One dead Vette (Long)
11-01-2005, 06:12 PM
#1
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One dead Vette (Long)
My dad bought a 91 about 2 months ago. Been driving it around quite a bit up in Oklahoma City. To work everyday, around town... about 40 miles a day or so.
On Friday he took the day off and came on down to Dallas for a Vette weekend with me. We were going to put them on the Dyno at RPM and then hit a cruise on Sunday. However, his Vette had other ideas.
Friday he drove the Vette the 200 or so miles down and got a motel room. We dropped by to go to dinner and when they went to get into the car it was running like crap. More like the timeing was way off. We shut it down and then headed out to dinner and such in another car.
Sat morning rolls around and we pull the dist off the car. The new roter is ate up like it was arching and the cap had some burn spots on it. What really threw him was the fact that the roter when the HB was setting at 0 was not point at #1. It was more over from there like the timeing chain was going out on it.
(I will give you some history on this car while we are waiting on the tow truck.... My parents bought this car from a couple in OKC that got it from their daughter. She bought the car and lived in AZ but was apparently unable to keep up the payments. They drove it some and for the last few months it has been parked. They told my dad that the car only had 91,000 miles on it but the Odo was messed up. It was showing 5700 miles on it. I noticed that there was an OLD oil change sticker on the windsheild and it was for a dealer. I figured what the heck and called the number on the sticker. After about three transfers and the last 8 digits of the VIN someone was able to pull up a history. The last time they saw the car was in 2002 and they had listed a whopping 163,xxx miles. The other oil change they had listed was 9 months before. We figured that they had not taken good care of it and this may be the orignal timeing set.)
We had the car towed to my place and went and bought a new timeing set, cap, and roter. We then started to pull the front of the motor off. When we got into the gears we first found that they were steel gears and not the nylon like GM was using on other cars in that time. (Do they use the nylon gears on vettes?) We also noticed that the gears were lined up exactly where they should be. Did not explane why the dist was not in the right place. We went ahead and swapped the gears and buttoned the car back up. We set the crank at #1 TDC and then re-stabbed the dist to get it in the right place. (Is this too old school for the computer cars like this?)
We go to start the car and it will not start. We have spark... It seems like no gas is flowing. We had to disconnect the fuel lines to get to the brackets and such to get to the timeing set. Is there a pressure loss lock out on the FP? We were going to check the FP Relay but when we crank we get over the 4PSI of oil pressure so it should allow the flow of gas from the pump.
Here is what I do know
The Fuse in the panel for the FP is good...
The car cranks like there is no tomorrow...
It has spark...
We hooked up the comptuer and it is throwing no codes...
We sprayed a bit of B12 into the TB while cranking and got nothing.
Is there a fuseable link on a 91? We are looking at my service manual for the 89 but there are a few changes. Just wanted to make sure that we are not missing something easy. Anyone have any ideas for us?
Tim Sapp
On Friday he took the day off and came on down to Dallas for a Vette weekend with me. We were going to put them on the Dyno at RPM and then hit a cruise on Sunday. However, his Vette had other ideas.
Friday he drove the Vette the 200 or so miles down and got a motel room. We dropped by to go to dinner and when they went to get into the car it was running like crap. More like the timeing was way off. We shut it down and then headed out to dinner and such in another car.
Sat morning rolls around and we pull the dist off the car. The new roter is ate up like it was arching and the cap had some burn spots on it. What really threw him was the fact that the roter when the HB was setting at 0 was not point at #1. It was more over from there like the timeing chain was going out on it.
(I will give you some history on this car while we are waiting on the tow truck.... My parents bought this car from a couple in OKC that got it from their daughter. She bought the car and lived in AZ but was apparently unable to keep up the payments. They drove it some and for the last few months it has been parked. They told my dad that the car only had 91,000 miles on it but the Odo was messed up. It was showing 5700 miles on it. I noticed that there was an OLD oil change sticker on the windsheild and it was for a dealer. I figured what the heck and called the number on the sticker. After about three transfers and the last 8 digits of the VIN someone was able to pull up a history. The last time they saw the car was in 2002 and they had listed a whopping 163,xxx miles. The other oil change they had listed was 9 months before. We figured that they had not taken good care of it and this may be the orignal timeing set.)
We had the car towed to my place and went and bought a new timeing set, cap, and roter. We then started to pull the front of the motor off. When we got into the gears we first found that they were steel gears and not the nylon like GM was using on other cars in that time. (Do they use the nylon gears on vettes?) We also noticed that the gears were lined up exactly where they should be. Did not explane why the dist was not in the right place. We went ahead and swapped the gears and buttoned the car back up. We set the crank at #1 TDC and then re-stabbed the dist to get it in the right place. (Is this too old school for the computer cars like this?)
We go to start the car and it will not start. We have spark... It seems like no gas is flowing. We had to disconnect the fuel lines to get to the brackets and such to get to the timeing set. Is there a pressure loss lock out on the FP? We were going to check the FP Relay but when we crank we get over the 4PSI of oil pressure so it should allow the flow of gas from the pump.
Here is what I do know
The Fuse in the panel for the FP is good...
The car cranks like there is no tomorrow...
It has spark...
We hooked up the comptuer and it is throwing no codes...
We sprayed a bit of B12 into the TB while cranking and got nothing.
Is there a fuseable link on a 91? We are looking at my service manual for the 89 but there are a few changes. Just wanted to make sure that we are not missing something easy. Anyone have any ideas for us?
Tim Sapp
11-01-2005, 06:58 PM
#2
Safety Car
Did you try to just replace the cap and rotor before pulling the distributor?
Are you sure you are at TDC on the #1 compresion stroke?
(If not the rotor wil be pointing to #6 -vs- #1)
how are you static timing the car?
Almost forgot low oil PSI has nothing to do with the fuel pump running, the ECM will run it for a short time when the ke is turned on then once the motor fires it will enable the FP with a constant signal and never does it look at oil presure
Are you sure you are at TDC on the #1 compresion stroke?
(If not the rotor wil be pointing to #6 -vs- #1)
how are you static timing the car?
Almost forgot low oil PSI has nothing to do with the fuel pump running, the ECM will run it for a short time when the ke is turned on then once the motor fires it will enable the FP with a constant signal and never does it look at oil presure
11-01-2005, 07:16 PM
#3
Melting Slicks
Couple things:
#1 You need to know the Harmonic Damper "0" is lined up with TDC by pulling the #1 plug (driver's side, closest to the front of the car) and with your finger on the hole verifying that there is a pressure build up (have someone else crank it). Then, line up the "0" on the HB and THEN install the distributor, making sure it's pointed right at the #1 cylinder. Then, manually check all the plug wires for proper cylinder orientation.
#2 Disconnect the EST wire (usually located inbetween the Driver's valve cover and the firewall - a black wire with a red or orange stripe). THEN start the car - it should run unless there's another problem. Using your timing light on #1 sparkplug wire and adjust the distributor until you get 6 degrees of advance on the harmonic damper markings. Tighten down the distributor, plug back in the EST wire and you should be good to go - unless there are other problems... lol
#3 If it IS getting fuel, you will smell it. You may want to go through all the fuses to make sure.
#4 CHANGE THE OIL. Sounds like you got swindled and this car has been abused. perform as much "routine" maintenance as you can, included plugs and wires. there may be a combination of things going on. The computer can compensate for a dead cylinder like you would not believe, so it's possible with that mileage that one or more cylinders are "dead" and your timing problems are compounding the issue (plugs are usually the culprit).
#5 Also, when you disconnected the fuel lines, did you put them back together in the right sequence? I believe there are two different sizes (one on each line) to prevent this, but double check it and make sure none of the fittings are leaking or misthreaded.
Do #'s 1-3 first, then report back your results. You HAVE to disconnect the EST wire (this "disconnects" the ECM from changing timing) otherwise the computer will tweak the timing as you are trying to set it - and you will be all over the place with your advance.
Let us know! And get a hayne's manual for that vette if any of this is Greek to you - they're invaluable even for the "easy" jobs.
#1 You need to know the Harmonic Damper "0" is lined up with TDC by pulling the #1 plug (driver's side, closest to the front of the car) and with your finger on the hole verifying that there is a pressure build up (have someone else crank it). Then, line up the "0" on the HB and THEN install the distributor, making sure it's pointed right at the #1 cylinder. Then, manually check all the plug wires for proper cylinder orientation.
#2 Disconnect the EST wire (usually located inbetween the Driver's valve cover and the firewall - a black wire with a red or orange stripe). THEN start the car - it should run unless there's another problem. Using your timing light on #1 sparkplug wire and adjust the distributor until you get 6 degrees of advance on the harmonic damper markings. Tighten down the distributor, plug back in the EST wire and you should be good to go - unless there are other problems... lol
#3 If it IS getting fuel, you will smell it. You may want to go through all the fuses to make sure.
#4 CHANGE THE OIL. Sounds like you got swindled and this car has been abused. perform as much "routine" maintenance as you can, included plugs and wires. there may be a combination of things going on. The computer can compensate for a dead cylinder like you would not believe, so it's possible with that mileage that one or more cylinders are "dead" and your timing problems are compounding the issue (plugs are usually the culprit).
#5 Also, when you disconnected the fuel lines, did you put them back together in the right sequence? I believe there are two different sizes (one on each line) to prevent this, but double check it and make sure none of the fittings are leaking or misthreaded.
Do #'s 1-3 first, then report back your results. You HAVE to disconnect the EST wire (this "disconnects" the ECM from changing timing) otherwise the computer will tweak the timing as you are trying to set it - and you will be all over the place with your advance.
Let us know! And get a hayne's manual for that vette if any of this is Greek to you - they're invaluable even for the "easy" jobs.
