1997 Gtp Running Funny

**chi_town** · 10-30-2009

So heres the scoop, been looking at every possible problem that i can think of that would make my car run like S**T. When i start the car and take it out of park, it almost always dies on the first start.. When i start it again it bogg's down and seems like it's not getting fuel , or im running out of fuel. This goes on for some time, i have to constantly push the gas almost to force it to go then eventually after maybe a mile or so of driving it clears up. It sounds like theres a vac leak but i've looked at every possible point , and found only these connectors that i actually disconnected completely with removing the line and it still did the same thing... I keep getting the same two check engine codes.

While driving it recently my gf has noticed that the boost guage only goes up half way.. I havn't really payed attention to the guage so i dont know for sure if that's normal if i just go WOT or if theres somthing else wrong..

As of now i have new plugs (Ac Delco's *platinum*) Moroso wires, Just replaced my MAF and also replaced the Screen within the tb, cleaned all the connections and idk what else it could be..

HELP PLEASE

Chi_Town

**DanGTP** · 10-30-2009

What were the code numbers?

**chi_town** · 10-30-2009

P1020,p1655 , i deleted the codes, and i have to continue to do that every time I get into the car for it to even move properly.. I did notice today that the wire that goes to the rear 02 is hanging down, it is no longer connected since i now have a 3" dp and had the exhaust shop ziptie it so it wouldn't break off and ruin the wire.. Well theres no end on it now so they deff didn't do what i asked haha ..

Do i need that wire? Or can i just cut it our and leave it at that ... And , just have the code deleted off of it.. If so what code is it ?

Chi_Town

**DanGTP** · 10-30-2009

That first one isn't relevant to GP's from what I found. It points to an oil pressure switch (your car only has a "dummy light" with no input to the computer), but only lists Mitsubishi as a manufacturer.

The second one is an evap purge fault, which I don't think would be causing any of your problems, either.

You can cut the wire off if you wish. Just make sure none of the ends can short out on anything. There are a few codes that would have to be removed. I don't remember the code numbers, but anything having to do with bank 1 senor 2.

**gtpinsc** · 10-30-2009

go to autozone and get them to check fuel pressure at the schrader valve.

**chi_town** · 10-31-2009

Im going to put my ODB back in the car today and see what codes it brings up.. Now after replacing the MAF and putting the TB Screen back in, could it be that i need to reset the computer? The engine that is in the car is from another GTP , i had to replace it maybe a month after ownership because it developed a rod knock...

I dont have an Autozone near me ... Who else could check the pressure at that valve other than a shop...

Now i also noticed that there are alot of rubber fittings that go from different lines around the supercharger... A few of them are cracked and were taped together with electrical tape... Could that be a issue? Seems like it's starving for fuel, and when doing so it sounds like a HUGE vaccum leak... I almost have to feather the gas just to get the thing moving, and it's only getting worse .. =(

Chi_Town

**gtpinsc** · 10-31-2009

check the vac line that goes into the intake right under the supercharger snout ... i had a vac leak there before and it caused my boost gauge to get stuck halfway and caused a throttle position sensor code... as far as fuel pressure they sell pressure gauges at just about any parts store

**chi_town** · 11-01-2009

Well last night i went ahead and was looking around the engine bay, and disconnected this thicker looking line that goes into this circle black thing that has a valve that "Opens and closes" when you hit the gas.. I dont know what it is but when i disconnected that it boosted at 100% and i got all my power back, but when i reconnected it , i would go right back down to 50%. It has to spots that look like you would have two lines going into it, but there is only one line connecting to it =/ i dontk now what it is, and i dont have my Haynes Man, to actually look and see so hopfully somone here can tell me what it is...

I checked that line and it seemed like it was fine at the location, pushed all the way up to it , and there didn't seem like it was leaking, the car just seems like it's starving itself and im really unsure as to what that could be, cus it does it at startup and most the time if i put it in gear it will shut right down, and you can hear a giant vac leak, then after i let it warm up half the time it just doesn't want to run that long at all, and like i keep saying it keeps getting worse. Im bringing it in on Tuesday but would much rather save myself the money and figure this out myslf =/.

**ThePrimerSuspect** · 11-01-2009

i had a beretta 2.8 that was having a similar problem. turned out to be the IAC stuck fully open. if it sounds like a huge vacuum leak around the throttle body that may be the cause.

**chi_town** · 11-03-2009

So i had the GTP looked at by a local mechanic, today and they couldn't find anything wrong with it other than the code comming up for the MAF... I replaced it with a used one with a 30day warrenty, and now i called for another used one and see if that will correct the problem. I did notice that when i installed this newsed one that i no longer had white smoke come out of the exhaust like it's -20 outside, so that made me happy =) but apparently theres somthing else wrong with it =/..

But they deff didn't figure out why i am only making 50% boost =( and im really feeling like im missing somthing =/... I disconnected somthing that i had been told was the fuel regulator, with a single vac that seems to go into the BBV? Correct me if im wrong, but when i disconnect it , i seem to get full boost, i can't seem to remember if i posted this but i guess ill repost it =).

I really want the problem fixed , and i would really like to start putting money into making the car faster , and running better than just putting money into getting the car to run right ...

Please PLEASE HELP!!!

CHI_TOWN

**Spazztic2003** · 11-03-2009

have you checked all vacuum ports to make sure everything was connected tight and cleaned?

your intake gasket can cause vacuum issues as well. might wanna check your torque specs on every bolt-on and make sure your engine is sealed off well, or you're going to be having a lot of intake issues.

**Spazztic2003** · 11-03-2009

oh and by the way, the black round thing you were talking about is associated with regulating vacuum inside of the supercharger. your PPV sensor may be bad.

**chi_town** · 11-03-2009

PPV Sensor? Where is that located?

Chi_Town

**silvermistchick** · 11-04-2009

just so you know you can leave that sensor disconnected. it hooks up to the boost by pass and is not needed if it is bad. mine is unhooked bf unhooked his and everybody else in our click lol. i had the same issue it wont build full boost? then we unhooked it and bam i was back burning up tires again. and seafoam the car then change the oil and enjoy it until something else messes up

**07CrimsonGT** · 11-05-2009

Chi Town:

Also would not hurt to throw a new fuel filter on it if it has one of the inline cannister types. Fuel filters are a commonly overlooked inexpensive maintenance item that have caused many issues.

Don

**chi_town** · 11-06-2009

My mechanic told me to leave it connected cus i am just building a Vac leak,so i have but i had it disconnected and i had full boost =( i miss burning tire, but the weird thing is i could be at a roll maybe 15ish and it wouldn't break loose but i've read other members have a nearly stock car and at 20ish they still break loose

As for seafoam: i used it in the last engine and the day i poored it into the oil i did half break booster cable,half crank case * like i've always done* and my engine went later that day, so im sorta scared to try it again on this engine
=( even though i LOVED the stuff it worked really good, and really did the trick on cleaning the engine out, and this engien was kept in a barn for the last few months so i can't amagine what kinda crap is built up in it ....

Fuel filter was my next thing, i still have a brand new one from my Bonneville that i recently sold, is it the same part number?

I have noticed my mpg is just horrible like 12ish around town and MAYBE if im lucky 20 on the hw... Fuelfilter might do the trick =)

What would be a good daily driving oil ? I normally use Mobile 1 syn, but i have been considering either going back to using Valv synthetic, or maybe RP?

Input is greatly appreciated!!

Chi_Town

**gtpinsc** · 11-06-2009

ive used RP religously, some ppl talk sh*t sayin its not worth it... however the US government uses it.

**chi_town** · 11-08-2009

Changed out my Maf with another used one and still seem to have the same problem at start up.. The car starts up fine other than the hard start.. which is another issue i wanted to address... And, it dies, it does so for a few starts and dies each time.. Than eventually it will run, but when i give it gas it seems to want to bog down like it's loosing gas or doesn't have enough gas , and it sounds like there is a vac leak comming from somwhere..

Im getting really sick of this issue, and would really like to enjoy the car , but it doesn't seem like anything i've done fixed the problem and i even had a shop look into it and they got it to reacure but didn't give me anything other than the MAF bad.. Could the MAF be bad once again? If so should i opt for a new one , and HOPE it's the issue or just get another used one...

I really need help with this problem...

Chi_Town

**DanGTP** · 11-09-2009

Are you still getting a code for the MAF? That used one may be no good, or you might have a broken wire somewhere. Have you tried un-plugging the MAF and starting the car?

**chi_town** · 11-09-2009

Yeah still seems to run bad so i unplugged the sensor that comes off the intake tube, and it seemed to clear it up alittle, but not fully... Hmm
Just doesn't seem like the car is putting out the type of power i would assume for somthing supercharged, that's all.. And, with all these small problems, it sorta just makes me want to get rid of the car that much more ...
What i dont understand is that , why when it starts to bog down it sounds like there is a vac leak somwhere but when it runs decent it doesn't have any type of leak?

I do know the fuel pump gasket needs to be replaced but i can't see that being the vac leak, i could see that comming up for the (P1655) code but that's about it...

Ideas?

Chi_Town