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Hello!
So I bought a 1987 Corvette It has been a fixer-upper lately coincidentally when I changed the Coolant temp sensor I realized the car was running really rich and running rough. I decided to take a look, I pulled a code 44 and inspected the spark plugs which were fouled with I believe black soot and smelled like gasoline. I also smelled the oil which smells like gasoline as well. Just to help make a justification here is my smog paper which says it failed HC under 15mph note that this was a week before my car started running rich and idling rough badly. Please if I can get a good answer as to what is wrong with the Vette, im afraid it could be bad oil piston rings but I'm not too sure. Also I can smell gasoline from the engine bay. before all this happen i've changed
FPR
MAF sensor & Relays
Coolant temp sensor
TPS & IAC
O2 sensor
Knock sensor
Last edited by mmadsen124; Nov 13, 2023 at 06:38 PM.
Unless you changed the oil after the FPR your risking your bottom end, next if you still have the Gassy oil the car will have a hard time adjusting it's emissions.
I also would not be surprised if at least your valve seals aren't Worn or stiff
Unless you changed the oil after the FPR your risking your bottom end, next if you still have the Gassy oil the car will have a hard time adjusting it's emissions.
I also would not be surprised if at least your valve seals aren't Worn or stiff
Yikes I guess i'll check my valve seals just in case, I've only driven the car like 5 miles after its rough idle and gasoline smell.
I suppose on my list is new spark plugs, fuel injectors, an oil change, and a valve seal inspection.
Your smog results show 0% O2. This is indicative of a rich condition. (There is more fuel than Oxygen available to burn it. O2 readings of 2-3% are nominal.) Surprisingly, your Nox is below limits, which indicates the cat converter is effective.
That plug is sooty, but not shiny-damp such as would be expected with a bad (leaking) injector. Do all the plugs look about the same? If yes, it is a global problem, and not isolated to just a cylinder or two. Or, those plugs are too cold a heat range. That Denso plug appears to be a K16PR-U11. It cross-references to a bunch of plugs, including many that are significantly colder than the Delco FR5LS that is OEM for the 87. (EDIT: This is incorrect. The FR3LS is the OEM plug for the 1987. The FR5LS is correct for the 88-up which is what I thought the OP had when I wrote this. I know the heads changed for 88, and it looks like the plug heat range did too.) I'd try to find Delco FR5LS and use those. The heat range of a FR5 is going to be hotter than that Denso that is in it now. A little hotter plug will help idle quality in city driving conditions.
You changed several parts. Did it run correctly after all the parts were changed, or did it begin to run 'rich' at the same time you changed the parts? One hint: There are two basic "one wire" O2 sensors for these early cars. A black wire sensor and a purple wire sensor. They can't be interchanged electrically, but fit in the same hole in the pipe. Does the replacement O2 sensor have the same color wire as the original that came out? ( I think the 87 uses a purple wire sensor, but don't hold me to that. It's been a long time.)
What is the fuel pressure when it is running? Both with the hose on the pressure regulator, and with the hose off. Can you access or borrow a scanner and read the BLM and INT values? (These will be <128 in Closed Loop for "rich".)
I wouldn't worry about "valve stem seals". Worn seals cause blue smoke on start-up, but generally aren't anything to fret over. If your seals are original to the car they've been bad for at least 20 years. Nothing to worry about now.
I would definitely change the oil soon if it smells like gasoline.
There's some ideas and suggestions. Cheers.
Hi thank you for the reply,
Im buying FR3LS (aka #41-629) which is what the manual recommends. So since I bought the car I didn't notice a gasoline smell, but the day after I noticed a slight rich smell coming from the exhaust. over time it got stronger. I started to do some maintenance as I was getting engine codes such as code 44,33,22,54. As I was swapping parts those engine codes cleared up. The only code I have left is 44. After replacing so many parts I realized that my car still had a hard cold start so I did some research I found out it could be a bad coolant temp sensor which they were right, as I swapped it out the car started up in two seconds but it started to run really rich smelling like gasoline, misfiring and idling rough. I let it run for 5 minutes hoping all the new parts I put in meant the car just needed to adjust itself but it still was running rough so I shut it down and decided to inspect the car, The oil smelled like gas and the spark plugs were fouled. The O2 sensor I swapped in is GM AFS21 Oxygen sensor which did look a bit different from the original one. I will inspect the wiring and all that as you stated, tomorrow. If it helps it threw the code 44 before I put in the new O2 sensor. Also, all my spark plugs are fouled.
Last edited by mmadsen124; Nov 13, 2023 at 11:04 PM.
EDIT: I took everything in this post down for now. Clarify this, please: Do you have a Code 44 or a Code 45?
Code 44 is "Lean Exhaust Indicated". A rich condition should be setting Code 45. If it IS Code 44, this makes no sense. Let us know.
Hi,
Yes i'm certain. I triple checked it says code 44 which is quite odd. Tomorrow i'm going to wipe the codes and put in new spark plugs then cruise around and see if I get a code 44 again. Also yes my vacuum hose to my fpr still smells like gasoline, and the CTS I changed is the cts at the front of the intake under the throttle body.
Last edited by mmadsen124; Nov 14, 2023 at 01:31 AM.
The injectors might be way too big. I would check the part number on them and see what lb/hr they are rated at
So I looked around the injector without taking it out. Only thing I was able to makeup was 5235211 PP 3D 660 on the sides, complete black finish. Looking at other forums I believe this part is 5235211-350 p/n 17111418. This is part seems to be meant for a 1986 while my car is a 1987, this part is also obsolete. Which may explain why I can't really find it online. These injectors are probably old as hell so maybe I should change them anyways. I also ohm tested them, they all seem to be healthy, but im sure the ohm test isn't the best test for functioning injectors.
Ok. I'm stumped. How can an engine that is running rich be setting the lean code? (And it is rich. The 0% O2 on the smog test is proof.)
Pull the pressure regulator hose off with the engine running. Does fuel come out of it? If yes, the new regulator is bad.
I looked at the injectors in your pic. While grainy, they appear to be the original Bosch EV1s that were used in the 86-88. These injectors are very reliable, and don't develop the issues from ethanol that the Multecs (1989-1991) do. If yours ohm out correctly, they are probably ok.
Alright so I just changed the oil nothin that unusual just the gas smell like we talked about, also inspected the 02 sensor I replaced too looks fine and the connector is away from the tailpipe to prevent bad ground. But the biggest concern is why the hell is there a hole in my transmission!?! I'm assuming if this was a major problem my car would've blown up by now, and I found this orange sensor* with a torn wire, never seen this before. Should I be concerned, I know sounds silly to ask 99.99 percent of the time the stuff in your car is there for a reason. so any thoughts? Gonna replace the sparkplugs and test the fpr like you said and use the fuel pressure gauge.
The Cut out in your Flex Plate cover Simple someone was to lazy to remove the cover when they were probably trying to find TDC and couldn't find by bumping, So they butchered. Easy Find in bone yard.
The Plug is a Wheel sensor It will be fine as is just Dab a little RTV to seal the crack, worst you would get is a Wheel Sensor Code and sensor isn't cheap.
Ok. I'm stumped. How can an engine that is running rich be setting the lean code? (And it is rich. The 0% O2 on the smog test is proof.)
Pull the pressure regulator hose off with the engine running. Does fuel come out of it? If yes, the new regulator is bad.
I looked at the injectors in your pic. While grainy, they appear to be the original Bosch EV1s that were used in the 86-88. These injectors are very reliable, and don't develop the issues from ethanol that the Multecs (1989-1991) do. If yours ohm out correctly, they are probably ok.
Alright so I changed the sparkplugs, booted up the car and the gasoline smell went away also unplugged the fpr and didn't see any fuel come out while it was running didn't smell gas fumes from the thing too. However, the car has a bad idle that dies. using the fuel pressure gauge. I turned the ignition to ON psi went from 20 then dropped down to 0 in the span of 5 seconds. Started the car and the psi stayed at 42 consistently. During that run time, no new engine codes popped up. I assume the only way would be to drive it around though later on.
What is the ambient temperature where you are ? '87 vette has a cold start injector with a temperature switch and it is probably introducing extra fuel on your start-ups . The only significant fuel pressure reading is while the engine is running . Pressure drop-off typically will only affect cranking time before starting .
What is the ambient temperature where you are ? '87 vette has a cold start injector with a temperature switch and it is probably introducing extra fuel on your start-ups . The only significant fuel pressure reading is while the engine is running . Pressure drop-off typically will only affect cranking time before starting .
Those injectors look original and need to go. They can't handle the ethanol in today's gas and had a tendency to short. They are likely the cause of your FP not holding with the key off.
Also, how's your vacuum at idle? There's a lot of old brittle vacuum lines in there.
Those injectors look original and need to go. They can't handle the ethanol in today's gas and had a tendency to short. They are likely the cause of your FP not holding with the key off.
Also, how's your vacuum at idle? There's a lot of old brittle vacuum lines in there.
Well then, guess i'll switch those injectors out, what oem injectors are up to date for the 1987 corvette? Also ya almost every vacuum line is old as hell, any good recommendations where I can get good vacuum lines?
What do ye know, these injectors are all gummed up. hopefully, this is the final solution to my problem. then I'll be passing that smog test and cruising. Gonna give my EGR a clean and some vacuum line replacement. Should I delete the cold start injector, if I do will the car have a hard start?
Last edited by mmadsen124; Nov 21, 2023 at 03:14 AM.
1987 Corvette what is wrong with it?
