Mancha87

Hello, I hope you guys can help me figure this out. I have an 86 camaro TPI all stock. The car will start and the engine will run beatifully untill I give it a little gas.

When I give I try to accelerate it, it dies on me. I can get it to stay on if I floor it. It will stay on once I get the car past 15 rpms, I just have to keep it revved. I got it take off like that & drove it around the block and I heard alot of popping under the hood. The mechanic could not figure out what it was. He wanted to start taking apart everything & anything it could be and replacing it.

My wallet cannot afford that. We already replaced the distributor cap+rotor & also the resistor+solenoid that goes under the distributor cap. Does anyone have any idea what could be causing this?

Also, my fans second fan starts running everytime turn the key to the on position. Something that it never did before, could that have something to do with it?

Mad_IROC-Z

This is where a shop scanner would come in handy. The mechanic should have been able to figure that much out.
Have you had a service or check engine light on? If so you need to check for any stored codes. Do NOT disconect the battery until you check for codes.

Also may want to replace you copmuter temp sensor. Its near the T-stat. If it has never been replaced it may have one yellow wire. New replacemnts have a yellow and a black that needs to be the ground. You may also need a pigtail if you have just the one wire and get a sensor that uses the two wire plug.

With a scanner the mechanic could compare what the computer seess the temp as and what the gauge says. But the sensor is not expensive.

Mancha87

There is a service engine code light on, I will search for the paper clip method on this board than get back to you with the error code. The mechanic did not have a shop scanner that would work for my yr car.

95 & up only he said. I guess the older machines are too expensive to keep updated

I will go out and check to see if the computer temp scanner has been replaced or not....Could this be the reason why my fans are kicking on everytime I turn the key foward?

Also would this cause my car to shut down everytime I try & accelertate?

Any idea why its making a loud popping noise under the hood?

Thanks,I really appreciate the help

chevymec

iTrader: (5)

Could be a clogged fuel filter or clogged cat.

9manastacio

iTrader: (4)

Whats your tps voltage at Closed throttle? Also, try unplugging the MAf and see if it runs better. What are the codes?

Mancha87

I could not find the computer temparture control sensor....It runs the same with the MAF sensor off as it does with it on. I was told that it was not suppose to run at all with out.

I don't know what TPS voltage is nor do I know how to check it and what does closed thorttle mean?

I will change out the fuel filter & see if that does anything. Also on the code, Icould not figure out how in the hell to read that thing....Correct me if I'm wrong but its suppose to flash 9X's before it gives me the code.

Than when it gives the code it will just flash the code out 3X's.

So if its a code 21 the light will just flash 21X's 3X's in a row....Right?

Mancha87

I changed the fuel filter, its not popping as much as it was earlier anymore. It only pops at low rpms once I get it in the twentys it does not pop anymore.

I took it out around the block and once I have it past twenty rpms it does not give me any problems but when I have to stop at a stop sign and take off again it starts trying to die and pop again.

Also it did something else very strange, when I was backing out of my driveway I lost power to my breaks...The car was still on but the brakes got really hard. Once I got out on the street the breaks started working fine.

Any and all advice is very much appreciated...thanks.

Mancha87

**Update**
Pinpointed the popping sound to the mass air flow sensor, I removed the part that holds my two air-filters in place and put my hand up to the sensor and I could feel the air popping.

Does this mean that its the MAF or is that just the only place that the air could possibly come out of?

I really do not want to go buy a new MAF if I dont have too. Thanks

Chevy86 IROC-Z

iTrader: (17)

that pop is the intake backfiring. Try adjusting your timing to 6* with the EST disconnected. The stalling is probably the TPS which is mis adjusted or failing.

Chevy86 IROC-Z

iTrader: (17)

Tune up your TPI system first. Then let us know if the problem persists.
1. http://www.highperformancepontiac.co...gta/index.html

2. http://mpikas.blogspot.com/2008/08/t...june-2000.html

Chevy86 IROC-Z

iTrader: (17)

Here a site that tells you how to extract the trouble codes. But the troublecodes here in the site are different so dont use the codes.
http://www.gnttype.org/maint/malf.html

Mad_IROC-Z

Thats a **** poor shop. I have a Snap-On Modis. Thats an expensive unit. Updates are expensive. But updates are for new model years! Pre 95 will not get updates as there is nothing new. And all the mechanic needs to do is look up the codes and watch the engine data. What a mook mechanic!!!

If you got your codes correctly and all you have is 21 that is TPS voltage high. If you have a digital multi meter back probe the center terminal of the TPS. The voltage at closed throttle should be .5 and at WOT 5v. The data on a shop scanner would show that.

Now my scanner has a graphing multi meter. With that while I am back probing I could open the sthrottle slowly and see if there are any drops. If there are then it would indicate a break. You can try this with your multi meter but open the throttle slowly as multi meters usually dont respond with a new reading quickly.

And if a Coolant Temp Sensor was unplugged the fan would come on as a default. Thats why I stay check the CTS and you will have one.

Chevy86 IROC-Z

iTrader: (17)

the fan could be operating in that manner if the fan relay has gotten stuck. Try tapping on the relay housing with a screw driver. Then turn the key. if the fan doesnt kick on, then the relay is the culprit in that scenario.

Mancha87

The sun went down on me....I'm calling it a day. Thanks for the heads up on the link chevy86 I will def look into doing all that good stuff once I can get the damn thing running right again. I am going to take it to another mech on tuesday & see if he can shed a little more light on the situation.

I will get back 2 you guys with an update tuesday. Thanks to everyone else that chimed in with some input.

305sbc

iTrader: (3)

The symptoms you described sound a lot like a failed TPS sensor. It could be something else, but that's where I would start if I were you. You can easily check that yourself and save some cash. There is a lot of info on this site about how to test it with a DMM. Just search for TPS adjustment.

Mancha87

**UPDATE**

Changed the fuel filter, no diffrence. Change Coolant Temperature Sensor.....Fans still kick on. I m going to look into that thread that was posted about the fans kicking in prematuarly.

Purchased TPS,IAC & MAF.

Firing order on plugs was the first thing I checked......more than once BTW and they are in the correct order.

When I installed the CTS the car kicked on but only if I hit the gas while I was turning the key and forced it to stay on. When I let off the gas it would die.

Also it was running worse than before, I think I may have caused more damage by not flushing the system for this cold weather, I just added antifreeze to the water. I know I know I'm a jackass. Now it sounds like I need new plugs and wires, probably even new distributor cap.

But I can bet a million bucks that even after that it will still run like crap, because of that stupid fan! I am going to try and fix that first than I will buy top of the line spark plugs,distributor cap & wires. (SUGGESTIONS ON BRANDS WOULD BE MUCH APPRECIATED)

Once I can get the fan issued resolved I will instal new MAF,TPS & I will prob take to MECH. for IAC cause I could not get the damn thing off today. first the socket was to damn thick than I bought a wrench and that crap was to thick also! PITA, I spent the whole day today out in the cold trying to get the damn CTS sensor off....Which I accomplised, did'nt fix **** but I got it done

But I could not get the IAC off..... Anyways thanks for the suggestions.

OH btw timing is a big concern for me but I need to get it into a shop for that. The car was running like **** before the fan issue started so I was gonna get it tuned up...all the works, even some f'n paint. But now I can't even get it running. I will keep you guys updated.

Mad_IROC-Z

Since you checked for codes and if you counted them out properly you did get a TPS code. That would be a good place to be checking. Do the tests for it. To properly install it you should have a multi meter (or scan tool with real time data) so it can be adjusted.

As for plugs and wires, AC delco or Autolite are good. Find a cap that has the brass terminals.

ASE doc

You need to stop throwing parts at this car. You've already spent enough to pay for a used scanner. The old Snap On MT2500 or "brick" as it's known by us in the industry, is available amost anywhere for about $350. It has the same basic scanner function as the MODIS mentioned above. Before you replace anymore parts, you need to start testing to see what's wrong. you may have installed a faulty CTS or have a poor connection. Did you do as instructed and install the replacement unit with a two wire connector? If so did you properly ground the low side circuit if needed? Did you perform a quality splice to the yellow wire if needed? if you already had the two wire CTS, is your connector okay? Also, if your old CTS was bad, your fuel trims may be way out of whack due to incorrect CTS data. It will take a minute for the ECM to adjust now that the CTS has been changed. You can reset the ECM by disconnecting the batt- for 30 seconds.

The cooling fan on your 86, as I remember, is run by a temperature switch which is located in the passenger side cylinder head, between #6 & #8 spark plugs. Check the wire to it for a short to ground.

Follow advice and check the TPS. Its most likely bad. Be sure to test the 5v referrence, and ground circuits to it. With a scanner you can easily test these circuits and the signal circuit as well.

JOHNB5000

The radiator fan switch is located on the passenger side of the block near the dip stick and starter motor. It has a mushroom shaped head similar to the knock sensor.

I replaced mine and the problem was fixed. Hope this helps

Air_Adam

Do you have the AC turned on? I haven't had a TPI car, but my LT1 camaro turns one of the fans on when the AC/defrost is turned on.

Chevy86 IROC-Z

iTrader: (17)

Thats normal operation. Only one fan turns on. The secondary turns on when the coolant gets too hot.

VincentZ28

iTrader: (2)

That car is an 86. It only has one fan not two. Your fuel pump is going out. Get a fuel pressure gauge that reads atleast to 60psi. Put it on the fuel rail, turn the key on and check the pressure. It should read 38-40psi. Anything less than that your fuel pump is bad. Funny no one has mention this to him. If its ok then you may need a ignition module. Its inside the distributor cap with wire plugged in to it. Oh yea!, check your fuses too.

VincentZ28

iTrader: (2)

84-86 cars don't have a radiator fan switch because they only have one fan. Dual fan cars have one. The computer an A/C controls the fan.

Chevy86 IROC-Z

iTrader: (17)

Even if the problem was a bad ICM, the ECM would spit out a code 42. Some 86 IROC's do have a dual fan system, IF the PO switched the single to a dual. You can also bypass the oil pressure switch by engaging a 12v jumper wire to terminal "G" to engage the FP without having to turn the ignition key.

Chevy86 IROC-Z

iTrader: (17)

I wish I remember where I read the info that Im gonna disclose, I read that the 86 single fan did in fact have a temperature switch on the passengerside head. It was used as a fail-safe device incase the ECM circuitry failed or if the Coolant Temp Switch failed. I could be wrong but Im just stating what I read a while back. What I do know is that popular to belief is that 305's had single fan and 350's had dual fans. As for the 1986 IROC-Z, actually there was about 50 IROC's that had dual fans and those where the 1986 350 TPI models that where used as test vehicles. Unfortunately the 86 350 was never released to the public.

Mancha87

My car does have a radiator fan switch, I found it today. I disconnected it and the fans still turned on so i did not bother replacing it. I am tired of throwing parts at the problem, I am just going to take it to an electrician on thursday and see what they tell me.

VIncent it is not the fuel pump I took it to a mechanic and they said the pressure was normal. On top of the that I just changed the pump about one month ago and I hear it priming everytime. Thanks for the suggestion tho.

ASE DOC, I am not that mechanically inclined nor do I have some of the tools mention above for checking TPS voltage.

I think this all revolves around that damn fan turning on. All my problems started when that started to happen. Hopefully the Elec. finds the problem and corrects it without taking an arm and a leg from me. Once that is taken care of I will tune it up with premium parts and get it painted...... I will keep you guys posted.

Thanks

Chevy86 IROC-Z

iTrader: (17)

Do you have a voltimeter or multimter? If you do, then you have what you need to check the TPS voltage. I have the single fan setup. But I dont know it the dual fan setup has a relay somewhere in the secondary fan wiring. If there is a relay, then tap on it with a screwdriver.It may be stuck. Last month at work, I turned on my IROC and the heater blower was on. I turned it off but the fan still was blowing hard. i switched the fan speed dial and it maintained the same speed. So I knew exactly what the problem was. I got my screwdriver and tapped on the relay next to the blower moter and problem solved. It clicked and turned off. i went back in the IROC and turned on the blower and sure enough, it responded accordinglily to the blower speed dial on my heater/AC controls. Verify if there is a relay within the secondary fan wiring. Dont just give up somthing so easily overlooked. Also check the relay (if equipt) for the AC system wiring.

Chevy86 IROC-Z

iTrader: (17)

http://92b4crs.tripod.com/86wiring/dia-pics/63-0.jpg AC Wiring diagram

http://92b4crs.tripod.com/86wiring/dia-pics/31-1.jpg Single fan wiring

Here is the page to a wiring diagram for our 86 IROC. i find it very valuable to me. http://92b4crs.tripod.com/86wiring/86wiringindex.html
Good Luck my friend.

Mancha87

I was actually looking into buying a multimeter they are pretty cheap but I will worry about that later, I replaced the CTS sensor & the fan is still turning on and I replaced climate control relay today which actually stoped the fan from runniing when I disconnected it but when I reconnected it the fan started running again.

This whole time I thought my car had two fans becuase I would hear it kick in @ 220 deg. BUT correct me if I'm wrong the fan does not even turn on unless it gets to the that temp. The car depends on the Air Dam & water to keep it cool.....

So when you say to check the secondary fan wiring what do you mean? I don't have a secondary fan.......

Either way I disconnected the radiator fan switch to see if that would make the fans stop running but it did not.....So I can only assume that there is a short somewhere, I do not have the time to check every little thing. This car is my daily driver & I am tired of relying on rides to take me to & from work.

Chevy86 IROC-Z

iTrader: (17)

HAHAHA. You thought your cooling sytem had 2 fans? Okay then. there shoud be a relay somewhere near the battery. There should be 4 wires coming out of it. One wire is controlled by the ECM (which grounds itself within the ECM). That wire is dark green with white. The other wire leads directly to the thick orange wire which is directly connected to the battery. The other wire is Black and red and it goes directly to the fan. The other wire from the fan is bolted or screwed into the ground (body). Finally the tan/white wire leads to the fuse under the steering column.

So forget the dual fan setup junk.

Coolant fan is turned by the ECM once the Coolant Temperature Sensor (not the Coolant Temp Switch, nor the Coolant Temp Sender) senses the coolant at 220*. To test IF the ECM is working properly, get a multimeter and put the selector to check the continuety. This test will tell you if the circuit is open or closed (closed as in a complete circle and open as in a break in the circuit). To better understand open and closed circuit, a light bulb turns on when the circuit is closed and it turns off when the circuit is open. So now that you understand what checking for continuety means (open or closed circuit), we can now test the coolant fan circuitry within the ECM. Get one probe (THAT'S WHAT SHE SAID ) and ground it to the car body or to the negative battery post. Now you'll have to expose the DARK/GREEN wire to expose the wire. Put the other probe in the wiring. Now turn on the Camaro and let her heat up to 220*. Monitor the multimeter the whole time!!!! If the display on the multimeter reads the number " 1 " even when the temp passes 220*, then the ECM may be bad. But once the temp reaches 220* and the multimeter begins to display a number around 500-900, then the ECM is good. This test is best performed with a pair of alligator clips.

Mancha87

Definatly learned something there...open closed circuit example. I appreciate you breaking that down for me. no BS I really do. I replaced the relay your talking about today and I would be more than happy to test it with a multimeter the way you said but at this point the car will no longer fire up.......

ASE doc

The cooling fan will also run whenever the AC is on, regardless of engine temp. An easier way to test ECM fan relay drive is to connect a test light to battery positive terminal and hold the probe tip against an exposed portion of the green/white wire. the light will come on when the relay driver activates.

Mancha87

ASE DOC clarify that for me a bit, is the green/white wire you are talking about the one that hooks up to relay that 86 IROCz was talking about? Also does the car have to be on?

Chevy86 IROC-Z

iTrader: (17)

Damn!! Less complicated. You got me on that one ASE Doc!
Below is an explaination of the wiring at the Coolant Fan Relay.

Chevy86 IROC-Z

iTrader: (17)

Yes. The Green/White wire is what we need to verify. That wire will tell us if the ECM is working properly once the temp reaches 220*. But if the test light turns on if the engine is cold, then the problem is the ECM OR the wire is grounded somewhere (shorted). But if it is shorted (green/white wire), I believe the fan will turn on even with the Camaro off.

Chevy86 IROC-Z

iTrader: (17)

Remember though, that Green?White wire will ONLY have 12 volts when the ignition is switched to "ON". It will not have current with the ignition off.

Chevy86 IROC-Z

iTrader: (17)

Damn man. If I lived close to you, I would help you on this one. But I live in SoCal. Way Too Far.

92_camaro_rs

i need help with vats can someone plz help me

92_camaro_rs

btw its a 92 camaro rs and i have no key for it to test the resistance? what do i do i want her to run

Mancha87

92 camaro RS start your own thread bro. Hi-jacking is not cool! Especially not when we are finally starting to make a little progress!

Now I feel like we are making some progress. I did what you guys said with the voltometer & without the key even in the ignition the fan turned on as well as the light in the voltometer.

In-fact the piece of crap did not turn off even after I disconnected the alligator clip from the positive terminal. So this means I do have a short/ground somewhere. Or a bad ECM. Where do I go from here?

Chevy86 IROC-Z

iTrader: (17)

wrong thread my friend. start a new thread here ( https://www.thirdgen.org/forums/tech-general-engine/ )
or ( https://www.thirdgen.org/forums/electronics/ ).

Chevy86 IROC-Z

iTrader: (17)

Sorry bud. There must be a short or the there is a 12 volt source that may be spliced into a wire or wires. Did you modify or rewire anything with the fan wiring system? Its OK to admit guilt. We are here to help you. I'll be back in an hour or 2. I gotta play husband and father for a little bit. The wife is breathin down my neck. Last night she asked me why I spend so much time on ThirdGen.org. I told her that the computer doesnt talk back to me. Boy did she get mad .

Mancha87

LMAO @ your response to the wife. I appreciate all the help dude. I have not modified anything that connects to the fan. I would not even know where to start messing with any of that stuff.

I did have to splice the wires for the CTS when I replaced it. It was probably not the best quality splice in the world, how would I check to see if its getting any power without the car having to turn on?

Oh & a few months ago in a failed heater core replacement attempt I disconnected the ECM cause the F'n thing was in the way but I soon there after abandoned that project cause I could not get to that hard to reach screw. No I did not forget to reconnect.

Chevy86 IROC-Z

iTrader: (17)

OK. First thing we need to do follow each of the four wire all the way to its destination to make sure that there is no short or extra splices. Its quite obvious that the Dark Green/White wire is feeding a 12 volt signal while the Camaro is off. SO trace that wire as far as you can, inside and out. Also follow the diagram that I provided you. Make sure the wires are connected the proper way. If you can take a picture of the coolant fan relay for me, I will try to get to the bottom of this. Also snap a shot of the wires too.

rayar

iTrader: (1)

Did you ever get it running right? It allmost sounds like a vacuum leak to me. No help on the fan issue. Good luck

Chevy86 IROC-Z

iTrader: (17)

When you put the CTS back together, did you match up the yellow with yellow and blue with blue? Also what was the method that you used to join the wires? I would HIGHLY suggest that you go to Autozone to get a roll of lead free solder and a soldering gun. Also get some "heat shrink tubing." Do not use electrical tape. After time, the stick adhesive will stick to the bare wires and you will lose contact. So what you gotta do is solder the wires together to make a no fail connection. But be sure to slide the heat shrink tubing before joining the wires or you will have to cut the wires agian to slide in the tubing. Maby thats the reason why the Camaro wont turn on. IIRC, the temp of the engine at start up is neccessary so that ECM can know how much fuel to inject upon start up. I think this plays a critical role with the 9th injector.

Chevy86 IROC-Z

iTrader: (17)

ASE doc, doesnt the CTS play a critical role when cranking the Camaro?

ASE doc

Absolutely, without CTS input the ECM has no idea how much crank fuel enrichment to add.

Mancha87

Took the car to an electrician he told me that their Scanner was not communicating with my ECM. They told me they wanted to replace the ECM.

I already purchased the ECM is replacing it relativly easy? Is their anything special I have to do to get the new one to work properly?

ninetyone

iTrader: (2)

disconnect your battery first,also, could be a bad prom. install new ecm drive it or let run a few min, then check for codes again.