problems when cold

crazyguy · PostPosted: Tue Dec 28, 2004 5:44 pm

what can cause poor throttle response when cold? when my car is cold it fires up just fine but has some pretty bad throttle response untill its warmed up. its ok if you accelerate slowly but if you open the throttle up to far to fast its not just a matter or it bogging down from getting to much throttle but it acts like its not getting any fuel. probally a bad explanation but i'll try to answer question if anyone has some that would help figure this out.

The Ethereal · PostPosted: Thu Dec 30, 2004 10:34 am

It could be a bad coolant temp sensor.

HondaHunter · PostPosted: Thu Dec 30, 2004 8:52 pm

5-spd or auto?

mines having someone of the same problem cause of my loose connecting/wasted "thermo-switch, but appearantly its only on the automatic cars

crazyguy · PostPosted: Thu Dec 30, 2004 10:03 pm

5spd. and I realized its not just when its cold, its all the time, just not as bad when hot. tested temp sensor(took awhile to find out how and what readings I was looking for) and its not good, tested TPS and it seems ok but I still ok but I gotta test my spare to see if its better, the way the car acts with different throttle it makes me thing its the TPS. im going to sit down with my spare parts and carefully test them.

HondaHunter · PostPosted: Thu Dec 30, 2004 11:44 pm

just change out the bad temp sensor first, and it the problem persists, see what else it could be, remember process of elimination will always work, not replace what i think is broken.

crazyguy · PostPosted: Fri Dec 31, 2004 12:11 am

yah thats what I will be doing. im just checking all my spare parts as well though to see if any of it is worth keeping. if I do change the TPS how do I adjust it properly?

The Ethereal · PostPosted: Fri Dec 31, 2004 5:10 am

Adjust the TPS to an output voltage of 0.48-0.52 Volts. You'll have to have the ignition on to do this.

crazyguy · PostPosted: Fri Dec 31, 2004 12:08 pm

?? my book only told me how to test the TPS by disconecting it and probing it with an ohmeter, to check voltage do I just probe the wires with it connected while the ignition is on?

slowx2 · PostPosted: Sat Jan 01, 2005 6:15 am

a good way to test the tps as follows:
get the thinnest sewing pin you can find and push the point through the middle wire on the tps wiring connector. switch the ignition to ON but dont start the engine, the measurements will be slightly different with the engine running.
Wait for fifteen seconds after turning the ignition key on.
then measure the voltage between the pin and the -ve battery terminal (or any good ground point) with a digital multimeter. with the throttle closed the voltage should be 0.48 - 0.52V. if not then adjust the tps to get the voltage in this range by loosening the screws and rotating the tps.
then smoothly hand-open the throttle; the voltage should increase smothly up to 4 or 5 volts (an analog meter is good for this).
make sure that there are no jumps or discontinuities in the voltage curve. the tps is just a variable resistor, like a volume control on an amplifier, and when they wear out their value can jump around if the wiper leaves the track, or if there is dirt on it.
remove the pin when you're finished and there should be no real damage to the wire.

NB: this is the process for my '91 excel, and i think it will be the same as for your car. the fifteen sec wait is to allow the throttle positioner in the 91 excel to reset, but if your engine has a idle bypass valve you may not need to do this. also if you made an adjustment to the tps, make sure you reset the ecu.
sorry for the long post.

Flying Eagle · PostPosted: Sat Jan 01, 2005 11:24 am

Don't worry about long posts, you posted up some good info and that is all that counts. People that just post-whore and post up multiple threads pertaining to the same thing before waiting for responses are the big offenders on these types of forums. If you have more info like this to share when people have problems, just put it up.

crazyguy · PostPosted: Sat Jan 01, 2005 3:44 pm

thats exactly what I needed to know. thank you. the stupid chiltons manual I have for mine(apparently haynes does not make a manual for the '92 colt) is almost useless. it gives the test as using an ohmeter which I have done but it dosn't tell how to adjust it if you have to replace it

what would be nice is to find a writeup or get somebody to do a writeup on how to test each sensor and and what the car will act like if that sensor is broken or not working correctly so we can just go straight to that sensor and test it.

Flying Eagle · PostPosted: Sat Jan 01, 2005 9:04 pm

Seriously broad spectrum of functions and properties to cover with what you are suggesting. I would suggest in retrospect that finding a full service manual like these .....
Repair manuals - the 5 W's
http://www.4g61t.org/phpBB2/viewtopic.php?t=9574

I have been through all kinds funky problems but nothing covers them like the factory manuals. I have the Chilton manual and it does a good job and even covers the Vista models but factory is still better in this case.
Most little problems are something that people can keep posting up as they get spotted fairly easily. The factory electrical manual includes sections on diagnosing and fully testing the functions of all serviceable sensor and moving pieces with electrics involved. There is an online manual located at http://www.geocities.com/berserko_1/c50/

I've found some other online reference materials but a little searching is in order!

slowx2 · PostPosted: Sat Jan 01, 2005 9:50 pm

sorry, i should have mentioned this in the other post, but i forgot about it.
my excel used to have a similar problem to what you described in that it bogged badly when i tried to accelerate before the engine had warmed up fully, and later happend at all engine temps. i initially thought it was a fuel problem, but in my experience ignition problems are more common, so after changing plugs, dizzy cap and rotor, fuel filter and replacing injectors for a reconditioned set (had to be done anyway) i finally replaced the spark wires, and this fixed the problem! because i hadnt changed the wires since i started playing around with this car, all the pulling off and puting on again must have done something to them, or else it was oil and dirt mix, and they must have been arcing to the head at low revs - medium load (2K). anyway, dont rule anything out with your iginition until you try it because to an inexperienced person like me, my problem seemed just like the engine was not getting any fuel rather than an ignition misfire. hope this helps some, cos this was a very annoying problem for me and it took me ages to find the cause.

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problems when cold

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