I went from a 305 to a 350 (as seen in my signature) and keep all stock TPI hardware. I was told to get an AFPR but i'm kinda fuzzy on how to set it. I know w/ the addition of headers my car runs ALOT hotter than it used to, so much so that i need to figure out how to bring it down some. I've been told running lean can cuz overheating, but w/ 50 psi and i believe 17 lb/hr inj, is that a possiblity? Would lowering the fuel pressure actually change the fuel/air mixture? Also, i think my timeing is 2* too much retarded (6 is recomended, i'm at about 8). Would my stock radiator be able to keep up w/ the mods i've added? Also, what can cause the throttle plates to stick open when the car is hot AND running? Bad TB spring? I've already lubricated everything, and can't figure out what the cause is. (too HIGH of a vacuum? (even possible?)) Also, why does a remote solenoid solve the heat soak problem?

 

Anyone have any ideas? The thing i can't find/understand about a remote solenoid, is that is just connects to the old one, so how would that change anything?

 

Injectors in a 305 TPI were 19 lb/hr and 50 PSI is way too much, you could be running lean because the injectors are taking too long to open against all that pressure.
8* is 2 * advanced, not retarded. Lowering the fuel pressure would definately produce a change in air/fuel , try 45 psi.
If you had the heavy duty cooling system in the car to begin with then the radiator should be fine, as long as it is clean.

Throttle blades can stick open for a variety of reasons but if it is only while running then something is binding the cable most likely.

The remote solinoid solves heat soak because that is the part that is closest to headers and gets cooked, also it has a thin housing which lets the heat into it easier.

 

I did notice that there was a "heavy duty" cooling system listed in my haynes manual, but how do i know if i have that? I understand the solenoid is very close to the headers, but i don't understand how heat impairs it's function, i could understand the starter motor being too hot. Also, why would attaching a remote solenoid (and wired to the old one) solve that problem, if the current must still go to the hot solenoid?

Thanks for the advice, i'm going to take down my fuel psi tommorrow and see how that works out.

My timing was supposed to be set at 6*BTDC, but I assume that is with all emissions working properly? I don't have my AIR system hooked up, so should I change the timing in light of that? Mine is set at 8* right now, b/c i'm not very good w/ setting up the timing, but i'll take another crack at it if it would show gains, or more durablity

 

No, keep the timing at 6*, the ECM has 6* set in for the base timing and makes its calculations for spark with the base figured in, so if you change the base the ECM's calculations will no longer be valid.

To the solinoid, it is just a big electromagnet with lots of wire in it, when heated the resistance of the wire wraps goes up and causes it to draw more amps when activated, if it can't get enough power to overcome the higher resistance it will not engage the starter. Also, over time the wire insulation will become burned and start to flake off the wires causing further problems.
With the remote solinoid it is wired to the existing one but I don't believe it is wired the same way the power leads were origionally.
I might be wrong here, I've never dealt with remot solinoid, other than the ford factory setup.

 

On the remote solinoid - when I put in my new 350 with headers it was to hot for my starter. I tried everything, wrapping the headers, wrapping the starter and the remote solinoid. Nothing worked until I installed a high torque mini starter. Now it turns over fine no matter how hot it is.

 

The remote soleniod, and cheap solenoid heat shield, and then Thermotec Starter heat shielding for good measure have solved the hot start problems, but i still can NOT get this car to run cooler, i've changed the timing to stock (6*), pressure tested the system, checked the coolant mixture (how much should this matter?). I can barely keep the engine at 220 (should be 180-190) w/ both fans running continously! My fuel psi is 44psi now, but i'm gonna try and take it down lower, i've heard that sometimes helps. Any other ideas? I'm still really confused on how fuel psi affects the flow rate of the injectors.

 

50psi is not too much fp for 19lb injectors on a 350.
You may have a coolant leak such as an intake leak which would lead to your overheating troubles.

 

Yes, but i have the 305 injectors, are these also 19lb or 17lb? And what do you mean by intake leak? Like, if i didn't seal the intake manifold properly, coolant could be leaking into the lifter valley? I've noticed NO loss of coolant (after 500 miles so far) and i've pressure tested the system (held strong for >5 minutes) Thanks for the input though, any other ideas?

BTW, does anyone have a picture of the "airdam" I think i have mine attached, but i'm abit confused on what it actually is. Is it the piece that is under the car, in front just in front of the AC evaporator running to the front clip?

 

Injectors for a 305 are rated at 19lbs/hr. I know of guys running 50psi with modded 305s. Since you have a 350 I think 50psi is a good starting point.

An intake leak can cause coolant to leak in to the lifter valley but if you aren't losing coolant then I wouldn't worry about that.

The airdam most refer to is directly beneath the radiator and hangs very low. It helps direct air up in to the front of the radiator.

 

runing the smaller injectors @ high pressure isnt really a good
thing for the larger cubic inch engine. your running the engine lean
because your duty cycle of the injector 90%+. using the 350 injectors
(22 or24 lb) injectors will lower the duty cycle (70% range) and you
can lower the pressure to achive better results.
your overheating is more likely caused by over lean a/f mixture.
some have done what your doing and hadnt had issues.. but your
difficulty sounds more fuel related.
airdeano

 

So is there anyway i can raise the fuel in the a/f ratio? I mean, would more pressure help that, or just continue to raise my duty cycle. For that matter, what exactly is a duty cycle? How is it rated in %?

I could still reallly use a pic of the airdam if anyone has one!!!

 

i would get a set of 350 injectors, and a stock 350 prom too. That way you won't have to change the injector constants in the computer when you switch to the larger injectors.

350 injectors are 24 lbs/hr. at 43.5 psi.

 

Well, i spied an RS today, and reliezed it had an airdam, and i do not, so that would explain my overheating, at least at >40 mph anyway.

Also, the 350 for the 87 TPI was only put out w/ an automatic, whereas the 305 and an auto and a T5 model. From what i understand, the 350 chip would work, but my SES light would always be on, and i'd like to avoid that if i could. But as for as changing the injector constants, what is that? how could i do that? Does anyone know a good place (reliable) to get prom chips burned? I know there is a tech article, so someone in thirdgen has to be pretty good at it by now!