TFS track heat installed.. PROBLEMS!!!!! RICK91GT or anyone

UnderPressureGT · Sep 21, 2004

My carw as stock with 5 pounds of boost and i am speed density..... It used to fall on its face under boost, but then the one way check valve fixed that..

today i had a buddy install a holley AFPR (not sure what FP it is set at), 24 pound injectors, and a track heat intake..

The car pulls VERY hard, but under boost at 4500 the car will fall on its face and make a ping sound..... it sounds as if i let off the gas but i really didnt........ now if i were drive 3/4 throttle under no boost, it will run strong up till redline.... what the heck is my problem here??

i did notice the line on my TB is OPEN that is supposed to be ran to the valve covers.... i have to plug that off.. would thatc ause my car to fall on its face?? Could he have not put my distributer back in right when he replaced the seal??? this problem is only happening under boost... i smell that the car is real rich but i dont think too rich would make it fall on its face?? please help guys

Grn92LX · Sep 21, 2004

Your getting unmetered air into the car or metered air is escaping through that unplugged port. Fix that and get a FP gauge so you can set your FP to 39psi and see what happens. What plugs and gap are you running?

UnderPressureGT · Sep 21, 2004

autolite 24's at .035..... i dont have a mass air meter FYI... would that little thing be the problem why it falls on its face under boost??? tonight after class i will borrow my friends fp gauge and set my fp to 39... but i doubt fuel is the problem.. or could it be?

Daggar · Sep 21, 2004

Install any boost guages or other vac drven accessories l8ly?

Boost or vac leaks (even small ones) can causewhat you describe.

SmockDoiley · Sep 21, 2004

Why would you install a supercharger with no intercooler, boost timing master, timing check, FP check or dyno run? Are you insane??!!??!?!??! Thats asking for disaster, and now what?? Your pinging which means your either running lean or running out of gas. You really shouldnt be installing power adders if you dont know what you are doing. Is mandatory you know what your fuel pressure is, and what your timing is before you go off hauling ass in your car. The reason it is falling on its face and pinging is because you are about to blow up your pistons or crap a head gasket. Please, do us all a favor and stop touching your car until you get your FP checked and your timing. Keep your FP up and your timing down, or just get it dynoed.

UnderPressureGT · Sep 21, 2004

SmockDoiley said:
Why would you install a supercharger with no intercooler, boost timing master, timing check, FP check or dyno run? Are you insane??!!??!?!??! Thats asking for disaster, and now what?? Your pinging which means your either running lean or running out of gas. You really shouldnt be installing power adders if you dont know what you are doing. Is mandatory you know what your fuel pressure is, and what your timing is before you go off hauling ass in your car. The reason it is falling on its face and pinging is because you are about to blow up your pistons or crap a head gasket. Please, do us all a favor and stop touching your car until you get your FP checked and your timing. Keep your FP up and your timing down, or just get it dynoed.

Dude are you SERIOUS.... before i touched the intake, i installed a oneway check valve with the blower and it ran soo good... and ask anyone.. an intercooler is not necessary with only 5 pounds of boost! the blower did soo much for power wise... my car runs consistent 13.2's with no mods except that blower!!! soo dont tell me i dont know what im doing because i know exactly what im doing.. before today the car ran EXCELLENT with the blower...

i did a few checks now

FP is set at 40.Timing is down to 8... that opening on the TB is plugged. does not ping, i just missaid what the problem was... it feels exactly like it did before i put the one way valve in... the car just falls on its face under boost.. i do not know why at all.. anything to look at?? it pulls very hard up till 4500 WOT and it just shuts off out of nowhere causing a HUGE jolt..... if i drove 3/4 throttle under no boost, it will be fine

edit: ... i forgot to say.. my FMU was calibrated for the 19 pound injectors... could that be the problem???

Daggar · Sep 21, 2004

Back to what I'd asked you before. Have you installed any boost/vac accessories recently?

UnderPressureGT · Sep 21, 2004

other then the FMU and boost gauge no.... the car ran fine after i added that... soo to answer, no

Daggar · Sep 21, 2004

Ok... try this. remove the boost guage from wherever it is in your setup and cap the fitting you removed it from. Go out and run it to see if you still have the same problem at 4500 rpm.

Edit: Of course I'm talking about jsut disconnecting it from the vac/boost system... not removing from the car altogether. if my theory is correct I'll tell you how to hook it back up.

UnderPressureGT · Sep 21, 2004

ok i will do that... i dont think its a fuel problem at all... are 24 pound injectors DEFFINATELY dooable with speed density? people do say they are.... if i dont have to convert to mass air just yet i wont..... its a VERY scary feeling... i get slammed to my seat and then at 4500, it just STOPS and i get jolted forward into the steering wheel for a spluit second.... and FYI i have the boost gauge on the vac tree on that boost port

Daggar · Sep 21, 2004

24s are fine with SD. i don't think it a fuel problem either. I'll check back in 20 min or so to see if it made a difference.

A small note about your combination of 24lb injectors and your FMU though. Totether they may be putting more fuel out there than you need for 6lbs of boost. We'll try and see if we can solve one problem at a time though.

Rick 91GT · Sep 21, 2004

I know where Dagger is going, he is thinking that something is stealing the vac giving the FMU a false reading, most likely the brake booster.

You need to isolate the vac sources away from each other, I run the boost guages to the manifold, I like to run the FMU to the tree, but not directly near the booster, you could also tap into another vac port in the manifold or other line. The blow off vale should be on a seperate source as well, most tee into the FMU line and that does seem to work. Vortech tells you to do it that wat as well.

Definitly get the TB port plugged up same goes for the valve cover port. Do you have a FP gauge in the car? The FMU should increase the FP accordingly, if you have a 24# disc which I bilieve is 10:1 you should be seeing 10 addtional pounds of fuel per 1 pound of boost, so if your base setting is 40, and you have a 10:1 FMU, and you see 5 pounds of boost you should see 90psi of fuel pressure.

UnderPressureGT · Sep 21, 2004

ahh question... the fact i didnt recal my FMU to 24 pound injectors, would that have anything to do with it??? i will get the recal kit tomorrow....

Daggar · Sep 21, 2004

FiVeLiTeR87GT said:
ahh question... the fact i didnt recal my FMU to 24 pound injectors, would that have anything to do with it??? i will get the recal kit tomorrow....

hehe... you read my mind. Check the edit in my last post.

Daggar · Sep 21, 2004

Vac guages are tricky things... they have some sort of differental slow relief valve in them that keeps the needle from wigging out from the smallest of changes. That little bit of relief causes havock with FMU's. The quickest easiest way to fix that problem is to install a restriction orifice inline with the vac/boost guage. Check the last line of my Signature.

UnderPressureGT · Sep 21, 2004

Rick 91GT said:
I know where Dagger is going, he is thinking that something is stealing the vac giving the FMU a false reading, most likely the brake booster.

You need to isolate the vac sources away from each other, I run the boost guages to the manifold, I like to run the FMU to the tree, but not directly near the booster, you could also tap into another vac port in the manifold or other line.

Definitly get the TB port plugged up same goes for the valve cover port.

TB is plugged up... FMU is on the B/R port on the tree.. the boost gauge is on the s/c port

UnderPressureGT · Sep 21, 2004

before my friend did my intake.. i had my fmu T'ed into my FPR and it ran just fine.... what do you think??

Daggar · Sep 21, 2004

FiVeLiTeR87GT said:
before my friend did my intake.. i had my fmu T'ed into my FPR and it ran just fine.... what do you think??

That should be fine. You still need to isolate the guage from the Vac system just temporarily to isolate it or rule it out as the problem.

UnderPressureGT · Sep 21, 2004

I just wanna add

I remember when i first put the blower on, i did NOT have an FMU or any other fuel mods... the car ran just as fine as it does after the FMU... soo how would the FMU be the problem just by switching to higher injectors and a new manifold???

EDIT: i will try unhooking the boost gauge tomorrow after class.. the boost gauge is hooked to the same spot as it was before the manifold sooo do you sitll think it could possibally be it?

Daggar · Sep 21, 2004

The FMU works by closing off the fuel return line and increasing the pressure in the fuel system (and injectors). When boost hits the FMU you're jacking up the amount of fuel the injectors put out (fooling the injectors and computer into thinking your injectors are larger than they are). With your current boost your injectors are large enough to handle the load. The problem is the fuel tables in teh stock computer. A 14.7 to 13 AFR is great for N/A, low compression, and moderate cam, but not for boost. So we use the FMU to tweak the AFR into the 12.5 range to prevent detonation. If your FMU is calibrated for 19lb injectors then it's jacking up the fuel pressure more than it needs to be for 24lb injectors. So you have a choice. Use the FMU to tune the car to the correct AFR or put the car on a dyno and have the fuel tables custom burned for your supercharged application.

On a side note... with 6 lbs of boost you could probably get away without the FMU using jsut the 24lb injectors. It's really tough to make that determination without a wideband 02 and reader though. There's no way to know if you're too lean or rich without one for sure.

Have you run he car yet?

TFS track heat installed.. PROBLEMS!!!!! RICK91GT or anyone

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