I own an 87 IROC. A few months ago I took out my old 305 and installed a freshly-built 355 with a mild cam. I kept the TPI setup, and I had planned on keeping the injectors from the 305 instead of getting larger ones. I ordered a custom chip from JET to fit that plan, however (as usual) plans changed. I installed that chip, but have since installed larger injectors, and removed the A.I.R. system (and installed a new cat that didn't have an AIR tube). Would that cause it to run rich? It idles fine, but if I run it anywhere above 2500 RPM it starts to bog down a little and the catalytic glows red hot & starts to stink. My oxygen sensor is new, and I have checked the entire ignition system and it is firing fine.

Since I have installed the larger injectors and removed the A.I.R. system, do you think I should have a new chip made?

Any help is really appreciated!

Rick

 

Yes, if you change the size of your injectors you have to recalibrate your chip. You are running way to rich if your catalytic converter is turning red. You can temporarily solve the problem by turning down your fuel pressure, or putting the other injectors back in. Running an engine too rich like that is very bad. Some of the things that can happen are, fuel washing the oil from the rings, fuel getting into the oil, melting catalytic converter, fouled plugs, heavy carbon deposits, etc.

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89 Transam GTA, 350TPI, auto, 3.27 rear, dual cats, gray.
Magnaflow cat-back,
K&N open element,
Best E.T. 14.63@95mph

 

never saw a catlytic glow red... i always thought if a car is running rich, that the excessive fuel will cause things to run cooler.... but i agree, definately need a new chip... I would look into a place called Performance Resource ( www.performaceresource.com ) i got my chip from there, and so did one of the guys in the local f-body club... very good chip.

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1988 Pontiac Trans Am GTA L98 5.7L, Black on Black with 114,000kms.
Custom 3" Stainless Exhaust Y-Pipe back (High flow Cat and Flowmaster Mufler)

 

Thank you for your help, guys!

I'll definitely be getting a new chip very soon then and I'll look into Perf. Resource when it comes time. Thanks again!

Rick

 

I would also recomend Preformance Resources, that's where my chip if from...Very good Chip.

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88 Formula 350
Upper and Lower SuperRam, 1000 CFM Accel Throttle Body, ZZ4 cam, 24# Motorsport Injectors, Larger Gutted Mass Sensor, Homemade Cold Air induction, Custom Burned PROM, MSD 6a box, MSD Distributor, Accel SuperCoil, Taylor 8mm wires, TB Bypass, B&M shift Kit, 160* Thermostat, Flowmaster Muffler,