as for the motor not turning over with the use of the key, i would check the easy stuff first, make sure the battery is charged
make sure the connections to the alternator and starter are in tact
then worl my way back thru the system,
when you say you jmped the starter, did you bypass the solenoid? seems like you may have identifid the problem right there,
if its not the solenoid, work backwards to the neutral safety switch, on manual cars it can also be the clutch switch
https://www.zip-corvette.com/85-89-high-performance-adjustable-maf-sensor.html
85-89 High Performance Adjustable MAF Sensor
Item Number: EH-521
heres a rather useful addition to the older c4 corvette tuning world, its a new (yes expensive)
but adjustable and thus some what tune-able MASS AIR FLOW SENSOR for the TPI corvettes
then keep working back to the ignition switch. if at any time you cross paths with some form of wiring from the alarm system, check that out too and make sure it isnt turning your whole program on its ear.
things you will need:
infrared thermometers are a very useful tool to track down issues with tuning, or mal functioning sensors , without verified facts your guessing.
this is the most consistently accurate I.R temp gun I've used for testing[/img]
http://www.testequipmentdepot.com/e...1100200223789&utm_content=All Extech Products
INFRARED TEMP GUN
if the injectors are stuck open the injectors defective or its in need of a careful commercial professional cleaning, verify if its the injector or the injector control pulse duration
replacement injector pig tails are available at rock auto for less than $5 each
http://www.harborfreight.com/11-piece-noid-light-and-iac-tester-set-97959.html
a good digital multi-meter,
http://en-us.fluke.com/products/digital ... meter.html
http://www.harborfreight.com/5-in-1-dig ... 98674.html
having a fluke multi meter and an assortment of test leads helps
FLUKE is the brand of choice but they are expensive, shop around, Ive still got the original fluke multi meter I bought in HIGH SCHOOL and it STILL WORKS Ive purchase several imported multi meters from harbor freight , in the last 10 years alone and only one still works
ALWAYS TEST ALL YOUR INJECTORS OHMS RESISTANCE, WITH A MULTI METER, IF YOUR ENGINE RUNS BADLY ,INDIVIDUALLY< THEY SHOULD ALL BE VERY CLOSE TO EQUAL, ANY THAT ARE NOT NEED TO BE REPLACED
http://www.fluke-direct.com/shop/itemDe ... urer=FLUKE
viewtopic.php?f=55&t=10141&p=41021&hilit=shop+manual#p41021
http://www.fluke-direct.com/shop/catego ... TERS&path=
http://garage.grumpysperformance.co...h-flicker-on-dash-and-radio.13593/#post-70202
some jumper wires (not battery jumper cables)
a test light
factory service manual
and a manual for that alarm if it becomes necessary.
Im always amazed at the guys that don,t
STOP AND GRAB A FEW TOOLS AND THE SHOP MANUAL.
break out the shop manual ,
THINK LOGICALLY ISOLATE AND TEST, CHECK YOUR FUSES AND FOR LOOSE ELECTRICAL GROUNDS AND CONNECTIONS TO SENSORS!
GET out the multi meter, and a fuel pressure gage,
and do a few quick tests for loose electrical connections, look for vacuum leaks and consistent fuel pressure on the fuel rails
and verify the alternator voltage is at or above 13.5 volts,
when things don,t run correctly and the guys that don,t
pull the trouble codes, they are skipping a step that may waste hours
obviously the basics always apply ,
you need to think carefully, don,t assume anything.
TEST AND VERIFY EVERY COMPONENT AND SENSOR FUNCTION!
Id suggest pulling trouble codes and verifying the basics of engine function,
are you actually getting spark at ALL the plugs?
are you getting injector pulse from the injector wire harness, do you have fuel pressure?
have you been checking the too verify your actually getting fuel out of the injectors,into the cylinders?
are all the fuses in the panel good?
have you verified that your alternator produces 13.5 plus volts,
that your getting spark at all the spark plugs ,have you verified the spark plugs are actually arcing and not fuel fouled?
your getting compression in all cylinders, all the rockers move, as the engine rotates?
ALL the sensors are fully functional,
your getting at least 10 psi of oil pressure as the engine spins while its trying to start,
you need to see the fuel pressure is consistently at 38-42 psi.
you need to verify the fuel filter and fuel pressure regulator and return line are functioning as designed.
verify all the electrical grounds are good,
and you use a noid tester to verify your getting the injector pulse.
what most people fail to do is test and verify, you can,t assume anything.
youll want too verify, youve got no plenum or runner vacuum leaks, and the catalytic converters are NOT restricting exhaust flow, theres no excessive exhaust system back pressure.
just because the injectors have pressure in the fuel rail, and get a pulse does NOT insure fuel flow thru them,
and having fuel rail pressure does not insure ITS GOOD fuel,
it can be tainted with water or rust particles in the fuel,
preventing fuel atomizing in the cylinders.
clogged catalytic converters can easily cause the engine to fail to flow air,
checking the plenum vacuum and exhaust back pressure and reading the exhaust fuel/air ratio,
use of an infrared temp gun, to verify cylinder exhaust temps are reasonably equal and a multi meter to set the TPS sensor and verify the ignition wire resistance will help.
simple stuff like verifying the firing order that you just know is correct (which may not be , so VERIFY IT) get over looked
and testing the coil and oxygen sensors and temp sensors sure helps.
After you verify theres consistent strong electrical spark at the spark plugs when your trying to start the engine and fuel pressure is consistent at the fuel rails,and your getting at least 7-8 psi of oil pressure,
IF you suspect a fuel delivery related issue, a good long spray of starter fluid into the throttle body and trying to start the engine with that extra fuel source may prove informative, if it trys to start with the extra fuel in the plenum but failed to start without it, its a good indicator the injectors are plugged or defective
this infos bound to be helpful at times
Sensor Locations
Sensor
Location
Engine Coolant Temperature Sensor. Front of engine, below Throttle Body.
Engine Oil Temperature Sensor. Left rear of engine, just above the oil filter.
Oil Pressure Sender/Switch. Top, left hand rear of engine.
Fuel Quantity Sender. Top of fuel tank, beneath filler pipe escutcheon panel.
MAT (Manifold Absolute Temperature Sensor). Underside of manifold air plenum at rear.
Outside Temperature Sensor. Right side of engine, top right corner of radiator.
In Car Temp Temperature Sensor. Coupe: above left seat near interior courtesy light, Convertible: center of cargo compartment lid.
MAF (Mass Air Flow) Sensor. Front of engine ahead of throttle body.
Oxygen (O2) Sensor. Left side of engine, in exhaust pipe.
TPS (Throttle Position Sensor). Right side of throttle body at the front.
Sensor Outputs:
Sensor
Measured Value
Engine Coolant Temperature Sensor. 185 Ohms @ 210F, 3400 Ohms @ 68F, 7,500 Ohms @ 39 F.
Engine Oil Temperature Sensor. 185 Ohms @ 210 F, 3400 Ohms @ 68 F, 7,500 Ohms @39 F.
Oil Pressure Sender/Switch. 1 Ohms @ 0 PSI, 43 Ohms @ 30 PSI, 86 Ohms @ 60 PSI.
Fuel Quantity Sender. 0 Ohms @ Empty, 45 Ohms @ 1/2 Full, 90 Ohms @ Full.
MAT (Manifold Absolute Temperature Sensor). 185 Ohms @ 210 F, 3400 Ohms @ 70 F, 15,000 Ohms @ 40 F.
Outside Temperature Sensor. 4400 Ohms @ 60 F, 2200 Ohms @ 85 F.
In Car Temp Temperature Sensor. 4400 Ohms @ 60 F, 2200 Ohms @ 85 F.
MAF (Mass Air Flow) Sensor. .4 Volts @ idle, 5 Volts @ Full Throttle.
Oxygen (O2) Sensor. .1 Volt Lean Mixture, .9 Volt Rich Mixture.
TPS (Throttle Position Sensor). .54 Volts Idle, ~ 5 Volts Full Throttle.
if you suspect water in the fuel pull the inside of the shrader valve
with a valve tool, and slip 12 feet of braid re-enforced 5/16" pvc hose over the valve ,
clamp it with a screw clamp
on the valve so theres less chance of a fuel leak, and let the fuel pump push a 1/2 gallon of fuel out of the fuel rail into a clear glass container on the floor , allow it to settle for 15 minures and look for water to settle out of the fuel.
http://garage.grumpysperformance.com/index.php?threads/c4-c5-corvette-trouble-codes.2697/
http://garage.grumpysperformance.co...s-cause-a-bad-idle-in-drive.14203/#post-72114
http://garage.grumpysperformance.com/index.php?threads/testing-1985-89-m-a-f-sensor.1475/#post-43635
http://garage.grumpysperformance.co...le-shooting-flow-chart-info.11536/#post-71845
http://garage.grumpysperformance.co...ittent-cylinder-miss-problem.9478/#post-57225
http://garage.grumpysperformance.co...g-your-tpi-maf-and-cpu-links.2825/#post-56790
http://garage.grumpysperformance.co...-you-failed-emmision-testing.3522/#post-52999
http://garage.grumpysperformance.co...and-verify-each-possibility.11219/#post-50643
http://garage.grumpysperformance.co...m-with-how-your-c4-corvette-runs-badly.15212/
http://garage.grumpysperformance.co...-idles-and-sometimes-stalls.10688/#post-46303
http://garage.grumpysperformance.com/index.php?threads/1991-c4-runs-like-crap.10616/#post-45635
Re: C4 sensor info
you really need a old computer, an ADL cable and software to read the info and of course YOU NEED a shop manual for YOUR YEAR CORVETTE, and a MULTI METER
reading links may seem like a waste of time , but having a shop manual, a decent up-to-date, scan tool and a multi meter and a good understanding of what your testing and why your testing it helps a great deal
like the old saying how do you eat an elephant ?......one little bite at a time! 
all the answers are readily available, theres known testing procedures and listed test results you can expect, and procedures listed in the shop manual for isolating and testing components, you don,t need to be a genius, you just need to be logical and persistent and not afraid to learn new things while getting your hands dirty at times, don,t get overwhelmed , break everything down too easy individual problems and tests, verify and test all the sensors,and test for factors like consistent fuel pressure, known temps,expected voltage or ohms resistance, and vacuum readings and don,t randomly start replacing parts as that gets expensive and its rarely the most efficient way to eliminate problems(unless you get really lucky) with modern computer diagnostic software you,ll have some advantages but think logically, most automotive problems still concern, loose electrical connectors, defective sensors, lack of compression, fuel delivery issues ,fuel pressure, vacuum, temperature or electrical issues.
http://www.helminc.com/helm
without pulling trouble codes and testing your simply guessing at best,
break the issue down into separate issues,
check ignition strength and timing,and voltage
check fuel supply/delivery pressure and volume
check cam timing and cylinder compression.
check valve train control and valve adjustment
check firing order and spark plug gap
check the valve lift, and for work lobes
check for vacuum leaks
adjust your iac and tps
check your exhaust back
pressure
verify sensors correct function
https://www.harborfreight.com/catal...core,f,EAFeatured+Weight,f,Sale+Rank,f&q=zr13
all the answers are readily available, theres known testing procedures and listed test results you can expect, and procedures listed in the shop manual for isolating and testing components, you don,t need to be a genius, you just need to be logical and persistent and not afraid to learn new things while getting your hands dirty at times, don,t get overwhelmed , break everything down too easy individual problems and tests, verify and test all the sensors,and test for factors like consistent fuel pressure, known temps,expected voltage or ohms resistance, and vacuum readings and don,t randomly start replacing parts as that gets expensive and its rarely the most efficient way to eliminate problems(unless you get really lucky) with modern computer diagnostic software you,ll have some advantages but think logically, most automotive problems still concern, loose electrical connectors, defective sensors, lack of compression, fuel delivery issues ,fuel pressure, vacuum, temperature or electrical issues.
http://www.helminc.com/helm
the correct matching SHOP MANUAL
TIMING LIGHT
IR TEMP GUN
VACUUM GAUGE
MULTI METER
FUEL PRESSURE GAUGE
COMPRESSION TEST GAUGE
keep in mind the basics you need to verify the fuel pressure is at about 40 psi if your dealing with a C4 corvette,
you should NOT have significant exhaust back pressure, clogged catalytic converters,
are a common problem on older c4 corvettes,
verify the fuses are not blown, the trouble codes do not show any problems,
all electrical grounds are reading good,
verify theres at least 14.5 volts at the battery while its running, so you know the alternator functions,
and all the injectors are functional with a noid light,
all cylinders should read within 10% and show about 150 psi or greater.,
on a compression test, verify the firing order,
set the spark plug gaps at .045 ,
and verify all the listed sensor values,
verify the cam lobes are not worn, verify you have at least 10 psi of oil pressure per 1000 rpm.verify theres no vacuum leaks
http://www.professionalequipment.com/ex ... ermometer/
Wide temperature range from -58 to 1832°F (-50 to 1000°C)
viewtopic.php?f=55&t=109
you might have clogged catalytic converters, the ignition timing may be way off, you might have a worn out cam, the fuel pump may be defective, some injector(s) may be defective,check the alternator out-put check the fuel rail pressure use a noid light on the injector wiring, check the fuses,
Ive found that the one most commonly over looked in my experience is that the stock exhaust system, is highly restrictive, especially if the catalytic converters are partly plugged and the stock fuel delivery system is not adequate,for the potential power, the heads and intake, allowable air flow potential, are all restrictive, and the stock cam timing and lift is already near max as it was designed to produce about 260 hp,and operate at under 5700 rpm, if you try too add an additional 100-200 hp, and 1000 rpm-2000 rpm to the engines power band, and too the engines output youll quickly find this to be a factor.
I've also occasionally seen guys, improperly index or install a cam without degreeing it in correctly and thus have power band limitations.
Id suggest you buy a factory shop manual, multi meter and a timing light, fuel pressure and vacuum gauge and start checking.
reading these links will be helpful
yes I know it will take some time and effort to isolate and test
but its the only 100% sure route to finding and fixing your problem,
don,t get over whelmed,
simply break the problem down to testing each basic sub system,
test each related sensor and electrical component and electrical sensor and connection.
some reading on the threads posted below, a bit of logic and deductive reasoning, and a multi meter and a shop manual will go a long way toward finding and fixing the problem.
this is the most consistently accurate I.R temp gun I've used for testing[/img]
http://www.testequipmentdepot.com/extech/thermometers-and-humidity-meters/infrared-thermometers/high-temperature-infrared-thermometer-58to1832f-50to1-laser-pointer-42545.htm?utm_source=bing&utm_medium=cpc&utm_campaign=NEXT - Bing Shopping - Extech&utm_term=1100200223789&utm_content=All Extech Products
INFRARED TEMP GUN
you always need a base line to start from, on a corvette.
a logical step by step approach and keeping accurate notes helps.
youll NEED a multi meter, a shop manual
and a timing light and fuel pressure gauge at a minimum,
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 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
http://garage.grumpysperformance.com/index.php?threads/c4-c5-corvette-trouble-codes.2697/
http://garage.grumpysperformance.co...ng-high-flow-cats-on-exhaust.8401/#post-29318
http://garage.grumpysperformance.co...s-cause-a-bad-idle-in-drive.14203/#post-72114
http://garage.grumpysperformance.com/index.php?threads/testing-1985-89-m-a-f-sensor.1475/#post-43635
http://garage.grumpysperformance.co...le-shooting-flow-chart-info.11536/#post-71845
http://garage.grumpysperformance.co...ittent-cylinder-miss-problem.9478/#post-57225
http://garage.grumpysperformance.co...g-your-tpi-maf-and-cpu-links.2825/#post-56790
http://garage.grumpysperformance.co...-you-failed-emmision-testing.3522/#post-52999
http://garage.grumpysperformance.co...and-verify-each-possibility.11219/#post-50643
http://garage.grumpysperformance.co...-idles-and-sometimes-stalls.10688/#post-46303
http://garage.grumpysperformance.com/index.php?threads/1991-c4-runs-like-crap.10616/#post-45635
