1988 C4/Intermittent issue
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Joined: Jan 2019
Posts: 81
Likes: 15
From: New Braunfels, TX
2020 Corvette of the Year Finalist (stock)
C4 of Year Winner (stock) 2019
1988 C4/Intermittent issue
Hi All,
Something else I just noticed. Once before, I had been driving for about 20 mins, made a quick stop and tried to start it up. It started, but the RPMs were very low on idle, then it died. I started it again and I had to pump the gas to keep it going. The "Service Engine Soon" light came on, It finally came up to normal idle speed and I drove home. Turned it off, then back on and it was back to normal with out the light being on.
Yesterday, I tried starting it and it sounded like the starter was clattering very loud when starting and it would start then die. Tried a couple of times more and the same thing. Then I waited about 10 mins and tried again. Perfect start with no issues.
Anyone else have this kind of experience? And if so, what did you do?
I think it may be haunted by the pervious owner. HA!
Thanks,
Tim's88
Something else I just noticed. Once before, I had been driving for about 20 mins, made a quick stop and tried to start it up. It started, but the RPMs were very low on idle, then it died. I started it again and I had to pump the gas to keep it going. The "Service Engine Soon" light came on, It finally came up to normal idle speed and I drove home. Turned it off, then back on and it was back to normal with out the light being on.
Yesterday, I tried starting it and it sounded like the starter was clattering very loud when starting and it would start then die. Tried a couple of times more and the same thing. Then I waited about 10 mins and tried again. Perfect start with no issues.
Anyone else have this kind of experience? And if so, what did you do?
I think it may be haunted by the pervious owner. HA!
Thanks,
Tim's88
Oil Producer
Joined: Apr 2014
Posts: 9,374
Likes: 2,736
Is this car manual or auto?
The clattering starter is weird. But not really. One thing you may have been told already is that will withg 90% certainty have more than one thing going on. Personally, I'd be jacking the car safely (using jack points) and putting the car up on stands, I always leave the jack on as redundancy on the side that I am laying under.
Then i'd be having a gander at your starter.
I cannot remember if you have an auto you might be able to remove the inspection cover and have a look at the starter engage the flywheel. obviously excercising caution. if its chipping metal bits you will want to know before you stick your face under it while somebody tries to start it.
The strange thing, and the only way i can see the clanking starter with the lugging engine running on start, is if there is somehow a connection between the trans/engine that isn't disengaging. which is why i asked about the type of trans.
----------------
but if you ignore the starter clanking noise for now, then i would buy/borrow/rent a fuel pressure gauge to ensure that is not an issue, i don't think it is, but its easy to rule out and you need to do these things in a methodical fashion. you can likely recreate the issue and observe pressures in the 40 area. long as that checks out ...
i'd move on to pulling the throttle body and then pull the IAC to inspect it. Do a full cleaning of the throttle body, including all the little passageways. Then search "minimum idle set for corvette c4" u will find instructions and carry that out.
if that doesn't help, then my suspicions are the coolant temp sensor, which is cheap enough to simply replace the part.
after that i'd wonder about the icm.
but....realize that if you really want to "get into it" then you need a scanner (aldlcable.com for your year and alot of time on laptop running free version of tunerpro rt) you can see what the values being returned to the ecm are and you should be able to spot the issue.
The clattering starter is weird. But not really. One thing you may have been told already is that will withg 90% certainty have more than one thing going on. Personally, I'd be jacking the car safely (using jack points) and putting the car up on stands, I always leave the jack on as redundancy on the side that I am laying under.
Then i'd be having a gander at your starter.
I cannot remember if you have an auto you might be able to remove the inspection cover and have a look at the starter engage the flywheel. obviously excercising caution. if its chipping metal bits you will want to know before you stick your face under it while somebody tries to start it.
The strange thing, and the only way i can see the clanking starter with the lugging engine running on start, is if there is somehow a connection between the trans/engine that isn't disengaging. which is why i asked about the type of trans.
----------------
but if you ignore the starter clanking noise for now, then i would buy/borrow/rent a fuel pressure gauge to ensure that is not an issue, i don't think it is, but its easy to rule out and you need to do these things in a methodical fashion. you can likely recreate the issue and observe pressures in the 40 area. long as that checks out ...
i'd move on to pulling the throttle body and then pull the IAC to inspect it. Do a full cleaning of the throttle body, including all the little passageways. Then search "minimum idle set for corvette c4" u will find instructions and carry that out.
if that doesn't help, then my suspicions are the coolant temp sensor, which is cheap enough to simply replace the part.
after that i'd wonder about the icm.
but....realize that if you really want to "get into it" then you need a scanner (aldlcable.com for your year and alot of time on laptop running free version of tunerpro rt) you can see what the values being returned to the ecm are and you should be able to spot the issue.
Thread Starter
Advanced
Joined: Jan 2019
Posts: 81
Likes: 15
From: New Braunfels, TX
2020 Corvette of the Year Finalist (stock)
C4 of Year Winner (stock) 2019
Is this car manual or auto?
The clattering starter is weird. But not really. One thing you may have been told already is that will withg 90% certainty have more than one thing going on. Personally, I'd be jacking the car safely (using jack points) and putting the car up on stands, I always leave the jack on as redundancy on the side that I am laying under.
Then i'd be having a gander at your starter.
I cannot remember if you have an auto you might be able to remove the inspection cover and have a look at the starter engage the flywheel. obviously excercising caution. if its chipping metal bits you will want to know before you stick your face under it while somebody tries to start it.
The strange thing, and the only way i can see the clanking starter with the lugging engine running on start, is if there is somehow a connection between the trans/engine that isn't disengaging. which is why i asked about the type of trans.
----------------
but if you ignore the starter clanking noise for now, then i would buy/borrow/rent a fuel pressure gauge to ensure that is not an issue, i don't think it is, but its easy to rule out and you need to do these things in a methodical fashion. you can likely recreate the issue and observe pressures in the 40 area. long as that checks out ...
i'd move on to pulling the throttle body and then pull the IAC to inspect it. Do a full cleaning of the throttle body, including all the little passageways. Then search "minimum idle set for corvette c4" u will find instructions and carry that out.
if that doesn't help, then my suspicions are the coolant temp sensor, which is cheap enough to simply replace the part.
after that i'd wonder about the icm.
but....realize that if you really want to "get into it" then you need a scanner (aldlcable.com for your year and alot of time on laptop running free version of tunerpro rt) you can see what the values being returned to the ecm are and you should be able to spot the issue.
The clattering starter is weird. But not really. One thing you may have been told already is that will withg 90% certainty have more than one thing going on. Personally, I'd be jacking the car safely (using jack points) and putting the car up on stands, I always leave the jack on as redundancy on the side that I am laying under.
Then i'd be having a gander at your starter.
I cannot remember if you have an auto you might be able to remove the inspection cover and have a look at the starter engage the flywheel. obviously excercising caution. if its chipping metal bits you will want to know before you stick your face under it while somebody tries to start it.
The strange thing, and the only way i can see the clanking starter with the lugging engine running on start, is if there is somehow a connection between the trans/engine that isn't disengaging. which is why i asked about the type of trans.
----------------
but if you ignore the starter clanking noise for now, then i would buy/borrow/rent a fuel pressure gauge to ensure that is not an issue, i don't think it is, but its easy to rule out and you need to do these things in a methodical fashion. you can likely recreate the issue and observe pressures in the 40 area. long as that checks out ...
i'd move on to pulling the throttle body and then pull the IAC to inspect it. Do a full cleaning of the throttle body, including all the little passageways. Then search "minimum idle set for corvette c4" u will find instructions and carry that out.
if that doesn't help, then my suspicions are the coolant temp sensor, which is cheap enough to simply replace the part.
after that i'd wonder about the icm.
but....realize that if you really want to "get into it" then you need a scanner (aldlcable.com for your year and alot of time on laptop running free version of tunerpro rt) you can see what the values being returned to the ecm are and you should be able to spot the issue.
Tim's88
Advanced
Joined: Feb 2017
Posts: 66
Likes: 26
From: New Zealand
Check the Service Engine Soon error code. If you're new to the car, it's easy to do. This will give you a starting point for proper diagnosis,
Under the dash on the driver's side you'll find an ALDL connector that is used to extract the info from the car's computer. For details on how to do this go here: https://www.corvettebuyers.com/c4vettes/codes.htm
I had intermittent difficult starts and lumpy idle and pulled a Code 34 from the memory. Fixed by giving the MAF sensor a clean together with new plugs...car now goes like a dream!
Under the dash on the driver's side you'll find an ALDL connector that is used to extract the info from the car's computer. For details on how to do this go here: https://www.corvettebuyers.com/c4vettes/codes.htm
I had intermittent difficult starts and lumpy idle and pulled a Code 34 from the memory. Fixed by giving the MAF sensor a clean together with new plugs...car now goes like a dream!
Last edited by raymnz; Jan 31, 2019 at 03:53 PM.
Melting Slicks
Joined: May 2014
Posts: 2,895
Likes: 592
From: New Port Richey FL
Since the car is new to you need to set a bit of a Baseline to know what you have Face it's a Clean History page for you. Does the Battery look old, are the Connections Clean and Tight. Old and Tired with Bad Connections Can Effect the Starter. When was Last Tune?
Now the Low Idle Remove the Air Snorkel and Mass Air Sensor, With Engine off Clean the Throttle Plates. and as stated by Previous do a Diagnostic/Trouble Code. Buy or Finding a Correct Scan Tool for the of the car can be a big help and of course the ever popular Factory Shop Manual.
Now the Low Idle Remove the Air Snorkel and Mass Air Sensor, With Engine off Clean the Throttle Plates. and as stated by Previous do a Diagnostic/Trouble Code. Buy or Finding a Correct Scan Tool for the of the car can be a big help and of course the ever popular Factory Shop Manual.
Last edited by s carter; Jan 31, 2019 at 04:27 PM.
