surging idle.

nvno1 · 08-26-2009, 08:45 AM

Good day folks,

I have done a ton of research and starting to lose it.

I figured that i might have to look elsewhere for some ideas as to what could be the cause, as my friend Kent says "sometimes it takes a second set of eyes to help fix the problem" and he has done so. Now that we got the car started the idle is a issue.

Any help would be great and I would love the feedback.

The detail are as such:
87 TII(s4) ecu, motor,tranny, wiring harness, TMIC and walbro 255 fuel pump. Got her to run but she is idling really rough. Boucing from 1000rpm to 1800rpms at a one second pulse. I have checked for vaccum leaks it doesnt appear i have any, my bac is not working i got that disconnected, runs cool (not getting hot), good compression 85psi frnt and rear, good oil pressure, fuel pressure is good, the ecu checks out fine as per testing with FSM sect4. The only think that is weird is the check connectors are not reading showing any response. no volts no nothing.

Rotary#10 · 08-26-2009, 12:34 PM

did you check your TPS?

nvno1 · 08-26-2009, 02:19 PM

Quote:

Originally Posted by Rotary#10

did you check your TPS?

sure did. that whats so strange? everything seems to be in order.

Phoenix7 · 08-26-2009, 02:22 PM

have you been taking the UIM on and off? maybe a bad leak after the AFM?

***TitaniumTT*** · 08-26-2009, 03:21 PM

85 psi is not good compression. Factory minimum is 88psi.

Regardless, a bouce that big is likely the result of a huge vac leak. Are your secondary butterfly's closed all the way? What are the "hg readings during the bounces?

nvno1 · 08-28-2009, 07:28 AM

Quote:

Originally Posted by Phoenix7

have you been taking the UIM on and off? maybe a bad leak after the AFM?

sorry for the delay in responding i have taken the UIM off twice, however the gasket is new and when i sprayed carb cleaner to check for vac leaks there is no change.

nvno1 · 08-28-2009, 08:15 AM

Quote:

Originally Posted by TitaniumTT

85 psi is not good compression. Factory minimum is 88psi.

Regardless, a bouce that big is likely the result of a huge vac leak. Are your secondary butterfly's closed all the way? What are the "hg readings during the bounces?

oh its not good. thanks for the info then. i was under the impression that 80 was the min. i used a regular compression tester with the little valve gone and it was old. the markings on the face were a little hard to read as it jumps from 70psi to 100psi in increments of 30 with smaller marks in between. i will try to get another gauge this weekend. the hg reading are like -5/-7@1000rpm and when she spikes up to like 1800rpms its like -12/-15. i will video the event hopefully today or this weekend.

08-26-2009, 12:34 PM	#2
Rotary#10 Rotorhead Join Date: Sep 2008 Location: "the town " Oakland iTrader: (1) Posts: 219 Rep Power: 17	did you check your TPS? __________________ Currently running: 90 GTUs converted to S5 TurboII. Track car. 90 N/A GTUs.. Running project car 89 N/A GTUs in Black #2 10/6/18 Blown coolant seal undergoing rebuild and restomod.

08-26-2009, 03:21 PM	#5
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son iTrader: (4) Posts: 4,581 Rep Power: 10	85 psi is not good compression. Factory minimum is 88psi. Regardless, a bouce that big is likely the result of a huge vac leak. Are your secondary butterfly's closed all the way? What are the "hg readings during the bounces? __________________ -The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. *-Angry Motherfcker Mode ENGAGED-**

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

08-26-2009, 08:45 AM	#1
nvno1 FB 4life Join Date: Aug 2009 Location: nc iTrader: (0) Posts: 32 Rep Power: 0	surging idle. Good day folks, I have done a ton of research and starting to lose it. I figured that i might have to look elsewhere for some ideas as to what could be the cause, as my friend Kent says "sometimes it takes a second set of eyes to help fix the problem" and he has done so. Now that we got the car started the idle is a issue. Any help would be great and I would love the feedback. The detail are as such: 87 TII(s4) ecu, motor,tranny, wiring harness, TMIC and walbro 255 fuel pump. Got her to run but she is idling really rough. Boucing from 1000rpm to 1800rpms at a one second pulse. I have checked for vaccum leaks it doesnt appear i have any, my bac is not working i got that disconnected, runs cool (not getting hot), good compression 85psi frnt and rear, good oil pressure, fuel pressure is good, the ecu checks out fine as per testing with FSM sect4. The only think that is weird is the check connectors are not reading showing any response. no volts no nothing. __________________ Dont be sorry, be careful.