1985 Corvette NO START
#1
1985 Corvette NO START
Recently picked up a 1985 Corvette L98 as a Fall / Winter project. I'm a novice and this forum has already helped a great deal in my understanding of these great cars - thank you!
Would like some advice / direction on my no start issue. Initially the vehicle had no fuel pressure at the fuel rail. Replaced the fuel filter, fuel sending unit and fuel pump and now have about 40 psi at the rail.
Picked up a spark tester and observe spark during cranking. Sprayed some starter fluid in the intake and the engine seems to catch momentarily but won't run. Stuck a pin into a couple of the injector connections and my test light seems to flicker during cranking suggesting the injectors are getting a pulse.
It's my understanding from the previous owner that the car sat for years without running but I don't have much background other than that. Consequently I've cleaned the gas take and blew out the fuel lines. I suspect the fuel injectors need cleaning or replacing. Would like to pull the injector caps first to measure resistance but unclear how they come off. I see a metal clip at the injector base, will that release the cap from the injector?
Before I go after the injectors do you suppose Timing might keep it from starting? Also, even though I observe spark at the plugs could the ignition control module be an issue or does spark at the plugs rule that out?
Thank you for any direction / help!
Would like some advice / direction on my no start issue. Initially the vehicle had no fuel pressure at the fuel rail. Replaced the fuel filter, fuel sending unit and fuel pump and now have about 40 psi at the rail.
Picked up a spark tester and observe spark during cranking. Sprayed some starter fluid in the intake and the engine seems to catch momentarily but won't run. Stuck a pin into a couple of the injector connections and my test light seems to flicker during cranking suggesting the injectors are getting a pulse.
It's my understanding from the previous owner that the car sat for years without running but I don't have much background other than that. Consequently I've cleaned the gas take and blew out the fuel lines. I suspect the fuel injectors need cleaning or replacing. Would like to pull the injector caps first to measure resistance but unclear how they come off. I see a metal clip at the injector base, will that release the cap from the injector?
Before I go after the injectors do you suppose Timing might keep it from starting? Also, even though I observe spark at the plugs could the ignition control module be an issue or does spark at the plugs rule that out?
Thank you for any direction / help!
#2
fpr?
Recently picked up a 1985 Corvette L98 as a Fall / Winter project. I'm a novice and this forum has already helped a great deal in my understanding of these great cars - thank you!
Would like some advice / direction on my no start issue. Initially the vehicle had no fuel pressure at the fuel rail. Replaced the fuel filter, fuel sending unit and fuel pump and now have about 40 psi at the rail.
Picked up a spark tester and observe spark during cranking. Sprayed some starter fluid in the intake and the engine seems to catch momentarily but won't run. Stuck a pin into a couple of the injector connections and my test light seems to flicker during cranking suggesting the injectors are getting a pulse.
It's my understanding from the previous owner that the car sat for years without running but I don't have much background other than that. Consequently I've cleaned the gas take and blew out the fuel lines. I suspect the fuel injectors need cleaning or replacing. Would like to pull the injector caps first to measure resistance but unclear how they come off. I see a metal clip at the injector base, will that release the cap from the injector?
Before I go after the injectors do you suppose Timing might keep it from starting? Also, even though I observe spark at the plugs could the ignition control module be an issue or does spark at the plugs rule that out?
Thank you for any direction / help!
Would like some advice / direction on my no start issue. Initially the vehicle had no fuel pressure at the fuel rail. Replaced the fuel filter, fuel sending unit and fuel pump and now have about 40 psi at the rail.
Picked up a spark tester and observe spark during cranking. Sprayed some starter fluid in the intake and the engine seems to catch momentarily but won't run. Stuck a pin into a couple of the injector connections and my test light seems to flicker during cranking suggesting the injectors are getting a pulse.
It's my understanding from the previous owner that the car sat for years without running but I don't have much background other than that. Consequently I've cleaned the gas take and blew out the fuel lines. I suspect the fuel injectors need cleaning or replacing. Would like to pull the injector caps first to measure resistance but unclear how they come off. I see a metal clip at the injector base, will that release the cap from the injector?
Before I go after the injectors do you suppose Timing might keep it from starting? Also, even though I observe spark at the plugs could the ignition control module be an issue or does spark at the plugs rule that out?
Thank you for any direction / help!
when you did your fuel system work, did you replace the fuel pump relay?
#3
Do you think the relay could cause my no start? The Vette does sound like it's fuel starved when it catches and won't run.
Thanks
#4
1985 Corvette
Kansas Brad, my 1985 was bought in 1992. Still using the same factory installed injectors. Had no problems with them about 19 years ago when I bought a kit to use a pressure can of injector cleaning liquid. Have not done any cleaning of the injectors since. The 85 runs great on low octane gas.
Last edited by 70ZZ3 96LT4; 10-08-2014 at 02:28 PM.
#5
Kansas Brad, my 1985 was bought in 1992. Still using the same factory installed injectors. Had no problems with them about 19 years ago when I bought a kit to use a pressure can of injector cleaning liquid. Have not done anything since. The 85 runs great on low octane gas.
Thank you!
#6
1985 starting procedure
I also never turn the ignition key from off to start immediately, have learned to turn the ignition key from off to the run position first listening for the fuel pump to pump fuel and listen for the fuel pump relay on the firewall in front of the driver to click off, then I turn the key to start my 1985. It always fires up immediately using this method, the engine hardly turns over before it is running.
I use this method on my three other cars with the same results.
Another thing you can do is call Gordon Killebrew. He worked at the Corvette plant when your Corvette was made. Google his name and read about his services and Corvette experience. The cost of a phone call may save you a lot of money chasing your Corvette's no running problem. Back when I bought my 1985 there was a call in service at the Corvette Action Center at the Corvette plant that you could address your C4 problems with just a phone call, I used it.
Last edited by 70ZZ3 96LT4; 10-08-2014 at 02:46 PM.
#7
Another thing about my old 1985, I have replaced the fuel pump. There is a pulsator piece between the fuel pump and gas going to the fuel line. The pulsator piece can leak the fuel pumps pressure pumped gas back into the tank.
I also never turn the ignition key from off to start immediately, have learned to turn the ignition key from off to the run position first listening for the fuel pump to pump fuel and listen for the fuel pump relay on the firewall in front of the driver to click off, then I turn the key to start my 1985. It always fires up immediately using this method, the engine hardly turns over before it is running.
I use this method on my three other cars with the same results.
Another thing you can do is call Gordon Killebrew. He worked at the Corvette plant when your Corvette was made. Google his name and read about his services and Corvette experience. The cost of a phone call may save you a lot of money chasing your Corvette's no running problem. Back when I bought my 1985 there was a call in service at the Corvette Action Center at the Corvette plant that you could address your C4 problems with just a phone call, I used it.
I also never turn the ignition key from off to start immediately, have learned to turn the ignition key from off to the run position first listening for the fuel pump to pump fuel and listen for the fuel pump relay on the firewall in front of the driver to click off, then I turn the key to start my 1985. It always fires up immediately using this method, the engine hardly turns over before it is running.
I use this method on my three other cars with the same results.
Another thing you can do is call Gordon Killebrew. He worked at the Corvette plant when your Corvette was made. Google his name and read about his services and Corvette experience. The cost of a phone call may save you a lot of money chasing your Corvette's no running problem. Back when I bought my 1985 there was a call in service at the Corvette Action Center at the Corvette plant that you could address your C4 problems with just a phone call, I used it.
Mr. Killebrew's site is quite impressive and the consultation fee is reasonable. Thanks for the lead!
#8
Drifting
welcome to the forum.....quite a few of us have 85's so don't give up on the forum and pay somebody....guessing you already have a fsm and fuel guage so you're halfway there.....make sure you're seeing fuel pressure when you're starting...fuel pump only runs two sec....if your fuel line is loose in the pulsator, your pressure will drop off and it won''t start...you wouldn't be the first to put a new pump in to have that happen
Also, check all your vac lines for cracks, (easier to do when running) make sure the egr valve is closed, and I'd pull the IAC and clean it and the port it goes into in the TB....i'm not that much of an expert but i'm sure the pro's will jump in and help....this is a great place for information...just be specific, always state your year...it helps alot...............good luck
Also, check all your vac lines for cracks, (easier to do when running) make sure the egr valve is closed, and I'd pull the IAC and clean it and the port it goes into in the TB....i'm not that much of an expert but i'm sure the pro's will jump in and help....this is a great place for information...just be specific, always state your year...it helps alot...............good luck
#9
welcome to the forum.....quite a few of us have 85's so don't give up on the forum and pay somebody....guessing you already have a fsm and fuel guage so you're halfway there.....make sure you're seeing fuel pressure when you're starting...fuel pump only runs two sec....if your fuel line is loose in the pulsator, your pressure will drop off and it won''t start...you wouldn't be the first to put a new pump in to have that happen
Also, check all your vac lines for cracks, (easier to do when running) make sure the egr valve is closed, and I'd pull the IAC and clean it and the port it goes into in the TB....i'm not that much of an expert but i'm sure the pro's will jump in and help....this is a great place for information...just be specific, always state your year...it helps alot...............good luck
Also, check all your vac lines for cracks, (easier to do when running) make sure the egr valve is closed, and I'd pull the IAC and clean it and the port it goes into in the TB....i'm not that much of an expert but i'm sure the pro's will jump in and help....this is a great place for information...just be specific, always state your year...it helps alot...............good luck
I'll go check those items you mentioned, thanks. I do seem to maintain fuel pressure during cranking and it appears to be holding after key off. Today I pulled the distributor cap to check static timing and see the rotor pointing at plug number 1 when the timing mark is at the timing plate (...too corroded to read degrees though). Of course the battery is down now so my crank testing will be limited until I get my new battery charger next week!
I won't be paying anyone to troubleshoot as this is something I want to learn and am in no particular hurry. Takes time to assimilate the various systems on this vehicle. My dash cluster was also dark but thanks to this forum pointing me to batte.com I was able to get it back up.
Thanks again!
#10
Drifting
your 85 also has a9th injector a cold start injector.....When I got my 85, I changed most relays and the iac based on threads in this forum...couldn't believe how bad the iac/plenum/tb was choked with carbon...doubt it's your timing....set it after she fires up....make sure your tps is set right.
try a little starting fluid when cranking......here's what I finally did..
try a little starting fluid when cranking......here's what I finally did..
#11
Impressive motor, Dixie! The only thing in common with mine is the Orange plug wires!
Did a resistance readings on some of the injectors this morning. Reading a consistent 16.3 ohms among four of them which seems roughly in range. I’ll check the others tomorrow and see if that holds. Adjusted the TPS up from 5.0 to 5.4 volts. Next check is the IAC valve and clean that up. I have been using starter fluid and it coughs a bit but hard to say if that constitutes running – but it wants to!
Borrowed a NOID tester and compression tester and will check that stuff tomorrow. If nothing obvious turns up I’ll return to square one and see where it leads.
Thanks for your input!
Did a resistance readings on some of the injectors this morning. Reading a consistent 16.3 ohms among four of them which seems roughly in range. I’ll check the others tomorrow and see if that holds. Adjusted the TPS up from 5.0 to 5.4 volts. Next check is the IAC valve and clean that up. I have been using starter fluid and it coughs a bit but hard to say if that constitutes running – but it wants to!
Borrowed a NOID tester and compression tester and will check that stuff tomorrow. If nothing obvious turns up I’ll return to square one and see where it leads.
Thanks for your input!
#13
Safety Car
I am assuming you have put a timing light on to verify the engine is firing? If not do that and verify you have fire. I have had tons of trouble in the last few weeks with firing on my "85.
Check your ignition coil and the distributor pick up coils. Test procedure here http://www.answers.com/Q/How_do_you_..._ignition_coil
Use an ohmmeter and check your pick up coil. Pull the 2 pin connector on your ICM and see if there is ANY resistance. Meter should show an open loop.
Only then would I go on to fuel.
Good luck.
Check your ignition coil and the distributor pick up coils. Test procedure here http://www.answers.com/Q/How_do_you_..._ignition_coil
Use an ohmmeter and check your pick up coil. Pull the 2 pin connector on your ICM and see if there is ANY resistance. Meter should show an open loop.
Only then would I go on to fuel.
Good luck.
#14
Instructor
Member Since: Feb 2014
Location: Lakeland FL
Posts: 139
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There's only a few things a 4 stroke motor needs to run. Air, fuel, compression, spark, and timed right.
You have air, you've eliminated fuel as a problem with the use of starting fluid and you seem to have spark. Check the others and you should find your problem.
You have air, you've eliminated fuel as a problem with the use of starting fluid and you seem to have spark. Check the others and you should find your problem.
Last edited by Mark8801; 10-11-2014 at 07:56 PM. Reason: A barrowed gif
#15
I am assuming you have put a timing light on to verify the engine is firing? If not do that and verify you have fire. I have had tons of trouble in the last few weeks with firing on my "85.
Check your ignition coil and the distributor pick up coils. Test procedure here http://www.answers.com/Q/How_do_you_..._ignition_coil
Use an ohmmeter and check your pick up coil. Pull the 2 pin connector on your ICM and see if there is ANY resistance. Meter should show an open loop.
Only then would I go on to fuel.
Good luck.
Check your ignition coil and the distributor pick up coils. Test procedure here http://www.answers.com/Q/How_do_you_..._ignition_coil
Use an ohmmeter and check your pick up coil. Pull the 2 pin connector on your ICM and see if there is ANY resistance. Meter should show an open loop.
Only then would I go on to fuel.
Good luck.
Since it was cheap and easy I replaced the ICM yesterday and the engine seemed to like it but not enough to continue running.
Thanks again for your thoughts - much appreciated!
#16
There's only a few things a 4 stroke motor needs to run. Air, fuel, compression, spark, and timed right.
You have air, you've eliminated fuel as a problem with the use of starting fluid and you seem to have spark. Check the others and you should find your problem.
Attachment 47833146
You have air, you've eliminated fuel as a problem with the use of starting fluid and you seem to have spark. Check the others and you should find your problem.
Attachment 47833146
Thanks for your input!
#18
Update: Replaced the fuel injectors and the 'Vette started right up!
Recap - This was a vehicle that had apparently sat unattended for years and happened to come across my path and although a novice in mechanics decided to take it on as a Fall/ Winter project.
The first issue (after installing a battery) was no pressure at the fuel rail. The fuel filter had previously been replaced as well as the plugs and wires.
Found that the fuel sending unit was leaking and replaced that as well as the attached fuel pump. This got me pressure (around 40 psi) at the rail and although the engine would catch it wouldn't run. Adding a little starter fluid would help it run for a second or two.
Looked like I was getting pulses at the injectors, spark at the plugs, and static timing seemed approximately correct. I jumped 12 volts to pin G at the OBD connector to force the fuel pump to remain on in case the oil pressure relay was shutting the fuel pump down but that didn't change the starting situation.
Still seemed like the engine was starved for fuel so ordered 8 Bosh III 24 psi re-manufactured injectors from ebay and installed them today. Vehicle started right up and idles fine. Took it for a couple of short rides and seems to run fine.
This Vette still needs lots of work to get it road ready but wanted to sum up this thread with the hope that it might help someone down the road. I've certainly gained much reading this forum and appreciate all the folks that relayed their issues and solutions.
Thank you all!
Recap - This was a vehicle that had apparently sat unattended for years and happened to come across my path and although a novice in mechanics decided to take it on as a Fall/ Winter project.
The first issue (after installing a battery) was no pressure at the fuel rail. The fuel filter had previously been replaced as well as the plugs and wires.
Found that the fuel sending unit was leaking and replaced that as well as the attached fuel pump. This got me pressure (around 40 psi) at the rail and although the engine would catch it wouldn't run. Adding a little starter fluid would help it run for a second or two.
Looked like I was getting pulses at the injectors, spark at the plugs, and static timing seemed approximately correct. I jumped 12 volts to pin G at the OBD connector to force the fuel pump to remain on in case the oil pressure relay was shutting the fuel pump down but that didn't change the starting situation.
Still seemed like the engine was starved for fuel so ordered 8 Bosh III 24 psi re-manufactured injectors from ebay and installed them today. Vehicle started right up and idles fine. Took it for a couple of short rides and seems to run fine.
This Vette still needs lots of work to get it road ready but wanted to sum up this thread with the hope that it might help someone down the road. I've certainly gained much reading this forum and appreciate all the folks that relayed their issues and solutions.
Thank you all!
#19
Melting Slicks
Update: Replaced the fuel injectors and the 'Vette started right up!
Recap - This was a vehicle that had apparently sat unattended for years and happened to come across my path and although a novice in mechanics decided to take it on as a Fall/ Winter project.
The first issue (after installing a battery) was no pressure at the fuel rail. The fuel filter had previously been replaced as well as the plugs and wires.
Found that the fuel sending unit was leaking and replaced that as well as the attached fuel pump. This got me pressure (around 40 psi) at the rail and although the engine would catch it wouldn't run. Adding a little starter fluid would help it run for a second or two.
Looked like I was getting pulses at the injectors, spark at the plugs, and static timing seemed approximately correct. I jumped 12 volts to pin G at the OBD connector to force the fuel pump to remain on in case the oil pressure relay was shutting the fuel pump down but that didn't change the starting situation.
Still seemed like the engine was starved for fuel so ordered 8 Bosh III 24 psi re-manufactured injectors from ebay and installed them today. Vehicle started right up and idles fine. Took it for a couple of short rides and seems to run fine.
This Vette still needs lots of work to get it road ready but wanted to sum up this thread with the hope that it might help someone down the road. I've certainly gained much reading this forum and appreciate all the folks that relayed their issues and solutions.
Thank you all!
Recap - This was a vehicle that had apparently sat unattended for years and happened to come across my path and although a novice in mechanics decided to take it on as a Fall/ Winter project.
The first issue (after installing a battery) was no pressure at the fuel rail. The fuel filter had previously been replaced as well as the plugs and wires.
Found that the fuel sending unit was leaking and replaced that as well as the attached fuel pump. This got me pressure (around 40 psi) at the rail and although the engine would catch it wouldn't run. Adding a little starter fluid would help it run for a second or two.
Looked like I was getting pulses at the injectors, spark at the plugs, and static timing seemed approximately correct. I jumped 12 volts to pin G at the OBD connector to force the fuel pump to remain on in case the oil pressure relay was shutting the fuel pump down but that didn't change the starting situation.
Still seemed like the engine was starved for fuel so ordered 8 Bosh III 24 psi re-manufactured injectors from ebay and installed them today. Vehicle started right up and idles fine. Took it for a couple of short rides and seems to run fine.
This Vette still needs lots of work to get it road ready but wanted to sum up this thread with the hope that it might help someone down the road. I've certainly gained much reading this forum and appreciate all the folks that relayed their issues and solutions.
Thank you all!
Tapping on each injector with a block of wood and a hammer repeatedly freed up the injectors and the car started. It has run great ever since.