1990 camaro 305 tbi injectors wont open
#1
1990 camaro 305 tbi injectors wont open
pls help!i have spent 1.5 million dollars on this car tryin to get it to run replaced everything from the chip key to the pickupcoil to the computer still no luck any help would be gratefully appreciated
#2
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Car: 1992 RS
Engine: Carbed 350
Transmission: 700R4
Axle/Gears: 3.42 posi
Re: 1990 camaro 305 tbi injectors wont open
So what exactly is the problem - we need details.
Will the car run if you put a small amount of gas in the TBI unit?
Do the injectors spray while it's running off that?
Does the fuel pump prime when you turn on the key?
When was the last time fuel filter was replaced?
Does the SECURITY light come on and/or flash when you are trying to start the car?
Your key has a pellet in it - you mentioned replacing a key chip - what exactly are you talking about? (details here)
- Did you get a new key?
- Was the new key same pellet as the old key?
- Did you try the VATS bypass method?
You mention a new computer - What year ECM did you replace with?
We need year of car, engine size, any mods you've done, what tranny, etc.
Will the car run if you put a small amount of gas in the TBI unit?
Do the injectors spray while it's running off that?
Does the fuel pump prime when you turn on the key?
When was the last time fuel filter was replaced?
Does the SECURITY light come on and/or flash when you are trying to start the car?
Your key has a pellet in it - you mentioned replacing a key chip - what exactly are you talking about? (details here)
- Did you get a new key?
- Was the new key same pellet as the old key?
- Did you try the VATS bypass method?
You mention a new computer - What year ECM did you replace with?
We need year of car, engine size, any mods you've done, what tranny, etc.
#3
Re: 1990 camaro 305 tbi injectors wont open
yeah had a new security key made its a 1990 camaro 305 v8 with a 700 r4 no mods all stock new fuel pump new computer new pickup coil i have replaced so many things its insane new module im at my wits end pump primes plenty of pressure injectors will open if wired hot just wont open on their own
Last edited by slider07; 02-22-2011 at 09:07 AM. Reason: forgot info
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Car: 91 T-Top RS
Engine: 305 TBI
Transmission: 700R4
Axle/Gears: To be determined at the JY.
Re: 1990 camaro 305 tbi injectors wont open
You should definitely consider answering all the questions there. Did you match the part numbers on the ECM, first of all? Second, Did you check the ground wires on the injectors? One wire is always hot (meaning if you get your multimeter set one 20v DC scale (40 if you have a nice one, but I doubt it, those are for people who do this for a living and can afford crap like that) with the red lead in the terminal on the pigtail, and the black one on the negative battery post, it should read 12.0-12.6 or so. If it's under 12.0, check your battery, if the battery read well and the injector wire doesn't, look for a bad wire. If the battery reads under 12.0, charge the battery or get a new one. If the problem isn't the battery, look for a faulty wire going to the ECM, or a bad ground past it. Most likely, you're going to find that you have a bad wire to the ECM by this point, but it's also possible your ECM isn't grounded properly.
Oh, and one more thing, with the DVOM set to the 200 or 400 ohms resistance scale (the thing that looks like the greek letter omega) check resistance across the two prongs on the injectors. They should both read between 1.16-1.36 ohms on an L03 TBI unit. If they're out of range, replace them.
One other thing, do you have a noid light?
Oh, and one more thing, with the DVOM set to the 200 or 400 ohms resistance scale (the thing that looks like the greek letter omega) check resistance across the two prongs on the injectors. They should both read between 1.16-1.36 ohms on an L03 TBI unit. If they're out of range, replace them.
One other thing, do you have a noid light?
#5
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Car: 1992 RS
Engine: Carbed 350
Transmission: 700R4
Axle/Gears: 3.42 posi
Re: 1990 camaro 305 tbi injectors wont open
Getting a new key won't help if the VATS module itself is the issue. VATS module sends a pulsed wave signal to the ECM telling it to run the injectors - ECM doesn't get that signal, it won't fire the injectors.
AND - if you replaced the ECM with one from a different year car, it's possible that YOUR VATS module is sending a different pulse wave frequency than what the ECM is expecting to receive (there are two frequencies I believe, 30Hz and 50Hz).
I'd go back to the original ECM, and try the new key. If that doesn't work, then I'd leave the original ECM (unless there was some other issue with it), and buy a VATS Module bypass box, available on ebay, from Painless, etc. These bypass boxes take the VATS module out of the equation, by sending either of the two frequencies that the ECM is looking for.
AND - if you replaced the ECM with one from a different year car, it's possible that YOUR VATS module is sending a different pulse wave frequency than what the ECM is expecting to receive (there are two frequencies I believe, 30Hz and 50Hz).
I'd go back to the original ECM, and try the new key. If that doesn't work, then I'd leave the original ECM (unless there was some other issue with it), and buy a VATS Module bypass box, available on ebay, from Painless, etc. These bypass boxes take the VATS module out of the equation, by sending either of the two frequencies that the ECM is looking for.
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Car: 91 T-Top RS
Engine: 305 TBI
Transmission: 700R4
Axle/Gears: To be determined at the JY.
Re: 1990 camaro 305 tbi injectors wont open
I think we're assuming too much here... Does the car crank or not? You're not being very clear on this issue. Please elaborate if you still need help, because as much as we try, we can only take shots in the dark. If it's cranking, your VATS is fine, if not, it may or may not be the problem. Please respond with details, or I will personally consider this thread dead, as I expect the others likely will as well.
Thanks,
Catalina
Thanks,
Catalina
#7
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Car: 1992 RS
Engine: Carbed 350
Transmission: 700R4
Axle/Gears: 3.42 posi
Re: 1990 camaro 305 tbi injectors wont open
NOT TRUE. If it cranks, that just means the VATS is grounding the starter enable relay (or, someone has wired in a ground for the starter enable relay). The VATS could still be messed up by not sending the pulse wave to the ECM, or by sending the wrong pulse wave to this swapped in ECM.
There are plenty of occurrences where folks got the starter to turn, but VATS still kept injectors from firing.
There are plenty of occurrences where folks got the starter to turn, but VATS still kept injectors from firing.
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Car: 91 T-Top RS
Engine: 305 TBI
Transmission: 700R4
Axle/Gears: To be determined at the JY.
Re: 1990 camaro 305 tbi injectors wont open
You're right, I didn't notice that none of the wiring diagrams I have here have the whole VATS module in one diagram. It's pretty stupid that it's like that, but looking more closely at the diagrams I've got, that's true. That could be a pain to diagnose for a parts replacer, though...
EDIT:
In light of this knowledge, I'm going to go ahead and kill my VATS while I don't depend on this car. My ignition lock cylinder is going up anyway and those keys are expensive...
/EDIT
EDIT:
In light of this knowledge, I'm going to go ahead and kill my VATS while I don't depend on this car. My ignition lock cylinder is going up anyway and those keys are expensive...
/EDIT
#9
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Re: 1990 camaro 305 tbi injectors wont open
If you think that the ECM isn't getting the VATs signal, pull the PROM out and try starting it. If it starts and runs you found the problem. NOTE: be sure to leave the small CALPAK in the ECM.
RBob.
RBob.
#10
Re: 1990 camaro 305 tbi injectors wont open
ok im trying my best to do it all the car will run if you put gas in tbi the computer is brand new from advance everything seems to be working except the injectors the guy who made the key scanned for vats code retrieved it showing to be number 5 of possible 15 light is working correctly im thinkin its the prom chip need to know if other vehicle proms will work?
#11
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Car: 1992 RS
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Axle/Gears: 3.42 posi
Re: 1990 camaro 305 tbi injectors wont open
Go ahead and replace the prom again, you're obviously dying to anyway. Then when that doesn't work, we go back to square one, which is where we are now but you won't answer the questions so we can help you.
Your initial post sums it all up quite well ... you've spent 1.5million dollars throwing parts at this car without troubleshooting the REAL problem. So why do you insist on continuing down that same path? It's getting you nowhere. A car is NOT a woman - throwing cash at it won't make it run!
There's a gazillion different reasons the injectors won't fire. With 99% of problems people want to replace ECM's just like you, and 99% of the time there's nothing wrong with the ECM - they jump to the same bad conclusion you have. There's nothing magical about a ECM - it just takes the data it's given, compares it to stored data charts, and then changes fuel tables and timing advance/retard signals to accomodate. It's not some Master Brain that magically sends out little workers to fix mechanical or electrical issues.
You should have figured this out by now, since you've already changed ECM once and car still doesn't work. I've been on this board 5+ years now, I've read at least 1000 people that changed there ECM - maybe 3 of them actually needed to. The ECM's are about the last thing that ever "goes bad".
Do you want to fix the car, or do you want to keep throwing ash at it. You don't need us for the latter. For the former, let's go back to basics and work through the REAL problem of why the injectors won't fire. I'll ask again...
1) Does the fuel pump prime?
2) Has fuel filter been changed in last 30 days?
3) Does the security light come on or flash when trying to start car?
Your initial post sums it all up quite well ... you've spent 1.5million dollars throwing parts at this car without troubleshooting the REAL problem. So why do you insist on continuing down that same path? It's getting you nowhere. A car is NOT a woman - throwing cash at it won't make it run!
There's a gazillion different reasons the injectors won't fire. With 99% of problems people want to replace ECM's just like you, and 99% of the time there's nothing wrong with the ECM - they jump to the same bad conclusion you have. There's nothing magical about a ECM - it just takes the data it's given, compares it to stored data charts, and then changes fuel tables and timing advance/retard signals to accomodate. It's not some Master Brain that magically sends out little workers to fix mechanical or electrical issues.
You should have figured this out by now, since you've already changed ECM once and car still doesn't work. I've been on this board 5+ years now, I've read at least 1000 people that changed there ECM - maybe 3 of them actually needed to. The ECM's are about the last thing that ever "goes bad".
Do you want to fix the car, or do you want to keep throwing ash at it. You don't need us for the latter. For the former, let's go back to basics and work through the REAL problem of why the injectors won't fire. I'll ask again...
1) Does the fuel pump prime?
2) Has fuel filter been changed in last 30 days?
3) Does the security light come on or flash when trying to start car?
#16
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Car: 1992 RS
Engine: Carbed 350
Transmission: 700R4
Axle/Gears: 3.42 posi
Re: 1990 camaro 305 tbi injectors wont open
Then I'd say you should try one of the VATS bypass modules from ebay or Painless or something - they run about $20 - $50. It gets wired into the ECM to give it the right signal to tell the ECM to turn on the injectors. There's 2 signals that I'm aware of, a 30Hz signal and a 50Hz signal - just make sure you order one that does either. I'm guessing that either 1) your VATS module is not sending the right (or any) signal to the ECM, or 2) the replacement ECM you got isn't getting the signal correctly (not correct ECM or something).
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