Starting at the beginning. I purchased a 67 mile TTA a little over a year ago and i'm still chasing a starting problem. The car had a knock at boost over 8psi. I was able to enlist the help of a local turbo buick expert. After testing for codes and finding none, we replaced the fuel filter and injectors. After installing the injectors, the car would not start. Fuel pressure was good,regulator was not stuck and nothing else seemed to be at fault. Out of the blue the car started and ran ok with no knock. Problem solved? Not so luckey. Jump ahead a few months to the night before the TA nationals. The car decides to not fire. As before it cranks fine but does not fire. I tried replacing the coil pack, ignition module, and ECM with known good units and no change. Each done as single steps to pinpoint the results. I also replaced the VATS module. When it cranks without firing, if I pull the ECM fuse and put it back, the car starts. It may start 5-6 times before deciding not to fire. HELP! When it does start, it's only after cranking for a few secconds. Any help would be greatly appreciated. Thanks, Steve
Need help with starting problem.
- Thread starter src76ta
- Start date
Which is it not getting now, fuel or spark?
You said you replaced the VATS module but what about the key? Could be the lock cylinder also. Here is a very good explanation of VATS and how to diagnose problems.
http://sethirdgen.org/vats.htm
You said you replaced the VATS module but what about the key? Could be the lock cylinder also. Here is a very good explanation of VATS and how to diagnose problems.
http://sethirdgen.org/vats.htm
Help with starting problem.
Thanks for the quick response. The fuel pump seems to be working. The problem seems to be with the signal being sent, or not, to the ECM. Last night when it cranked but would not fire, I pulled the 7.5a injector fuse and inserted a test light and got no power. While the probe was still in the socket it suddenly come on with nothing being done. I replaced the fuse and started the car. Two or three tries later after firing each time, I was back to no start. This time I pulled the ECM fuse and found no power there with the key in the on position. I turned the key to crank a few times and power returned. I reinstalled the fuse and the car started the next six times in a row. The only thing that i'm not used to is the cranking for 2 or 3 seconds before it fires. Is this normal? I'll try the resistance test on the key reader tonight. The turbo buick guy that gave me the known good parts to try suggested the reader also,but with the car having low miles its hard to believe that somthing like that could be worn to the point of failure. Thanks again.
Thanks for the quick response. The fuel pump seems to be working. The problem seems to be with the signal being sent, or not, to the ECM. Last night when it cranked but would not fire, I pulled the 7.5a injector fuse and inserted a test light and got no power. While the probe was still in the socket it suddenly come on with nothing being done. I replaced the fuse and started the car. Two or three tries later after firing each time, I was back to no start. This time I pulled the ECM fuse and found no power there with the key in the on position. I turned the key to crank a few times and power returned. I reinstalled the fuse and the car started the next six times in a row. The only thing that i'm not used to is the cranking for 2 or 3 seconds before it fires. Is this normal? I'll try the resistance test on the key reader tonight. The turbo buick guy that gave me the known good parts to try suggested the reader also,but with the car having low miles its hard to believe that somthing like that could be worn to the point of failure. Thanks again.
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- May 9, 2002
87buick3825
Senior Member
- Joined
- Jan 8, 2004
- Joined
- May 9, 2002
SOMETHING sure is intermittant....The worst kind of malfunction to find....Its a little like hunting ghosts
I think you'll find that the LC2 BUICK and TTA engine electrical systems are almost identical....FP is different in that protochol, that's the only difference I know besides the chip. Feel free to correct me if I'm wrong
Russ Selerno told me he replaced the key switch in my TTA early on in the mid 1990's.
Good Luck!
lee
Starting problem
Thanks for all the info. I need to check both items mentioned. This is my first thirg gen so its all trial and error. Shawn O'Conner has been helping me with loaner parts and has saved me a ton of $$$. What a guy! I'll post what ever I find and thanks again for the help.
Thanks for all the info. I need to check both items mentioned. This is my first thirg gen so its all trial and error. Shawn O'Conner has been helping me with loaner parts and has saved me a ton of $$$. What a guy! I'll post what ever I find and thanks again for the help.
Starting problem
Well, I finally found time to check the orange connecter by the battery. Is the two wire fusible link the one you were talking about? It was connected properly. The three keys I have for the car all read 52 ohms. The ignition switch read 52 ohms in the off position and for all 10 to 15 times I switched it on and off. I inserted a volt meter probe in beside the ECM fuse in an attempt to determine the voltage when the car woulden't start.TTA 557 started no less than 8 times in a row with no more than a .3 volt fluctuation from the first start to the last. Talking about mixed emotions.
Well, I finally found time to check the orange connecter by the battery. Is the two wire fusible link the one you were talking about? It was connected properly. The three keys I have for the car all read 52 ohms. The ignition switch read 52 ohms in the off position and for all 10 to 15 times I switched it on and off. I inserted a volt meter probe in beside the ECM fuse in an attempt to determine the voltage when the car woulden't start.TTA 557 started no less than 8 times in a row with no more than a .3 volt fluctuation from the first start to the last. Talking about mixed emotions.
The car has always cranked. The problem first appeared after changing the injectors the first time. The problem has been on and off since then and continued even after replacing a temperary set if injectors with the stock rebuilt set. This seems to eliminate the posability of a bad injector,as suggested in the protochol, that would cause repeated ECM failure. No codes are preasent and the security light does not stay on.
I plan to pick up an injector test light today to rule those out. The car has been driven so little that most of the starting problems have been when engine is cold or has only been idled up to temp.I considered the possibility of a sticking oil pressure safety switch. Have these ever been a problem?
Ok, you said the car always takes 2 or 3 seconds to start. When you turn the key to on do you hear the pump prime. If your fuel pump relay is bad, the oil pressure relay is a back up. But wont let it start till it sees 4 psi of oil pressure resulting in longer starting time. Now if one of the things like the oil pressure relay or oil pressure sensor is on its way out then it would result in a no start. But this doesnt explain why there is no power at the ECM fuse.
Injectors sould ohm around 12 to 13 if I remember correctly.
Injectors sould ohm around 12 to 13 if I remember correctly.
Update. All injectors test the same at 15.5 ohms.
I put every thing back together and started the car to see what would happen. It started no problem so I let it run for 5 minuets. I shut it off and just for the hell of it tried to restart it. Cranks but won't start. I pulled out the volt meter and while the key was in the on position I read 12.5 volts or better at the ECM fuse, and both of the injector fuses. I then read voltage at the ECM fuse while cranking and got about 9.5 but the car did'nt fire. I watched the security light to see if it stayed on while cranking and it didn't. However, I noticed that the oil pressure gauge pegged past 80 psi when the key was in the on position. I tried the key on and off a few times and most of the time the gauge stayed at the left red section before cranking.
Occasionally it would peg to the right. With this in mind I tried starting the car with the gauge in both positions. When it was in the low red position the car started. When it was pegged the car only cranked. I'm out of space.
I put every thing back together and started the car to see what would happen. It started no problem so I let it run for 5 minuets. I shut it off and just for the hell of it tried to restart it. Cranks but won't start. I pulled out the volt meter and while the key was in the on position I read 12.5 volts or better at the ECM fuse, and both of the injector fuses. I then read voltage at the ECM fuse while cranking and got about 9.5 but the car did'nt fire. I watched the security light to see if it stayed on while cranking and it didn't. However, I noticed that the oil pressure gauge pegged past 80 psi when the key was in the on position. I tried the key on and off a few times and most of the time the gauge stayed at the left red section before cranking.
Occasionally it would peg to the right. With this in mind I tried starting the car with the gauge in both positions. When it was in the low red position the car started. When it was pegged the car only cranked. I'm out of space.
Is there an oil pressure safety switch or somthing that works with the pressure sending unit that would keep the car from starting ? Yes the pump runs when the key is turned on. For a few secconds. After cranking, if the car doesn't fire you can hear the pump run for 5-7 secconds. Early on I tried restricting the return line to see if the regulator was stuck but it had no affect.
Ok, sounds like the oil pressure switch is the problem. Its located below the oil filter, pretty easy to get to from the bottom. When is sees the 4 psi it closes(a circuit) and alows the car to start. Sounds like yours is fubar, its souldnt peg over like that.
Thanks for sticking with me on this. I was running through the test procedures for the fuel pump relay circuit making good progress but I don't know where the fuel pump test terminal is. I also need to find the ALDL connector to complete the test. At this point everything is pointing to the oil pressure switch. Is this switch only common to TTA's?
