power goes at about 3500 rpm

cartert

Member
Dec 18, 2006
54
0
6
louisville
Two days ago I decided to try to fix the annoying ticking sound I had coming from the engine bay. I also noticed an exhaust leak at the manifold and had read on here that the a loose mani can make a ticking noise. I tightened all the studs, replaced the gasket, and used copper rtv on the gasket. The good news is exhaust leak stopped; bad news ticking still remains. I guess the tick is a valve and plain starting fix that next weekend.

Worst news; coming home from school Friday I just felt the need to “gun it” for the first time since I had the manifold off. All was going good I hit boost like normal and had 7 psi like normal, but after 3500- 4000 all power seemed to cut out. Boost stayed at 7 psi and I was still flooring it but the rpm were barely rising if any.

What the engine did felt similar to when you try to top out a car with a limiter on it, at 125 or so with plenty of power left they just bog down and refuse to keep accelerating.

Anyone know what I’ve got going on here? This is really starting to piss me off.
:3d_frown:
 

88supraFAST1

7M WHAT
Feb 8, 2006
421
0
0
Battle Ground, Wa
cartert said:
Two days ago I decided to try to fix the annoying ticking sound I had coming from the engine bay. I also noticed an exhaust leak at the manifold and had read on here that the a loose mani can make a ticking noise. I tightened all the studs, replaced the gasket, and used copper rtv on the gasket. The good news is exhaust leak stopped; bad news ticking still remains. I guess the tick is a valve and plain starting fix that next weekend.

Worst news; coming home from school Friday I just felt the need to “gun it” for the first time since I had the manifold off. All was going good I hit boost like normal and had 7 psi like normal, but after 3500- 4000 all power seemed to cut out. Boost stayed at 7 psi and I was still flooring it but the rpm were barely rising if any.

What the engine did felt similar to when you try to top out a car with a limiter on it, at 125 or so with plenty of power left they just bog down and refuse to keep accelerating.

Anyone know what I’ve got going on here? This is really starting to piss me off.
:3d_frown:

sounds like an air or fuel problem maybe ignition. check vacuum lines, check fuel pressure.
 

PowerTrip Performance

Custom Fabrication
Dec 5, 2005
209
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0
Oregon
www.myspace.com
You didn't mention it at all, but it could have been left out...did you happen to change your spark plugs at that time? I've gotten numerous calls from customers that describe the same symptoms after changing spark plugs. They forget to close the gap (or gap them according to factory specs) Gotta close that gap so the boost doesn't blow out your fire power!:icon_razz
 

cartert

Member
Dec 18, 2006
54
0
6
louisville
I was driving yesterday and punched it once and power cut out again at 3500 or so, I punched it again and it pulled strong without any problems all the way through 1st, 2nd, & 3rd. This confused me so I did stopped and floored it again, this time it screwed up again.

I don’t think I left of a vacuum line and I even checked again. I don’t think it’s a boost leak b/c it stays at 7psi the whole time and even if boost was leaking it would still pull decent, but instead it comes to an almost complete halt. I don’t think it’s the spark plugs, I didn’t even touch them.

I checked the timing and its off some could this be a cause?
 

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
10,730
1
38
Valley of the Sun
starscream5000 said:
Are you throwing any codes?


^^^ Check this ;)

Base timing can cause a problem like this...especially if it is off by a big amount. Set it per the TRSM:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=IG&Page=20
You MUST short terminals TE1 and E1 to set timing accurately.

Gap your plugs as mentioned previously...inspect the condition of your spark plug wires.

Do you have an adjustable fuel pressure regulator installed?