95 Bonneville with starting/ running issues
#1
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95 Bonneville with starting/ running issues
Mostly wanted to thank Danthurs for his sticky on harmonic balancer removal on the 3800 Gen II...without it I would have been DOA out at the boneyard yesterday on those 1/4" bolts for the puller. Can't post to his sticky so came here...might as well add my experience:
Bought car to flip it. No run, no spark. I used easyautodiagnostics.com (link below) to isolate the crank sensor as the fault. I also noticed the plastic shield that should go between the harmonic balancer and the sensor is missing on my engine...get the balancer off and see that strips of serpentine belt have wrapped themselves around the interrupter ring on the balancer! Also the three pegs on the sensor that talk to the ring were all damaged. I guess those are the hall effect sensors with a common magnet in the middle. That middle one was tore up real good. So there you go. Nice to get such obvious visual confirmation of the diagnosis! Word to the wise; NEVER leave that little shield off if you're in there! Not taking a chance with this balancer, already have one off at a yard and waiting for me. Also got the shield yesterday. Should have this running today!
Mealgood
Bought car to flip it. No run, no spark. I used easyautodiagnostics.com (link below) to isolate the crank sensor as the fault. I also noticed the plastic shield that should go between the harmonic balancer and the sensor is missing on my engine...get the balancer off and see that strips of serpentine belt have wrapped themselves around the interrupter ring on the balancer! Also the three pegs on the sensor that talk to the ring were all damaged. I guess those are the hall effect sensors with a common magnet in the middle. That middle one was tore up real good. So there you go. Nice to get such obvious visual confirmation of the diagnosis! Word to the wise; NEVER leave that little shield off if you're in there! Not taking a chance with this balancer, already have one off at a yard and waiting for me. Also got the shield yesterday. Should have this running today!
Mealgood
#3
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thanks, 2kg4u. Guess I forgot the link I promised above. I have found this site VERY useful, not just on this car. Very efficient:
Part 1 -GM 3.8L Ignition Module Test and Crank Sensor Test (3X, 18X)
Mealnogle
Part 1 -GM 3.8L Ignition Module Test and Crank Sensor Test (3X, 18X)
Mealnogle
#4
Senior Member
True Car Nut
thanks, 2kg4u. Guess I forgot the link I promised above. I have found this site VERY useful, not just on this car. Very efficient:
Part 1 -GM 3.8L Ignition Module Test and Crank Sensor Test (3X, 18X)
Mealnogle
Part 1 -GM 3.8L Ignition Module Test and Crank Sensor Test (3X, 18X)
Mealnogle
I use that site all the time. It'* one of the best I have found, and I often refer our members to there.
#5
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Update - engine fired right up after I buttoned it up with sensor. Lopes a bit at idle when it warms up but revs nice, no smoke. Check engine light on but I don't have the serpentine belt on so I'll take it one step at a time. Anybody know if the engine mount needs to be removed to do the belt?
Oh; the Autozone harmonic balancer installer was almost useless. Fortunately the local Napa guy who I've worked with before told me exactly what to do; go to the hardware store and get threaded stock, then get washers that allow me to step down to use the smaller size nut which you then turn to torque the balancer on. Worked like a charm. Stock was 3/8 x 24 x 36...I think 36 was the length...had to hacksaw it shorter to use it. Surprising with all the 3800s on the road, and needing to pull the balancer to do the crank sensor, that neither the standard puller or installer works on these...oh well.
Mealhappy
Oh; the Autozone harmonic balancer installer was almost useless. Fortunately the local Napa guy who I've worked with before told me exactly what to do; go to the hardware store and get threaded stock, then get washers that allow me to step down to use the smaller size nut which you then turn to torque the balancer on. Worked like a charm. Stock was 3/8 x 24 x 36...I think 36 was the length...had to hacksaw it shorter to use it. Surprising with all the 3800s on the road, and needing to pull the balancer to do the crank sensor, that neither the standard puller or installer works on these...oh well.
Mealhappy
#7
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thanks, jwfirebird. I'll go grab one from the yard; $5 is better than $32, and I'm not sure this has a '95 engine in it. They supposedly swapped a replacement in there. I assume they swapped over all original accessories but that'* assuming. Per Autozone the belt is '95 only.
I gotta get under and look for numbers on the engine. I guess '95 was the first year of cross-bolt mains? That'* one thing I'll look for. Also gotta remove the hotwire running to the fuel pump. Per the PO I should be able to just plug the stock wires in. I think they were desperately trying whatever they could think of when it stopped running. Saga continues,
Mealness
I gotta get under and look for numbers on the engine. I guess '95 was the first year of cross-bolt mains? That'* one thing I'll look for. Also gotta remove the hotwire running to the fuel pump. Per the PO I should be able to just plug the stock wires in. I think they were desperately trying whatever they could think of when it stopped running. Saga continues,
Mealness
#8
Senior Member
True Car Nut
they have crappy connections, i ended up soldering the wires together in my inlaws old 96 because the pump was intermittent and i was tired of screwing with it. they were and did drive it till it went to the junk yard anyway. you might be able to get new pigtails from rock auto or something not sure whats available
as far as 95 i thought it was very similar to the 96-99 with slightly different controls for the obd 1.5
as far as 95 i thought it was very similar to the 96-99 with slightly different controls for the obd 1.5
#9
Retired
If its the N/A engine, then its a Series 2. It was put in 95-2005. Series 1 ended in 1994, and I don't even think any 95 production cars ever got a Series1.
FYI, there are some sensors that is 95 alone. 96, 97 and 98-99 year groups practically have there own sensors. They may look the same, but are actually different. What'* different, I don't remember. That'* why I always tell members, when you do an engine swap, KEEP all of your sensors and transfer them over. That way, you will at least know you have the CORRECT one and that they were working PRIOR to the swap.
Dan has a How-To on the serpentine belt removal. It'* on a */C'd engine, but it will work either way...
https://www.gmforum.com/mechanical-1...c-belt-278821/
CEL light could be because the PCM is not seeing alternator voltage when the engine is running, but I could be wrong.
FYI, there are some sensors that is 95 alone. 96, 97 and 98-99 year groups practically have there own sensors. They may look the same, but are actually different. What'* different, I don't remember. That'* why I always tell members, when you do an engine swap, KEEP all of your sensors and transfer them over. That way, you will at least know you have the CORRECT one and that they were working PRIOR to the swap.
Dan has a How-To on the serpentine belt removal. It'* on a */C'd engine, but it will work either way...
https://www.gmforum.com/mechanical-1...c-belt-278821/
CEL light could be because the PCM is not seeing alternator voltage when the engine is running, but I could be wrong.
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#10
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Okay, need some help here. Another hotwire is the fuel pump, apparently wired to 12V switched such that it stays on with key on/engine off rather than shutting off after priming. PO told me 'just plug the stock connector back in and it'll work', which led me to believe that it was a futile diagnostic attempt. Now that I take the tank down a few inches to see where he spliced in, it'* way too far up in there for me to do much. There are 4 wires at the connector back there and that wire seems to be the right one, but no power with key on so probably an open/short somewhere. In any case, it looks like I will have to leave his hotwire at the pump and then route backwards to patch his hotwire to the correct wire that should feed it and splice there.
Trouble is, I have no way to see even where that wire routes to the front of the car, presumably to the fuel pump relay. I see it as a tan wire but I don't currently have a wiring diagram for the '95. Looking at the relay center underhood, I see 6 standard relays running along the bottom row. Anybody know which one is for the fuel pump? Anybody know a reasonably do-able way for me to patch in somewhere between there and the rear of the car where the pump is? Maybe right behind the relays? Thanks,
Mealhunger
Trouble is, I have no way to see even where that wire routes to the front of the car, presumably to the fuel pump relay. I see it as a tan wire but I don't currently have a wiring diagram for the '95. Looking at the relay center underhood, I see 6 standard relays running along the bottom row. Anybody know which one is for the fuel pump? Anybody know a reasonably do-able way for me to patch in somewhere between there and the rear of the car where the pump is? Maybe right behind the relays? Thanks,
Mealhunger