Engine Engine stalls after running 10 minuter

Hi,
Running FelPro 1250’s?
Cyl balance test is OK.
Codes point to a fuel system issue. Vapor locking. Have a gauge to plug on the rail’s Schrader valve to measure fuel pressure?
Pull a few plugs & read the electrodes via color.
Have you checked your vacuum line’s routing when you reassembled?
Check for cross contamination of coolant in oil, it may also partially burn off, I.e, sweet smell from exhaust.
Engine temp staying stable?
Start the car with the radiator cap off & look for bubbles indicating a combustion to coolant passage leak path.
Is your PCV system functioning properly?
Are you running the correct PCV valve?
May be normal or greater than normal amounts of combustion gases escaping from a head gasket or similar path ending up in the crankcase that your PCV simply cant keep up with, pressure taking out gaskets or gases diluting the required 02 levels, causing it to stall.
TPS should be <1 volt @ idle.
A TF s1 Cam should be able to run relatively stable without a tune.
See if any of these line up for you.
-John

Did you have the front of the car jacked up when you filled it? Could be some small air bubbles from the heater core.

Hi,
Funny, was just typing to you, lol
What year is your Pony?
Need a HC test to confirm combustion is source, but consistent bubbles, that’s something.
I do a fair amount of H/C/I swaps, tuning. Most H/C/I swaps aren’t overly complicated & it’s common errors that snag us.
Were the heads checked for flat (</=0.007/Ft), shop prep the heads & do a pressure test?
Very good, located bubbles & doing a leakdown. Good start.
If you lost an intake gasket(s) due to surface irregularities, e.g: leak, a few times, get a little aggravated, overtorquing intake bolts can peel a head up enough to cause a head gasket leak..
Any other smog removed during this GT40 swap/Cam swap, or was it only the Thermactor pipes?
-John
Using RTV around the coolant ports? A little bit will get you past minor surface irregularities...then another bead after that setup around the coolant ports. Happen to take any pics of the intakes coolant passage area irregularities for a look see?

Hi,
Very good. I agree with your thought on what’s occurring, I’ll detail why. Good precautionary, avoiding Ethylene Glycol’s devastating affects on your bearings.
INTAKE INSTALL ONLY:
On SBF/BBF motor’s, early SBC’s, in addition to using (2) small topside gasket dab(s) of Hi Tack-one in front, one in the rear so gaskets don’t shift, I’ll use a continuous bead of permatex on both sides of 1262’s gasket’s coolant passages, (1) on the head side, (1) on the intake.
Additionally, I was suggesting a very light skim coat to cover up the moderate pitting you’d mentioned of the lower (Corrosion based-?) you previously described to/in addition to the beads around the lower intake to head coolant passages. between intake ports Now, method to avoid much of this...
HEADS INSTALL BEFORE INTAKE:
New heads. Before torquing the heads, you can grab all the intake bolts with the gasket(s) installed, intake bolts finger tight with an additional 5 Ft/lbs in proper sequence with a torque wrench minimizes head creep while they're being torqued down.
The real issue is the head locators doubling as Dowels.
OE’s (2) split pin’s leave quite a bit of slack for creep. The bolts taper up top to bring things in clos-er, studs are the best, but don’t have that same effect.
I’ll run these on most street motors, they really help. Full hollow pins, light taps with a soft hammer & they’re in.
https://www.summitracing.com/parts/tfs-51400420
After your (1st) torque pass of (3) head steps of torquing, back off the intake bolts will avoid interfering with your head torque numbers as little as possible can & do shift significantly, but not after your 1st pass.
Have learned over the years, the 1250’s work better for you than 1262’s.
Snip out the coolant passage crosscorner gasket section.
The Intake & head need be free of all old gasket material, debris, hospital clean surfaces and then torquing the lower needs to be done in the correct center- out crisscross sequence in stages. N.P., will post if you need it..
I’m pretty certain you don’t bother with the cork lower to block gaskets & use a good bead of Permatex. No idea why they even include them, lol.
The printoseal’s are good gaskets but certain (like 1262’s) are purposed as full Competition gaskets, suitable for a motor that’s Blueprinted, with frequent tear downs & higher accuracies.
Their surface area is slim, with a very square race motor they’re great with large port heads (note coverage around the coolant passages is small vs 1250 Gaskets). Not my choice unless I have a motor disassembled in the shop, and dead on alignment on between heads, block, intake is a breeze.
If I see error in a valuable intake, I’ll opt for a known square surface and a >/=32RMS finish value and mill 0.300 off each side and drop 0.25 intake spacers in both vs “making it work with Permatex”. I don’t much like that, to be clear, wrong approach, but things in the real world aren’t always so accurate, it works reliably, done neatly and Permatex remains pliable, shifting with engine’s heat cycles.
What head’s are you running, TrickFlow 170’s, AFR’s?
I hope this helps, not the first I’ve seen & causes lots of headaches.. Laying the intake down & bolting lightly to one head, light behind the motor & looking across it will help gauge things. The OE Ford steel core (Black) gaskets also work well, if lined up tight.
Good luck!
John

**I began drilling 289-460’s decks with (3) 3/8” holes, reaming +.0002 for dowels for a light press if an aftermarket block, protruding 3/16”, heads the same +0.011 over. I’ll only do the block’s holes on a Mill, but made a jig with Tungsten inserts & locators for aligning the holes in the heads with a W letter drill (0.386) to keep alignment tight. Also lines up to cut the required head gasket openings.
That works every time.

Rocky....
Hi, I apologize for not getting back to you sooner, some medical things came up.
This is what I see.
You’ve got a solid 95’ 5.0, cylinder balance test and leak-down both suggesting the Motor is healthy. I’m not privy to the oil pressure, I’m guessing it’s solid. (?).
Money spent into this, top end, Heads, TFS-1 Cam, lifters, R.Rockers, all the extra’s.
Pic’s helped greatly when posted.
Observation: Intake’s seal surface is in an advanced state of corrosion, degradation, pitting, deep file marks, with an earlier failed attempt to use a filler putty like Devcon, JB Weld, etc.. Visually, difficult to discern whether actual welding was attempted.
Those fillers work fine to hold parts in place, repair threads in a pinch, repairing correctly once possible, usage for repairs under stress within an engine is creating a time bomb. It blows under & that’s the end.
Little original surface area is now left for intake gasket crush for sealing reliability against 10-12 PSI of coolant pressure.
With everything going as they should for your setup right now, I’d suggest (at least) seeking out an alternative GT40/ GT40 Intake.
Chucking that intake & finding a decent one for 100$, bolt it up & never looking back would end speculation. Gasket pic’s below on TF heads, fit GT40’s similar.
Glad to hear it’s running better, I’d had no doubt the combo is solid. Just no clue the intake was that severe. Not much margin left for a gasket.. Only putting in my .02, it’s got great potential, of course you want it to remain reliable.
Talk soon..Good luck!
-John


So, going across that intake’s flange..there’s major pitting, (Heavy) file marks, and remnants of the filler(Blk. Arrows).

GT40P, reasonable surface.

Mock: Felpro 1250’s on left, Ford black graphite gaskets on the right; as viewed. TrickFlow T.W. 170cc hand polished ports.