Something is wrong with my new motor....

[hoss331stang]

Something is wrong with my new motor...

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my combo is in the sig......and keep in mind..I HAVE A CARB, NOT EFI.

Sometimes, just sometimes....it spits and sputters and doesn't make power. it doesn't wanna pull or anything.....and then, again, after i've been driving for awhile my transmission gets real hot and doesn't wanna go into gear....its the stock t5 by the way... ....

This motor is Two weeks old, it has less than 1000 miles on it. I have MSD 6AL box, MSD billet distributor, and Accel coil. I have a rebuilt 650 Holley Double pumper carb. The rest is in my sig.

My question is, why does it spit and sputter, kinda feels like its skipping on a bunch of cylinders and jerks around real bad.....i mean when i first crank it up it will do fine, but once it warms up its terrible......what do u guys think?

 

[gp001]

Hows your electrical/charging system? You MSD box likes to have good voltage. Could you fan be kicking in and drawing too much power?

 

[hoss331stang]

i wouldn't think so, i have a brand new battery and 130 wt altenator

and the voltage meter is always up......

i could have a bad wire going somewhere tho???

 

[jesserose17]

I would think it has to do with fuel system... perhaps the carburetor, especially since it runs ok when cold with choke closed, but terrible when it warms up. I would make sure the butterfly valve shaft in carb is ok, not too loose or worn.

 

[ratio411]

Bad coil?

Sticking choke?

Fuel pressure?

Float sticking?

Vapor lock? (Check routing of fuel lines. Maybe one is too close to a heat source.)

Any one of these, and a million others, could be your problem.
Hope this gives you some ideas.

Also, when it is sputtering, do you notice smoke? Smell fuel?
Any popping/backfire?

Dave

 

[ratio411]

Plug heat range...

Could be too hot a plug.
You say other parts are getting hot. How about the engine temp?

Dave

 

[hoss331stang]

IT BACKFIRES! whats that mean!!!???

 

[hoss331stang]

and i smell fuel!

 

[D.Hearne]

I'd think a sticking choke too.Ditch the choke completely. Also the T-5. check the timing again. Does the problem only occur when the fan comes on? Also agree with the other things ratio411& gp001 suggested.

 

['69Stang]

IT BACKFIRES! whats that mean!!!???

Does it backfire through the carb ar the exhaust? It could be running too rich.

 

[Pakrat]

I'd be inclined to suspect the Choke or vapor lock off the start as well. Here are some simple ways to either fix or at least eliminate them as a suspect without spending any cash yet. First, disconnect the lead going to the choke and try running without it for a while, see how the warm engine reacts to it. (FYI I also keep mine disconnected. It's a summer car and warm starts are horrible when it is connected for some reason). Second is to follow along the fuel lines, and any spot that seems even remotely too close to a heat source, clamp a clothes pin or two along the line to help disipate the heat, and see if that helps. Absolute worse case you what the problem isn't now.

Pak.

 

[hoss331stang]

When you say your trans gets really hot, that's odd especially since you have a manual trans. The heat must be coming from the engine so my guess would be that your carb is getting very hot causing fuel to vaporize. It will run like crap when the carb overheats. Could be the manifold is getting very hot too. Do you have the heat riser in the manifold blocked? Is the carb well isolated from heat with a thick gasket? I have a 1/4 inch gasket on my carb. Does the engine overheat?

nah it doesn't over heat, but the carb could be....and also, i don't even have a choke assembly...so the choke isn't the problem....

 

[mp67]

What kind of fuel pump do you have? If mechanical, it could have a bad diaphram that causes it to start losing out after driving for a little while.(not because of heat). If its electric, you may have it mounted to close to a heat source, such as exhaust, that causes it to stop pumping after exhaust heats up. Happened to me before.

 

[HistoricMustang]

Check the vent on your fuel tank/cap and make sure it is not plugged.

HistoricMustang
www.historicmustang.com

 

[mp67]

What kind of fluid is in your T-5? I would suspect the tranny and sputtering is unrelated. T-5's don't use gear oil and I believe that can cause shifting problems if the wrong oil is used. I believe they just use ATF. Thats why I asked what you have in yours.

 

[hoss331stang]

i don't know what kind of fluid it has....but i mean i can just feel the heat comming off of it, it makes the interior like an inferno on a cold day!

and the motor...i've realized it only does it SOMETIMES. sometimes she'll go, sometimes shes slow....lol...seriously

anybody know what this could be?

 

[jesserose17]

Huh? Isn't ATF for auto tranny? T-5 is manual transmission... so therefore it uses gear oil, right?

 

[mp67]

Huh? Isn't ATF for auto tranny? T-5 is manual transmission... so therefore it uses gear oil, right?

Weird huh? The t5 and tremecs use ATF. Some people put in synthetic ATF or light gear oil and I've heard that can cause shifting problems in T5.

Hoss, are you sure the heat is not from your exhaust? Did you upgrade exhaust when you put in new motor? New long tube headers or duals? Seems odd that a t5 would put out that much heat to feel it inside the car. Think your sometimes sputtering with engine could be fuel related. Fuel pump, trash in tank, partially clogged line or filter. If it was electrical, I would think it would be doing it all the time. Always hard to diagnos over the internet though. Good luck.

 

[D.Hearne]

Gear lube is too heavy for the T5's. If it was putting out that much heat, the thing would have had to been in a meltdown mode inside. I've used 30-40 weight motor oil in an M5OD1 ( 89 Ranger 5 speed) to correct a noisy transmission, worked well, except for the seals started to leak. After changing the seals, it worked fine with it.

 

[hoss331stang]

Did you upgrade exhaust when you put in new motor? New long tube headers or duals?

Yes, i did, BBK Longtubes to a 2.5 inch BBK H....Maybe thats it man! good thinking! I would've never thought of that, even though those longtubes go right under me...

Anyway, i'm starting to think its fuel related too. I'm gonna take off the carb and take off the bowls to see if there is any trash in there or see if a float is sticking.....then i will put an in-line filter before it hits the carb. If there is trash in there i will get it out and that filter will stop anymore from comming in.....