1984 fuel pressure

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
coyotejoe said:
84 stock crossfire TBI should there be pressure to the injectors after being parked for a couple of hours? mine doesn't have any pressure in the fuel lines.
http://www.helminc.com/helm
http://www.factoryrepairmanuals.com...ice-manual-2-volume-set-original-shop-repair/

your working at a huge dis-advantage if you don,t have a factory shop manual for your specific year car, and basic tools like a multi-meter, and vacuum /pressure gauge
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http://www.harborfreight.com/fuel-injection-pump-tester-92699.html
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https://www.summitracing.com/parts/anm-cp7838
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and rev the engine a few times and watch the fuel pressure it should in theory remain in the 38 psi-42 psi range for most TPI and TUNED PORT efi cross fire will be closer to 14 psi


http://www.harborfreight.com/5-in-1-dig ... 98674.html
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viewtopic.php?f=50&t=3110&p=12074&hilit=multi+meter#p12074

which port is your MAP sensor hooked to??? there are 3 ports on teh back of the throttle bodies.. the center port is usually blocked off as its only used to sync the throttle lever adjustments..

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there are a whole bunch of grounds to check...
yes a defective TPS sensor on an older early c4 corvette is almost expected,especially with that sensor approaching 32 years old if its OEM.
ricks suggestion to test the TPS sensor is a good idea


http://www.ecklerscorvette.com/corvette-throttle-position-sensor-1982-1984.html
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http://www.ecklerscorvette.com/corvette-throttle-position-test-switch-wiring-harness-1984-1991.html

A MULTI METER AND TIMING LIGHT WILL BE USEFUL
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and check means.. actually taking the fastener out and wire brushing both sides of each ring terminal. then reinstalling them with cleaned fasteners..

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Read more: http://forums.superchevy.com/corvet...-l83-crossfire-carb-conversion/#ixzz40kd2b09R
youll NEED a multi meter, a shop manual and a timing light and fuel pressure gauge at a minimum, any time your serious about running down and trouble shooting problems, youll also want to read the links and sub links below and ask questions
set and verify your ignition timing, pull trouble codes,set your tps and iac,, then check for vacuum leaks on the lines and intake,then get out your multi meter and verify all the sensors, chances are good its a defective heat sensor or defective o2 sensor, a logical step by step approach will lead you to the problem, youll be amazed at what youll learn reading links. use of a shop manual and multi meter can be very helpful.
the 1984 corvette has several very restrictive engine components that can be upgraded to allow much better power, swapping to a slightly more aggressive cam like a crane 114132 sure helps, especially if matched to the proper valve spring upgrade and 1.6:1 ratio roller rockers

http://garage.grumpysperformance.com/index.php?threads/renegade-intake-for-cross-fires.2796/
better cylinder heads
http://garage.grumpysperformance.com/index.php?threads/sellecting-cylinder-heads.796/#post-2596

http://garage.grumpysperformance.co...ing-parts-and-a-logical-plan.7722/#post-49738

http://www.hotrod.com/how-to/engine/ccrp-1209-eight-budget-sbc-head-shootout/

http://www.edelbrock.com/automotive/mc/cylinder-heads/chevy/e-series-sb.shtml

and a low restriction exhaust and headers,would be almost mandatory upgrades

one of the better current c4 corvette exhaust system designs is made by www.melrosecorvette.com


two stainless mufflers similar in design to this with a 3" inlet and dual 2.5" outlets seem to match the application, but measure very carefully after the exhaust is installed to verify you have the required clearance to mount and correctly connect them of course, before ordering
http://www.jegs.com/i/Flowmaster/389/80430402/10002/-1?parentProductId=1030933

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If your intent is to significantly boost the cross fire engines power curve (and who doesn,t) keep in mind the stock twin throttle body injectors can support about 250hp if you turn the fuel pressure up to about 15 psi, but above that power level, your going to need to swap to higher flow rate injectors to keep up with the increased air flow and fuel demands
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http://www.harborfreight.com/5-in-1-dig ... 98674.html
put a fuel pressure gauge on the fuel rail on the shrader valve,

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a vacuum and fuel pressure gauge is useful

30 minutes later Yes,I'd look for at least 7-10 psi, and 13-15 psi minimum running, but an hour later, I think is expecting to much, by then its usually bled down
BUY A FACTORY SHOP MANUAL ITS MANDATORY WHEN YOU OWN AN OLDER VETTE
fuel pressure drops if the injectors,leak, the fuel pressure regulator leaks, or the fuel pump leaks and ALL THREE will to some extent over time , the key is finding out if your dealling with an expected loss rate or something defective

http://garage.grumpysperformance.com/index.php?threads/got-a-cross-fire-corvette.640/#post-50502

http://garage.grumpysperformance.co...lf-the-time-starts-and-dies.11187/#post-50245

http://garage.grumpysperformance.com/index.php?threads/1984-crossfire-vette-won-t-run-right.10096/

http://garage.grumpysperformance.co...p-after-running-out-of-fuel.11309/#post-51483

http://garage.grumpysperformance.co...ard-starting-tpi-crossfire-or-lt1-vette.1401/

http://garage.grumpysperformance.co...-system-trouble-shooting-flow-chart-info.596/
 
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