, the map sensor is located behind the upper intake, is everything connected properly, if its unplugged the car won't start

Coolant temp sensor is it connected, if its unplugged it thinks the coolant temp is around -40 or -50 degrees and can often lead to flooding and not starting

I mean you did a heap of work to the car do a general sanity check to make sure nothing you did could have caused it.

Hope this helps.

 

 

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First and foremost, 🖕. That response wasn't warranted at all. 

Second, thank you so much white93z34 for all the tips. Truthfully, I should've started with the gaskets, plugs, and wires just to isolate any issues with the timing belt. I may not have the issues I have had I done that. Knocking the motor down to the LIM on a GM is something Ive done multiple times. I'm comfortable with that. Timing belts got me spooked.

Third, I've verified the map and coolant sensors are connected along with the vacuum to the map sensor. I've got good stream to the fuel rail at the Schrader valve. The battery's been charged. The tach needle doesn't move on crank. I've yet to test the other things suggested.

Fourth, I can get the car started by depressing the gas pedal all the way and keeping the rpms high for a bit. The car will stay running. But it runs like shit and won't restart without doing the same thing again. The exhaust smells like gas a bit more than I'd like too.

Last, the fuel filters on the short list. I've only owned the car 3 weeks

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how was that response unwarranted? He's trying to point you in the right direction on what next to do to diagnose. Unless I missed something you seem bitter about nothing. A lot of us have been here for years and want to help the new guys, dont get your panties in a bunch because your ego was a little hurt

 

Check what these guys are saying. If you have fuel pressure, is it getting to the cylinders? Could be some blocked injectors, could be injectors not firing. Check the plugs to see if they're wet, maybe you have fuel but no spark. He asked about your tach, check that, maybe you have a bad crank sensor or something.

 

This may be a dumb question but I've done lots of dumb things: did you plug all the injectors back in after doing work? All the connectors that you unplugged? There's just so many variables it's hard to say, just have to start checking things one at at time. Good luck!

 

I read your last post again, if it runs but rough it sounds like you're not firing on a cylinder or two. One at a time unplug each spark plug and try and see if you can start it and if it behaves the same. Might be able to narrow down where the issue is

Edited by Psych0matt
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For what it's worth, I really appreciate all the advice, guidance, and well wishes to get the old girl up and running again. I just really don't think being told to let someone else do the work for me was necessary based purely on the fact that I don't own or rent tools that, frankly, I've never needed.

That said, somewhere along the way, I screwed the pooch. After removing the plenum again I've found I left a throttle wire disconnected and a vac line from the fuel rail to the back of the plenum (fuel pressure regulator to the map sensor I believe) disconnected as well. The plugs are also fouled. In addition, since the plenum was off I pulled the valve covers to make myself feel better on the timing. I'm off on the rear. The front appears retarded by a cog spline, maybe 2. I wasn't diligent enough when I checked the first time. The rear appears to be the worst. The one nearest the firewall appears dead on. The other retarded by about 3 cog splines. I really can't explain it. I definitely got my work cut out for me

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  • 3 weeks later...

Got her running boys!! Not only that, she runs tip top again!! It was timing all along. Fabbed some tools in my father in laws shop to replicate those in the Kent moore kit and worked like a charm. A big thank you to those who offered help and guidance through my first real foray into the 3.4L dohc joys and frustrations. It's been better than 12 yrs since my z34 and I never tackled projects like gaskets or timing on it.  This is really a great group!!

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9 minutes ago, j_train5344 said:

Got her running boys!! Not only that, she runs tip top again!! It was timing all along. Fabbed some tools in my father in laws shop to replicate those in the Kent moore kit and worked like a charm. A big thank you to those who offered help and guidance through my first real foray into the 3.4L dohc joys and frustrations. It's been better than 12 yrs since my z34 and I never tackled projects like gaskets or timing on it.  This is really a great group!!

Great news!

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