samiam91RS

did the paper clip trick and got those 2 codes..34 and 43.
supposedly the code 34 states

MAP sensor circuit error (signal low indicating high vacuum)

so, quick run down..the setup was from an 89, and its a 5.7 TPI..it DID have a MAF setup and now that I have a 91 its running as a MAP...

so, high vacuum, as in a leak i suppose? heres another run down, after the swap theres two connections on the right side (passanger side) of the actual TPI throttle body. two connections vertical of each other, both have no lines and are poorly "capped off" with rubber caps that are split open and are not sealing anything..so im wondering if this is the deal. that maybe they belonged to the used to be MAF or whatever.
other than that i have no idea what else could be causing it. after doing a search on it, ive seen ppl say it could be the burn sensor, IAC, FP regulator and other stuff. but im not just going to dump money on stuff thats not necessary at the moment,

however, itll start up and run pretty good when cold, but after warming up a bit it runs, idles rough and will eventually cut off. i do, however, have the stock injectors and will be replacing those soon, but 1st i want to fix the discrepancies of the trouble codes. any help would be greatly appreciated. sorry to make this long, but i also wanted to give a good visual for everything thats going on. as far as a code 43..knock sensor, im guessing ill just replace it as it could be bad...?

thanks in advance everyone.

racethesunlive

I have almost the same setup you have now... had a '89 350 put in and changed over to map from maf. I had the 43 error as well! Replacing the knock sensor made a huge difference in how well the engine was running and also how much power i was getting out of it. Definitely take care of the code 43 knock sensor problem first

samiam91RS

thats what im thinking also now that i know what it is...especially since the knock sensor was a hand me down and it could have either been faulty from the start or just been abused before being installed.

i also read that they're very fragile. i was also thinking that...i think the knock sensor is for a 350, but my PROM chip is for a 305...so im wondering if that is throwing it off...?

i doubt it, but i need to do something, its shutting off on me, running poorly and getting HORRIBLE gas mileage...

I also noticed that one of my spark plug wires are arcing..somehow the rubber is split and exposed..im guessing from the heat of the headers..so need a new wire or even a complete set..even though theyre fairly new wires....but i still doubt that one wire is causing all this..

racethesunlive

When you get a code 43 bad knock sensor the car goes in 'limp home' mode... aka dumps in gas and takes the timing way back. It thinks something is causing a constant knock and tries not to damage the engine further. That would explain your horrible mpg and poor running engine...

I've heard that different knock sensors 'listen' at different voltages so yes the 305 would be different from the 350 sensor (mine was just rusted to death)

hope changing out the sensor fixes your problems!

samiam91RS

well that makes a lotta sense...and that also explains why its been doing that ever since the swap was all complete..just have no idea why its starting to bog down and run like crap now..then again it probably never ran to its full potential.

so im trying to think if i should put a 350 knock sensor in to replace...or a 305 knock sensor..since there is a 305 prom chip in it.
but, im thinking that a 350 chip will work fine and that the one that was given to me was jacked up in the process or install or just a bad one...since i found out that they screw into a water jacket and they can go bad or get rusted out..like yours.

thanks for the info.

LAFireboyd

iTrader: (3)

Your profile says your engine is a 5.0, but you said the "set-up is from an '89, and it's a 5.7 TPI." So you mean the TPI set-up(only) is from a 5.7, and you're swapping it onto your 5.0? Or are you saying the engine you're working on is actually a 5.7? Because regarding the knock sensor, it makes a difference, so you need the correct one.

The MAF system('85-'89) does use a different knock sensor than a MAP system('90-'92). Also, a 305 uses a different one than a 350.

At the bottom of this page for TPIParts it shows the knock sensors for all the different years:
http://tpiparts.net/82_92_camaro_sensors?b=1

But a local auto parts store would be easiest, and Auto Zone also lists different knock sensors for different years and engine sizes.

John 89 Formula

the ports on the throttle body are for the air breather (top) in the pass valve cover, and the, i think, charcoal canister. I'm pretty sure that they both pull vaccuum so if your not going to use them they need to be properly blocked off.

LAFireboyd

iTrader: (3)

Yes, as John said, the ports on the throttle body are: top port is for the valve cover breather(a metal tube, though I've seen people replace that tube with a hose); middle port goes to the solenoid on the evaporative emissions canister; and the bottom port is for throttle body coolant flow, which you can bypass, if you haven't already.

samiam91RS

sorry about that..i swapped from a 5.0 TBI to a 5.7 TPI, and the 89 engine (which is the 5.7 TPI) is whats sitting in my engine bay as of now. the whole set up from oil pan to plenum. sorry for the confusion..
so, thats what i meant, like i understand the engine is a 350, so i need a 350 knock sensor.
BUT the PROM chip is for a 305, and i was told that ill just need a tune and ill be ok.
so, will the 305 chip bump heads with the 350 knock sensor?

correct the engine was an 89 with a MAF but now its a MAP since its in my car, 91, to pass emissions...so im guessing when they ask what year engine for parts, i tell em its a 91..?

samiam91RS

i checked it out again and what i saw was the bottom most valve is all capped off with a hose clamp..the next one (middle-ish) goes to like the valve cover on the pass side (like you stated) through some tubes..
and the top one, has a rubber cap on it but its not clamped down at all and is a huge leak if thats a vaccum type port..

im guessing if that top one isnt needed (for whatever its ment to go to) ill just cap it off and hope that thats what the code is getting it from.

thannks for the info

samiam91RS

there is a rubber hose going to the valve cover, but im thinking it was the middle one, and the top one had nothing being routed to it at all.
yea the bottom most one is capped off good, so i dont need to do that.

im just hoping that the top one that has nothing, i can capp off and it'll be alright still.

p8dnful

I have a '90 Iroc-Z with a 5.0L TPI and I'm having similar issues to what you're having. I changed the Cap & Rotor, Ignition Module, Coil, and Spark Plugs thinking that would solve the problem. That didnt help so then I changed the Knock Sensor and MAP sensor. After that I found out that the Timing was off. Every time I set the initial timing to 6 degrees like the specs ask for the car runs beautiful with full power for about a mile or so then it gives and runs like crap all over again. The computer advances the timing for some odd reason. The computer isn't throwing out any codes NO matter how much of a rough idle it has. Does anyone has any idea where the ESC Module or ESC Sensor is located?
As for the Throttle Body ports... the top port connects to the PCV valve on the valve cover. The middle port connects the EVAP Canister and the bottom port is for the coolant. There's a Schematic Blueprint on page 4-32 in the Emissions section of the Chilton Repair Manual for 1982-1992 Camaro. Both the 5.0L and the 5.7L has the same set-up

samiam91RS

i think the esc module is located under the hood on the driver side...from a picture i seen when i did a search some dude posted a pic with some stuff pointing out what was what.
looked like it was by the master brake cylinder.
thanks for the info but im still kinda confused and cant see my chiltons till i get back home (on vacation)
i was gonna ask if anyone can post a pic of theirs please showing the TPI throttle body setup with the hoses?
tried to find one in a search, but no luck so far

LAFireboyd

iTrader: (3)

Ok, here ya go... None of my own pics are close enough to see it clearly, so I did a search of the net for pictures of TPI engines, and this is one of the better ones I found for seeing the hoses connected to the throttle body. It's an '86 Trans Am.

Top port: there's a short hose connected to a metal tube, and that tube curves downward(you can see it disappearing behind the alternator), then runs along the base of the runners back to the breather in the valve cover.

Middle port: small hose, and it goes over to the evaporative emissions (smog/charcoal) canister, and it connects to the solenoid on the top of the canister.

Bottom port(throttle body coolant exit port): it's a heater hose... usually connected to the heater diverter valve. But in this pic, the person has deleted the diverter valve and has the heater hose going directly back to the heater core. This is the port that can be bypassed, so yours might not have a hose connected there.

samiam91RS

thats deff weird then..i think mine is all backwards. if im not mistaken (and ill double check as soon as i get home from work) my top one has nothing, the bottom one, capped off and the middle one, is connected to the valve breather cap..like i said ill double check and ill also post a pic of how its set up. but im sure whatever it is, its causing it to also act weird. thanks for the run down and the pic, i appreciate it. get back soon

LAFireboyd

iTrader: (3)

Here it is again, but I've cropped that area out of the pic, enlarged it, and I've done some really hi-tech colorizing LOL.

top port, white = valve cover breather. You see it disappearing behind the alternator, then it turns back and runs underneath the wiring harness at the base of the runners, and you see it again at the back where it comes up and over the harness and connects to the breather.

middle port, green = evap canister hose. Your canister is probably on the drivers side, being a Camaro, so your hose would have to turn toward that direction after it leaves the throttle body.

bottom port, red = throttle body coolant passage exit. That's where the heater hose exits the throttle body and would normally connect to the heater diverter valve before running to the heater core. In this pic, he's deleted the valve, and the hose runs to the heater core directly.

samiam91RS

dude thats an awesome run down, and i thank you for that!

so, now i see whats all messed up...my top one is the one thats poorly blocked off, and the MIDDLE one is whats going to the breather cover! so im going to switch em around and run a new hose to the black canister, and yes it is on the driver side...ill post pics also. wow i sure hope this mix up fixes my problem..

samiam91RS

on the evap can, im holding the "plug" that was inserted on a connection that looked like it could be from a hose that runs off the TB. is this it?
and do i have to run a hose from that port to there? or can i cap it off? either one, is no biggie.

samiam91RS

alright, so i swapped hoses and had to o to the store to get a 3/8 size hose for the top connection, ran it to the valve cover. and the middle one i routed all the way to the charcoal canister with 5/16 size hose, bottom one capped off and bam started her up, ran kinda funky for a min and then idled nice and smooth..reset the comp and started back up and no more code 34!

thanks for the help everyone and i sure hope this post can help others in the future if theyre doing a swap or something.

took it for a ride and it was hella more powerful even with the bad knock sensor still, so im happy for the moment, didnt know that was causing that much of a problem