weird idle and temp problem

[mrgetbig50]

so i finally got the car running because the wrong afm was on there. when i started it i noticed it was idling ridiculously high. after i adjusted the throttle cables and backed up off the idle stop screw it now idles CONSISTENTLY at 1100...so i took it for a drive and noticed it runs hot when sitting there..like it will creep up toward 3/4 of the way but when im moving it will go down to either half or just a hair over half...

i sprayed some carb cleaner around where vacuum leaks would be and nothing was found.

i bled the cooling system as good as i could and still does the same thing


could the dme be throwing out weird fuel maps causing it to run lean? that could explain the temp and idle problem

plz any help is appreciated...cuz once again i feel like this..:hitler:

[mrgetbig50]

o the engine is a m20 stroker...eta block with the 2.5 head...everything on the head is late model stuff..cooling system is the same from a 86 325es

dme is a 173 with a turbonoz ebay chip.....was running fine before installed in this car

[jlevie]

Running hot at idle is most commonly the result of a failed fan clutch.

[mrgetbig50]

would that also lead to a slightly higher idle speed?

[jlevie]

The fan clutch would have nothing to do with the idle speed. High idle is most commonly associated with intake leaks, but a bad idle switch in the TPS, a bad ICV, or a mis-adjusted throttle or TPS are possibilities.

[mrgetbig50]

Is there any way to test the tps and how would I go aboutadjusting the throttle body?

[jlevie]

You can use an ohmmeter to check the switches (idle & WOT) in the TPS. If either switch is bad the TPS must be replaced.

Correct adjustment of the throttle & TPS is done by:

1) Run the engine until it is at normal operating temperature
2) Disconnect the ICV and adjust the throttle stop screw for an idle of 950rpm
3) Adjust the TPS so that the idle switch closes when the throttle arm is 0.030-0.060" off the stop screw
4) Reconnect the ICV and the idle should stabilize at 750rpm

Before doing the adjustment make sure the TPS is good, that there are no intake leaks by having a smoke test run, and make sure the ICV is clean and it's vane moves freely. If after adjusting the throttle and TPS if the ICV doesn't buzz when the ignition is switched on, the ICV is bad, there's a wiring fault in the harness, or the DME is bad.

[mrgetbig50]

Ive also tried unplugging the icv and when I did nothing changed. What voltage should I be reading at the connector to the icv?

[jlevie]

Ive also tried unplugging the icv and when I did nothing changed.

That suggests that the ICV is bad, the TPS is bad or mis-adjusted, there's a wiring fault between the DME and ICV, or the DME is bad.

The first step is to check the TPS and possibly adjust it. Once you know that the DME sees the idle switch closing if the ICV doesn't vibrate with the ignition on, ohm out the ICV wires from the DME to the ICV. If they are good, swap in a known good ICV. If that doesn't help swap in a known good DME.

[hurttech]

Another quote from Jlevie.

The main relay and DME pin 18 receive power from the smaller of the to wires

that connect to the battery's positive terminal. That wire incorporates an

in-line fuse. When the DME is presented with a start signal, it grounds the

main relay pin 85 and furnishes power to the fuel pump relay, injectors, and

DME.

I'm fairly certain you have it hooked up right as the car more than likely wouldnt run at all.

[mrgetbig50]

Hey jlevie is here a certain chip or a tune that is necessary to make a engine like this stroker build run smoothly? Hurttech and I did the tps checks everything seemed to check out fine

[rjfurlan]

Correct adjustment of the throttle & TPS is done by:

1) Run the engine until it is at normal operating temperature
2) Disconnect the ICV and adjust the throttle stop screw for an idle of 950rpm
3) Adjust the TPS so that the idle switch closes when the throttle arm is 0.030-0.060" off the stop screw
4) Reconnect the ICV and the idle should stabilize at 750rpm

Nice instructions, but how do you get in there to loosen up the tps screws without taking off the throttle body?

[mrgetbig50]

Nice instructions, but how do you get in there to loosen up the tps screws without taking off the throttle body?

i think he means adjust it till it reads continuity at the given measurement...the pins that you read it at is in the bently manual

to get to it just remove the intake boot with those vac hoses just to make life easy

[mrgetbig50]

just plugged in a baum scanner and it spit out a dme code........ugh

[appelbaum]

Was there every a solution for this?