Anthony0128

92 camaro 305. Just can't seem to get it run, I sent it to a mechanic and he says the timing was off he fixed it but the car still does not start. It'll turn on but dies almost immediately. I've searched countlessly through the forums trying to find a answer and I just can't seem to find any reason why it does what it does. I've replaced everything from the pump to the dizzy and nothing. I think it's about time I give up. Any one who can point me to what I should look at or anything else I can do please put some input.

JdubRS

If it won't run, how did the mechanic check/change the timing? Have you checked into VATS problems? Seems to be a common issue.

Anthony0128

He did it correctly by unplugging the est and what not that whole process. And that's what I'm getting to next. Down here in Texas I got a guy who is going to check it for me today, he told me the key car not pick up the key well anymore or it lost memory of the car or something like that. So he's checking it today to see if it did or not. Cause like I said car starts has fuel has spark, but then stells. It can run on starting fluid all day long but alone it won't. New pump new tank new everything from fuel to the ignition components. Hopefully it is the vats

Bob88GTA

iTrader: (2)

It's NOT VATS. The car will not even turn over if VATS was the issue.

Operation: Operation is fairly simple, but lets discuss what all makes up the PassKey system. The most obvious part is the key. The ignition key as a little "chip" in it. This is a resistor "pellet". There are 15 possible resistances, therefore 15 different types of keys each with a different resistance. This reduces the likelihood of a potential thief from having the correct resistance resistor on hand. Then you have to have a special lock cylinder to "read" the key. I use the term "read" loosely, because it does anything but read the key. I will explain more later. Next is the VATS module. It does most of the security work. It is the "brains" of the system. The module is what actually "reads" the resistance, but has to do it via the contacts in the lock cylinder and the related wiring. Think of the module as a Multimeter, and the wires and contacts the Multimeter Leads. The module reads the resistance and determines if the resistance is the correct value. The module will go into several modes, depending on what the module sees. There is "Tamper" "Normal" and "Fail Enable".

Normal: Normal is when the correct resistance is seen during cranking and the module will ground the Start enable relay, and send a "Fuel Enable" signal to the ECM. This basically "turns on" the injectors. If the Fuel Enable signal is lost or not sent, the injectors will never pulse. The signal is a unique "Pulse Width Modulated" signal, which is a series of rapidly switched "on" and "off" voltages. Once the relay is grounded, voltage is allowed to the "S" terminal of the starter, and the ECM is told to pulse the injectors and the car starts.

Tamper: This mode happens when the vehicle is cranked, and the resistance value as seen by the module is not the same as the value stored in the module. When this happens, the module shuts down for 4 minutes. Even if the correct resistance is then seen, the car will not start for the 4 minute "time-out". Each attempt to start the car within the 4 minute "lock out" period, will reset the timer. The security light will also illuminate for the 4 minutes. The Start Enable Relay will not energize and the Fuel Enable signal will not be sent. HINT: if the key pellet is dirty, it will put the module in the "Tamper" mode. If your car fails to crank/start and the security light comes on, try cleaning the pellet, wait 4 minutes, and try again.

Fail Enable: This mode is to help keep the motorist with the right key from being stranded. If a failure happens to the PassKey system AFTER a valid start, this mode is initiated. It allows the vehicle to be restarted, even with a failure present. The security light will remain illuminated to let you know a failure is present. However, this also means that the car can be started w/o a key, and is vulnerable to potential thieves. If battery power is lost while in fail enable mode, this mode will be lost and the next attempted start w/ the system malfunctioning will cause Tamper Mode.

Anthony0128

Well that explains why it wouldn't be vats. But if not vats then what would it be ? The ecm? I'm all out of ideas. Everything is there to get it running but the damn thing won't stay running. Any other ideas ?

Bob88GTA

iTrader: (2)

TPI or TBI?

Anthony0128

TBI

Bob88GTA

iTrader: (2)

Ok, Check a couple of things. Fuel pressure and oil pressure switch work together. Without OP when cranking, it won't fire the injectors. Do you have pressure when cranking?

Next....Check Injector Fuse in Fuse panel.

Then check this diagram out.
http://austinthirdgen.org/mkportal/m...ine_wiring.gif

Bob88GTA

iTrader: (2)

And this...
http://austinthirdgen.org/mkportal/m..._continued.gif

Anthony0128

I'll take a look at it today I was also beginning to think it might be that. Cause the car cranks for 5-10 seconds before actaully turning on. Fuel pressure stays good idk about oil. The pump stays on even after stalling. So then am I looking at the op switch?

Bob88GTA

iTrader: (2)

Yes, while cranking, watch OP Gauge in car. It needs to see something like 5psi to tell the FP to keep pumping. You will always get the prime, like when it try's to start.

Anthony0128

I'll give it a shot I guess I won't mess with the vats. Thank God it isn't that, so let's say it is the ops do I just take it out and put a new one. I'll check the wiring as well it's right above the oil filter on my car

Bob88GTA

iTrader: (2)

Yes, R&R it.

redneckjoe

you can pull your oil pressure switch out and test it if you have compressed air and a multimeter. but the oil pressure switch is a back up, fail safe in case your fuel pump relay goes bad.
this video might explain it better?

Anthony0128

Fuel relay is new too

Anthony0128

Alright well I bought the OPS hopefully this is the cause it all. My mechanic told me he doubts it but it doesn't hurt to try. He knows a lot but I mean I feel as if you all know more about this certain vehicle. Well thanks for the input I'll get back with an update soon

henryd3

iTrader: (128)

Maybe this could help. This guys post was right under your and his seems similar to yours. Maybe it really is a VATS thing??
https://www.thirdgen.org/forums/tbi/...nt-get-my.html

Anthony0128

I'll find out tomorrow, but I'm stuck in between it being vats or a sensor. Some say it can't be vats but then again it can be. Honestly I hope I find the problem

Anthony0128

Rick's camaros sells a bypass module is it any good ? I'm going to give it a shot and see what happens. This whole vats thing has got me confused but hopefully this bypass will end all the insanity

Bob88GTA

iTrader: (2)

...

redneckjoe

my son had a TBI running real crapy. we took the throttle body apart and found some junk inside it. cleaned it out, reassembled and it had a nice conical spray pattern after. maybe you got some junk build up in there?

Anthony0128

Throttle body has a rebuilt kit too. Everything is clean. Maybe clogged injectors? But they're brand new. And Bob I still haven't purchased anything im waiting to here back from my mechanic, and im trying my best to figure out what it is but with no codes and everything being checked I'm stumped

Anthony0128

What I do not understand is last August I got it running, it was doing well but I couldn't accelerate past 3000 rpm. I was stuck with that and I left the car alone just changing out parts here and there. After a while the car did not want to start anymore and I had no clue to why it was doing that. It would start then stall. So I decided to switch out the injectors, whole distributor, wires, coil, plugs, fuel relay, cts, iac, tps, new tbi pod. After all that nothing changed. Timing was off got that fixed but yet nothing. Changed out the fuel pump and still nothing. As of right now all it starts then stalls. My question is why did it run then just stop. I went as far as cleaning the tank put fresh gas and still nothing

redneckjoe

it will idle as long as you dont give it any gas, correct?

Anthony0128

Well yes for about 5 seconds then it cuts off

redneckjoe

sounds like you should do a fuel pressure check. you need between 9-13PSI. could be a pinched or clogged line from the tank to any where.
you injector resistence should be 1.0-2.0 ohms.
you can energize you fuel pump by running 12 volts to terminal G in the ALDL connector. its the bottom left pin.
there was also 2 different style IAC valves, type 1 & 2. some were 10 & others 12mm. IDK which you need.
your fuel pressure regulator is new?
just tossing some stuff out there to check.
i'd also check for vacuum leaks really good. maybe pull the hose off your brake booster and shove a bolt in there temporarily to eliminate the booster being a possible leak.

Bob88GTA

iTrader: (2)

I understand Anthony. I'm scratching my head right now.

Ty92Z

iTrader: (11)

I'm in no way saying it's VATS, but you should read the above referenced thread. The guy had a very similar issue where VATS would allow his car to crank, but would cut his fuel after a few seconds.

Anthony0128

@RedneckJoe mechanic did a test and he said it was right where it should be, so that's a good thing but I wasn't there to make sure it was so tomorrow I'm going to go check it out myself, the pump is working good but I'll do that anyway, I'll check out the resistance as well all of this is great help I really appreciate it. Yes the regulator is new so I don't think anything would be wrong with it. And I'll test that brake booster leak too just to take it out of the equation.
@Ty92z I read over that thread a few times which is why I thought it could be a possibility. Im thinking about buying a bypass module but I'm 50/50 about it. I'll check over everything redneckjoe asked to. If nothing turns out bad I'll go ahead and buy the bypass. It's an easy installation anyway.

Thanks all who have been helping me with this problem. I just my car running again is all.

Bob88GTA

iTrader: (2)

What Anthony needs is a flow TS Book/guide/manual for one thing, throwing parts at it for the last 6 months.

I read the thread you referenced TY92Z. I guess it could happen. I stand corrected. I'll remove my "dead horse" statement so I don't get "I told ya so after he gets it running."

I'm gonna sit on the sideline and watch for now.

Anthony0128

It's all good Bob I'm not here to tell anyone anything, help is all I ask and that's what I'm getting. Once I figure out the problem I'll inform you all about it

Ty92Z

iTrader: (11)

Lol, I certainly wouldn't do that to you sir. I agree, he should troubleshoot the system to hopefully eliminate or validate it as the culprit. That same thread I believed has a link to a troubleshooting guide.

bluers91

Did you replace the fuel filter?

If it were the pump or VATS it should throw a code.

VATS will typically flash the security light on the dash and not allow it to even crank over.

When my car did this it turned out being the fuel pump.

When I first got my car it wouldn't go over 3000 rpms while driving because the fuel filter was so clogged you couldn't even blow through it.

Bob88GTA

iTrader: (2)

OK, I couldn't sit on the side line. I was never a sitter! I read the above thread that TY92Z posted. Pretty interesting at post #21. The guy is told to remove the prom. The computer will not be looking for the VATS any more and if VATS was the problem before PROM removal, the car SHOULD start; LIMP HOME MODE, but it will start.

That itself could help determining if the VATS is the problem at least. Worth a shot maybe. Here is the thread again

https://www.thirdgen.org/forums/tbi/...o-350-tbi.html

Anthony0128

Yes the fuel filter is new i even took it blew some air through it to make sure nothing was clogged. And I'll try that out too the whole prim removal. This problem has got us all confused sorry for the headaches

Anthony0128

My mechanic is telling me that can't be the problem but I still want to try it out anyway. It is my car lol. He still has to put the oil pressure switch on but if that don't work I'm for sure buying the bypass module.

Faolan

Any update?

Anthony0128

Mechanic still doing some work tomorrow I'm having a guy check for the vats I'll let you know how it goes

Lucid

iTrader: (4)

That's your clue right there. Sounds like something is cutting off the injectors. I wish I knew more about TBI to help. I am a TPI guy. Did your mechanic use a noid light on the injectors? If you are priming, and the engine runs with starter fluid, you should have fuel spraying. Do TBI cars have Fuel Pressure Regulators?


If it were my car I would try to do the bypass and see if I could get the thing running.
https://www.thirdgen.org/forums/tech...-i-bypass.html

Anthony0128

Thanks for the reply! I've been thinking about it and yes the regulator is new also the injectors, today I'm having someone go check out anything and everything with the vats to see if it's causing the problem. I'll update you later on to see if it is that

Anthony0128

Update: Vats was not the problem. I am now very clue less as to what it could be. I was told to switch out the injectors again and if it's not the injectors then the wiring is to them is bad or the ecm is bad. So I'm narrowed down to two things. I'll be switching out the injectors first to see if that's the problem.

henryd3

iTrader: (128)

Since you have said that it initially starts but then cuts off I would think that indicates the injectors are working. Have you looked down in the TBI while that happens to see what kind of spray pattern is happening? It does kind of seem like wiring or ECM that triggers the injectors if faulty, buy I really don't know either. Hope you find the solution soon

Anthony0128

The spray patter is a nice cone but then it cuts off, the wires hooked up to the injectors are a little burnt from a few backfires, but they still send a signal to the injectors, my problem has something to do with fuel. I was told to switch the injectors out anyway just to make sure they're not faulty, then I'm going to get another ecm just to see if that's the problem I've heard you'll usually get a code but I'm not getting anything just 12 repeating it self. I personally don't believe it's the ecm but I dont know until I try.

redneckjoe

maybe a dumb question, but does leaving the gas cap loose make it run better? IDK if that uses a vented cap?

even though you have rebuilt the TBI, there might be some junk in there? take the torx screws loose and look inside.

Anthony0128

No it doesn't help, I'll update you to see what happens next thanks for the help!

henryd3

iTrader: (128)

I always thought injectors either work or they don't. Can't imagine them working then not and then working again

Lucid

iTrader: (4)

How did you rule out VATS? Also, did you Ohm the injectors with a multimeter?

Anthony0128

Had a guy check it out last night and he bypassed it but it did nothing. He then told me it isn't a security problem and thats what I'll do, how many ohms should I be reading?

Tuned Performance

iTrader: (92)

Vats is only active during initial startup,
Tbi injectors should be about 2.5 ohms. The injector driver could be shutting down if the injectors are shorted.
Did you ever check you Map (your other thread) ?

Anthony0128

Yeah the map is fine, a comouter was hooked up to check out everything and the sensors are fine, and alright I'll check out the injectors but I was told just to replace them to see if they're faulty, but you all wouldn't assume it's a ecm problem?