89 TPI runs bad and has code 36
01-05-2009, 09:38 PM
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89 TPI runs bad and has code 36
Hi all,
I have an 89 6 spd that has recently started running like crap. Well it only runs bad at 3k rpm and higher when you are on the throttle hard. It is running great at part throttle, and even wot from 1k to 3k rpm feels normal. Once it gets past 3k though it just dies like someone stuck a cork in the throttle body. Ive checked the plugs and wires cap and rotor they are all great.
It had a code 35 and 36 so i removed and cleaned the maf (it was pretty dirty) and disconnected the battery to clear the codes. The code 36 came back which i believe if for the maf burnoff proceedure so i dont know why that would cause it to run rough.
The fuel filter was changed at 121k and car has 155k on it now, but until we bought it at 135k it had sat for a while with no gas in it. Thinking i may have just rattled enough gunk loose to clog the filter i bought a new one today but havent put it on yet.
I checked the air filter, and i also removed and cleaned the throttle body. I had it on the lift over the weekend and thought it could possibly be the precats were blocked (it has no main cat) so i gutted the precats. All of this has yielded a noticable improvement in performance in the range were it has been running fine, but it has made no change to the upper rpm problem.
Im hoping its just a blocked fuel filter, that would be a nice $12 fix, but i dont usually get that lucky. I do mostly highway driving and my gas mileage has been up around 24-25mpg. I have no idea when the o2 sensor was ever replaced, but id say its working ok with that kind of gas mileage.
I cant see why the burnoff proceedure for the maf would cause this problem, but its not kicking any other codes. It runs bad though and i want to fix it cause the way it runs now id lose a race to a school bus.
Thanks!
Tom
I have an 89 6 spd that has recently started running like crap. Well it only runs bad at 3k rpm and higher when you are on the throttle hard. It is running great at part throttle, and even wot from 1k to 3k rpm feels normal. Once it gets past 3k though it just dies like someone stuck a cork in the throttle body. Ive checked the plugs and wires cap and rotor they are all great.
It had a code 35 and 36 so i removed and cleaned the maf (it was pretty dirty) and disconnected the battery to clear the codes. The code 36 came back which i believe if for the maf burnoff proceedure so i dont know why that would cause it to run rough.
The fuel filter was changed at 121k and car has 155k on it now, but until we bought it at 135k it had sat for a while with no gas in it. Thinking i may have just rattled enough gunk loose to clog the filter i bought a new one today but havent put it on yet.
I checked the air filter, and i also removed and cleaned the throttle body. I had it on the lift over the weekend and thought it could possibly be the precats were blocked (it has no main cat) so i gutted the precats. All of this has yielded a noticable improvement in performance in the range were it has been running fine, but it has made no change to the upper rpm problem.
Im hoping its just a blocked fuel filter, that would be a nice $12 fix, but i dont usually get that lucky. I do mostly highway driving and my gas mileage has been up around 24-25mpg. I have no idea when the o2 sensor was ever replaced, but id say its working ok with that kind of gas mileage.
I cant see why the burnoff proceedure for the maf would cause this problem, but its not kicking any other codes. It runs bad though and i want to fix it cause the way it runs now id lose a race to a school bus.
Thanks!
Tom
01-06-2009, 07:57 AM
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Have you tested your fuel pressure ??
If your injectors are the stock Multecs, that could be a problem, also.
Check out FIC's sticky at the top of C4 tech.
Here is code 36 from my 86 FSM. Be aware that the fuel pump relay's connections are placed differently on your 89.
http://members.shaw.ca/corvette86/Code%2036.pdf
This pic shows the 89 relay connections.
If your injectors are the stock Multecs, that could be a problem, also.
Check out FIC's sticky at the top of C4 tech.
Here is code 36 from my 86 FSM. Be aware that the fuel pump relay's connections are placed differently on your 89.
http://members.shaw.ca/corvette86/Code%2036.pdf
This pic shows the 89 relay connections.
