Issue with hesitation on cold start

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KJ Ryu
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Re: Issue with hesitation on cold start

Post by KJ Ryu » Fri Nov 15, 2019 3:18 pm

:-bd
Ron

2005 KJ, Hit-n-Run, 2am 6-17-2012, Totaled. :mad:
1977 SJ J10, 4v360, T18, D20, 37x14s, SOA & SF on tons, still ugly.
1978 SJ Wagoneer, 4v360, QT, 33x12.5s, lift by Sawzall :-bd NOT Running :(
1977 SJ J10, SniperEFI 401, QT, D44s, 31X10.5s :fsj:
2006 KJ
Mars wrote:One man's trans leak is another's penetrating oil :D

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babywag
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Re: Issue with hesitation on cold start

Post by babywag » Sat Nov 16, 2019 10:31 am

Theodore wrote:
Fri Nov 15, 2019 4:43 am
babywag wrote:
Thu Nov 14, 2019 10:23 am
Timing control isn't hard to add. Just some wiring and couple parts.
You need the hardware to read and burn a new chip though.
Or buy one...

Really need to reset initial timing though. If you're @ 0° that is a huge power killer.
Thanks for recommendation & patience with the questions - learning a lot in the process. ? - do you know, off-hand, what you have initial timing set to? So far, we've had initial set on the low end 0-5 & as far out as 17-18 initial, based on various recommendations - and, to date, the story reads like Goldilocks... sounds like we've just not hit 'just-right' yet.

Am looking into getting a vacuum gauge to hopefully zero-in on it to minimize the amount of tinkering required to get to 'just-right'.
Set timing to ~10 and leave it be.
Briefly looking @ logs, you have some issues.
#1 ecm battery voltage is low, should be much higher than 12.x
#2 it looks lean have you checked your fuel pressure?
#3 o2 sensor data is dropping out/falling out of where it should be...where is sensor mounted? Uber lean and/or cooling off?
#4 IAC counts seem pretty high, have you done initial setup procedure? (minumum air/tps adj.)

Need much much more data to get an accurate idea of what is going on.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.
email me I never receive PM notifications and frequently do NOT see them.

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babywag
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Re: Issue with hesitation on cold start

Post by babywag » Sat Nov 16, 2019 10:37 am

I'll add *if* it is very lean when cold, and you really hammer the throttle do you get a "pop" out of the throttle body?
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.
email me I never receive PM notifications and frequently do NOT see them.


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Theodore
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Joined: Tue Sep 04, 2018 5:26 pm

Re: Issue with hesitation on cold start

Post by Theodore » Sat Nov 16, 2019 12:21 pm

babywag wrote:
Sat Nov 16, 2019 10:31 am
Theodore wrote:
Fri Nov 15, 2019 4:43 am
babywag wrote:
Thu Nov 14, 2019 10:23 am
Timing control isn't hard to add. Just some wiring and couple parts.
You need the hardware to read and burn a new chip though.
Or buy one...

Really need to reset initial timing though. If you're @ 0° that is a huge power killer.
Thanks for recommendation & patience with the questions - learning a lot in the process. ? - do you know, off-hand, what you have initial timing set to? So far, we've had initial set on the low end 0-5 & as far out as 17-18 initial, based on various recommendations - and, to date, the story reads like Goldilocks... sounds like we've just not hit 'just-right' yet.

Am looking into getting a vacuum gauge to hopefully zero-in on it to minimize the amount of tinkering required to get to 'just-right'.
Set timing to ~10 and leave it be.
Briefly looking @ logs, you have some issues.
#1 ecm battery voltage is low, should be much higher than 12.x
#2 it looks lean have you checked your fuel pressure?
#3 o2 sensor data is dropping out/falling out of where it should be...where is sensor mounted? Uber lean and/or cooling off?
#4 IAC counts seem pretty high, have you done initial setup procedure? (minumum air/tps adj.)

Need much much more data to get an accurate idea of what is going on.
Thanks for taking a look. I agree i have issues :-) Just today, I was going to take a look at the power steering pump squeal/vibration & had the mounting bracket sheer off as i turned the wheels... See post for details on the ongoing debacle: viewtopic.php?f=7&t=17942. Looking at the bracket, it looks like a previous owner left out a bolt that goes into the block, that would've created a triangle, thereby reinforcing the bracket. Ugh.

To answer your questions with what i know right now:
re: #1 - battery voltage @ ecm: did check battery voltage and it reads 12.51, but given the ongoing issue w/power steering, i can't start the jeep to test voltage at the alternator. Will take a look once i get the PS issue fixed.
re: #2 - fuel pressure: i've not been able to check it yet. A few weeks ago, I bought a Actron fuel pressure gauge & the TBI schrader valve, but it appears the schrader valve may be bad. It's plumbed in just after the fuel pump, but the gauge reads no fuel pressure. Pushing in on the schrader valve doesn't release fuel. Haven't gotten a chance to troubleshoot it any deeper to date.
re: #3 o2 sensor dropping in/out: sensor is mounted in the driver's side exhaust pipe about a foot below the manifold, just about even with the bottom of the oil pan.
re: #4 IAC counts seem pretty high, have you done initial setup procedure? (minumum air/tps adj.): i followed the instructions re: pintle adjustment, etc., but i admit i'm new at this.

Right now, the focus is on power steering & finding a mounting bracket to get the Jeep back road-worthy. Once i get parts replaced, and going again, will be back on this.


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Theodore
Posts: 93
Joined: Tue Sep 04, 2018 5:26 pm

Re: Issue with hesitation on cold start

Post by Theodore » Sun Nov 24, 2019 4:41 pm

Am back in business & have a running/driving Jeep - got the power steering pump issue fixed today. A forum member PM'd me from El Paso a few days back; Received the power steering parts on Friday in good shape & got everything installed today. Test drove the Jeep this evening - it's never driven so well - has always had a mystery squeak & an intermittent jerky steering wheel - all that's gone now.

Update on the cold start hesitation issue... The vacuum gauge order arrived from Amazon on Monday, but porch pirates decided they needed it more than i did; leaving the empty shipping materials on the porch. Filed a claim w/Amazon, item was out of stock & is now on backorder with no target date to ship. Hurrumph - so, it'll be a few more days before i'll have a chance to look at it. Hopefully, it'll arrive before cold weather does.


Topic author
Theodore
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Re: Issue with hesitation on cold start

Post by Theodore » Tue Nov 26, 2019 7:10 pm

Hey babywag, ? - saw your comment about setting initial timing at ~10 & leaving it; and it made me wonder how you got to that number? A few weeks/months (time flies...) back, i was reading about timing in the owner's manual, & service manual, and following circular references that eventually led to the 'Emissions Sticker' under the hood. To date, we've bounced back & forth from 0 initial (per AFI's owner's manual) - assuming ECM control & Factory Spec otherwise. At 15-17, we saw severe hesitation & lack of power, max speed of ~60mph & missing. At 0, it runs much better, but with hesitation when cold. So far, i've not had a chance to try ~10 - it'll be a couple of weeks before i can do anything else w/it.

The Emissions STicker calls out 17+-2, but it wasn't until tonite that i saw a few articles online about timing for high altitude areas, which made me run outside & check our sticker, and what do you know? - It's a High Altitude sticker, and we're in a low altitude area (~1200 ft). Assuming retarding 2deg/1000ft, gets us back to 11+-2, which is within the ~10 degrees you'd called out earlier.

For curiosity's sake, does anyone have a pic of a 'low altitude' sticker for a 1990 360? So far, i've not been able to find one online.

Here's our Emissions sticker, from our 1990 GW w/360 engine.
Image


Topic author
Theodore
Posts: 93
Joined: Tue Sep 04, 2018 5:26 pm

Re: Issue with hesitation on cold start

Post by Theodore » Tue Nov 26, 2019 7:48 pm

Poking around tonite, I found a low altitude sticker on a sister forum, showing 10+-2.
Link to image: cant get it to pull via original link, for some reason:
http://www.diplomat-b.de/Jeep/base%20emission.jpg

Screenshot & pulled into imgur:
Image

Link to entire post:
http://ifsja.org/forums/vb/showthread. ... ost1345926

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babywag
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Re: Issue with hesitation on cold start

Post by babywag » Thu Dec 05, 2019 9:17 am

I say 10° because as you found that is stock.
If you're using a stock distributor many times more results in pinging. They need to be checked/adjusted before running higher initial.

It's important to verify FP and do initial setup as well.
More so because the log you posted appears lean.
Timing won't "fix" a fuel problem.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.
email me I never receive PM notifications and frequently do NOT see them.


Topic author
Theodore
Posts: 93
Joined: Tue Sep 04, 2018 5:26 pm

Re: Issue with hesitation on cold start

Post by Theodore » Thu Dec 05, 2019 10:32 pm

Thanks, Will take a look when I get back in town.

Re: fuel pressure - I have an Actron gauge with the TBI Schrader valve inline connector in the fuel line just before the filer, if I remember correctly, but for some reason am not able to get a reading. ? - with the car running, and gauge not connected, I assume I should be able to push in the center pin & get gas to spray..., true? Trouble is: I dont. Havenot yet had a chance to talk to Acton tech support.

Re: initial setup: Am planning on starting over once timing is set to 10, now that I have a scanner.

Thanks for,the advice - will let you know.


Topic author
Theodore
Posts: 93
Joined: Tue Sep 04, 2018 5:26 pm

Re: Issue with hesitation on cold start

Post by Theodore » Fri Mar 06, 2020 4:52 pm

Theodore wrote:
Sat Nov 16, 2019 12:21 pm
babywag wrote:
Sat Nov 16, 2019 10:31 am
Theodore wrote:
Fri Nov 15, 2019 4:43 am


Thanks for recommendation & patience with the questions - learning a lot in the process. ? - do you know, off-hand, what you have
initial timing set to? So far, we've had initial set on the low end 0-5 & as far out as 17-18 initial, based on various recommendations
- and, to date, the story reads like Goldilocks... sounds like we've just not hit 'just-right' yet.

Am looking into getting a vacuum gauge to hopefully zero-in on it to minimize the amount of tinkering required to get to 'just-right'.
Set timing to ~10 and leave it be.
Briefly looking @ logs, you have some issues.
#1 ecm battery voltage is low, should be much higher than 12.x
#2 it looks lean have you checked your fuel pressure?
#3 o2 sensor data is dropping out/falling out of where it should be...where is sensor mounted? Uber lean and/or cooling off?
#4 IAC counts seem pretty high, have you done initial setup procedure? (minumum air/tps adj.)

Need much much more data to get an accurate idea of what is going on.
Thanks for taking a look. I agree i have issues :-) Just today, I was going to take a look at the power steering pump squeal/vibration & had the mounting bracket sheer off as i turned the wheels... See post for details on the ongoing debacle: viewtopic.php?f=7&t=17942. Looking at the bracket, it looks like a previous owner left out a bolt that goes into the block, that would've created a triangle, thereby reinforcing the bracket. Ugh.

To answer your questions with what i know right now:
re: #1 - battery voltage @ ecm: did check battery voltage and it reads 12.51, but given the ongoing issue w/power steering, i can't start the jeep to test voltage at the alternator. Will take a look once i get the PS issue fixed.
re: #2 - fuel pressure: i've not been able to check it yet. A few weeks ago, I bought a Actron fuel pressure gauge & the TBI schrader valve, but it appears the schrader valve may be bad. It's plumbed in just after the fuel pump, but the gauge reads no fuel pressure. Pushing in on the schrader valve doesn't release fuel. Haven't gotten a chance to troubleshoot it any deeper to date.
re: #3 o2 sensor dropping in/out: sensor is mounted in the driver's side exhaust pipe about a foot below the manifold, just about even with the bottom of the oil pan.
re: #4 IAC counts seem pretty high, have you done initial setup procedure? (minumum air/tps adj.): i followed the instructions re: pintle adjustment, etc., but i admit i'm new at this.

Right now, the focus is on power steering & finding a mounting bracket to get the Jeep back road-worthy. Once i get parts replaced, and going again, will be back on this.
Finally had a chance to get back on this. Have done a lot since we spoke last. To date, i've:
- reset initial timing to 10 degrees
- initial setup for IAC
- initial setup for TPS
- reset idle to around 650-700 warm
- cleaned battery terminals, alternator connections, & ground wire
- checked fuel pressure - its showing 12 lbs
- not done anything w/o2 sensor.

Wagoneer is running the best it ever has, when warm, but i still have the hesitation when cold - other than the idle is slower, i can't really tell a difference. I pulled another data log going from home to work: engine was cold; outside temp was around 40. Had to feather the gas to pull out; again, once it warmed up to around 100, i could gun it w/o issues.

Babywag, et.al. - do you see anything in the data log?
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babywag
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Re: Issue with hesitation on cold start

Post by babywag » Mon Mar 09, 2020 8:17 am

Still looks lean...
Can up fuel pressure 1-2psi, add to VE tables, etc.
Voltage still a little low should be a little higher.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.
email me I never receive PM notifications and frequently do NOT see them.


Topic author
Theodore
Posts: 93
Joined: Tue Sep 04, 2018 5:26 pm

Re: Issue with hesitation on cold start

Post by Theodore » Mon Mar 09, 2020 6:31 pm

Am wondering whether I have a fuel pressure regulator issue. Didn’t strike me til yesterday, but when I turn the key, the fuel pump kicks on to prime the system for a couple seconds, then kicks off, and as you can see in the attached movie clip, the pressure bleeds off. Cold start takes 8-10 engine rotations before it starts.

Video of fuel pressure gauge at cold start:
https://imgur.com/gallery/hyS8BOq

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babywag
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Location: Land of Fruit Loops & Coconuts

Re: Issue with hesitation on cold start

Post by babywag » Sat Mar 14, 2020 11:52 am

Theodore wrote:
Mon Mar 09, 2020 6:31 pm
Am wondering whether I have a fuel pressure regulator issue. Didn’t strike me til yesterday, but when I turn the key, the fuel pump kicks on to prime the system for a couple seconds, then kicks off, and as you can see in the attached movie clip, the pressure bleeds off. Cold start takes 8-10 engine rotations before it starts.

Video of fuel pressure gauge at cold start:
https://imgur.com/gallery/hyS8BOq
Long as it holds STEADY while running AND under HEAVY accel, it is working as designed.
There is nothing stopping pressure from bleeding off when the fuel pump isn't running.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.
email me I never receive PM notifications and frequently do NOT see them.


Topic author
Theodore
Posts: 93
Joined: Tue Sep 04, 2018 5:26 pm

Re: Issue with hesitation on cold start

Post by Theodore » Sun Mar 15, 2020 1:08 pm

Have seen a few articles that talk about similar pressure drops either being injectors leaking (checked & we are good there - no leaks), and failed check valve in fuel pump. With that, am wondering whether the check valve is the issue? When we started down the path, I noticed that the fuel filter was installed after the pump, such that the pump couldve picked up dirt from the tank. Am also starting to notice at cold start time, the engine will start and run for a few seconds then die, easily starts back. But, it is doing it more often lately.

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