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GENERAL => Problems & Solutions => Topic started by: 89BlackTGP on August 23, 2009, 12:55:34 PM

Title: Cant Get More BOOST..
Post by: 89BlackTGP on August 23, 2009, 12:55:34 PM
Well since the TGP has been done i drive it around the country here often.. i have only ran 2 tanks of gas so far since its been done..  So since i have been driving it it hasnt bothered me until now.. i cannot boost past 8 psi.. The chip has been tuned by adam for the 5 spd swap and to take more boost i believe 14 psi.. Well today i said screw it i wired shut the wastegate arm and disconnected the actuator and according my autometer boost gauge i am at a steady 10 PSI at WOT.. I cant not get any more boost.. I am confused.. someone please help me out.. Thanks
Title: Re: Cant Get More BOOST..
Post by: GPChief on August 23, 2009, 03:33:15 PM
Sounds like you make have a "leak" somewhere bleeding off boost.  Check all hose clamp's to the IC & TB.  The lower one for the IC used to give me issues once and a while.
Title: Re: Cant Get More BOOST..
Post by: 89BlackTGP on August 23, 2009, 05:21:22 PM
i actually have just recently changed the IC pipes over from the older pipes i had.. i know the clamps are tight.. i remember tightening them down.. but its wierd that i cannot get anymore than 10 PSI its not going up or down its just a constant 10...
Title: Re: Cant Get More BOOST..
Post by: flybynite on August 25, 2009, 04:57:39 PM
Restricted exhaust system, blown compressor seal and low fuel pressure are a few possibilites. 
Title: Re: Cant Get More BOOST..
Post by: 89BlackTGP on August 25, 2009, 05:11:10 PM
Quote from: flybynite on August 25, 2009, 04:57:39 PM
Restricted exhaust system, blown compressor seal and low fuel pressure are a few possibilites. 

Exhaust system is free flowing no cat and no mufflers.. but is a full system..

Blown Compressor seal?? now what other issues would i have with that being blown besides not able to boost?

Low Fuel pressure... I have a new WALBRO installed.. i have not checked the rail it will not hurt to check it either so i will do that but i know it has a high pitch whine to it and can hear it pump...


Is there any other possibiltys? its strange that it wont boost past 10 PSI wastegat wired shut at WOT..
Title: Re: Cant Get More BOOST..
Post by: flybynite on August 25, 2009, 06:33:41 PM
If the compressor housing seal was blown you would feel air blowing out around the housing. I can hit 16psi pretty quick with the same tune you have. Check fuel pressure, ohm injectors and check the palstic line for the boost gauge for any crimping or breaks. Whats the condition of the turbo???
Title: Re: Cant Get More BOOST..
Post by: 89BlackTGP on August 25, 2009, 06:51:07 PM
Quote from: flybynite on August 25, 2009, 06:33:41 PM
If the compressor housing seal was blown you would feel air blowing out around the housing. I can hit 16psi pretty quick with the same tune you have. Check fuel pressure, ohm injectors and check the palstic line for the boost gauge for any crimping or breaks. Whats the condition of the turbo???

I will check fuel pressure. I think I had a gauge on it when I first started the car when it was pit back together but I'll check it again.

Fuel injectors are yellow tops from a 94 5.0 stang.  I will ohm them to be sure they are good.

How would I check for leaks around the compressor housing? I have not noticed any air leaks around the turbo. But I do still have oil coming out the front breather but my motor only has 300 miles on the rebuild.

The turbo I got from a member in san Antonio from 60degreeV6. He stAted to me it was rebuilt and ran it on his Tgp for about 3,000 miles and then upgraded.


Edit: the autometer gauge was just put in. I did wrap it with wire loom for protection. But will double check.
Title: Re: Cant Get More BOOST..
Post by: flybynite on August 26, 2009, 07:42:15 PM
Flakey knock sensor?? Do you have access to a scan tool?
Title: Re: Cant Get More BOOST..
Post by: GhrarhG on August 27, 2009, 02:30:45 PM
If the gauge is right, it has to be a leak in the charge piping or restriction in the exhaust. I suppose a restriction in the intercooler is a possibility. I'm not sure what injectors or knock sensor have to do with anything if the waste gate is wired shut and the pedal is held to the floor.

Bad injectors/knock/knock sensor issues would be plausible if he was using the computer controlled waste gate actuator, but this
QuoteWell today i said screw it i wired shut the wastegate arm and disconnected the actuator and according my autometer boost gauge i am at a steady 10 PSI at WOT
kinda eliminates that.

An important question is where is your boost gauge tied into? It could be that you are in fact hitting 14psi and the gauge is wrong or the plumbing to it is leaking. Being able to log the run would be a big indicator. If your MAP sensor is reading over 170 kPa, your gauge is inaccurate.
Title: Re: Cant Get More BOOST..
Post by: flybynite on August 27, 2009, 06:26:07 PM
Quote from: GhrarhG on August 27, 2009, 02:30:45 PM
I'm not sure what injectors or knock sensor have to do with anything if the wastegate is wired shut and the pedal is held to the floor.
The way the code is designed if knock is sensed the ecm will reduce boost and retard timing.  By retarding the timing you slow the exhaust flow dramatically reducing boost levels. If the boost solenoid if not being utilized the ecm will just pull timing at a much faster  rate...   :thumb:
Title: Re: Cant Get More BOOST..
Post by: GhrarhG on August 28, 2009, 10:07:08 AM
Interesting, I didn't realize that it pull enough timing to do that. Good to know.
Title: Re: Cant Get More BOOST..
Post by: 89BlackTGP on September 01, 2009, 04:01:33 AM
Quote from: flybynite on August 26, 2009, 07:42:15 PM
Flakey knock sensor?? Do you have access to a scan tool?

I dont have access to a scan tool.. but should i try to change the knock sensor anyway?
Title: Re: Cant Get More BOOST..
Post by: flybynite on September 01, 2009, 05:31:09 AM
Quote from: 89BlackTGP on September 01, 2009, 04:01:33 AM
I dont have access to a scan tool..
A simple scan tool like this will pay for itself in a years time... 
http://cgi.ebay.com/ebaymotors/Auto-X-ray-EZ-link-Scanner-GM-OBD-1_W0QQcmdZViewItemQQ_trksidZp3286Q2ec0Q2em14QQhashZitem2302b4e9e2QQitemZ150369266146QQptZMotorsQ5fAutomotiveQ5fTools
Title: Re: Cant Get More BOOST..
Post by: 89BlackTGP on September 01, 2009, 07:19:29 AM
I am going to watch it and see what the price will be toward the end.  Do you know of any hardware and software for a laptop that does just about the same?
Title: Re: Cant Get More BOOST..
Post by: GPChief on September 01, 2009, 08:25:40 PM
Tuner pro??
Title: Re: Cant Get More BOOST..
Post by: flybynite on September 05, 2009, 08:35:28 AM
Here is the software   
http://www.tunerpro.net/
Title: Re: Cant Get More BOOST..
Post by: 89BlackTGP on September 07, 2009, 11:27:41 AM
well i changed the knock sensor and no change in anything..

I did in fact buy that OBD 1 scanner off of ebay so i shall be getting that soon..

Is there anyway to check the injectors without taking the plenum off? like the engine harness that plugs into the computer? will that give the same reading? i just put the UIM on and dont want to buy more gaskets..
Title: Re: Cant Get More BOOST..
Post by: TGP Nick on September 07, 2009, 01:28:23 PM
Yes, you need to remove the intake plenum to check the injectors.

You should be able to re-use the gasket as well.
Title: Re: Cant Get More BOOST..
Post by: Prospeeder on September 08, 2009, 07:52:49 PM
The UIM gaskets can be reused a few times, but new ones are hardly 8 dollars.....
Title: Re: Cant Get More BOOST..
Post by: 89BlackTGP on September 10, 2009, 01:41:34 PM
Adam,

I got that scanner today. What do you want me to look for when I have it monitoring the system? I'm not 100% how this works bit so far I got the basics and got my vehicle programmed in and played around with it with the car at a idle.
Title: Re: Cant Get More BOOST..
Post by: flybynite on September 11, 2009, 07:24:25 PM
PM sent
Title: Re: Cant Get More BOOST..
Post by: 89BlackTGP on September 29, 2009, 01:09:55 PM
Well I Ohm'd the injectors today and took the BOV off to be sure it wasnt leaking.. Well the BOV wasnt leaking so thats back on.. I took the wire off the wastegate so the MBC is running that again.. I double checked everything under the hood and it all looked good.. The readings from the Injectors below.. I am running Ford 5.0 Mustang Yellow Tops

Cylinder         Injector Ohm Reading

1                  14.9
2                  15.1
3                  14.9
4                  15.1
5                  14.9
6                  15.1


And my 2 spare injectors since i bought these from a Mustang with the V8 and only used 6 :laugh:

Spare             Ohm Reading

1                   14.1
2                   14.1


Im still confused on why i cant get anymore BOOST
Title: Re: Cant Get More BOOST..
Post by: TurboGTU on October 21, 2009, 12:17:56 AM
Did you cap off the bov. sometimes the spring inside is weak and when boost comes on it creaps open. I had a leak at the throttle body once. Bad clamp and torn hose.
Title: Re: Cant Get More BOOST..
Post by: GPChief on October 22, 2009, 03:40:33 PM
Quote from: TurboGTU on October 21, 2009, 12:17:56 AM
Did you cap off the bov. sometimes the spring inside is weak and when boost comes on it creaps open. I had a leak at the throttle body once. Bad clamp and torn hose.

There is a leak somewhere......Its just finding it.  One of the first things I did on one of my cars was replace the hoses with silicone hoses and "Worm Gear" clamps, it mas made full boost ever since.
Title: Re: Cant Get More BOOST..
Post by: 89BlackTGP on October 22, 2009, 04:11:20 PM
Quote from: TurboGTU on October 21, 2009, 12:17:56 AM
Did you cap off the bov. sometimes the spring inside is weak and when boost comes on it creaps open. I had a leak at the throttle body once. Bad clamp and torn hose.

No i replaced the BOV pipe with a stock pipe with no BOV.. and still did not solve the problem.. All clamps and couplers were inspected throughly and i made sure they were good..
Title: Re: Cant Get More BOOST..
Post by: TurboGTU on October 24, 2009, 11:29:17 PM
One last thing, x-over flinge to manifold leak.THey are not the best.