ruff idle problems

[aaron92fox]

every since we switched my heads,cam,and intake over my car has been idling really ruff. up and down constantly and then die. sum times when it gets warm it will stay running?

i have replaced the tps and iac and its still doing it just not as bad now. there is a spacer plate behind the iac with some set screws in it to close off one of the ports? (not sure what it is really) messed with them a lil tonight and it seemd to help a lil but not completely??

any other things i can try to get rid of this problem?

[Gearhead]

every since we switched my heads,cam,and intake over my car has been idling really ruff. up and down constantly and then die. sum times when it gets warm it will stay running?

i have replaced the tps and iac and its still doing it just not as bad now. there is a spacer plate behind the iac with some set screws in it to close off one of the ports? (not sure what it is really) messed with them a lil tonight and it seemd to help a lil but not completely??

any other things i can try to get rid of this problem?


The IAC spacer plate is a band aid really. But, you may get it to idle somewhat better by backing out the set screws in the plate.

You did the base idle reset, checked TPS voltage, and timing, all that type of thing ??

[aaron92fox]

You did the base idle reset, checked TPS voltage, and timing, all that type of thing ??[/QUOTE]

you lost me on all that? :lol: how and what and what kind of tools.....

[blown96cobra]

Do you have a bend before your maf? Cold air intake, fenderwell type? If so yank the elbow off and bolt the filter on the Maf and try that, those damn things send turbulence through the maf and cause all kinda idling issues. Especially I u have a cam with more than 220 deg of duration at .050 lift.

[aaron92fox]

yeah its fender mount,ill try that tonight when i get home.

[jccox77]

i have a fender mount in 2 of mine both with cams and dont have that issue i dont have the spacer in the iac either have u tried takin out the spacer and reseting idle and checkin timin, tps and fuel pressure yet

[Gearhead]

You did the base idle reset, checked TPS voltage, and timing, all that type of thing ??

you lost me on all that? :lol: how and what and what kind of tools.....[/QUOTE]


Base Idle Reset Procedure
1. Clean TB with carb cleaner and nylon brush (toothbrush size). Engine off, fully open TB blade and spray/brush TB until all gunk and oil residue is cleaned.

2. Allow to dry, or close TB blade and start engine until it clears all carb cleaner fumes/liquid.

3. Let engine idle...if it doesn't, increase idle speed via TB stop screw until engine stays idling on its own.

4. Disconnect IAC valve, if engine dies repeat 3 with IAC disconnected.

5. Set idle speed to the lowest setting possible between 650-850 rpms with IAC disconnected. It is key to use the lowest possible to prevent idle surge, rolling, etc once the IAC is connected as follows.

6. Turn engine off, and reconnect IAC

7. With Ign On Eng Off, check TPS voltage output....if it's between .8vdc - 1.0vdc, it's OK. This voltage check should be done between the Green and Black wires at the TPS side connector as shown in the pic below (FYI: Green = TPS Signal, Black = SIGRTN, and Orange = VREF)....(-) terminal of the DVOM on the Black wire and (+) terminal on the Green wire.



8. Disconnect battery (-) for 3-4 minutes.

9. Reconnect battery, start engine, allow it to idle for 2-4 minutes to confirm setup,

10. If idle speed falls too low or stalls, increase idle speed via the TB set screw a little at a time.

11. Turn engine off for 20 seconds, re-start engine and repeat 9 - 11 if required.

12. Reconfirm TPS output is within the .8vdc - 1.0vdc range optimum range.

NOTES:

1. No need to reset ECM KAM (reset computer), the TPS minimum value used for idle control, is reset automatically by the EEC-IV every time the ign is cycled on-off for 20 seconds-on.

2. If the TPS output is within 0.6vdc - 1.1vdc, it's still acceptable, since no TPS failure codes will be generated, and it falls within the EEC-IV .5vdc - 1.19vdc working range.
13. Allow a 10-20 minute "relearning" period under normal driving conditions (drive cycle).....you're done!

[1992MustangDW]

you sure you don't have a vacuum problem?