The RenX Files: High idle problems

[mntllycrzy]

does anyone have a wiring schematic for this circuit???

 

[KonstantinXJ]

IAS drivers to Renix ECU is TDA2004

http://www.alldatasheet.com/datasheet-pdf/pdf/25037/STMICROELECTRONICS/TDA2004.html

:scottm:

Konstantin Grijznov.

 

[mntllycrzy]

i'm sorry, i don't understand how that was supposed to help

 

[B.RAIDER]

OPPS............Posted in wrong thread..............

 

[mntllycrzy]

is the tps supposed to be set at .83 or .2? is it the same for auto and manual?

 

[Ecomike]

is the tps supposed to be set at .83 or .2? is it the same for auto and manual?

The ECU side of the TPS (manual or automatic), (87-90 years) should read 0.83 V at idle, ignition switch power on, engine off.

 

[mntllycrzy]

The ECU side of the TPS (manual or automatic), (87-90 years) should read 0.83 V at idle, ignition switch power on, engine off.

so it is the same for manual and automatic? and i still check between B and C?

 

[Ecomike]

so it is the same for manual and automatic? and i still check between B and C?

Yes.

 

[mntllycrzy]

so now that i'm totally stumped do i take it to a dealer?

 

[Ecomike]

so now that i'm totally stumped do i take it to a dealer?

PM with the whole story, all the details, start to finish, year.....etc.

 

[mntllycrzy]

all the details are in the previous postings

 

[89xj]

so now that i'm totally stumped do i take it to a dealer?

did you get the tps wet when you cleaned the throttle body?

have you tried a new tps?

 

[mntllycrzy]

i didn't get it wet, i took it off the throttle body when i cleaned it. didn't use any water just gum cutter. i reset it to .83. now it idles really low at start up and it idles up higher the hotter it gets

 

[mntllycrzy]

i also tried a known good tps from another jeep, same effect

 

[mntllycrzy]

i also cleaned the air filter, i can't imagine that had anything to do with it

 

[89xj]

so it's taken me two days of reading this thread and fartin around with the heep. I've checked, cleaned, and tightened the ground on the block, and on the firewall. I have set my tps at .83v. i have checked and replaced vaccum lines, i have checked and tightened manifold bolts. the throttle body was removed and cleaned, and the problem still persists. when i start it up, the heep idles perfect right around 700-750. once i start driving the idle sticks up at 1500-2000 rpm. this actually all started when the throttle body was removed and cleaned and reinstalled. so at this point i'm pulling my hair out and i'm stressed out over it so any help would be great. I'm pretty sure that for some reason the iac is not closing. the iac was removed, cleaned, and reinstalled. i even tried swapping it out with another jeep. i tried disconnecting the battery and leaving it disconnected. when i take the air tube off of the throttle body and the engine is running, if i put my thumb over the hole that the iac sucks air thru it idles down to about normal. so i'm pretty sure something is telling it to stay open. any thoughts?
by the way, this is an 88 4.0 with m/t. it's a 4dr laredo.
thanks in advance

if this all started from removing the TB than recheck all your work. throttle linkage, TB gasket leak....

ive heard of people putting the arm of the TPS on the wrong side if the throttle linkage.

here is a shot in the dark that i have done on my 89. i put the vacuum line that goes to the bottom of map on the screw post of the map and not on the vacuum port. also check that the map vacuum line to the side of the TB is on the correct port. IIRC, the port on the side of the TB is a rubber piece that appears to have 2 holes when there is only one that the line can fit into.

your problem has to be the result of pulling off the TB to clean it.

 

[mntllycrzy]

i've had the tb off three or four times since the initial cleaning. i have replaced the new tb gasket with another new tb gasket. the vac port on the side of the tb is plugged in, i didn't remove it from the map sensor so it shouldn't be wrong. the only throttle linkage i disconnected was at the arm on the tb itself and there's only one way for it to go on. the problem definitely increases with temp i'm thinking. on cold start up it barely runs, then once it is warm it idles up to 2k. if i try another tps, one from an automatic, what happens if i plug in both connectors?

 

[Ecomike]

i've had the tb off three or four times since the initial cleaning. i have replaced the new tb gasket with another new tb gasket. the vac port on the side of the tb is plugged in, i didn't remove it from the map sensor so it shouldn't be wrong. the only throttle linkage i disconnected was at the arm on the tb itself and there's only one way for it to go on. the problem definitely increases with temp i'm thinking. on cold start up it barely runs, then once it is warm it idles up to 2k. if i try another tps, one from an automatic, what happens if i plug in both connectors?

Sounds like an intake manifold or exhaust manifold leak that increases in size and air flow rate as the engine warms up.

Disconnect the O2 sensor, and see if it stops. If it does stop it is the exhaust manifold leaking at the gasket or a crack in the manifold.

Check for loose manifold bolts, top and bottom.

 

[mntllycrzy]

i have an automatic tps, do i plug in both sensors?

 

[Ecomike]

i have an automatic tps, do i plug in both sensors?

You only need the flat 3 pin connector to be connected. The square 4 pin connector is for a TCU, Transmission (automatic) computer which you do not have or need since yours is a 5 speed manual transmission.