metallica21156

i wanted to know where the 4.3 CPI peaked in torque. i was driving my truck which is a 95 jimmy with cpi caold air intake and flowmaster on it that if i take off with the truck it has some force pushing me into the seat and then it hits 2,500 RPM it all of a sudden acts like a turbo kicks in and the truck all of a sudden thows me into the seat more. it will stay like this until it shifts gears. i haven't changed the way i'm pushing the pedel and the trucks in 1st gear the whole time. any ideas?

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95 jimmy. Vortec V6. 4.3 liter CPI. ,2.5" catco cat, 2.5" cat back with flowmaster muffler, 40 street series split rear, 2 12" audiobahns in custom box,K&N CPI intake system.

71 Mustang coupe- project car. stock 302 with Cobra intake, holley 650dp, afco racing radiator, headman headers, msd distributor, 2.5" from the headers. Mag 500's with black center caps, C4 tranny with shift kit, Mach 1 body lay out.

90 cav, 2.2 tbi, gas getter.

BlazerLT

Yes, what you are seeing is the IMTV valve opening up.

It opens up around 3000rpms or at high throttle angle.

You get the best of both worlds with the CPI. High torque at low rpms and when the IMTV valve opens up, you also get torque in the higher rpms.

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1995 Factory Blazer Service Manual for sale, PM if interested.

metallica21156

i just think its kinda cool that if u have somebody with u and it kicks in that they ask if it has turbo. i've had somebody ask me before. also when does the 4.3 peak in HP?

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95 jimmy. Vortec V6. 4.3 liter CPI. ,2.5" catco cat, 2.5" cat back with flowmaster muffler, 40 street series split rear, 2 12" audiobahns in custom box,K&N CPI intake system.

71 Mustang coupe- project car. stock 302 with Cobra intake, holley 650dp, afco racing radiator, headman headers, msd distributor, 2.5" from the headers. Mag 500's with black center caps, C4 tranny with shift kit, Mach 1 body lay out.

90 cav, 2.2 tbi, gas getter.

metallica21156

could it also be the cat taking a dump? it rattles sometimes.

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95 jimmy. Vortec V6. 4.3 liter CPI. ,2.5" catco cat, 2.5" cat back with flowmaster muffler, 40 street series split rear, 2 12" audiobahns in custom box,K&N CPI intake system.

71 Mustang coupe- project car. stock 302 with Cobra intake, holley 650dp, afco racing radiator, headman headers, msd distributor, 2.5" from the headers. Mag 500's with black center caps, C4 tranny with shift kit, Mach 1 body lay out.

90 cav, 2.2 tbi, gas getter.

BlazerLT

you sure it is what is rattling?

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1995 Factory Blazer Service Manual for sale, PM if interested.

metallica21156

the mufflers a flowmaster. can't be from it. cats never been changed and u can smell it sometimes.

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95 jimmy. Vortec V6. 4.3 liter CPI. ,2.5" catco cat, 2.5" cat back with flowmaster muffler, 40 street series split rear, 2 12" audiobahns in custom box,K&N CPI intake system.

71 Mustang coupe- project car. stock 302 with Cobra intake, holley 650dp, afco racing radiator, headman headers, msd distributor, 2.5" from the headers. Mag 500's with black center caps, C4 tranny with shift kit, Mach 1 body lay out.

90 cav, 2.2 tbi, gas getter.

BlazerLT

Why can't it be from the muffler?

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1995 Factory Blazer Service Manual for sale, PM if interested.

wolfox

Flowmasters have spot welding on their baffles and do rot out, causung them to shift and rattle. It's why I didn't get one.

metallica21156

the mufflers only a month or so old. when it rattles you can hear it under it from the cat. plus it stinks. the cats going bad and the CPI dumped in it for a few months.

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95 jimmy. Vortec V6. 4.3 liter CPI. ,2.5" catco cat, 2.5" cat back with flowmaster muffler, 40 street series split rear, 2 12" audiobahns in custom box,K&N CPI intake system.

71 Mustang coupe- project car. stock 302 with Cobra intake, holley 650dp, afco racing radiator, headman headers, msd distributor, 2.5" from the headers. Mag 500's with black center caps, C4 tranny with shift kit, Mach 1 body lay out.

90 cav, 2.2 tbi, gas getter.

BlazerLT

If the noise is coming from the cat, take it back to where you had it installed.

It will have a warranty.

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1995 Factory Blazer Service Manual for sale, PM if interested.

metallica21156

the cats never been changed. 77,000 miles on it. alot of city driving shook it loose. muffler and exhaust was custom by me.

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95 jimmy. Vortec V6. 4.3 liter CPI. ,2.5" catco cat, 2.5" cat back with flowmaster muffler, 40 street series split rear, 2 12" audiobahns in custom box,K&N CPI intake system.

71 Mustang coupe- project car. stock 302 with Cobra intake, holley 650dp, afco racing radiator, headman headers, msd distributor, 2.5" from the headers. Mag 500's with black center caps, C4 tranny with shift kit, Mach 1 body lay out.

90 cav, 2.2 tbi, gas getter.

BlazerLT

Easy then, replace the cat.

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1995 Factory Blazer Service Manual for sale, PM if interested.