Too much cranking
01-16-2015, 12:28 PM
#21
Advanced
Thread Starter
Yes, not saying that it's not something more complicated, but in my case, time and time again, I have come up with elaborate and sophisticated higher level solutions to symptoms on my cars, only to discover that it was something really simple and rudimentary. Especially since you bought the car used and are not sure of the condition of the plugs and other components, I would definitely start with the basics (it likely needs them anyway) to set down a baseline.
I have a feeling this will likely solve your excessive cranking issue. Could be your ignition system is working overtime to overcome the excessive resistance created by your old or carbon coated plugs on a cold start. Ignition control module might be getting old and temperature sensitive on its way out too, although I believe that is usually more heat-related.
Keep us updated!
I have a feeling this will likely solve your excessive cranking issue. Could be your ignition system is working overtime to overcome the excessive resistance created by your old or carbon coated plugs on a cold start. Ignition control module might be getting old and temperature sensitive on its way out too, although I believe that is usually more heat-related.
Keep us updated!
01-17-2015, 03:02 AM
#22
Race Director
If you want to force the fuel pump to come on you can jumper the pins of the oil pressure switch connector (orange and red wires). That will connect 12 volts from the battery directly to the fuel pump.
01-17-2015, 10:09 AM
#23
Advanced
Thread Starter
Gary
01-17-2015, 11:35 AM
#24
Le Mans Master
It doesn't sound like a fuel pump and or relay.
You stated that you had pressure when you turn the key on, and that with the engine running you have pressure then too. To me that says you have fuel and that is not your problem.
Some other things were mentioned, like spark plugs, wires, coil, timing, etc. It sounds to me like some/all of these are more likely your problem.
Good luck.
You stated that you had pressure when you turn the key on, and that with the engine running you have pressure then too. To me that says you have fuel and that is not your problem.
Some other things were mentioned, like spark plugs, wires, coil, timing, etc. It sounds to me like some/all of these are more likely your problem.
Good luck.
Last edited by QCVette; 01-17-2015 at 04:43 PM.
01-17-2015, 07:32 PM
#25
Advanced
Thread Starter
It doesn't sound like a fuel pump and or relay.
You stated that you had pressure when you turn the key on, and that with the engine running you have pressure then too. To me that says you have fuel and that is not your problem.
Some other things were mentioned, like spark plugs, wires, coil, timing, etc. It sounds to me like some/all of these are more likely your problem.
Good luck.
You stated that you had pressure when you turn the key on, and that with the engine running you have pressure then too. To me that says you have fuel and that is not your problem.
Some other things were mentioned, like spark plugs, wires, coil, timing, etc. It sounds to me like some/all of these are more likely your problem.
Good luck.
I am definitely changing the plugs, wires, etc. when I get a chance. Did not have time today. I think what a lot are talking about here is not a bad fuel pump or fuel pump relay, but the signals such as DPRs from the distributor and the oil pressure switch sending a signal when the oil pressure reaches 4 psi. These are signals telling the fuel pump relay, the engine is cranking,,,,,turn on. I am new at injectors systems myself.....old carburetor guy here.
01-17-2015, 07:56 PM
#26
Burning Brakes
Not to hijack the thread or anything, but my '84 takes "a number of cranks" before she starts. I had just chalked it up to the CFI, is that accurate, or should I expect to crank less?
01-17-2015, 08:06 PM
#27
Advanced
Thread Starter
I have heard that its the nature of the beast and others say it should start quicker. I'm going to jumper the fuel pump relay so it has power right away to see if this makes a difference. If it does, my fuel pump relay is not being told to come on soon enough for some reason. Otherwise I will move forward with the new plugs, plug wires & coil. Will keep everyone posted when I find time to get back on it. I am new to fuel injection systems & corvettes....what is CFI?
01-17-2015, 08:18 PM
#28
Burning Brakes
Max,
I have heard that its the nature of the beast and others say it should start quicker. I'm going to jumper the fuel pump relay so it has power right away to see if this makes a difference. If it does, my fuel pump relay is not being told to come on soon enough for some reason. Otherwise I will move forward with the new plugs, plug wires & coil. Will keep everyone posted when I find time to get back on it. I am new to fuel injection systems & corvettes....what is CFI?
I have heard that its the nature of the beast and others say it should start quicker. I'm going to jumper the fuel pump relay so it has power right away to see if this makes a difference. If it does, my fuel pump relay is not being told to come on soon enough for some reason. Otherwise I will move forward with the new plugs, plug wires & coil. Will keep everyone posted when I find time to get back on it. I am new to fuel injection systems & corvettes....what is CFI?
01-18-2015, 12:32 AM
#29
Race Director
Nothing is easy to get to on a Vette. 
The oil pressure switch connector is behind the distributor. Mine has a lock ring on it that must be released first before the connector can be unplugged. The later 3 wire oil pressure switch/sender just unplug. Then you can jumper between the orange and red connector pins. I suppose you could back probe the connector with it still in place.
The oil pressure switch connector is behind the distributor. Mine has a lock ring on it that must be released first before the connector can be unplugged. The later 3 wire oil pressure switch/sender just unplug. Then you can jumper between the orange and red connector pins. I suppose you could back probe the connector with it still in place.
Last edited by Cliff Harris; 01-18-2015 at 12:34 AM.
01-18-2015, 10:51 AM
#30
Instructor
Hello all,
Purchased a 1989 C4 5.7L with 128,000 miles several months ago and having been giving it a once over. When I go to start it, it seems to crank longer than it should before starting. This is when the engine is cold or hot. I can shut it down after driving it and start it a minute later with too many cranks. I'd say its turning over at least a dozen of times. I've seen some guys on here claim that it was the nature of the beast.
Here is what I have done to try to rectify the problem.
1. New fuel pump.
2. Removed pulse dampener and replaced with a section of hose & clamps.
3. New Bosch fuel injectors.
4. New fuel pressure regulator diaphram at the tune of $70.00....ouch.
Here are what my fuel pressures are.
Key on only: Goes to 42 and then drops to 40
Engine running:38
After I shut her down after running pressure immediately drops to 30, holds at 30 for 10 minutes then drops to 0.
Since the spark plugs look difficult to get at, I imagine they probably haven't been changed in a while....will try that next.
Any other ides?
Thanks................
Purchased a 1989 C4 5.7L with 128,000 miles several months ago and having been giving it a once over. When I go to start it, it seems to crank longer than it should before starting. This is when the engine is cold or hot. I can shut it down after driving it and start it a minute later with too many cranks. I'd say its turning over at least a dozen of times. I've seen some guys on here claim that it was the nature of the beast.
Here is what I have done to try to rectify the problem.
1. New fuel pump.
2. Removed pulse dampener and replaced with a section of hose & clamps.
3. New Bosch fuel injectors.
4. New fuel pressure regulator diaphram at the tune of $70.00....ouch.
Here are what my fuel pressures are.
Key on only: Goes to 42 and then drops to 40
Engine running:38
After I shut her down after running pressure immediately drops to 30, holds at 30 for 10 minutes then drops to 0.
Since the spark plugs look difficult to get at, I imagine they probably haven't been changed in a while....will try that next.
Any other ides?
Thanks................
01-18-2015, 09:02 PM
#31
Advanced
Thread Starter
Checked several plugs today, they were nice & brown but the gap was .045. My Chilton Manual specs the gap at .035. That's all I had time to work on today. I am definitely adding a fuel filter to my list.
01-25-2015, 09:24 PM
#32
Advanced
Thread Starter
New fuel filter went in today.....did not fix. Moving on to plugs & wires next.
01-26-2015, 11:10 AM
#33
Instructor
Mine did that when I got it..
I purchased Taylor cap, wires and rotor arm from Summit and a new coil from Ecklers who had a great deal on stock coils. My old rotor arm actuall crumbled to dust when I removed it. No idea how it all still ran.
The difference was amazing and still is, it starts before you actually hear it cranking even when left idle on a battery tender for a couple of weeks in the winter (they use a lot of salt on the roads hereabouts which dissolved my fuel and brake pipes last year).
It runs perfectly and this year will treat the 150k mile motor to new fuel pump, Bosch injectors and an adjustable fuel reg as I like to fix stuff before it breaks..
p.s. make sure you don't have any vacuum leaks either. That caused me issues with hesitating when trying to join the traffic. Removed all of the vacuum lines apart from them what control the fuel reg and the ventilation doors.
I purchased Taylor cap, wires and rotor arm from Summit and a new coil from Ecklers who had a great deal on stock coils. My old rotor arm actuall crumbled to dust when I removed it. No idea how it all still ran.
The difference was amazing and still is, it starts before you actually hear it cranking even when left idle on a battery tender for a couple of weeks in the winter (they use a lot of salt on the roads hereabouts which dissolved my fuel and brake pipes last year).
It runs perfectly and this year will treat the 150k mile motor to new fuel pump, Bosch injectors and an adjustable fuel reg as I like to fix stuff before it breaks..
p.s. make sure you don't have any vacuum leaks either. That caused me issues with hesitating when trying to join the traffic. Removed all of the vacuum lines apart from them what control the fuel reg and the ventilation doors.
Last edited by exitwound; 01-26-2015 at 11:13 AM.
01-26-2015, 11:50 AM
#34
Advanced
Thread Starter
Mine did that when I got it..
I purchased Taylor cap, wires and rotor arm from Summit and a new coil from Ecklers who had a great deal on stock coils. My old rotor arm actuall crumbled to dust when I removed it. No idea how it all still ran.
The difference was amazing and still is, it starts before you actually hear it cranking even when left idle on a battery tender for a couple of weeks in the winter (they use a lot of salt on the roads hereabouts which dissolved my fuel and brake pipes last year).
It runs perfectly and this year will treat the 150k mile motor to new fuel pump, Bosch injectors and an adjustable fuel reg as I like to fix stuff before it breaks..
p.s. make sure you don't have any vacuum leaks either. That caused me issues with hesitating when trying to join the traffic. Removed all of the vacuum lines apart from them what control the fuel reg and the ventilation doors.
I purchased Taylor cap, wires and rotor arm from Summit and a new coil from Ecklers who had a great deal on stock coils. My old rotor arm actuall crumbled to dust when I removed it. No idea how it all still ran.
The difference was amazing and still is, it starts before you actually hear it cranking even when left idle on a battery tender for a couple of weeks in the winter (they use a lot of salt on the roads hereabouts which dissolved my fuel and brake pipes last year).
It runs perfectly and this year will treat the 150k mile motor to new fuel pump, Bosch injectors and an adjustable fuel reg as I like to fix stuff before it breaks..
p.s. make sure you don't have any vacuum leaks either. That caused me issues with hesitating when trying to join the traffic. Removed all of the vacuum lines apart from them what control the fuel reg and the ventilation doors.
01-26-2015, 12:28 PM
#35
Instructor
When doing the cap and rotor, it is the perfect opportunity to do the ignition control module as it sits under the rotor on your car. Eliminates just one more hard starting variable and is a good thing to do if it has never been changed anyway. Likely, it is still the original one that came with the car. Be sure to use the gel that comes with it during install to prevent premature failure.
01-26-2015, 12:38 PM
#36
Advanced
Thread Starter
When doing the cap and rotor, it is the perfect opportunity to do the ignition control module as it sits under the rotor on your car. Eliminates just one more hard starting variable and is a good thing to do if it has never been changed anyway. Likely, it is still the original one that came with the car. Be sure to use the gel that comes with it during install to prevent premature failure.