No Power ?

aod92 · Aug 3, 2005

I just had my trick flow twisted wedge heads ported and now my car slowed down from what it was before. Could the heads be ported to much for the stock short block? When they flowed the heads stock they flowed 253.5 and after they were ported they flowed 272.4 The cam i'm running is an anderson b31 and a trick flow street heat intake. I'm confused and need help . I dont know what the hell is going on. The car is much slower than before. I was even wondering if the valves were adjusted wrong would that slow me down? Also the car is running real warm like 1 to 2 notches from red on the stock gauge. The cooling system is completely different than i had before . I went from reverse to standard flow on the wp because i got rid of my power steering. Also i have an electric fan now instead of a clutch fan. Could the belt be slipping on the water pump since the grooved part of the belt is on the flat side of the pulley? Any help would be appreciated. Thanks

txstang84 · Aug 3, 2005

the belt could be a possibility, but unless you hear it squealing, it's probably fine...did you upgrade your cooling system when you put on the new heads? and i hate to ask, but when you installed the heads were the gaskets on right? if they're installed backwards the car will definitely overheat...

and since it's getting hotter, the computer will pull timing to keep it from knocking, a really good tune, and getting your cooling issues in line will help immensely...

you could've kept your rev rotation pump with an a/c delete kit from TFS or march perf...i ran that way for several years with no overheat problems. the fan also will contribute if it doesn't pull enough air.

if it runs like absolute crap though, how big is the cam? did you upgrade your fuel system to compensate for the better heads and bigger cam? there's alot of questions to be asked here, need some details...

txstang84 · Aug 3, 2005

and yes, if the valves are adjusted wrong, that will contribute to the way it performs...if they're too "tight" the idle will more than likely be down and it will probably bog down and run like sh**

if they're too loose, you won't get the full effect from the cam, and it'll sound like a sewing machine on steroids

...guess i should've asked a minute ago, i'm guessing your running an AOD by your nic, did you get a higher stall for the bigger cam? that will effect its performance as well-until you get up in the rpms

aod92 · Aug 3, 2005

My fuel system should be more than enough. I have 30lb. injectors 255lph intank pump and an acufab regulater. My car is a 92 i didn't know it could take timing out by itself when the car gets hot. And the trans i'm running is a c4 with a 4000 stall. The anderson cam i'm running is a pretty mild cam. I believe it compares to the motorsport b cam.

txstang84 · Aug 3, 2005

yeah, i read up a little bit on the cam, but from the sounds of it, you have more than enough mods to support the engine and it's power level...

the eec-4 is a very versatile and complicated piece, it's going to make adjustments to fuel and spark based on a myriad of information...especially coolant temp-when it's in warmup mode, it runs a little richer to bring up the temp, when it reaches op temp, it leans them out for normal operation. when it gets hot it pulls timing and fuel to try and cool the engine down a little

and with a 4k stall, well, from what the rec. on the cams page at AFM, thats a little high, but i'm betting it used to get up off the line in a hurry...

the heating issue...man, honestly, i would've stayed with a stock style pump, and gotten a thicker rad. the cooling fan may not be pulling enough air to keep things cool though, and when it gets hot, it's gonna run weak for the same reason as stated above, since 5.0's don't have a knock sensor, the computer has to compensate for "safe" levels of timing lead and fuel enrichment based on how all the sensors are reading and referenced off of preprogrammed operation "maps"...i'd try to tackle the cooling problem first though...the only thing that might remedy it at the moment would be to try putting on your engine driven fan and see if that helps or hinders your situation, if it helps then you can bet the fan isnt' pulling enough air, if it doesn't you've got other issues...

we're working with a friends '95 Cobra, and it's got some problems getting warm too, a 331 with normal bolt ons, and a better rad have yet to keep this damn thing cool...but we think the cooling fan just isn't cutting on soon enough.

i gotta get going for a bit though, duty calls, and it's probably gonna be awhile-but there are several highly knowledgeable people on here that are well versed in the operation of the eec, and they could more than likely steer you in the right direction...hope this helps a little bit at least

jaymac · Aug 3, 2005

have you run codes? ANy sensors out of specified range?
One line away from the red is not "warm", it's unaccaeptably HOT. The computer will start shutting down all sorts of things far before that "line".
What kind of fan do you have? Are you sure it's working properly, etc.? T-stat working?
Sounds like alot of problems stemming from one main problem IMO...

aod92 · Aug 3, 2005

The fan i have is from a junk yard. I don't know what it came out of but it covers the whole radiator and it pulls air very well. I can even feel the air standing in back of the car. I also am running a 3 core radiator so that should be more than enough also. I'm not running any o2 sensors i don't know if this helps or hurts me. The guys at pro-m when they were still open said not to run them because all the do is confuse the computer more. Before the head porting and the standard flow wp the car always ran real cool so right now i believe i have alot of places to look for a problem. I just hope one of my head gaskets isn't on backwards. Thanks for all the help again. Also what should my fuel pressure be set at?

z9_87 · Aug 3, 2005

With the ribs on the smooth water pump pully, i bet its sliping some or the revs flow doesn't cool well enough. When engines are hot they dont run as well especially as hot as yours is running. When my engine gets above the 1/2 way mark on the factor temp, it runs about a .1 slower.

vristang · Aug 3, 2005

aod92 said:
The fan i have is from a junk yard. I don't know what it came out of but it covers the whole radiator and it pulls air very well. I can even feel the air standing in back of the car. I also am running a 3 core radiator so that should be more than enough also. I'm not running any o2 sensors i don't know if this helps or hurts me. The guys at pro-m when they were still open said not to run them because all the do is confuse the computer more. Before the head porting and the standard flow wp the car always ran real cool so right now i believe i have alot of places to look for a problem. I just hope one of my head gaskets isn't on backwards. Thanks for all the help again. Also what should my fuel pressure be set at?

O2 sensors! Problem Solved!

Unless there is something I missed (like you are running a carb) the prob is the O2 sensor, or lack thereof.
For Pro-M to tell you this is a little scary. Was it that guys last day?

The computer has to have fuel ratio info to make decisions on what the a/f ratio should be and how long to open the injectors (among other things). Without the O2 sensor the computer is probably in a "limp" mode.

Fuel pressure should be set at 38-41 depending on who you ask. I think most of the literature calls for 39psi.

txstang84 · Aug 3, 2005

even though the ribs are riding the pulley, it should still push water through the block, but concerning the t-stat, did you pull it out or change it sometime during this swap?

man, honestly, it definitely is running wayy too hot, you might wanna try going back to the rev rotation pump and get the a/c elim kit-i still run it, you can run it with or without the p/s pump, and it's a clean easy install...or maybe, did you happen to buy a rev rotation pump and not know it?? if it spins backward, it certainly will not cool the engine...just speculating

the O2 sensors...couldn't tell ya on that one, but I'd run them simply because it tells the computer if you're running rich, lean or stoich (to a certain degree). And if you have a good tune, then it shouldn't "confuse" the puter...

anyway, I share the mutual fear of having a head gasket on backward-my 306 suffered a similar dilemma during initial assembly, but once it shot a volcano of coolant across my Dad's driveway and backyard, we pulled the heads and sure enough that's what had happened (10 years ago)

with the 30lb'ers, try running it at about 42 for the moment, and if it smells like a old chevy pickup, (rich) lean it out a little bit.

hope this helps-guys if any of this sounds wrong, lemme know

txstang84 · Aug 3, 2005

cool...someone to confirm the O2 sensor question...

aod92 · Aug 3, 2005

Well first thing tommorow i'm going to buy some o2's . And i only had my fuel set at 30 so maybe not enough fuel? I'm appreciating all the feedback this is a great site.

aod92 · Aug 3, 2005

The t-stat i replaced last year its a 160. I never took off the housing so i saw no reason to replace it. But changing back to reverse flow is starting to sound better i have an edelbrock reverse flow wp i can throw on to see what happens.

txstang84 · Aug 3, 2005

oof 30, yeah, that's a little low-i'm surprised it idles with that low fp...t-stat seems a little low though...(?) at that temp the computer would never make it out of warm-up mode and constantly run rich....confirmation anyone?

aod92 · Aug 3, 2005

And just out of curiosity does it sound like my heads are ported to much for my combo?

jaymac · Aug 3, 2005

I would switch to a 180*, based on the info I've gathered from Stangnet.
Th "no O2's" shocked me. Maybe someone knows something I don't?!?!?!?
FP is too low- do u have an adj. reg.?
Don't know about the heads flowing too much but I would "GUESS" no. I may be wrong though...

vristang · Aug 3, 2005

First things first. Put in a 180 stat (I would suggest the stock temp, but many will argue that to the death). Bump the fuel pressure up to 39. Get the O2 sensors and give the computer a chance to figure out that they are there. Drive the car a little and I think you will be very happy with the results.

If you still have problems after this then you can consider the heads. Most likely they are not causing any problems though. They may be a bit much, but it would most likely make your powerband peakier, and higher in the revs.

aod92 · Aug 4, 2005

Thanks for all the help guys. I will do these things all of you have suggested and keep you updated. Also with a 180 t-stat instead of a 160 won't the car run even hotter?

txstang84 · Aug 4, 2005

not necessarily...but if you put in a 160, it'll probably never make it out of warm up loop, and will constantly run a little rich, which is good for power, but man...that raw gas smell gets on my nerves after awhile

vristang · Aug 4, 2005

aod92 said:
Thanks for all the help guys. I will do these things all of you have suggested and keep you updated. Also with a 180 t-stat instead of a 160 won't the car run even hotter?

The idea is to get the temp up. The computer does distinguish from warm up and warmed up by the temp (maybe not exclusively?).

There is no reason to run a 160 on the your car. Here is why hotter is better, to a point naturally.
Everything in the combustion chamber, including fuel, air, the cylinder walls, piston, and valves, will take on heat during combustion. The heat is what causes the air trapped in the combustion chamber to expand. The expansion of the heated gasses pushes on the piston. If you are putting more and more heat into the cylinder walls because the coolant keeps taking away more and more heat, then you lose power and efficiency.
There are trade-offs. Cooler intake air is more dense, but it does soak up more heat energy before it can combust. Obviously running too hot will destroy the motor.
The best answer for efficiency is probably the stock stat, but 180 seems to be everyones favorite, as a happy compromise.

Note that I define efficiency as best power per unit of fuel. Not necessarilly the same as mpg.

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