Problems with the 3.4 TURBO-again

[d.o.h.c]

OK so my car ran great and I need to do some things to it, like ball joints, tie rods, front breaks,ect. So I did everything encluding the a/c compressor and lines. I also did change my 3psi spring to a 7 psi spring in the wastgate. I brought it up to the dealer ship and had a 4 wheel alignment and a/c charge and when I got it back it ran good not under boost though. So I go to give it boost and I get to 3 psi and it hits a rev limiter of some sort. I had this same problem with it no boosting before and it was the FMU vacuum line. But I checked everything, FMU fule lines, FMU vacuum lines, all good. So I am asking what would cause the car not to boost past 3 psi. Any help is well appreciated becasue right now when I give it gas it starts to pull and then it just hits a stop.

[d.o.h.c]

I would like to fix this tomorrow, it is really pissing me off

[1988GTU]

Have you checked the diaphragm to the fpr? Do a couple fuel pressure tests.

[d.o.h.c]

Diaphram? How do i check this

[1988GTU]

pull the vacuum line off to the fpr and see if fuel is leaking out of the port/hose when engine is running.

[d.o.h.c]

So start the car, pull the vacuum hose off. Then what

[1988GTU]

pull the vacuum line off to the fpr and see if fuel is leaking out of the port/hose when engine is running.

Start Car:
pull the vacuum line off to the fpr-
see if fuel is leaking out of the port/hose when engine is running.


If so = faulty

[d.o.h.c]

took the hose off and no fuel came out, so I am guess thats good.

[d.o.h.c]

this is really pissing me off, everything is working so good, ac is good, no more lifter tap, its just this one thing. What would cause it to not to boost more then 3 psi.I dont know because when I got home the hose was melted, it hit the turbo, but it was not before. So can the car run to 3psi stock, no fmu?

[d.o.h.c]

hold on the FPR or the FMU

[1988GTU]

which ever controls your fuel pressure. Also check the actuator vacuum line.

[d.o.h.c]

Well the FMU adds pressure to the boosted system and the FPR is on the fuel rail. What is that acutator?

[1988GTU]

= actuator
Check to make sure it holds a vacuum (upto the setting it is intended for) .


Yes check that.

[d.o.h.c]

the first pic is a internal wastgate. How do I check to make sure it hold theset spring rate? The second pic is a FMU, I took the vacuum line off this and no fuel came out.

[1988GTU]

That is a wastegate that attaches to the above actuator rod. Are you external gated? If so, check that vacuum line to it.
If you have internal gate style..
Apply regulated air pressure to the actuator, starting at 0 and slowly increasing pressure while observing actuator rod movement. The actuator should start to move at set psi. The actuator should hold set spring psi for 25-30 seconds.
Testing the external style is similar, just find which port you need to hook up a pump to and read the psi you pumped into it. Be sure to have the top on.