Boost but no pull?
#105216
July 04, 2003 12:26 am UTC
July 04, 2003 12:26 am UTC
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Joined: Oct 2002
Posts: 535 Ottawa
Ros Guiller
OP
Member
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OP
Member
Joined: Oct 2002
Posts: 535
Ottawa
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Hey guys, a buddy of mine developed a problem recently, but he's having trouble registering here. Anyways, the boost gauge shows 11 psi, but the car doesnt accelerate like it used to, and the lag (14B) has increased (full boost acheived at 4000rpm), and when he shifts gears, theres lots of lag again, and he has to wait for the turbo to spool, when before, it was almost instant.... He says it happened almost overnight. He says he tested the compression and it was perfect, the timing, the grounds, the ecu caps and it was all perfect, vacuum leaks as well, cat is not clogged. I suggested a boost leak because my GF's car experienced the same thing, and it ended up being a loose intercooler hose. In his case, its different because you can see the boost rise, and you can hear the turbo, but you can't really feel the boost. Its worse in the lower gears. If you step on it in the higher gears, it KINDA pulls better. For the record, it's a 1G.
I'm thinking the timing is being pulled by the ECU. I guess there's no way to tell without a datalogger, and he doesnt have one. Plugs are new, wires are new. The clutch isnt slipping. And the boost DOES build, so I don't see how it could be a wastegate issue.
So, any ideas?
Series V RX7 Turbo II
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Re: Boost but no pull?
#105217
July 15, 2003 07:52 pm UTC
July 15, 2003 07:52 pm UTC
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Joined: Jan 2001
Posts: 473 ancaster, ontario
marty edwards
Member
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Member
Joined: Jan 2001
Posts: 473
ancaster, ontario
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It still could be the wastegate, or a combination of a worn-out turbo (chipped blades) and wastegate cracks. When I replaced my 14B, it was still holding 15 lbs. of pressure, but it took forever to get there (4000-4500 rpm)! What happened with mine was the wastegate had a fair sized crack in it, so instead of turning the turbo, the exhaust gas was slowly leaking out the crack. If you're not getting all the exhaust gas pushing the turbo, it will take much longer to build boost. At 4000 rpm you're pushing out twice as much exhaust gas as 2000 rpm!
1991 TSI AWD - Big 16G @ 17 psi
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Re: Boost but no pull?
#105219
July 16, 2003 07:23 pm UTC
July 16, 2003 07:23 pm UTC
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Joined: Jan 2001
Posts: 473 ancaster, ontario
marty edwards
Member
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Member
Joined: Jan 2001
Posts: 473
ancaster, ontario
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That's good to know! So it was that the exhaust was escaping, and not pushing the turbo! You think you'd hear that leak!!
1991 TSI AWD - Big 16G @ 17 psi
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Re: Boost but no pull?
#105220
July 16, 2003 08:13 pm UTC
July 16, 2003 08:13 pm UTC
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Joined: Jan 2003
Posts: 2,673 Bolton
Dean Boyle
Insane Member
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Insane Member
Joined: Jan 2003
Posts: 2,673
Bolton
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Originally posted by marty edwards: That's good to know! So it was that the exhaust was escaping, and not pushing the turbo! You think you'd hear that leak!! Nope. My old setup was completly cracked from the 1g mani, turbine exhaust housing to the o2 housing. After I did my 7cm port-job system (2g mani, brand new turbine exhaust housing and o2 dump housing), I went from full boost @ 4500rpm to 3200rpm. World of difference.
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