yet another surging idle problem!!!

[rhandwor]

Orginal equipment egr valves don't have a spacer. Just some aftermarket valves.

[Ian Szgatti]

Whatevr happened to testing the TPS.. any conclusive results? The MAP was replaced, but was that system vac checked?

[rnj]

I only have a dmm. I don't have a scanner to test the tps. I should be able to us the dmm though. I just need to figure out how to measure it.

[rhandwor]

What ever happened did you ever get the problem fixed?

[Ian Szgatti]

Originally Posted by rnj

I only have a dmm. I don't have a scanner to test the tps. I should be able to us the dmm though. I just need to figure out how to measure it.

If your interested, i could tell you exactly how to test the TPS with your multimeter. Let me know.

[rnj]

rhandwor, no I'm still having problems. (Although, it did pass emissions)I cleaned the egr, but it wasn't bad at all. Still not sure if it is leaking though. I need to find my vac tester. I do notice the temp gauge does not stay at 195*. I keep getting code 44, I was told that the ecm is sensing a rich condition, and is leaning it self out. I did read that the thermostat can cause a lean condition, but I'm not convinced on that. I do think it has somehthing to do with the timing. I did advance it a bit, and the car doesn't jerk as hard when I floor it. It still surges with a steady throttle in the 30-45mph range. I'm going to try to test the tps. At the same time I'm going to move the crank back and forth by hand to see how much play there is. I did notice that the chattering from the engine is not as noticable now. before it would chatter pretty consistently, but I have hardly noticed it now. I found a procedure on how to check the tps, but wasn't sure if it was right. This is what I found.

Throttle Position Sensor - Testing

Set DMM to read DC Volts.

Connect black COM lead probe tip to the TPS ground wire.

Connect red Volts lead probe tip to the TPS Reference Voltage wire.

Turn ignition ON. Do NOT start engine.

Look for a 5 volt reading - (some manufacturers may differ - verify correct reference voltage for the specific vehicle being tested).

If reference voltage is too high or too low, look for a problem with the wiring harness or PCM.

After establishing reference voltage is O.K., connect the red Volts lead probe tip to the TPS to PCM signal return wire.

Look for low voltage at idle position that will smoothly increase as throttle is applied. Any fluctuation of the DMM Bar Graph or erratic voltage readout indicates a bad sensor. Verify factory specs for low voltage (idle) setting, even one tenth off can make a difference in vehicle performance. The high (full throttle) voltage should reach at least 80% of the reference voltage.

Turn ignition OFF when test is complete.


If you guys can let me know if this is accurate I would appreciate it. And if it is do you know the specs I should be reading?

[Ian Szgatti]

Originally Posted by rnj

rhandwor, no I'm still having problems. (Although, it did pass emissions)I cleaned the egr, but it wasn't bad at all. Still not sure if it is leaking though. I need to find my vac tester. I do notice the temp gauge does not stay at 195*. I keep getting code 44, I was told that the ecm is sensing a rich condition, and is leaning it self out. I did read that the thermostat can cause a lean condition, but I'm not convinced on that. I do think it has somehthing to do with the timing. I did advance it a bit, and the car doesn't jerk as hard when I floor it. It still surges with a steady throttle in the 30-45mph range. I'm going to try to test the tps. At the same time I'm going to move the crank back and forth by hand to see how much play there is. I did notice that the chattering from the engine is not as noticable now. before it would chatter pretty consistently, but I have hardly noticed it now. I found a procedure on how to check the tps, but wasn't sure if it was right. This is what I found.

Throttle Position Sensor - Testing

Set DMM to read DC Volts.

Connect black COM lead probe tip to the TPS ground wire.

Connect red Volts lead probe tip to the TPS Reference Voltage wire.

Turn ignition ON. Do NOT start engine.

Look for a 5 volt reading - (some manufacturers may differ - verify correct reference voltage for the specific vehicle being tested).

If reference voltage is too high or too low, look for a problem with the wiring harness or PCM.

After establishing reference voltage is O.K., connect the red Volts lead probe tip to the TPS to PCM signal return wire.

Look for low voltage at idle position that will smoothly increase as throttle is applied. Any fluctuation of the DMM Bar Graph or erratic voltage readout indicates a bad sensor. Verify factory specs for low voltage (idle) setting, even one tenth off can make a difference in vehicle performance. The high (full throttle) voltage should reach at least 80% of the reference voltage.

Turn ignition OFF when test is complete.


If you guys can let me know if this is accurate I would appreciate it. And if it is do you know the specs I should be reading?

That procedure is right on the money. Low signal voltage to expect would be from .45v to 1v. High signal will be about 4v to 4.75v.

[rhandwor]

With your mileage and having to move the timing is a sure sign of a loose timing chain. I think it is stretched about 60 degrees and the computer keeps hunting finds a good spot then the timing changes moving the rpm up and down.
A new two piece timing set and gasket & seal with a readi sleeve is what the engine needs. 200,000 on the original set it is way past time. The parts will be cheaper than a tow home. Rent a propane heater for the garage and find a good warm day. You should be able to do this in one day.

[rnj]

How many miles is the timing set in this engine good for? and when I move the timing mark to see how many * it is off how can I tell for sure how many it is off by. I've only set the mark to factory before, but never payed attn to the marks. how is that read. I'm going to do the mark on the dist. also. I've come across some info on changing the iac. mentioned that you need to compare the old and new and set the new to the old. I just swapped it out, never payed attn to the two together. they both looked identicle. Is that somthing you need to do when swapping the iac?

[rhandwor]

Normally they were towed in around 150000 when I had a garage. The gear for the camshaft had a plastic coating and it wears and they either break off or it will jump a tooth. I may have had one towed in around 198000 to 205000 but I don't remember exactly.
Turn the dist. clockwise about 60 degrees past top dead center. Then turn it counter clockwise to top dead center. Pull the dist. cap use white out and mark where the rotor tip is above the dist case.
Have somebody watch the rotor as you turn the engine clockwise by hand with a ratchet when it just starts to move stop. Look at the timing mark on
the engine this will tell how much it is stretched.
If yours has never been changed and it is original equipment your are on borrowed time.

[rnj]

Does it matter where I get the timing set, what would you recomend??? Also, we've been driving the car they way it is, and I noticed that when I give it alot of gas, the heat when it is directed to the floor starts comming out of the vents until I let off the gas. I just noticed that. Was just curious.

[rhandwor]

I would just go to Advance Auto or Auto Zone I think they use TRW sets.
I think the vacuum drops when you floor it and with the age on the car you have some small vacuum leaks.

[rnj]

I found my vac. tester, what reading , or readings should I find. and do I need to test in different locs, ar just one.

[rhandwor]

Try to find a port on the intake manifold. Check it at idle and when gunning the engine. Also use a long hose and check the vacuum on the road. List the readings and we will try to interpret what you are getting. Be aware that timing affects the readings. Be sure to state if steady or fluxating.

[rnj]

I've been really busy lately, haven't had a chance to check vac. Just curious, will i have to remove the oil pan to change the timing set, or can I just drop it and reuse oil pan gasket?