Won't Start

[azruss]

A couple of things to look at. It is possible the fuel pressure relief valve on the fuel rail is stuck open. don't know how to test this except to pull an injector and see if it is spraying. Also take a very close look at the big rubber thingy that runs from the AFM to the plenum. it must be leak free. they are classic for cracking around the cold injector connection.

[bmorgan5]

Yeah - I've been talking to Brad about this situation... It's down to the regulator. It's just not passing any fuel. I have a brand new one and the old one (it didn't fail - I just replaced it to be sure - ha). So I'm now looking at the fuel pump. I replaced it recently with an Airtex E2182. I'm getting about 64psi at the regulator. Brad has the idea that maybe the pressure is too high and it's keeping the regulator from opening it. My only problem with that idea is that I've tried to blow air past it (with a vacuum on the vacuum port) and I cannot get air through either. Seems improbable that both regulators went out (one is brand new.) I don't know...

[So Cal Mark]

it sounds like you have the fuel lines reversed. The regulator is on the return side. I ran across this once on a car that had an engine rebuild at a shop that wasn't familiar with Fiats. They couldn't make it run

[bradartigue]

I have a theory that he has a pump delivering very high pressure, and the regulator isn't functioning correctly. Zero fuel is entering the fuel rail on his car, the pump pre-regulator is 68psi. I don't really know the failure state of a regulator, but I can see where a fully closed regulator hit with about 30 pounds more than the design pressure, would stay stuck in the position it is in, closed.

I have to admit I've experienced almost no regulator or pump issues in my life, with FIATs and other cars, K and L jet. But I never tried using anything but Bosch pumps - except once used an Airtex to make a car mobile. That brand new pump was noisy from new...and that's all I remember of it.

[bmorgan5]

I'll look at that but I'm not sure... If so it's very confusing since the return is a threaded connection. I didn't change them, so... Honestly, I hope you're correct - that would be easy. But I also hope you're wrong 'cause I'm going to feel really stupid - but this would re-support the first approach to car maintenance - it's usually the simplest thing. Now many times do I have to learn this lesson...

I do not know Fiats... yet. But I'm trying my best.

Thank y'all so much. I'll give it a shot.

[bmorgan5]

Man - the more I think about it, the more I think that might be it and how stupid... And to think I have an ME degree. I probably shouldn't tell anyone that.

Wait - I just figured it out. I bet I accidentally swapped the lines in the back when I installed the fuel pump. AHHH!!! That makes sense. I was welding the new floor pans in and (I forgot why) I removed both lines at the back. I bet I put them back backwards. I'm looking forward to getting home and trying this. Thank you all very much.

[bradartigue]

Man - the more I think about it, the more I think that might be it and how stupid... And to think I have an ME degree. I probably shouldn't tell anyone that.

Wait - I just figured it out. I bet I accidentally swapped the lines in the back when I installed the fuel pump. AHHH!!! That makes sense. I was welding the new floor pans in and (I forgot why) I removed both lines at the back. I bet I put them back backwards. I'm looking forward to getting home and trying this. Thank you all very much.

That would explain a few things...high pressure, low volume turns into high pressure, no volume. Also make sure the +/- on that pump are right, an Airtex may very well run backwards!

[So Cal Mark]

haha, nailed that one. It's an odd occurrence and if you're not familiar with how that FI system works it can stump you

[bmorgan5]

Ok - so that was it. I did it when I welded in the floor pans - I pulled the lines (not good to weld around gasoline) and I replaced them backwards. Quite embarrassing. It now cranks but won't idle. On to the next hurdle. Thank you.

[bmorgan5]

It's been months - the car has been sitting while I rebuilt my spitfire. But it's time to sell this car and now it doesn't want to always start. I got it in this morning - it cranked right up. Not a problem. I moved it out to wash it. Two hours later and now it won't crank. It stumbles at first and then it just turns over. Every time - it stumbles for a second then just turns over. I have a feeling someone here knows exactly what this is, but I'm at a loss.

[bmorgan5]

Update: A shot of starter fluid and she cranked up. I babysat it until it was warmed up and everything was great again. So would that be the cold start injector? BTW - I have going through Brad's diagnostics and everything checked out electronically. The only weird thing is that the TPS is all the way clockwise. But it closed.

[RRoller123]

You mean when you turn the key there is a delay, the starter doesn't immediately engage, and then after a second or two it does?

Pete

[bmorgan5]

No - the car has no trouble turning over. The starter is not the problem. Maybe stumble isn't the right term. The engine starts to fire then it stops. Every single time I turn the key, the engine sounds like it wants to fire up but then it goes back to just the starter turning over the engine. If I let it sit for a few minutes, it fires more but still always goes back to just turning over.

But I sprayed a little starter fluid in the air intake and it cranked right up. It needed a little help staying at idle but once it warmed up, it was great.

I've just been reading and I think I might have a possible suspect. The temperature sensor connector in the front T is broken. It still fits on there but it isn't very tight. And I could be wrong, but this issue seems to appear only when the temperature drops a little. Today the temperature is mid 50s. I didn't notice this when it was in the 80s or higher.

[RRoller123]

Pull the CSI and try to start it, with the CSI spraying into a clear glass container. #5 allen for top screw, #5 ball joint allen for bottom crew. This is to make sure that the CSI shuts off within about 6-8 seconds or so. It could be that you are "flooding" the engine, and although this sounds odd in an FI system it is possible. Also make sure the Thermal Time Switch connection on the bottom of the intake plenum is properly connected, so the CSI is shutting off when it should.

I had a somewhat similar circumstance, that played out this way: I am so used to my modern cars, where you just hit the starter and the computer takes over and you can let go of the key, that I was doing this on the Spider without realizing it. Didn't hold start key position long enough and the engine sputtered but then died. Turned it all the way off, the tried to crank it over and it did exactly as you describe. I pulled the air boot and there was strong gas smell and moisture present all the way back to the throttle plate. I think the problem is that a completely new CSI cycle was started when the computer reset, causing it to be too rich in the plenum. The CSI, when it sprays, wets just about everything in the plenum.

What to do? I put my wet vac hose into the throttle, used it to pull a bunch of air out for about a minute, unplugged the CSI, and started it. It stumbled badly and ran very rough for about 1/2 minute, getting slowly better, and then smoothed out as the excess gas worked through the plenum system. I consciously hold the start key now until it actually starts, and it has never happened again.

[bmorgan5]

Thanks Roller,

I did a quick check of all the connections - all appears to be in order.

But it cranked when I sprayed starter fluid in the intake. That doesn't sound like flooding.

So I just pulled the CSI connection and connected a noid to it. Nothing. It didn't flash once. So, per Brad's book, I need to check each terminals to ground. I did and they both showed a connection, so then I checked the wire from CSI to thermal switch and it seems to be connected as well. So I guess I'm ordering a new thermal time switch? Does that sound right?