Toyota h8r

Well after many times off trying to fix my car im forced to ask to you all smart people how to fix my car

I installed the whole top end of a 1991 L98 on my 1968 327 with a mild cam. (214/224 and .442/.465 AT 1.5 rocker with 112LSA)...nothing crazy

No matter what i do either setting the tps and IAC min air will the car idle down to desired rpm. I hook up my laptop and using datamater 8D the computer calls for the engine to idle to 650rpm but will idle at 750 to 1500 rpm. I am going to try to set min air for IAC and then not plug the IAC back in. The motor will idle down in gear to 850-900rpm but out of gear will jump to 1200-1500rpm.

Ive tried changing every sensor and such to no avail....

HELP? O_o please
im about ready to rip the garbage off known as TPI and go back to a carb lol.....

Air_Adam

Have you done any tuning with it? You'll really need to - that cam is significantly bigger than anything a stock L98 ECM will know what to do with, and it will act even bigger in a 327 than it would in a 350. In a 327, you'll want to set the target idle a little higher than a stock L98 idle setting... probably around 800 in drive would be good.

Thats not a solid lifter cam is it? That can cause problems with the knock sensor - are you using the knock sensor for a 305 or a 350? You should be using the 350 unit.

TKOPerformance

Truthfully I'd probably ditch the knock sensor completely. I agree that the 350 sensor is going to be closer to accurate since a 327 and a 350 share the same 4.00" bore, but in truth these sensors are dialed in for one particular engine. You can run a resistor between ground and the sensor plug to keep from getting an SES light. I don't use mine because a previous owner, who we'll refer to as "Jackass", thought it would be cool to have a geardrive in the engine.

Erratic idling is a sure sign of a cam that the ECM can't make hide nor hair of. Your cam is slightly bigger than any stock L98 cam, and the LSA is narrower. I have no doubt that this is your problem. You need a custom burned PROM, and your 327 TPI should run just fine.

Toyota h8r

okay i forgot to mention the car HAS been tuned. I used a moates.net chip adapter setup and friend has the hardware to tuner the chip.

things changed:
5.7 to 5.3L
22# injector constant to 24#(my lt1 injectors)
eliminated VATS
changed fan temps

but when i hook my laptop up to the car and use datamaster the computer calls for the motor to idle down to 650 but the motor will actually sit in gear and rise to 1200-1500 depending on the cars mood

the car has been tuned....and i have done the min air...the car will idle at 650rpm like it should...but hook the EST and IAC back up....1500 idle comes RIGHT BACK. Its embarrassing....

i can have the iac unhooked and est hooked up and the car will idle up. When you fire the car up dead cold, it will idle around where it should, then as it warms up it doesnt want to hold a low idle. Im actually lost at this point due to doing everything by the book and still does the exact same thing

Toyota h8r

and no its not a solid lifter...its a hydro flat tappet like found in 85-86 tpi cars

the cam isnt big as you all think....its DAMN close to one of an old SLP cam for tpi cars.....hence why im using this cam

RED86Z28

Considdering what the stock engine had, that cam is not mild at all for a SD TPI. You need to do more tuning beyond the injector size.

Toyota h8r

like? im a new guy to this fuel injection crap lol.....im hoping this car can run better

Guest

Start checking for things like vacuum leaks, throttle body blades sticking open. Does not sound like a tuning issue and certainly not the cam/ecm combo doing it.

Dewey110

According to information that I have received from numerous sources when builing my engine I was told that the Factory Map sensor will work with a cam profile up to 210 degrees duration. The speed density systems are real sensitive to pressure variations in the intake. I am having a custom chip made for my car from PCMFORLESS.com. It is only costing me $157.00 with 2 day shipping. I sent them the cam data from the spec card and flow data from the heads so they can compensate for this.

RED86Z28

Im not the best with exactly what to change but the fuel maps need to be modified. I would find someone who has expireance tuning tpi.

Toyota h8r

we have a winner!

figured id let people know what was wrong with my car.....massive intake leak that vacuum gauge nor carb cleaner spraying deal didnt show. Also, swapped out the gm multitec 24# lt1 injectors for a set of SouthBay fuel injectors(24# ford racing ones)

car is running best it ever has with tpi......still not carb performance but ill deal with this lol. I have murdered my poor 700r4....no 2nd gear now.....oh well. Im thinking about doing a th350 swap....reason being is i just scored a 95 lt1 motor for 300 bux Be fun redlight to redlight car

LT1>327TPI.......lt1 for rest of summer then swap in the LQ4 like planned