Fast idle after lean backfire through manifold

[Fix4Dirt]

Dang.. I knew I should have kept that old Toshiba lappy.. I'm kind of surprised it doesn't work with Win 11. Not like 11 just came out. I'll keep shopping. TY

yep np

 

[J_C]

If you don't want to do any programming (which you can't on an '00 anyway), I'm happy with my bluetooth BAFX and using my android phone as a host. The full (not really "full", is called "Lite) version of Forscan is $7 not free for android, but the free demo version will do one PID (sensed value) at a time which is enough for many purposes including long term fuel trim.

However I don't know if it supports whichever CAN version the '13 Civic might use. I'd still prefer a bluetooth (or wifi if for use with an iPhone) dongle that doesn't need a laptop, as something I keep in the glovebox and can use at a moment's notice. I mean I do have a laptop and USB bluetooth dongle I can use to connect to it if I need the full windows version of Forscan.

Since the Civic uses canbus, you might just get one of those little $8 translucent blue dongles for it in addition to one for the Explorer, then keep one in each vehicle. Unfortunately it is hit or miss if those support the J1850 that the Explorer uses, even when it's specifically stated that all vehicles '96 and newer are supported. That's exactly the case with the little blue dongle i keep in my '14 Explorer, works fine with it but won't work on the '98.

 

[Motorhogman]

Maybe this ??

BAFX Products ANDROID Bluetooth OBD2 Scanner Code Reader diagnostic Tool Elm327 | eBay

Find many great new & used options and get the best deals for BAFX Products ANDROID Bluetooth OBD2 Scanner Code Reader diagnostic Tool Elm327 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[Motorhogman]

If you don't want to do any programming (which you can't on an '00 anyway), I'm happy with my bluetooth BAFX and using my android phone as a host. The full version of Forscan is ($6?) not free for android, but the free demo version will do one PID (sensed value) at a time which is enough for many purposes including long term fuel trim.

However I don't think it does HS-CAN which the '13 Civic might use. IDK. I'd still prefer a bluetooth (or wifi if for use with an iPhone) dongle that doesn't need a laptop, as something I keep in the glovebox and can use at a moment's notice.

Since the Civic uses canbus, you might just get one of those little $8 translucent blue dongles for it in addition to one for the Explorer, then keep one in each vehicle. Unfortunately it is hit or miss if those support the J1850 that the Explorer uses, even when it's specifically stated that all vehicles '96 and newer are supported. That's exactly the case with the little blue dongle i keep in my '14 Explorer, works fine with it but won't work on the '98.

Funny... I was shopping and look at what I found..

 

[J_C]

^ That's one of the ones I have, works great on my '98, but I don't know if it supports your Civic. Does it use HS-Can or need MS-Can? The BAFX can't do MS-CAN AFAIK, unless they released a newer version that can. Last I knew, you had to add a switch and do a wiring mod to make it support both HS and MS Can.

Your '00 uses J1850 so for it, this CAN situation doesn't matter.

More info:

Modify BAFX OBD2 Adapter MSCAN using FORScan? - TopScanTool

How to modify BAFX OBD2 in to add the HS/MS CAN switch? Reading DTCs in all of 5 HS CAN modules and 2 MS CAN modules will always require only 1 shift.

topscantool.com

 

[J_C]

Hmm, there is a new development with Forscan for Android. Google Play blocked their account, or something, it's confusing. They pulled the app a couple years ago but put it back up, and took it down again a few times, and changed the API, and now it seems Forscan developer is tired of this game.

Get on Google Play now and search "Forscan" and it doesn't list it, but I can still find the Lite version on Google Play using a web search, it is here:

https://play.google.com/store/apps/details?id=com.astech.forscanlite&hl=en_SG&gl=US

Support Request

Support Request

Anyway, looks like new android version users have to get it (Lite paid version, OR the free demo version) from Forscan's server directly instead of Google Play.

Download FORScan

 

[Motorhogman]

Hmm, there is a new development with Forscan for Android. Google Play blocked their account, or something, it's confusing. They pulled the app a couple years ago but put it back up, and took it down again a few times, and changed the API, and now it seems Forscan developer is tired of this game.

Get on Google Play now and search "Forscan" and it doesn't list it, but I can still find the Lite version on Google Play using a web search, it is here:

https://play.google.com/store/apps/details?id=com.astech.forscanlite&hl=en_SG&gl=US

Support Request

Support Request

Anyway, looks like new android version users have to get it (Lite paid version, OR the free demo version) from Forscan's server directly instead of Google Play.

Download FORScan

TY for the education.

 

[Motorhogman]

^ That's one of the ones I have, works great on my '98, but I don't know if it supports your Civic. Does it use HS-Can or need MS-Can? The BAFX can't do MS-CAN AFAIK, unless they released a newer version that can. Last I knew, you had to add a switch and do a wiring mod to make it support both HS and MS Can.

Your '00 uses J1850 so for it, this CAN situation doesn't matter.

More info:

Modify BAFX OBD2 Adapter MSCAN using FORScan? - TopScanTool

How to modify BAFX OBD2 in to add the HS/MS CAN switch? Reading DTCs in all of 5 HS CAN modules and 2 MS CAN modules will always require only 1 shift.

topscantool.com

I'm not to concerned about the Honda. Don't know a thing about it's diagnostics or computer system. It only has about 60,000 mi on it. Runs great. Knock on wood. No recalls or mechanical issues at all. Next to my Harley it may be the most dependable vehicle I've ever owned.. I can't complain about the Explorer Sport either though.

 

[C420sailor]

Should be able to run it in Win 10 compatibility mode

Forscan is 100% the way. Can’t read the Civic, but it does WAY WAY more for your Ex than any scanner

 

[fast_dave]

@Motorhogman

Question since I didn't see you mention it, nor anyone ask: At an time during your fuel pump replacement did you disconnect the battery?

If you did, the ECU (computer) more-than-likely re-set itself to factory parameters (the same parameters the day it left the assembly line/factory - AKA "baseline parameters")...

Thus, your problem might be as simple as the ECU just need a weeks worth of drive cycles to "re-learn" your parameters, and then the idle speed will come down.

(Without the backfire) I had this "high idle speed" condition & subsequent re-learn occur on my OHV every time I disconnected my battery for a major repair.

It took at LEAST a 4-5 days of varied driving conditions to settle down.
Also - the re-learn required the A/C on and off a few minutes per drive cycle.
My gas mileage was also down a few MPG during the time period - just want you to be aware that that is also normal.

Costs nothing - go simple and try that before throwing parts at it.

Your mileage may vary and hope that helps and Happy New Year!

PS - It (high idle) also occurred when I: cleaned my MAF, replaced my spark plugs and wires, and wanted my ECU to go back to factory (to ultimately obtain good MPG) since I had new parts installed. In short, the ECU adjusts for a dirty MAF, Old Plugs and Wires, deteriorating 02 Sensors, restrictive air filter, etc... Again, after approximately a weeks worth of drive cycles, the idle settled back down from 900 to 650.

 

[Blown09]

If you want a cheap diy smoke setup, just buy a cheap-o fog machine online. I’ve used one of my Halloween ones before in a pinch. A bit clumsy, but it does work. I use the brake booster line to spray in the manifold. One issue with using a fog machine is, don’t put the hose directly on the nozzle, you have to spray the smoke into the hose from about an inch away(kinda a two person job). Again, not the proper way, but a cheap and fairly easy way to do a leak test if you only need to do it a couple times.

 

[J_C]

You can do a cheap one-two times smoke test with a $7 pump and a thin cigar, and nothing to build, just plug and play.

Multi-Use Transfer Pump

Amazing deals on this Multi-Use Transfer Pump at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

That nipple cap thing in this above linked video isn't needed, just connect pump hose to brake booster hose, and plug/cover the intake snorkel at the air filter box so smoke makes it that far (at least to the MAF sensor where intake is metered) but doesn't escape there.



Unlike the guy in this 2nd video, you keep pumping, is why he wasn't getting much smoke out.

There are other youtube videos showing use of same/similar orange hand pump. You'll get more smoke faster, leaving the cigar sitting out (in a low humidity area) to lose moisture for a few days, or put in a low temp. oven for a while to dry it out.

 

[Motorhogman]

@Motorhogman

Question since I didn't see you mention it, nor anyone ask: At an time during your fuel pump replacement did you disconnect the battery?

If you did, the ECU (computer) more-than-likely re-set itself to factory parameters (the same parameters the day it left the assembly line/factory - AKA "baseline parameters")...

Thus, your problem might be as simple as the ECU just need a weeks worth of drive cycles to "re-learn" your parameters, and then the idle speed will come down.

(Without the backfire) I had this "high idle speed" condition & subsequent re-learn occur on my OHV every time I disconnected my battery for a major repair.

It took at LEAST a 4-5 days of varied driving conditions to settle down.
Also - the re-learn required the A/C on and off a few minutes per drive cycle.
My gas mileage was also down a few MPG during the time period - just want you to be aware that that is also normal.

Costs nothing - go simple and try that before throwing parts at it.

Your mileage may vary and hope that helps and Happy New Year!

PS - It (high idle) also occurred when I: cleaned my MAF, replaced my spark plugs and wires, and wanted my ECU to go back to factory (to ultimately obtain good MPG) since I had new parts installed. In short, the ECU adjusts for a dirty MAF, Old Plugs and Wires, deteriorating 02 Sensors, restrictive air filter, etc... Again, after approximately a weeks worth of drive cycles, the idle settled back down from 900 to 650.

Oh yeah. Battery was disconnected for the duration of the project. I'm familiar with what you are saying. Did considered it. In the past it's never taken any time to return to normal idle after a battery disconnect. This truck doesn't see 1,000 mi a year. I will be driving as is for a while. I did order a an OBDII tool. Give something new to play with. TY for your input.
Forgot to mention. The fast idle happened before the battery disconnect, it started doing that after a couple of lean backfires through the intake while trying to start when it wasn't getting fuel..

 

[Motorhogman]

You can do a cheap one-two times smoke test with a $7 pump and a thin cigar, and nothing to build, just plug and play.

Multi-Use Transfer Pump

Amazing deals on this Multi-Use Transfer Pump at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

That nipple cap thing in this above linked video isn't needed, just connect pump hose to brake booster hose, and plug/cover the intake snorkel at the air filter box so smoke makes it that far (at least to the MAF sensor where intake is metered) but doesn't escape there.



Unlike the guy in this 2nd video, you keep pumping, is why he wasn't getting much smoke out.

There are other youtube videos showing use of same/similar orange hand pump. You'll get more smoke faster, leaving the cigar sitting out (in a low humidity area) to lose moisture for a few days, or put in a low temp. oven for a while to dry it out.

I like that TY

 

[Motorhogman]

Should be able to run it in Win 10 compatibility mode

Forscan is 100% the way. Can’t read the Civic, but it does WAY WAY more for your Ex than any scanner

TY. I'm slowly wading into the scanner stuff.

 

[Motorhogman]

Made the home made smoker. Looks like I've located the area. Can't see exactly where the smoke is coming from. Blowing out from behind the T stat housing. Looks like a manifold seal as some of you suspected. UGH here we go again.. Thanks for the smoker idea. It worked !

 

[Turdle]

Is the fuel rail dampener vacuum line down there?? I think it is. Might have popped off

 

[Motorhogman]

Is the fuel rail dampener vacuum line down there?? I think it is. Might have popped off

Maybe .. I'll look closer. Just popped off the upper manifold.

 

[Motorhogman]

Upper manifold off.. seals all look seated.. I don't see any signs of cracks in the manifold. . I'll look into Turdle's suggestion before pulling the lower.

 

[Motorhogman]

Vacuum line is on the dampener securely. All the seals on the lower manifold are in place and look good. I don't see any cracks, least none obvious to these old eyes. I've had enough of this today. Wednesday or Thursday I'll clean the manifolds up a little, put a straight edge on them and order new seals. I was hoping to see a seal blown out of it's groove. I know for certain the smoke was coming from the front of the manifold area behind the T stat housing.

Any other thoughts ?