Lost power, need help

[Flavadave4]

I finished installing a set of Thumper heads, Tmoss Intake, TFS1 cam........the car seemed to like 20* of initial timing, no knocks or pings. Idle is smooth, cam sounds great but get out on the street and it feels like it lost a little bit down low, pulls about the same through the mid range and fades away up top.

3.73's with a 5 speed.....it has always had good low end, I feel like i have lost the torque

I think i might be running out of fuel when i mash the pedal, I am still using the stock throttle body, MAF and injectors. Do you think I should get an adjustable pressure regulator and gauge so i can make sure i am getting enough fuel pressure. Could i be choking the combo with the stock TB and MAF?

I dont expect to be pulling wheelies or running 11's...............
Like i said it seems to run good, but its just missing somthing

 

[poneypower89]

I say you have way too much initial timing.. bring it down to 10* base and tell me how it feels after that.

BTW, it could be slightly choked.. but in NO WAY should it feel slower.

 

[Flavadave4]

I say you have way too much initial timing.. bring it down to 10* base and tell me how it feels after that.

BTW, it could be slightly choked.. but in NO WAY should it feel slower.

well we started with 13* and it felt doggy......thats what it was set before.
then bumped it to 14* and the same. Ran the scan tool and it said to set it at 20* so i did. felt alot better on the street but not all there

 

[JChalfan]

Are you setting the timing with the spout removed? It's the little plug on the distributor harness, right by the dizzy. You have to remove that before you set base timing.

Jeff

 

[Flavadave4]

Are you setting the timing with the spout removed? It's the little plug on the distributor harness, right by the dizzy. You have to remove that before you set base timing.

Jeff

Engine warm and spout out........
I forgot to mention the cam was installed with a new chain and gear set 2 degrees advanced as instructed by Thumper

 

[JChalfan]

Bump.

Lets see what the night crew has to say.

Jeff

 

[tmoss]

OK, the cam was degreed in? Did you verify TDC on the #1 piston with the heads off and check that the timing marker and balancer were set dead-on?

This sounds like a timing or fuel issue.

 

[Flavadave4]

OK, the cam was degreed in? Did you verify TDC on the #1 piston with the heads off and check that the timing marker and balancer were set dead-on?

This sounds like a timing or fuel issue.

I am positive #1 was TDC the cam was set in the 2A position. I am really thinking it is a lack of fuel. Isn't the stock regulator set at 39 PSI.....with more intake air could it be dropping the fuel pressure

 

[JChalfan]

I am positive #1 was TDC the cam was set in the 2A position. I am really thinking it is a lack of fuel. Isn't the stock regulator set at 39 PSI.....with more intake air could it be dropping the fuel pressure

Unless your stock pump is failing or your fuel filter is clogged, it shouldn't be a lack of fuel issue.

Yes, fuel pressure is regulated at 39psi. The amount of air you are flowing will have no effect on fuel pressure. Your fuel pump is constantly pumping into the fuel rail, past the injectors, and then to the regulator (FPR). The FPR lets a certain amount of fuel past which flows back into the fuel tank. This regulates the pressure in the fuel rail at a constant psi, about 39. (it lowers the FP a bit at idle, but that's not really relevant)

Your mass air flow sensor's job is to measure how much air is entering the engine, and send that information to the computer. The computer decides how long to open each injector based on information from the MAF and a bunch of other sensors. My point is that your computer should recognize the fact your are now flowing more air, and adjust for it.

With your combo, you shouldn't be maxing out 19lb injectors yet.

While a bigger TB and MAF would help out your combo, the stock ones wouldn't cause enough of a restriction that it felt slower than stock.

Have you ever replaced your fuel filter?

Anyways these are just some early-morning ramblings, hope they made sense. Caffeine hasn't kicked in yet.

Jeff

 

[tunedin302]

Dave,
Did you change anything else when you did the swap? cap, rotor, wires, plugs etc??

 

[04sleeper]

The TB won't make much difference but I would get an aftermarket MAF.

Like an 80mm Pro-M.

 

[JChalfan]

The TB won't make much difference but I would get an aftermarket MAF.

Like an 80mm Pro-M.

Agreed, but he needs to find the problem before adding another variable to it all.

Jeff

 

[Flavadave4]

To answer a few questions and bring you guys up to speed......

3 weeks ago my fuel pump crapped out, so I installed a Walbro 190lph....it has worked great since then. i also installed a new fuel filter.

With the HCI swap I installed new:
Distributor cap, rotor, wires and plugs gapped to
.052, water pump. thermostat and flex fan.

Like a said the car runs smooth and sounds great, no skips, sputters, bucks, pops or backfires. It just is not pulling as hard as it used to and it should be pulling harder than it used to!

It has to be something small. I took the intake tube off with the MAF left in the tube, it was on the garage floor all weekend long. I am going to take that apart tonight and clean it......maybe a spec of dirt or somthing is in it? Also going to check to see it the distributor is not a tooth off or something..........

I'll let you guys know later tonight, please keep the ideas coming!

 

[Flavadave4]

Agreed, but he needs to find the problem before adding another variable to it all.

Jeff

Thats on this winters list of mods
I dont want to add another piece to the puzzle until this is figured out.

 

[tunedin302]

I have a feeling you got a dizzy that a tooth off.

 

[mob]

I dont think the car would run that good with the dizzy a tooth off. I put my dizzy a tooth off when I did my intake swap and the car would start, and then just die unless I gave it gas. I highly doubt with it a tooth off it would run perfect just not pull as hard. It sounds like you missed something, or maybe the fuel pressure is off, I would say no way stock t/b and injectors could cause that. But now that I think of it, I think if he got a 70mm t/b and bigger MAF it may help. Its hard to say if just that could be restricting it that much though. Check the fuel pressure.

 

[Flavadave4]

Clean MAF, spark timing and Fuel pressure are 3 easy things to look at so i am going to start there and see what happens.....if they all check out at least i know they are right and it will only cost me alittle bit of time.

 

[stang8urimport]

Being a tooth out doesn't matter if he is still adjusting to 20 degrees timing. You could be 180 degrees out, and if you were ABLE to turn the head of the dist enough, you could get it back to correct.

If it is SLOWER then before, you need to check things like fp, make sure the timing is correct.. and you aren't 20 degrees the other way, although I don't even think it would run

Another thing to check is gasket alignment. If the lower to head intake gasket is obstructing the air flow, this could cause your loss in power.

Good luck bud!

 

[Flavadave4]

Being a tooth out doesn't matter if he is still adjusting to 20 degrees timing. You could be 180 degrees out, and if you were ABLE to turn the head of the dist enough, you could get it back to correct.

If it is SLOWER then before, you need to check things like fp, make sure the timing is correct.. and you aren't 20 degrees the other way, although I don't even think it would run

Another thing to check is gasket alignment. If the lower to head intake gasket is obstructing the air flow, this could cause your loss in power.

Good luck bud!

If i was one tooth off, but advanced to 20* the dizzy might only be really at like 8* or 10*................is that what you are saying?

 

[JChalfan]

If i was one tooth off, but advanced to 20* the dizzy might only be really at like 8* or 10*................is that what you are saying?

He's saying it doesn't matter if the distributor was put in 1 tooth off. You could turn it enough to make up for being one tooth off. If your timing light says you're at 20*, you're at 20* whether or not the dizzy's a tooth off.

Of course make sure you aren't using an adjustable timing light, thinking it's a regular one.

Jeff