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Hey gang! I searched the posts but did not find my exact scenario, so I'll post here and if I am repeating, please forgive me and let me know where to find the correct info.
So, I bought an 89 from an older gentleman who could not get it to start, actually I pretty much stole it. He did say it was at a shop during hurricane Matthew but the shop stated that the water level only reached the bottom of the doors (this was a lie of course as I am pretty sure the water reached the center console). Anyhow, everything electrical seems to work fine except for the power windows but I'll figure that out later. I have the typical VATS issue: I turn the key - nothing, I hear the starter enable relay click, no crank. Here is what I have done so far:
1. Bypassed the key using a resistor even though my key is reading correctly at the bottom of the column.
2. Bypassed the start enable relay (vatssucks.com)
3. I did notice that I cannot hear the fuel pump priming so I applied 12v to terminal G and the fuel pump runs.
4. Tried turning the key while I had 12v running the fuel pump and I still get nothing, no crank.
5. Attempted to remove the "bread box" (dumbest thing in GM design history by the way) to get to the VATS module. Finally was able to get the bread box out enough to get to the module but I do not know how to "test" the module.
6. I checked the battery and connections and all seem to be good. I even tested the fuel pump relay by the brake booster and it seems to be fine according to the testing methods found here in the forums.
I have not gotten under the car to try to jump across the starter to see if that works because even if I did, I still have no fuel. So, is there a way to test the VATS module itself, is there some other test I should be doing that I have not mentioned here? I do have plans to order an FSM but have not done so yet. I was hoping the experts here would have some tips for me.
And yes, I know I bought a car that had some water in it, but like I said, everything seems to work properly except for the starting issue. And besides, for $2500 (told ya I stole it), I bought it as a project and that seemed like a screaming deal. So if you have any tips, please let me know and I thank you in advance!
I have the typical VATS issue: I turn the key - nothing, I hear the starter enable relay click, no crank. Here is what I have done so far:
1. Bypassed the key using a resistor even though my key is reading correctly at the bottom of the column.
2. Bypassed the start enable relay (vatssucks.com)
If you hear the start enable relay clicking, then the problem is not VATS. IF...it's the start enable relay. If that is the relay that's clicking then the problem is in getting power from the battery to the starter, or the starter/solenoid itself.
I don't believe that the fuel pump has anything to do w/VATS. On my '92, pump will prime even w/o a VATS resistor pellet confirmation. I think your problem is elsewhere. When the key is ON, what is the Security light doing?
If you hear the start enable relay clicking, then the problem is not VATS. IF...it's the start enable relay. If that is the relay that's clicking then the problem is in getting power from the battery to the starter, or the starter/solenoid itself.
I don't believe that the fuel pump has anything to do w/VATS. On my '92, pump will prime even w/o a VATS resistor pellet confirmation. I think your problem is elsewhere. When the key is ON, what is the Security light doing?
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In the 1989 models according to the schematic I have for the vats system, it does cut the fuel system as well if the vats has been activated. I will have to try to get the car in the air next week so I can check the connections at the starter.
All info I have found on here so far says that the ecm might not be receiving a signal from the vats module to prime the fuel pump to pressurize the fuel rail. I will try to get to the starter this upcoming week when I have some time off and see what I can find out there, thanks guys!
If you hear the start enable relay clicking, then the problem is not VATS. IF...it's the start enable relay. If that is the relay that's clicking then the problem is in getting power from the battery to the starter, or the starter/solenoid itself.
I don't believe that the fuel pump has anything to do w/VATS. On my '92, pump will prime even w/o a VATS resistor pellet confirmation. I think your problem is elsewhere. When the key is ON, what is the Security light doing?
.
Also, when the key is turned on the security light stays on for a couple seconds and then goes out.
It cuts the pump completely. Pump won't come on unless I apply 12v to terminal G.
So it doesn't prime even? It does it for a second or two the first time. So turn it on and it primes. Turn it off and back on, it DOES NOT prime again for maybe 10 minutes? Are you sure it isn't even priming after a long time of key off?
@Aklim: Here's how the fuel pump "prime" and VATS interrupt work. If you post from a base of knowledge, you won't confuse peeps with erroneous information that costs them time and money.
When ECM powers ON, the fuel pump runs for appx 2 seconds and stops. IF distributor reference pulses are then received by the ECM, the pump is turned back ON. Ie, when the engine is cranked, the pump turns back on.
The "15 minute wait" is actually FOUR minutes, but the FSMs suggest using 5 minute intervals for VATS checking. The fuel pump prime has nothing to do with the "VATS Wait".
I'm not sure what we differ on besides the wait duration after the unsuccessful VATS verification attempt. His car won't crank so we don't have distributor signal to worry about. Turn they key on and it primes if everything but the VATS is not working or at least, that is what happens with my 91 when I put a piece of tape on the VATS pellet. I wasn't sure about the 4 minutes or 10 or 15 but I think you get the idea. With the VATS pellet taped, my furl pressure gauge spikes the first time after a long time since turning the key. IDK if I wait for 4 minutes or 10 or 15. I'm not with either by FSM or the car to check
You guys are great, I will be sure to check all of this on my days off. Right now if I turn the key, the fuel pump does not run at all, not even for 2 seconds. The only way I can get the fuel pump to run is by supplying 12v to terminal G. I need to get under the vehicle to check the starter and solenoid. Which I will do on my day off. But even if I discover that that is bad I still have the fuel pump issue to figure out as well. I've checked all of the fuses, and there is no corrosion and they are tight and good. I've checked the fuel pump relay and it seems to be working fine as well. I have some relays at home and I may try to bypass the factory relay to see if I can get it to work that way. I was thinking in the beginning that this may have been a Vats issue but the more I look into it I agree it doesn't seem to be. I just wanted to be sure to test everything to rule out any possible issues.
Not VATS. Do some basic starting circuit diagnosis.
Well, I diagnosed the starter and it was getting all of the proper signals. However I couldn't get any response out of it at all. This confirmed that my starter or solenoid was dead. I went and bought a new starter, put it on, and when I turn the key I actually got a response out of the starter. However, the old starter I removed did not have any shims the new one though I actually had to shim it as it was not engaging with the flywheel. Once this problem was solved I turn the key and she runs kinda. The first time she ran for about 3 to 4 minutes and then shut off. Later this evening I was able to get her to start and she ran for about 15 minutes and then shut off. Now I cannot get it to start. It will crank but it will not start. I found it confusing that it would run for random times before it would shut off. I will have to diagnose the fuel system and change the filter. I have not hooked up a pressure gauge to the fuel rail yet. When it did run, it actually sounded really good. I will keep working at it and keep you guys posted and let you know what I come up with next. Again, thanks for the help I really appreciate it!
10-26-2018, 08:18 PM
VATS testing woes...
