Have fuel and spark-wont start

[taylor120]

Hello everyone

So today I got back to working on my 81 FI Spider. I bought the car a few weeks ago and I took out the radiator to inspect some damage and have since fixed it. I also took out the A/C system and put everything back together today. I didn't touch anything to do with fuel or ignition other than removing the afm and air box.

Once I was done putting everything back I raised the front of the car, flushed the cooling system and burped it. I noticed the trany line leaking so I shut it down so i could clean the line and inspect for the exact location of the leak. I had to remove the afm, air box, and intake tube to get down to the trany line. When I went back to start the car it would not start due to a dead spot in the starter. so after a while of cranking and changed battery it will crack, but not fire at all. The temp never reached 190, maybe 160 tops.

Here is what I checked.

-Good grounds
-Good spark #1 cylinder
-Good pulse across the coil terminals with test light
-Good pulse at injector wires
-fuel pump running and getting to fuel rail
-took off #1 injector and it is spraying well

If I have spark and fuel, why won't it start? The double relay was bypassed by the PO, and I don't know if I need to do all of the diagnostics on the ecu/afm b/c I have fuel and spark at the cylinders. I guess I could check fuel pressure, but I must have enough pressure if its opening the injector.


My AFM looks like junk, the cover was missing when I bought the car. But if I have spark and fuel shouldn't it pop over even if the AFM finally took a crap?

Any ideas guys?

Thanks!!!

[rlux4]

Your logic is good. If the AFM is bad it won't send the signal to the ECU which would modulate the injectors according to the position of the flap. If you're getting injector pulse the ECU is getting this signal. It would need to be running to see if the ECU is getting a correct signal from the resistance track of the AFM.
Was it running before you did the radiator? If so, because you had the AFM off, the air intake system is suspect. Check that you have no air leaks on the intake compontents.
Ron

[taylor120]

Thanks Ron, I will check that tomorrow.

Yes, it was running before I pulled the radiator and A/C. It was running today!! It wasn't until I pulled the air box and intake again today to check on the trany line leak that it wouldn't start again.

I read if you have a crack in the intake tube it may not run. Is this correct? I could see it running with a miss, but is it true it may not run at all if you have a large leak?

Thanks again!

[So Cal Mark]

any large leak will let air bypass the afm, then the flap doesn't open. If I were you, I'd check the boot at the bottom of the afm. It's pretty easy to catch that lip when you install it and create a large air leak

[azruss]

i found it doesnt have to be completely air tight. with mine, if the tube to the cold start pulled out of the plenum, the car wont run. if the tube is in place, but not sealed, the car ran.

[taylor120]

well the good news is I made sure the intake tube was not cracked and the tube going to the aux air was loose, so it started right up this morning after I tightened it.

But it started to knock like hell as soon as it started. Like I said before, I just bought it a few weeks ago, and I just got the historical plates in the mail yesterday. I haven't even put it on the road yet. I have just been cleaning it up and getting the lights and such working. I can't believe this. It didn't have the slightest engine noise when I bought it. The oil was nice and clean, but not a fresh oil change. I like it when the oil isn't a fresh change, this way you can see that they aren't hiding anything. Well that’s the idea anyway. No water in the oil, no metal in the oil. It doesn't sound like top end noise, it sounds too deep for that. I don't see any holes in the pan or block. It couldn't have just happened this morning when I started it I don't think. I have never rev'd the engine past a few grand.

Any Ideas on what am I looking at to do a normal rebuild $$ ? I'm in Ohio. I can pull the motor and do most of the work I guess. Who knows what kind of mess I will have when I get inside. Should a take a quick video of it so you guys can hear/see it? I know the cam towers are leaking oil, but I don't see any holes in the block anywhere. Anyone close have a good replacement motor for sale

I guess I'm just having bad luck this year. The motor just blew in the wife's minivan this summer. It was a Chrysler Town & Country with only 65k on it and it spun a main. I know I'm going to get an "I told you so" when the wife finds out.

[rlux4]

It could be the auxilliary shaft. Time the valves and check that the auxilliary pulley is in the correct orientation. If the aux. shaft is in the wrong orientation the lobe on it will hit a bolt on the #2 rod connector. This is a common mistake that's made and it will knock pretty loud.
Ron

[taylor120]

I just checked the timing marks on the cam pulleys and the aux pulley, and if I did it right, they are correct. Both cam pulleys were pointing at the indicators, and the aux was around 1-2 o’clock. You know what, I didn’t check to see if the crank was at TDC. Should I check the crank pulley too, or does that not matter if the other three all line up?

I did smack the starter yesterday since it has a dead spot, but I didn’t hit the oil pan. So I don’t think it’s the pick-up since it sounds so deep.

[So Cal Mark]

could an object have gotten into a cylinder when you had the intake system off? The crank does need to be at tdc when you line up the other 3 pulleys. The aux shaft alignment is pretty critical, make sure the dot on the sprocket is pointing at the tensioner pivot bolt with the crank at tdc

[taylor120]

Hi Mark, Well I didn’t really take off the intake. I just took out one injector to make sure it was indeed working. The only other part of the “intake” side of things was the air delivery tube from afm to throttle body. I don’t know what, or how, anything could have gotten in when doing this. I didn’t end up with any missing bolts or screws…

[So Cal Mark]

I'd recheck the aux shaft timing then. Did you remove any spark plugs?