3500 24x cps

[gar70614]

my 3500 is runnin bad. its idles high then stalls or idles ok then chokes wen u try to bring the rpms up. my scan tool shows a bunch of codes but there all because the the pcms still lookin for a auto tranny that doesnt exist. no code for the 24x crank sensor but the scan tool shows 0 rpms from it? could it be malfunctioning or wired wrong causing the car to run badly? im not exactly sure wat the 24x input controls but any help would be awsome.

[sprucegagt]

The 24x sensor is used for minor timing changes for low rpm and idle quality. I'm pretty sure it's not used as an RPM pickup. The 7x crank sensor you should be using is your RPM pickup.

[gar70614]

on the scanner it shows the engine rpm but for the 24x it shows its out put in rpms and its showin zero?

[Superdave]

well.. is it plugged in? lol

[gar70614]

truthfully i havent checked yet lol but im 99.9999999999% sure it is. jw wat a non working sesor might cause an engine to do.

[60dgrzbelow0]

Have you done anything to (or perhaps recently swapped) your Throttle Body? Keep the Throttle Position Sensor in mind as being involved while you are looking around to solve the up and down idling problem. Doing your own TB Service would eliminate two sensors (TPS and IAC) from the problem equation as well.

[gar70614]

iac seems ok ive changed it with a few spares and nothing changed the tps however is diffrent story. it threw a code for it so i tryed another i had with no change. my question i have a throttle body for a 95 cav so should i use a cav or 660 tps? the tps shows like 46% persent at idle then 99% at wot? think i need to run a cav tps?

[gar70614]

o and checked today b4 te snow decided to start the 24x is wired right and its only 6 months old and but the cars only run a couple weeks so it might have 2 miles on it.

[IsaacHayes]

Uhm, TPS sounds bad... Or out of alignment.... No idea how a cav TPS compares. But put one on made for the TB to be sure... The voltage range will be the same but the position of how the TB moves it might differ so that might be your problem... But I've used a 3100 TPS on a 3.5 DOHC TB and they worked just the same...

[carbon]

Doesn't the 3500 only have the one wheel on the crank and neither the 24x or 7x? This is why it needs an external crank trigger for swaps...

[sprucegagt]

Yes. But the OP may be using a 3400 timing cover.

[gar70614]

im using the 3500 timing cover it has the three (think theres 3) holes for the sensor and a 3400 balancer for the timing wheel. the external is for the 7x for the icm because the 3500 has a 56x wheel on the crank

[gar70614]

does anyone know the symptoms of a bad 24x sensor? its not throwing a code for it but still stumped on to as why the pcm isnt seeing a signal from it? its new and i checked the wiring they r all correct (custom harness) so wat would a bad 24x cause.

[60dgrzbelow0]

sprucegagt has it exactly correct. But to elucidate the subject... here are two links to forum discussions that cover all the variations on the themes of what sensor is supposed to do what...( I know... I get the 3X and the 7X mixed up all the time, too) and the symptoms that arise when they misbehave. The attached photos are from the 3.4L engine sensors for the 93-95 F-Body...so your arrangements might differ slightly. Here you go...

http://60degreev6.com/forum/f100/no-spark-t43677/page2

http://camaroforums.com/forum/archive/index.php/t-28644.html

http://www.automotivehelper.com/topic535109.htm