Okay that didn't work. Now what.

My thought that the metro had skipped a tooth on the timing belt turned out to be wrong. I went ahead and put the new timing belt on anyway. But still having the same issues.

It'll start and roughly idle for a second prior to dying. If you give it any throttle it'll bog and die. If you lightly feather and pump the throttle it'll rev up slightly but sometimes will get a backfire through the throttle body.  

I double checked the timing marks, made sure the distributor rotor was pointed at the number one cylinder and pulled the valve cover to make sure the number one valves were closed.  Everything is as it should be. 

I would have sworn it was a timing issue but everything checks out. What should I be looking at next?

Fuel pressure and volume.

Will it run on starting fluid?  This will be hard to check without a remote starter switch or a helper.

Is it still cap and rotor? I don't remember with those cars. 

Startup, then fail to idle sounds like MAP/MAF to me.  I don't know how Metros meter fuel, but it sounds efi related to me.

In reply to Tyler H :

+1 vacuum leaks.  Look for them and kill them.

verify fuel pressure both when cranking and after shutoff (could be a bad pressure regulator).

All of those sound viable but my first guess was same as knurled's - not enough fuel. 

Starting fluid while stumbling should tell you if that's it.  

My similar issues taught me a lesson I’ll use for the rest of my life:

Same symptoms to a “t”. I started with a new fuel pump but it didn’t fix the problem. So I tried timing, I tried a known issues with the wiring harness, I tried EVERYTHING to no avail.

Guess what? IT WAS THE FUEL PUMP ALL ALONG! I had gotten a bad replacement and just assumed it couldn’t possibly be the fuel pump.

Anyway, check the fuel pump!

Thanks guys. I'll check the fuel pressure if I can figure out where I can pull a reading from. 

Knurled. said:

Fuel pressure and volume.

 

Will it run on starting fluid?  This will be hard to check without a remote starter switch or a helper.

I'll have a helper tomorrow. It's about time for these guys to start helping out anyways. 

In reply to ebonyandivory :

I can’t tell you how many times I’ve seen bad new parts. You think the new part is good and go Looking at other stuff that makes you crazy when nothing is fixing it. 

sergio said:

In reply to ebonyandivory :

I can’t tell you how many times I’ve seen bad new parts. You think the new part is good and go Looking at other stuff that makes you crazy when nothing is fixing it. 

especially if they're from autozone and the equivalent. 

I always say to test the fuel pressure, not show me the box it came in.....

NEW = Never Ever Worked.  

It sounds like fuel to mee too.  You can use an unlit propane torch in the air cleaner box to see if it runs longer.  Also handy for finding vacuum leaks.

44

I'd say lean as well, but...

I'd also throw a set of plugs in it just for E36 M3s and giggles. I chased a off idle stumble that I knew was a carb problems for a couple of weeks before a old guy told me to try changing the plugs. Sure enough he was right. That's now my first step for just about any issue.

grover said:

sergio said:

In reply to ebonyandivory :

I can’t tell you how many times I’ve seen bad new parts. You think the new part is good and go Looking at other stuff that makes you crazy when nothing is fixing it. 

especially if they're from autozone and the equivalent. 

It seems like *everyone* is "the equivalent" anymore. 

carbed 4 cylinder swap.

Starting fluid is a wonderful thing for diagnostic purposes.  If it starts and runs on starting fluid, you know that it is not spark, compression, or timing.

And you already seem confident that timing and compression are okay, which leaves fuel and spark as the questionables.  And the chug/fail is very consistent with insufficient fuel, as the car runs on priming fuel and then dies.

Still fighting this and we are rapidly running out of time. Was getting no fuel pressure through at the TB. Changed Fuel filter because why not and no change. The old filter had a ton of crap come out of it when I turned it over. Dropped the tank and pulled the pump out. Some rust in the tank but nothing too major. Cleaned the tank out.  Hooked the gauge up to the pump and am getting 35 PSI which is what it should be getting according to the boss. I haven't looked up the specs. Blew air through all the lines with no issues. Put the tank back in and am waiting for the boss to repair the bolt he broke on the injector so I can test everything.

What's the chances of a rubber fuel hose delaminating on the inside and blocking flow similar to what brake hoses sometimes do? I would think they would just bust and leak at that point.

What year vehicle, and what's the MAF/MAS like?  Like Tyler H said before.

To elaborate on it a bit, if the system is an 80s/early 90s flapper door or spring door setup, they fire approx 2 seconds worth of fuel on cranking.  They rely on the door opening to click the fuel pump relay on all the time.  If something happens to that internal switch, the wiring or the connection, you'll have that exact situation.

In reply to WonkoTheSane :

It's a 1994 Geo Metro 3cyl. I believe it has a MAP sensor? Not really sure. I can handle Bosch CIS injection and carbs. EFI is not in my wheelhouse.

Check your 5v reference and make sure it's 5v. 

I had a nightmare car that ended up being a shorted coolant level sensor pulling the reference down to 3.4v. Unplugged the sensor and this car I had been shotgunning parts at to solve similar issues suddenly ran perfect. 

It was a similar era GM car too. 

FWIW my explorer did that and it ended up being the IAC

I've had similar issues with a GM 4.3l.  Turned out it was the crap in tank hose dissolving likely due to ethanol.  This was the hose between the pump and the tank Hardline that is submerged in fuel.   I would get enough fuel to start and run at a rough idle but any throttle wouldn't work.  I ended up buying a Delco pump with ethanol safe fuel hose 3 years ago and it's been fine since.    If you put a new pump in and it's easy to pull you could check it to make sure the hose is hooked up right.

In reply to Nick Comstock :

If changing the rubber fuel hoses is easy, just change them.