toms93lx

here is the deal i have a 93 lx 5.0 it has a hanging idle and ping.

when the car is cold it seams to runn ok but once it starts warming up when i get into the power (around 2,500 rpm) it pings and the idle seems to hang around 1,500 rpm ( seems like cruise control when driving) if i stop the car and let it sit it takes it about 30 seconds to calm down to 900 - 1000 rpm. sometimes when it is sitting idle it will run up slow to 1500 then back down to 1000-900 it will do this over and over but not all the time. example --- i could turn the car off and re start it and it wont do it but turn it off and restart it and it will.
these are the things that i have had done so far to try to figure this out ....
new tps.....new egr and egr position sensor...new pcv and screen..new egr vacumm switch....new O2 sensors.....new gasgets on all of the in take(minus manifold to block) had a speed shop do a vacumm check and fuel presure test ( they found no vacum leaks and fuel pressure was normal)-----new air bypass----new plugs.....new cap and rotor and coil and wires.......intake was cleeaned and had fuel system cleaned (drip bag for the fuel and fogger for the intake).....computer has been reset and idle has been reset......

i want to avoid taking it to a ford dealer but i am all out of ideas

any help will be help

oh one more thing dont know if it matters to you guys but ...i get about 150 miles out of 12 gallons of gas as far as performance it run pretty good but i think it should run better than it does

MustangBradley

Your timing is off. Have you ever had the distributor out? You could have reinstalled it one tooth off. Or, you just have it way too advanced. Set your idle back to stock and see if your idle returns to normal.

Or, for fun, loosen the distributor hold down bolt just enough so you can rotate the distributor by hand. Leave the spout connector in. Start the car, as it idles, turn the distributor slowly in either direction. Notice the change in idle speed. Now, pull out the spout connector. If the car dies, your timing is off a lot. All that spout connector does is tell the computer that the base timing has been set. Once the spout is in, the computer takes over the advancing of the timing.

Buy a shop manual for your car and it will tell you all you need to know about setting the timing and many other nuggets of knowledge.

toms93lx

one of the first things i thought was timing..... i have it set at 12 over instead of the factory 10......never pinged before then started to do it out of the blue.......ill try what you said but whitch way do you reset the idle....

the dealer ship and manual will tell you to just unhook the batery and re conect it and let the computer relearn .....but have had people on here tell me to unhook idle air bypass after unhooking the battery then hook up battery and start it up and let it run then turn it off and hook up the air bypass.... i dont it both ways ......now the only thing that ther dealer ship told me that i couldnt find in the manual was setting the tps.......the dealer ship will tell you to set the tps using the set screw not moving the tps and as long as it is inbetween .6 and .9 its good.....

fyi .......i can back my idle set screw out all the way and still wont get under 900 rpm .....when it should die shouldnt it .......

but the thing i wonder is seems ok when its cold.......

now how can i tell if the timming advancement module that is on the distributer is not faulty.....now old school carb cars you can rev the motor and see the timming advance with a light but .......dont these distributors with the module (not vacum advance) need to have the motor under load for it to advance corectly .......dont know just a thought

oh i never had the distributor out but could it have jumped some how

toms93lx

is everyone stumped ?

MustangBradley

The distributor would not jump a tooth. If this is a recent problem, then my theory of 'one tooth off' is not your problem.

Most of the big box auto parts stores can test your TFI. Search the threads on this site for how to do that. Also, there are threads to test the PIP as well.

I suspect a timing issue here but am unsure what the cause is. Once you do the tfi and pip troubleshooting, you should know more. Or at least it will eliminate those as the problem.

And do the KOEO and KOER tests.

fiveOH1985

what octane gas are you using? put in 93 and see if that stops the spark knock. if it doesnt, your timing is too advanced

toms93lx

hey guys ....FYI..... i think that i have a bad lifter or pushrod or need to adjust my rockers.......pretty sure now about that ........

i finally did the salt and pepper .....didnt change a thing...still hangs when it warms up........

what controlls the EGR Vacumm switch......i am get a code 84 and 91 and 41 but 91 and 41 are bogus becouse of the 84.....

i dont think my vacum switch is switching and its new ....so you know i havent checked the voltage ...i am going to but need to now what controls it

dreamer1uk

All those new parts you replaced, did you even test them before wasting your money on them??

41 - o2 sensor voltage low/always lean.
84 - EGR circuit failure.
91 - (depending on if you have a continuous code or if you did KOEO/KOER test) - shift solenoid or o2 sensor out of range/always lean.

Theres a few cases that could cause your issues as already described by a few of the replies in a timing issue. But also take into consideration that you may have a lower intake manifold gasket leak and/or stuck closed/open EGR valve.

toms93lx

hey i did the salt and peper fix and it didnt change anything.....


KOEO i only get code 84......

KOER i get 84 and 41 and 91.........

all my vacum is good but the vacum switch is not switching the egr
ford told me that when you get 41 and 91 at the same time , that it is for some other reason not the O2's.....

if my computer is sending the voltage to the Vacum switch and that switch is not getting that voltage ....why?.....is it my computer

toms93lx

ok i think i got it narrowed down to a problem with the circut for the egr vacum switch

i need to figure out how to test the signals from the O2's to computer and the computer to the egr vacum switch

how and what should i read