New Engine Help- Shuts off shortly after startup

[redsn95gt]

Got my engine to finally turn over. It idles for a very short time (and roughly i will add) then dies in a few seconds. I think the longest I was able to keep it on was about 15 seconds and I was pushing the gas a little bit to keep it up, it was just sputtering at this point.

On the infamous start checklist, I have narrowed down my possibilities to the following:

K.) Engine fires briefly, but dies immediately when the key is released to the Run position. Crank the engine & when it fires off, pull the small push on connector (red wire) off the starter relay (Looks like it is stuck on a screw). Hold the switch in the crank position: if it continues to run there is a problem with either the ignition switch or TFI module. Check for 12 volts at the red/green wire on the coil with the switch in the Run position. Good 12 volts, then replace the TFI. No 12 volts, replace the ignition switch.

I confirmed I am getting +12V at coil with my multimeter with key in crank position. Using stock TFI module, worked great before engine was out.

6.) Spark & fuel pressure OK.

Yes, confirmed all 8 plugs are getting spark with a tester light attached. Fuel pressure is healthy, around 30psi off, 40ish psi starting. Using stock regulator, I also have a Kirbin adjustable and a Aeromotive adjustable I can fit if needed, was waiting til after it was at least idling to put on.

A.) Failed IAB or improperly set base idle (no airflow to start engine). Press the throttle ¼ way down and try to start the car. See the "Surging Idle Checklist for help with all your idle/stall problems.

Made sure to confirm I am TCD compression with spout on #1 wire. I also confirmed by setting it to TDC exhaust to see what happens (it doesnt start lol)
Where is this "Surging Idle Checklist"? Id love to see it.

C.) Engine ignition or cam timing off: only likely if the engine has been worked on recently).

This is my biggest fear.. I am not 100% certain I was at TDC when the chain was put on. None of my pictures show the cylinders. I guess I have a 50/50 chance of it being correct? I am running the chain with 0 degrees advance as recommended by the Anderson cam card.

EDIT - No longer my biggest fear. Took the plunge today and pulled the timing cover only to discover I did it 100% correctly my first time. If anything, it feels really good to know its correct. Nothing beats spending several hours scraping gaskets and getting RTV all over yourself.

I also did a compression check for leaks, got a healthy 90+ psi on all 8 cylinders. Results were very close to each other.

This is the build specs:
Rebuilt 302 (now 306) with Federal Mogul rebuild kit
Anderson AF-N41 Cam (i've seen this run on a stock tune on youtube so i know it can at least idle)
Holley Systemax intake manifold
AFR 165 heads
1.6 Scorpion Rockers
30# injectors
Pro-M mass air for 30# injectors
255lph Walbro pump
BBK Air Intake
BBK 70mm Throttle Body
Re manufactured Stock Distributor w/ MSD cap
Stock Coil
Stock TFI
94 GT 5 speed ECU

 

[toyman]

Two things. First where do you have the timing set? I don't get a clear picture that indictes it's at 10* BTC. And second, the compression numbers are very low (90 psi) for a rebuilt engine. They should be at least 150 psi.

 

[redsn95gt]

Two things. First where do you have the timing set? I don't get a clear picture that indictes it's at 10* BTC. And second, the compression numbers are very low (90 psi) for a rebuilt engine. They should be at least 150 psi.

1) I have heard mixed input on this, right now I am at 0* for initial timing. I will try 10*

2) For my test, I was only running the starter about 2 seconds to get 90psi, if I keep cranking, it definitely goes up well past that. How many turns should I do for a test?

Thanks!

 

[toyman]

1) I have heard mixed input on this, right now I am at 0* for initial timing. I will try 10*

2) For my test, I was only running the starter about 2 seconds to get 90psi, if I keep cranking, it definitely goes up well past that. How many turns should I do for a test?

Thanks!

Well, first I don't believe the car will stay running at 0* timing. As for the compression test, crank until the psi is at it's peak. I would think that that would occur within a few seconds. If the max is only 90 psi squirt some oil into the chamber. If the pressure doesn't change there is a valve sealing problem. If it increases then there is a piston sealing ring issue.

 

[redsn95gt]

Thanks, good to know. I did not get to try the car at 10* yet, my water pump had a small leak and I ended up pulling it off and doing a permatex rtv water pump gasket sealer for it instead and I wanted to let it sit overnight. Tomorrow if theres no more leak, I'll give the 10* a try and try looking at the compression test again.

 

[Adam95GT]

Thanks, good to know. I did not get to try the car at 10* yet, my water pump had a small leak and I ended up pulling it off and doing a permatex rtv water pump gasket sealer for it instead and I wanted to let it sit overnight. Tomorrow if theres no more leak, I'll give the 10* a try and try looking at the compression test again.

How are you doing your compression test? are you holding the throttle open? Doing atleast 5 revolutions?


But i agree with everyone else... you need 10* timing to run well.

 

[99FiveOh]

Even if the compression is sort of low, maybe the rings need time to seat which can only happen if the motor is ran for a good amount of time. But I think you'll find that you have a timing issue.

 

[redsn95gt]

How are you doing your compression test? are you holding the throttle open? Doing atleast 5 revolutions?


But i agree with everyone else... you need 10* timing to run well.

I am testing with compression gauge, doing 1 plug at a time, disconnected distro and fuel pump relay. I was just turning key to start for about 2 seconds, it was difficult to count the start revolutions, i could count at least 5-7 in 2 seconds. If I left it a little longer than 2 sec, readings would be 110pish, 3 sec was 125-135psi, thats as long as i held it open. I did not touch the throttle at all during the test. I wonder if i just keep it on for 5-6 sec if it would reach 150psi

 

[toyman]

You do want the throttle fully open while doing the compression test. Having someone who can crank the engine and hold the throttle open while you watch the gauge is helpful.

 

[Adam95GT]

You do want the throttle fully open while doing the compression test. Having someone who can crank the engine and hold the throttle open while you watch the gauge is helpful.

pretty sure you should have all the plugs out as well not one at a time and the fuel pump should be disconnected

 

[redsn95gt]

Ok today was a success! Set the timing at 10* and she fired right up. It still dies out if I don't give it a little gas, but its sounding much better. I haven't had anyone around to give me a hand, i'm sure some adjusting on the dizzy will help some more. I have a timing light ready to lock in the timing when I get a second set of hands. I think I started a small earthquake in china when this thing fired, I definitely did not expect this thing to sound quite this loud, they are going to stick me with the big blocks at the track i swear!

 

[99FiveOh]

did you have the spout out when you set the timing? Did you remember to put it back in after?

 

[redsn95gt]

Yea, I had the spout out at first, wasn't really running well, then put it back in and it almost can idle without pressing the gas pedal. I'm going to tweak the position of the dizzy today to see if i can get it to idle on its own, then hit it with a timing gun.

 

[99FiveOh]

Did you time the car WITHOUT the spout connector? Then put it back afterward?

 

[redsn95gt]

Haven't been able to time it yet with a light. Still haven't got the base timing set to where i can just walk away from the car without it stalling out. And to make matters worse I locked the keys in the car so thats a nice time waster.

Heres a video of it now. Never mind the gauge needles all over, I had the cluster out and I didn't get them back on in the correct spots.
YouTube - ‪95 Ford Mustang 306 Ported AFR 165s Holley Systemax AFM-412 Cam Startup‬‏

 

[99FiveOh]

So let me get this straight. You timed it WITHOUT a timing light? I don't understand how you could accomplish this. You MUST use a timing light, there is no eyeballing it or timing it by ear. I'm confident that once you time it properly with a light, it will run like a top.

 

[redsn95gt]

So let me get this straight. You timed it WITHOUT a timing light? I don't understand how you could accomplish this. You MUST use a timing light, there is no eyeballing it or timing it by ear. I'm confident that once you time it properly with a light, it will run like a top.

I haven't used a light yet correct, so technically I haven't really done any timing beyond the base time to get the engine to fire up. (10* BTDC and got the dizzy to sit exactly at #1 plug) I had the spout connector out previously just to see how it would react.

 

[redsn95gt]

Ok, today was a bit better, then went bad and I called it a day. Tweaked the dizzy to the point where the car could idle and I could stand outside of it. Its running but man that motor shakes (solid mounts however). So I hooked up the timing light and tried to have a go, removed the spout connector, aimed the light, could see my timing mark was off from my line about almost an inch. I drew my mark at 0* but I did my base time at 10*. Should my line be at 10*? If i change the dizzy to anything but what I am at now the car stalls, so I am not even sure how I am going to time this thing.

In the end some neighbors came over trying to help, we re-set the base time again then I couldnt get it to start up and called it a day.

BTW in case you havent noticed, I have never timed an engine before

 

[toyman]

Ok, today was a bit better, then went bad and I called it a day. Tweaked the dizzy to the point where the car could idle and I could stand outside of it. Its running but man that motor shakes (solid mounts however). So I hooked up the timing light and tried to have a go, removed the spout connector, aimed the light, could see my timing mark was off from my line about almost an inch. I drew my mark at 0* but I did my base time at 10*. Should my line be at 10*? If i change the dizzy to anything but what I am at now the car stalls, so I am not even sure how I am going to time this thing.

In the end some neighbors came over trying to help, we re-set the base time again then I couldnt get it to start up and called it a day.

BTW in case you havent noticed, I have never timed an engine before

Are you looking at the correct spot. From this picture you can see the straight edge of the pointer is where you want to see the timing mark. Not at the half circle. The pointers have been know to break at the mid point.

 

[redsn95gt]

It looks like the edge was flashed out on your pic. I'm not using the half circle you mention, I see that in your pic too. I'm using the pointing edge, it actually says 'TIME' engraved on it. When I aimed the light at it today, I could see my drawn timing mark about 1in below it, closer to your half circle. Remember, my timing mark is drawn at exactly 0* and not 10* where I set my base time.

I know I'll figure this out eventually!