herbz28

iTrader: (1)

OK just ot give you a little history. original motor was pulled and a l03 was installed along with the tpi setup from the original motor. the motor was originally tbi. Anyways I have the idle set at about 900rpm. when i first start the car it idles at about 1500rpm sometimes a little higher till it is warm then slowly drops down. as i drive the car and i start to come to a red light when i push in the clutch it will drop about to i would say 700 but then shoots back up to about 1300 till i come to a complete stop then slowly it will drop back to idle. it will also sometimes get as low as 500 when it is idling. Any ideas? I am going to change the spark plugs and i have been running some marvel mystery oil in the fuel to try to clean some things up. i also pulled the air snorkel off and cleaned the throttle body it was kinda messy.

as for the cooling issue i know these cars run hot sometime but usually my temp stays around 200 but lately it has been getting around 240. i hear the fan kick but what kinda scares me is when iturn the car off sometimes i hear it gurgle in the overflow and then my gauge shoots up to the redzone(this happens then the car is turned off but then goes back to normal when you turn the car on.) It makes me nervous because it does not do it all the time. Could it be a bad water pump or a clog. i plan on flushing the system this weekend. Anything i could do to help this. Any help would be appreciated.
The car does have a few more quirks like once it stalled when i pulled up to a drive thru and pushed in the clutch. it just completely stalled but then restarted right after wards. Thanks again and appreciate the help

camaronewbie

Yikes!

1) I hope the swapper switched the fuel pump in the tank for a TPI pump - a TBI pump will not feed enough pressure for a TPI setup (if it runs at all, I guess they probably did).

2) Cooling - might just need a new fan switch - maybe a lower on switch. I assume most TPI cars had dual fans for a reason - maybe the single can't keep up by turning on at a later (hotter) time? Not sure - my 350 carbed does fine with a single TBI fan, but I run a seperate fan controller that's adjustable and I have it set to come on at 190, so I never see above 220 ever.

3) idle - I have no idea - you need to go through the entire swap, and make sure everything was done correctly. Even then, if the motor has TBI heads on it, might be enough restriction to confuse the TPI chip (since TBI heads are so restrictive). But I'd go through piece by piece and make sure all TPI sensors are connected and functioning properly.

Hard to imagine that anyone would swap a piece of junk like a LO3 into a TPI car. I guess maybe if it was just the block and the TPI heads were retained it might not be an issue. What about cam - have any idea which cam they used? TBI cam is about the smallest peanut cam there is, that would possibly confuse a TPI chip as well.

herbz28

iTrader: (1)

i am not sure about the cam. the heads have the center screw valve covers and . As for the fuel pump i can hear it kick on adn what not and the car runs great has plenty of power. as far as going thru the swap i am very unfamilar with the tpi setup so i would not even know where to begin i do hear some noise from the exhaust that sounds like a miss but i am just not sure. i will try to see if i can track down the owner that did the swap and see what is done to the motor. it also has the dual fan setup and i dont think one of the fans is kicking on i will have to check it out. thanksfor the responce camarownewbie

ASE doc

The uneven idle sounds a bit like a worn thottle shaft. When the throttle shaft develops excessive runout(worn shaft), TPS will be inconsistent and can cause inconsistent idle. Check the throttle shaft for runout. Use a voltmeter to check TPS and sweep the throttle a few times, watching for the base reading to vary from one sweep to the next. This is a sign of worn thottle bushings. Check fuel pressure while driving the car. Check the IAC for a damaged pintle or restricted passages.

herbz28

iTrader: (1)

your talking to someone that really knows nothing about throttle bodies.and where can i find the tps and what should the voltage be. i have a voltmeter but am unsure what i need to be doing. thanks again

ASE doc

The TPS is on the passenger side of the throttle body, opposite the throttle lever. It has a 3 wire connector. The wires are blue, black, and gray. You want to test for voltage at the black and gray wires(pins A&B). Voltage with key on and engine off should be about .5v. At wide open throttle, it should be about 4.5v. The main thing you're looking for is inconsistency in the voltage at closed throttle as you cycle it open and closed several times. Even .05v either way can confuse the ECM. Also, watch for glitches and drop outs as you slowly sweep the throttle from closed to wide open.

herbz28

iTrader: (1)

ok that helps alot and do i need the car running or can i do it with the car off and i just have a cheap volt meter what should i set the selector at? thanks again for all the help. I want to knip this in the butt as for the runout how do i check for that it has the double butterflies in it thanks again your awesome

ASE doc

You want the ignition on and engine off. Set the voltage scale at 20v. If the readings are lower than what I said, try the 50v scale. Cheap voltmeters have low input impedance and can cause inaccurate readings. The higher scales have higher impedance. Visually check for runnout by pushing and pulling back and forth on throttle lever. It should have almost no free play in it. The TPS test will also point out worn thottle shaft bushings.

herbz28

iTrader: (1)

thank you so very much i really appreciate it. i will check this when i get home and have my volt meter with me. thank you very much ase will check it tonight and post my results tomorrow morning dont have internet at home

camaronewbie

OK - that might have something to do with cooling then.

Dual fan cars - there is a primary and a secondary.

Primary fan is controlled by the computer - it gets it's coolant temp info from the sensor on/at the thermostat housing. And I believe it turns on at 217 or something.

Secondary fan controlled by the fan switch in pass side head between #6 & #8 spark plugs. It turns fan on when temp reaches something high (I think 238).

Also, secondary fan goes on with A/C.

If car has A/C, turn key on with car cool, and turn on A/C - if a fan comes on, remember which one - that is the secondary fan. Then run the car until it warms up with the A/C off, and see which one comes on - that is the primary fan.

If the same fan comes on with each occurrence, then your problem is in the fact that the ECM controlled fan is not connected properly, and thus no fan is running until the secondary fan kicks on at a much higher temp.

If the secondary fan comes on with the A/C, but not when the car gets above say 240, then your fan switch in pass side head is bad.

herbz28

iTrader: (1)

ok i checked the tps and it was off a bit wa reading kinda low so i adjusted it and got it set at .5 closed throttle and wot it was 2.45. i also changed the spark plugs and it helped with the idling. well i dont have my ac hooked up. i removed the belt and unplugged it so it does not turn on at all. would that be a problem at all?

ASE doc

When the AC is tuned on, or when in defrost, the head unit will comand the compressor to run and send a signal to the ECM to increase idle to prevent stalling from the added load of running the compressor. With the compressor belt off, you'll get increased idle speed, as high as 1,500rpm. When the AC Demand signal drops off, the idle will drop sharply. If base idle is not set right or if the throttles are coked, this sharp rop can cause stalling.

The voltage readings you're getting from the TPS tell me that your voltmeter is causing a false low reading. Or you have a problem in the 5v referrence circuit(unlikely). Try using a higher scale on your voltmeter. You really need a voltmeter with 10 Megaohm/V input impedance for testing the sensor circuits on that car.

herbz28

iTrader: (1)

would i still be able to test the fans even with the ac not hooked up is what i was wondering. I will just get a new tps sensor and solve all the problems. i am also looking at getting a new throttle body anyways. any recommendations? everything i am guessing is pretty much stock other than the original motor being a tbi and converted to tpi. also i had a plug i found on the drivers side near the drivers side rear valve cover. Any idea what it could be

ASE doc

The AC has no affect on the cooling function of the fans. The fans should function normally with the AC disconnected. When testing the fans, be sure the AC/Heater control is in the off position.

herbz28

iTrader: (1)

ok turned on the ac with the car cool and no fan kicked on. the other fan kicks on at about 230 i think and it turned off when it reached 220. is that my secondary fan then? i looked at the thermostat housing and i did not see any plug near or around it that would possibly be a temp switch. i will look again and see what i can find. there are a few people that live close by me that can help me with this

ASE doc

Just reading camaronewbie's post on checking the fans. He's telling you to use the AC to check which fan is primary and which is secondary. Also, using the AC tells you that at least the secondary fan itself as well as the relay are okay. I want you to go from there and test both fans using a jumper connected to ground to back probe the green/white wires on both fan relays. The relays are both close to the battery. you may have to loosen the battery hold down and move the battery aside to get to one relay. By back probing the green/white wire on each relay, you should get the corresponding fan to come on. Do this with the key on.

Check the FP/Fan fuse in the underdash fuse panel before starting the test. If the fans dont work, test for power on the tan wire with the key on. Test for power at the large orange wire. Does the relay click when you touch the grounded test lead to the green/white wire? If not, and you've verified power on the tan wire, you have a bad relay. If the relay clicks and the fan doesn't run, check for power and ground at the fan with the relay activated. If the fan is getting power and ground and not running, then the fan is bad.

Most often the cause of the fans not working are the temp sensors/switches. The primary fan is controlled by the ECM according to input from the ECM temp sensor. If the sensor is not reading correctly, the fan will not function correctly. This sensor, mounted at the front of the intake manifold, under the T-stat, will cause the engine to perform badly as well if it reads very far off. You can quickly test the primary fan by very breifly jumping the two terminals in the connector with a paperclip with the key on. The fan should activate when these terminals are jumped. Dont do this more than once or twice as it can be hard on the sensor input of the ECM. If the fan works when this test is peformed but doesn't work when the engine is hot, replace the ECM coolant temp sensor.

The secondary fan is controlled by a fan temp switch in the pass side cylinder head, bettwen and above 6&8 spark plugs. Grounding the wire to this switch should turn the fan on. If not, go back to the relay tests above. If the fan works when this wire is grounded but not when the engine is hot(240degrees), replace the switch. Be careful of all connectors not to damage them. Some you can replace from your local parts store, others are harder to find.

herbz28

iTrader: (1)

thank you very much ase that is going to help me alot. I do hear a fan kick on when the temp gauge is around 230 and then it turns off when the temop reaches 220. Do you have a picture or somewhere online where i could look at a repair manual photo? Again thank youso much for helping me out on this

ASE doc

I have the Helm's factory service manual, which I believe anyone who services their own car should have. When I'm working, I have access to Mitchell and All data. Honestly, I think that both Mitchell and All Data could do alot better when it comes to information on the 3rd gens. I dont have a way to post pictures from the book. You can find wiring diagrams by using the search tool. This forum has been going for some years and has compiled alot of solid tech info and diagrams in its archives. The search tool gives you access to all of that information.

herbz28

iTrader: (1)

[/IMG]is this my temp sensor for the thermostat sorry if the picture is so big this is located right under the thorttle body and right above the waterpump

ASE doc

The picture didn't post. Sounds like the one. The wires to it yellow and black.

herbz28

iTrader: (1)

is this better

camaronewbie

Sorry for creating confusion - if your A/C has been removed, then there is no pressure, thus the high pressure switch signal wire won't make a signal to turn on the fan, so that's not a good method of 'testing'. I was trying to keep it simple (since my wife insists I'm simple-minded ).

herbz28

iTrader: (1)

no worries i am just going to replace the temp sensor and also try and locate the sensor on the passenger side head ans replace that as well. i do hear a fan kick on when the car gets warm and if i remember correctly the fan that kicked on is the passenger side fan. Thanks again everyone for helping me so much with this. i am alsogoing toreplace the air dam seeing how it is kinda beat up

ASE doc

Im prety sure that the pass side fan is the secondary fan. It should come on about 240. Sounds like that one may be fine. Did you try the test of jumping the temp sensor connector? This will tell you if the fan, relay and wiring are okay.

herbz28

iTrader: (1)

i have not had a chance to jump them yet i am currently at work and just walked out to my car to see if i could locate it. I was not able to get to that particular plug because the alt bracket was in the way. i was also told that there is a sensor between the #1 and #3 cylinder is the temp gauge sensor and another sensor that is the fan switch sensor is below the #6 cylinder and that that sensor i posted is the tpi sensor to tell it when to go to into closed loop. Does that sound correct? when i get off work i am going to head over to my friends house and see if we can locate those sensors and test it.

herbz28

iTrader: (1)

ok here is what i found i checked the sensors the temp sensor on the drivers side was ok but when i checked the sensor on the passenger side for the fan switch it was broken and not connected. i opushed in the connector as far as i could and it seemed to stay in there so we will see what it does for right now till i can buy a new sensor thanks ase foir all your help u rock

ASE doc

The sender in the driver's head is for the temp gauge. The CTS for the ECM is at the front of the intake manifold. Good job on finding the poor connection on the fan temp switch.

herbz28

iTrader: (1)

could not have done it without you ase thanks again

ASE doc

Wow. Am I ever behind the curve here. Just now saw the photo you posted. That would be your CTS. Also just read post 25. The ECM only has one coolant temp sensor(CTS). The ECM uses the info from the CTS for many things, from temperature fuel correction, to operating the primary cooling fan.