C4 Corvette Exhaust
Safety Car
Joined: Oct 2008
Posts: 4,689
Likes: 4
From: Yucaipa CA
I am not sure on a 89 .... maybe by distributor .... My best friends 90 got plugged converters but never did what both out cars did. his just felt like it was pulling a boat and struggled above 60mph. His also got pretty quiet even though it had muffler eliminators. get the rpm up for like 3 minutes at night and look under car and see if exhaust is glowing
Last edited by jeffp1167; Sep 30, 2010 at 07:21 AM.
Burning Brakes
Joined: May 2010
Posts: 840
Likes: 4
From: High Point NC
I would ohm the injectors just to make sure. Truth be told a lot of shops will take full advantage of women, they try it all the time with my wife. Hell they even try to snow my father-in-law sometimes.
Anyways, it will only take 5 minutes to ohm them all out and make sure they are not the problem.
Anyways, it will only take 5 minutes to ohm them all out and make sure they are not the problem.
Racer
Joined: Jul 2010
Posts: 308
Likes: 2
From: Kansas City MO
I would check the fuel pressure when running and also how well it holds pressure when the engine is shut off. If the diaphram in the regulator ruptured you'll be running so rich and dumping fuel into the intake it'll barely run and when it does it'll be flooding out all the time...
Also - when is the last time all of the secondary ignition stuff was changed (cap, rotor, coil, wires, plugs)? You may have a simple secondary ignition problem that may or may not be masking other issues...
Also - when is the last time all of the secondary ignition stuff was changed (cap, rotor, coil, wires, plugs)? You may have a simple secondary ignition problem that may or may not be masking other issues...
Drifting
Joined: Mar 2002
Posts: 1,251
Likes: 2
From: Thomson Georgia
A P430 code is OBDII. OBDI will not show converter codes.
If you have a timing light, you can check the timing via the harmonic balancer timing marks. You can lock out ESC by unplugging the computer control control wire near the power brake booster on the wire loom, seems I remember brown in color. You can check the TPS setting to see if it is working, if it is not it could give you problems like you describe
If you have a timing light, you can check the timing via the harmonic balancer timing marks. You can lock out ESC by unplugging the computer control control wire near the power brake booster on the wire loom, seems I remember brown in color. You can check the TPS setting to see if it is working, if it is not it could give you problems like you describe
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
In post #7 of that thread, I showed the only single connector that was in my main harness -- where I THOUGHT the EST should be. But, in the 2nd pic of that thread, you can see a small portion of a tan/black wire just below the one I pictured. THAT was the EST. That wire headed over to the fuel pump relay harness as I said above.
My connector was taped to the bottom side of that harness, making it difficult to see. But it was there.
FWIW, someone else recently had a similar issue. It turned out their timing was off because their balancer had slipped. I think they'd reset their timing to the incorrect position where their balancer had (incorrectly) rotated.
Melting Slicks
Joined: May 2010
Posts: 2,082
Likes: 3
From: Conowingo Maryland
from what you are saying to me it sounds fuel related. I would test fuel pressure, flow, and quality (to make sure no water or contamantes). You need to elimate one thing at a time. If I recall right your car has a rev limitor that is only active in park or nutral when padel is held to the floor. If that is the case you will bounce around 1500 to 2000 rpms if held steady(someone correct me if I am wrong) testing exhaust efficenty is pretty simple. attach a vacume gauge at idle it should read about 20 slowly increase rpms vacum will drop when you get to about 3500 hold steady vacum shoud recover close to 20 I would say anything less then 16 would be of consern and that is when I would start looking at exhaust. Another test is to use a infered temp gauge. check temp going into cats and then exiting cats they should be close to the same with the exiting temp slightly hotter. if the inlet to the cats are hotter it is an indication that the cats are clogging.
Thread Starter
Instructor
Joined: Dec 2009
Posts: 236
Likes: 0
From: Houston Texas
Well today I fired her up again and I played around with the EST bypass wire put nothing happened but, It did start and it ran for a while (in the shop; didn't drive it) it was rough but I was able to keep it alive by feathering the throttle. So once it died after about 5 minutes of running with a very rough idle I tried to fire it up again and nothing so I decided to climb under the hood and see if there was any gas in the fuel rails, I pushed down on the nipple and it sputtered some gas and then air for about 2-3 seconds; I am not sure if the air should have been there but once it blew for about a second or 2 the gas started squirting out and it only did it for a couple of seconds, once I bled the fuel lines I tried cranking again but nothing it sputtered a few times and didn't start (could have flooded to prior cranking). I am starting to think that maybe it is the fuel pump, does it sound like it? If so do you know were I can get my hands on a new one for a good deal that will bolt in without excess work?
Thread Starter
Instructor
Joined: Dec 2009
Posts: 236
Likes: 0
From: Houston Texas
I would ohm the injectors just to make sure. Truth be told a lot of shops will take full advantage of women, they try it all the time with my wife. Hell they even try to snow my father-in-law sometimes.
Anyways, it will only take 5 minutes to ohm them all out and make sure they are not the problem.
Anyways, it will only take 5 minutes to ohm them all out and make sure they are not the problem.
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Burning Brakes
Joined: May 2010
Posts: 840
Likes: 4
From: High Point NC
That does sound exactly like when my fuel pump went on mine. Except mine happened 60 miles from home.
Racetronix who is a vendor here had a GREAT deal on their kit. You might search the FS section and find their contact information.
Racetronix who is a vendor here had a GREAT deal on their kit. You might search the FS section and find their contact information.
Thread Starter
Instructor
Joined: Dec 2009
Posts: 236
Likes: 0
From: Houston Texas
Thanks bud! I will read into it
Thread Starter
Instructor
Joined: Dec 2009
Posts: 236
Likes: 0
From: Houston Texas
Ok, I pulled the fuel pump to see if there was anything noticeably wrong and I dint see anything but I did see there was a "float" mounted to it, I assume it is to take readings on gas levels. So I peered inside the gas tank and I saw a white trey that I assumed the bottom of the pump fit into, but funny thing was I also noticed, I didn't see any gas
. now I know that this is not true because less then an hour ago the car was running like it had been running the last few days (which was crappy). Also let me clarify I did see gas but very little in the trey like a 1/4 inch, and the gauge told me I had about half a tank left before I pulled the pump.
. now I know that this is not true because less then an hour ago the car was running like it had been running the last few days (which was crappy). Also let me clarify I did see gas but very little in the trey like a 1/4 inch, and the gauge told me I had about half a tank left before I pulled the pump.
Last edited by C4 Monster; Sep 30, 2010 at 08:04 PM.
Drifting
Joined: Mar 2002
Posts: 1,251
Likes: 2
From: Thomson Georgia
That fuel well you're seeing in the tank is to help keep the pump covered in fuel during vehicle movements.
At half a tank, the top of the well would be covered with fuel. Half a tank on the gauge would be around 8 gallons, about 1/3 of a tank.
It sounds like you have a float or sender issue. Seems I remember the pump well has slots in the bottom to help keep fuel in there when the tank is low.
Repair the sending unit, or replace the float. The float is very light, 1 oz about. Heavy or sloshes, bad.
Take the fuel pump relay out, or unplug the oil pressure sending unit (3 wire), turn the key on and move the float level and see if the gauge responds to changes, if not, repair or replace.
Reason for stopping the pump from running, gas cools and lubricates the pump. Very low fuel level causes cavitation and will cause the pump to fail, if it hasn't already.
Ethanol is corrosive and is not a lubricant. Ethanol BAD.
At half a tank, the top of the well would be covered with fuel. Half a tank on the gauge would be around 8 gallons, about 1/3 of a tank.
It sounds like you have a float or sender issue. Seems I remember the pump well has slots in the bottom to help keep fuel in there when the tank is low.
Repair the sending unit, or replace the float. The float is very light, 1 oz about. Heavy or sloshes, bad.
Take the fuel pump relay out, or unplug the oil pressure sending unit (3 wire), turn the key on and move the float level and see if the gauge responds to changes, if not, repair or replace.
Reason for stopping the pump from running, gas cools and lubricates the pump. Very low fuel level causes cavitation and will cause the pump to fail, if it hasn't already.
Ethanol is corrosive and is not a lubricant. Ethanol BAD.
