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82 injectors not spraying smooth

fatboyreyn

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116
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east coast
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1986 red
hey guys, need some help with 1982. sat for 14 months. was told it ran great before it was parked. emptied fuel tank, changed fuel filter. checked pump, there is flow. ( jumpered wires at relay. Put new injectors and gasket kit and cleaned everything up. Now the problem. Car starts right up if I pour a little gas in throats. When I turn the key, injectors sometimes spit for a second, but not a spray. When the car is running for the few seconds after I pour gas in, the injectors are again trying to spray, but it is far from a fine mist. Is the spray from the injectors supposed to be a nice strong spray? Is it possible the pump produces flow but no pressure? I didn't do anything with the regulators on the bodies. I also tried keeping the jumper on the pump relay while trying to start it, but still comes out of injectors sloppy. Any advice, boys?
 

jdp6000

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Aug 23, 2004
Messages
646
Location
Aurora, Ontario, Canada
Corvette
1982 CROSSFIRE
Spray pattern should be an even cone shape...pulses continuously. If the system is working right on cold start up you should get/hear a prime pulse for a split second. You should also hear the pump turn on for 2 seconds just before every start up.

Fuel pump does supply 9-13 psi. Rear TBI regulates the pressure to the injectors. If the pump does not supply enough pressure the rear TBI can not do its job. Best thing to do is check the fuel pressure between the 2 TBI's it should well ahead of 9 psi and steady.

If you are not getting proper spray its probably the fuel pump. It is one of the most common problems. replace it with an 85 pump. Provides about 40 psi and the rear TBI steps it down to about 13 psi or so.

Check your 2 TBI fuses. Check all the fuses for that matter including the one beside the battery.

Jim
 

wishuwerehere82

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Location
Rochester, NY
Corvette
Red '82 Coupe,Sebring Silver '98 Coupe
Check the pressure between the TB's first. You should have a solid 12-13 PSI at the TB's. If you don't, then get a new pump.
Another problem that can happen in the tank is the rubber line at the fuel pump neck can get brittle and leak.


So the pump will run, and it will flow, but it won't build pressure.

If you have pressure, then check the injector pulses with a test light between the orange wires and the engine block. You should get 4 pulses for every one revolution of the engine. If you don't get any pulses or voltage at the injectors, then check your two injector fuses.

The Crossfire system fires the injectors with a signal from the tach feedback in the distributor. So if the tach signal is interupted the injectors will not keep firing, even though it spits a few pulses when the key is turned on.

Check this link
http://www.crossfire.homeip.net/twinnie/system.html
for detailed info on the operation of the Crossfire with electrical schematics included. Thanks Twinnie!
 

fatboyreyn

Well-known member
Joined
Aug 31, 2006
Messages
116
Location
east coast
Corvette
1986 red
hey guys, need some help with 1982. sat for 14 months. was told it ran great before it was parked. emptied fuel tank, changed fuel filter. checked pump, there is flow. ( jumpered wires at relay. Put new injectors and gasket kit and cleaned everything up. Now the problem. Car starts right up if I pour a little gas in throats. When I turn the key, injectors sometimes spit for a second, but not a spray. When the car is running for the few seconds after I pour gas in, the injectors are again trying to spray, but it is far from a fine mist. Is the spray from the injectors supposed to be a nice strong spray? Is it possible the pump produces flow but no pressure? I didn't do anything with the regulators on the bodies. I also tried keeping the jumper on the pump relay whi

I noticed the oil pressure guage pins to the right after a few cranks. the sending unit(near distributor) looks brand new. also I think I have a code 12. It's hard to tell between engine light check code, and a distributer feedback code 12?
 

wishuwerehere82

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Messages
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Location
Rochester, NY
Corvette
Red '82 Coupe,Sebring Silver '98 Coupe
I noticed the oil pressure guage pins to the right after a few cranks. the sending unit(near distributor) looks brand new. also I think I have a code 12. It's hard to tell between engine light check code, and a distributer feedback code 12?

If the Oil gauge pegs, it means it has lost contact with the sensor.
That will shut the engine right down as soon as the oil gauge pegs.
Clean up the contacts on the pressure sensor and connector and make sure the contacts are on the connector blades.
If the wires are touching the firewall, get them back away from it. Mine did that a few times, and it pulled the connector off the gauge, and the engine shut down.

You should get 3 12 codes followed by 3 12's flashing on the check engine light for no codes, 7 12's is a no tach signal. Or 3 12's, a 41, and a 3 12's is a tach to ECM interuption. You probably won't get any codes until the engine starts if you have had the battery disconnected. But if you pump some gas in the TB's long enough to fire it, it may give you some basic info.
 

jdp6000

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Aug 23, 2004
Messages
646
Location
Aurora, Ontario, Canada
Corvette
1982 CROSSFIRE
If you get 3 12's followed by 3 12's there are no codes stored. The Stored codes are between the 3 12's. So a code 42 would be 3 12's followed by 42 followed by 3 12's signalling the end of the test.

The oil pressure sensor is capable of shutting off the gas. Its weired how it works. I and others have unplugged them an the motor has continued to run. Only thing I can figure is is it senses "0" it will shut off the the gas. If it doesn't send a signal the motor will run. Try unplugging it and crank the motor. There is obviously a problem if its pegging right. Check the wires that come from the distributor. Are the fine? Unplugged does it still peg right?

Jim
 

wishuwerehere82

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Red '82 Coupe,Sebring Silver '98 Coupe
Jim's right about the codes. I haven't done it in so long that I forgot the sequence. I edited my previous post to correct it.
Mine will not run with the Oil sender disconnected, it kept pulling off and shut off the engine.
 

jdp6000

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Messages
646
Location
Aurora, Ontario, Canada
Corvette
1982 CROSSFIRE
Jim's right about the codes. I haven't done it in so long that I forgot the sequence. I edited my previous post to correct it.
Mine will not run with the Oil sender disconnected, it kept pulling off and shut off the engine.

You are right it shouldn't run. I'm just wondering if his will spray right with the sender unplugged then stop when the signal is finally sent.

Also try clearing the computer memory by pulling the fuse in the battery compartment.

Jim
 

jdp6000

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Aug 23, 2004
Messages
646
Location
Aurora, Ontario, Canada
Corvette
1982 CROSSFIRE
Reynold,

If its one thing I've learned its you need to be real specific in what these crossifres are doing. I see in one place you said you are getting spray from one injector and at another place no spray from either.

Lets go back to the beginning and this is important. Open the hood take the cleaner off. Turn the ignition key. Do you hear your pump cycle on for 2 seconds? Do you hear the injectors kick in? Do you see a 1 second spray (prime pulse)? Is the oil pressure guage at zero? If you have the above. Turn the key. Does the oil pressure go to plus 20 psi? Do you see spray from one or the other injector? When the oil pressure gauge pegs right does the spray stop???

Jim
 

wishuwerehere82

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Messages
2,314
Location
Rochester, NY
Corvette
Red '82 Coupe,Sebring Silver '98 Coupe
Regarding the Tach output:
The tach signal comes out of the distributor on the single light brown wire next to the red Battery wire. The spade connectors inside the ditributor cap can push up inside the cap when you connect the tach lead and not connect. To ensure this makes contact, unscrew the screws on the coil cover and remove the cover. Then push the spade leads down into the connector. Check for broken wires to the spade connectors too.
 

fatboyreyn

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Aug 31, 2006
Messages
116
Location
east coast
Corvette
1986 red
guage o when sender unplugged, wires are clean and not touching wall. I ordered a new sending unit
 

fatboyreyn

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Aug 31, 2006
Messages
116
Location
east coast
Corvette
1986 red
turn key on, injectors dribble for a second, oil pressure guage at 0. crank motor, injectors dribble, oil pressure guage pins, check engine light goes off, car won't start.
 

wishuwerehere82

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Red '82 Coupe,Sebring Silver '98 Coupe
OK, so while you are waiting for parts....
Here's what normally happens.
When you turn the key on, you should hear the fuel pump come on for about 2 seconds, then shut off after it reaches pressure. Kind of a ZZZZZZZZZZ CLICK sound.
The injectors will spray a couple of times to prime the manifold. When I say spray, I don't mean dribble.
So at this point, I would say to check your fuel pressure with a gauge between the TB's. You will need to get some tubing with the same fittings that are on the TB's and make a rig that T's off to a pressure gauge.
To check the regulator, put the gauge on the fuel line after it comes out of the front TB, this is the pump pressure. After it goes into the rear TB, fuel goes through the regulator and the excess pressure is returned back to the tank through the line on the front of the rear TB.

Either your pump is not making pressure, or your pressure regulator is running wide open.
When you rebuilt the injectors, you took the top plate of the injector tower on the rear TB and the regulator is under that plate. You may have inadvertently changed the regulator setting, or not gotten something back in place in the right order. Check the diagram on the first link I posted.

In case you are wondering, the Crossfires are a bit trying when it comes to debugging problems, due to the computer/injection interaction. But works well once you get it all right.
Here's our not-so-secret weapon for finding the answers to just about every problem.

http://www.crossfire.homeip.net/

Though the Corvette Action Center has many helpful people, the Crossfire Injection Vault is dedicated exclusively to the Crossfire L83 engine. As I see you know about it already, it's just a matter of time before we help you figure it out.
 

jdp6000

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Joined
Aug 23, 2004
Messages
646
Location
Aurora, Ontario, Canada
Corvette
1982 CROSSFIRE
turn key on, injectors dribble for a second, oil pressure guage at 0. crank motor, injectors dribble, oil pressure guage pins, check engine light goes off, car won't start.

Not sure if the oil guage pinning when disconnected is right. do you have power at the injectors?? Do you have a test light? Test for power on each of those wires.

Jim
 

jdp6000

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Joined
Aug 23, 2004
Messages
646
Location
Aurora, Ontario, Canada
Corvette
1982 CROSSFIRE
I posted this at another site. Guy had a similar problem. FWIW it turned out to be his injector fuses...they looked good on inspection but were actually fried.

Assuming you have 9-13 psi it could be the HEI module (according to the shop manual). Book says no fuel from either injector check the following:

On the passengerside of the distributor there are 4 wires which come from the HEI, blk/red, tan/black,white,ppl/wht. Its the ppl/wht you need to pay attention to. Check that wire...is it good? Check the connector all those wires go to...is it okay...unplug and clean it.

If no change go to the ECM Find the wire marked CKT430 (on black connector)...should be the purple with a white strip...its the only wire that color. Turn the ignition to "on" for 10 seconds. Put the red meter wire on that one... ground the black meter wire. Steady voltage equal to battery strength idicates a bad HEI module. Less then 1 volt means that wire is open or shorting to ground, or bad HEI connector or or bad HEI. Varying voltage between 1 and 2 volts means the connector on the ECM is bad.
 

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