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1997 gtp hard time picking up speed


joker1s1
08-19-2010, 07:30 PM
Today my car started acting like it was starving for gas. I stepped on the gas to get up to speed quickly with no problems, then after cruising at 30 or so mph it just had no power. Every time i stepped on the gas it would lose power. On the way home i noticed if i could get the rpms over 1500 or so it would run fine. The only mod i have is a one size smaller pully. Also would bosch platinum +2 work in this car. Thanks for the help.

tblake
08-19-2010, 07:40 PM
Not a fan of Bosch, but your problem sounds like its something else.

Try unplugging the MAF and running it like that.

Then check fuel pressure.

Report back with your findings.

joker1s1
08-19-2010, 08:57 PM
Unplugged mass air flow and ran it that way. Hesitated at first but then ran good. Soon as i plugged it back in it started chugging. Thanks for your help.

tblake
08-19-2010, 09:16 PM
You found the problem.

I too had that same issue, Last thursday, leaving an amusement park, hottest day of the year, in rush hour, with a g/f that wasn't too happy. Car had no power, and died. Unplugged MAF and it ran good and got us home.

I wonder if the heat outside has something to do with why all these MAF's are failing.

joker1s1
08-21-2010, 12:44 PM
That wasn't the problem. It started doing the same thing this morning with a new maf in it. Yet it seems to run better with it unplugged.

BNaylor
08-21-2010, 01:00 PM
As Tim suggested check your fuel pressure at the front fuel rail Schrader valve. It should be around 48-55 psi on a L67 SII 3800 engine at fuel pump prime. Also, check for knock retard (KR) if possible. What grade fuel are you using?

What brand spark plugs are you currently using or how old? Do not use the Bosch multi-electrode gimmicky spark plugs. Use the OE Delco or NGK double platinum or newer Iridium only but with the proper heat range. Since you have an undersize SC pulley for more boost installed the Autolite Copper Core plugs are a good choice. Use 605 or 104 which are one and two ranges colder.

joker1s1
08-21-2010, 01:21 PM
Plugs are ac delco iridiums. Not sure how old but had two that were cracked on the ceramic. At least 3 years old. I dont have acces to a fuel pressure gauge but the fuel pump was changed last year. Also just did the intake gasket about a month ago.

joker1s1
08-21-2010, 02:02 PM
Just checked fuel pressue and it is down at 15 to 20 psi. Does that mean it needs another fuel pump or would the filter be plugged

BNaylor
08-21-2010, 02:20 PM
Try the easy things first but fuel pump is possible although you replaced it in the past. Fuel filter and just in case the fuel pump resistor bypass procedure at the link below.

Click here (http://www.automotiveforums.com/vbulletin/showthread.php?t=658282)

joker1s1
08-21-2010, 05:40 PM
It ran for about a minute in high speed mode then shut off. Now it wont start anymore. Let it sit for half hour and turned on key, fuel pump runs real slow. This will be the 5th fuel pump now, 302,000 miles

tblake
08-22-2010, 10:03 AM
Try the fuel pump resistor bypass.

http://www.automotiveforums.com/vbulletin/showthread.php?t=658282

BNaylor
08-22-2010, 10:12 AM
Tim it looks like he did the bypass but from all indications the fuel pump is bad.

5th fuel pump over 302K miles. Ouch!

grandprixgtx00
08-22-2010, 02:40 PM
You're running a 3.4 pulley with no support mods? IMO that may be part of your problem right there. Not a good idea :2cents:

joker1s1
08-22-2010, 07:29 PM
Cant remember what size pulley but i didnt have to change belt size. It has been on for about 3 years now. I think i found the problem. The strainer on bottom of pump came off. It was laying in the tank. The pump itself had alot of crap come out of it ( dirt ). Strangely enough this pump lasted longer than a store bought one. Got it online, pump only.

troy1
08-22-2010, 10:12 PM
You need to clean your tank out if you got a lot of dirt out of the pump. You could be restricting the flow when the strainer is on and burning out your pump by making it work so hard

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