1988 iroc-z 350 tpi - runs poorly when hot (190-200degrees)
If car has been tuned-up, new high performance radiator , new 52mm tpi throttle body , mass flow sensor working , k&n air filter good , but car still runs poor when at max temp - Is there problems with early chevy injectors
or something else I can do other than spend big dollars for new injectors?
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Re: 1988 iroc-z 350 tpi - runs poorly when hot...
Does it run poor at full throttle or between quarter and half throttle? Does it hessitate? If it does the EGR valve may be worn out. I had an 87 transam with TPI and was having problems with it stumbling and hesitating when it was warmed up. If the car starts hard and you have these problems then the issue may be low fuel pressure. Hook a guage up to the fuel rail and make sure you are getting pressure. If you are only getting a few pounds of pressure it may be the fuel pump or fuel pressure regulator. Good luck and if you thought this information was helpful please rate it when you get a chance.
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First, did you check the fuel filter to see if it was clogged (cheap fix to replace it if you haven't recently)? Second, there's a fuel pressure regulator at the back of the tpi rail (back by the distributor). This has a diaphragm and spring in it. If the diaphragm leaks, the fuel pressure will be erratic. If you're going to check the diaphragm, I'd recommend installing an adjustable fuel pressure regulator where the stock (non-adjustable) fuel pressure regulator is at. The rail also has a bleed down circuit which will drop the fuel pressure once the vehicle is shut off. Third: the in-tank fuel pump could be on the way out.
you can run this motor carburated if you want by purchasing an after market conversion intake and carburator setup. if you want to leave it fuel injected you will need to swap wiring harnes and everything, computers and sensors you will have to run manual guages for the temp sensors and oil pressure guage and alternator due to your speedo being unable to accept them.
Clogged fuel injectors. Or, starting fluid is basically high octane fuel which doesnt require efficient or hot spark plugs to start, so maybe you need to look at your ignition system, especially your spark plugs, wires, or cup rotors -- perhaps they are not delivering a hot enough spark for regular fuel. While at it, also check the ignition timing. In other words, clean your injectors and get a tune up. Finally, make sure the throttle body is not leaking air.
SOUNDS LIKE A VACUM LEAK,POSSIBLY INTAKE GASKET OR VACUM HOSES,GET SOME BERKIBLE 2+2 SPRAY DOWN INTAKES WHERE MEET HEAD AROND THROTTLE BODY AND ALSO EGR VALVE TO MAKE SURE IT ISN'T PARTAILY STUCK OPEN, VACUM LINES AIR INTAKE HOSE BETWEEN THROTTLE BODY AND AIR FLOW METER,ALSO MAKE SURE ITS NOT DRY ROTTED AND SUCKING AIR,THE ENGINE IDLE SHOULD GO UP OR DOWN DEPENDING HOW BIG THE LEAK