still overheating
05-19-2004, 10:31 PM
#1
Burning Brakes
Thread Starter
still overheating
My 79 with a 89 TPI is overheating at highway speeds.New thermostat. seals,water pump
hses, aluminum radator,spal fans. I can run all day in traffic on a 90 degree day with the air on amd run 180 degrees. If I run the car and rev the engine at 3500 for about 5 minutes the temp runs up to 220. The center of the ram horns start to run red. Let the engine idle and the enginee cools to 180 in about 2 minutes. I am running true dual exhaust with no cats. is there a change when I was running a cat and when I removed it was empty. Could the media from inside the cat clogged the mufflers?????? :banghead: :banghead:
hses, aluminum radator,spal fans. I can run all day in traffic on a 90 degree day with the air on amd run 180 degrees. If I run the car and rev the engine at 3500 for about 5 minutes the temp runs up to 220. The center of the ram horns start to run red. Let the engine idle and the enginee cools to 180 in about 2 minutes. I am running true dual exhaust with no cats. is there a change when I was running a cat and when I removed it was empty. Could the media from inside the cat clogged the mufflers?????? :banghead: :banghead:
05-19-2004, 11:16 PM
#2
Le Mans Master
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Re: still overheating (toyvet1)
It sounds suspiciously like your timing is too far advanced or you are running way lean. I know very little about TPI, but I know that keeping Air/Fuel mixture in the correct range at all speeds and conditions is very important.
Since you have a TPI engine, you might try for some help over in C4 techical or look at the 3rdGen.Org http://www.thirdgen.org/newdesign/tech/
Good Luck!
Since you have a TPI engine, you might try for some help over in C4 techical or look at the 3rdGen.Org http://www.thirdgen.org/newdesign/tech/
Good Luck!
05-20-2004, 12:19 AM
#3
Re: still overheating (toyvet1)
You can tell if there is a clog problem by taking a vacuum test. Check the vacuum of the engine.....
Are you sure the sender is reading correctly? Did you change the sender recently. The current verision from AC delco, GM and most parts house's will not send the correct Ohms reading. Well's is the only company that I'm aware of that makes a sender that will give you the correct ohms reading.
Timing could be a issue too! As mentioned in a prior post.
Alum. Radiator... Why?
What pound rad cap do you have on the car?
Is the car boiling over?
Most later model cars will run between 180 and 200 with the air on. This is a normal temp range?
Red
Are you sure the sender is reading correctly? Did you change the sender recently. The current verision from AC delco, GM and most parts house's will not send the correct Ohms reading. Well's is the only company that I'm aware of that makes a sender that will give you the correct ohms reading.
Timing could be a issue too! As mentioned in a prior post.
Alum. Radiator... Why?
What pound rad cap do you have on the car?
Is the car boiling over?
Most later model cars will run between 180 and 200 with the air on. This is a normal temp range?
Red
05-20-2004, 12:51 AM
#4
Burning Brakes
Re: still overheating (REDRED62)
Timing..... check water pump.... Do you have dual electrics? be Cool radiator? GOOD LUCK
Also check your fan on off times....
[Modified by timbo79, 12:52 AM 5/20/2004]
Also check your fan on off times....
[Modified by timbo79, 12:52 AM 5/20/2004]
05-20-2004, 02:22 AM
#5
Le Mans Master
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Re: still overheating (toyvet1)
Ram horns starting to turn red reminded me of a thread like this one:
http://forums.corvetteforum.com/zerothread?id=224055
HTH
:seeya
http://forums.corvetteforum.com/zerothread?id=224055
HTH
:seeya
05-20-2004, 07:21 AM
#7
Le Mans Master
Re: still overheating (toyvet1)
hot exhaust manifolds.... Lean, or resticted exhaust, or RETARDED (not enough advance) for the RPM and load timing will cause that. Not in any particular order.
05-20-2004, 11:21 PM
#8
Burning Brakes
Thread Starter
Re: still overheating (toyvet1)
Okay I got home and started trouble shooting this evening. Checked for exhaust blockage by checking engine vacum. 19 inch vacum at idle, holds steady at 17 at 3000 rpm for about a minute. While care was revving I check exhaust output at tail; pipes seamed good but car has a slight miss/popping from both tips. Ingition timing is 6 degees at idle so I think that is in the ballpark.Will change cap rotor and plugs next.Fuel filter only has 2500 miles on it. Plan on indexing the distributor to timing mark tomorrow to double check it. Ecm shows no stored trouble codes. O2 sensor is only 1 years old.Any tips on checking if engine is running lean ?
