Pennock's Fiero Forum
  Technical Discussion & Questions
  ALDL log analysis help request (hard both cold and hot start, smoke)

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
ALDL log analysis help request (hard both cold and hot start, smoke) by cebix
Started on: 05-20-2020 03:38 PM
Replies: 4 (87 views)
Last post by: cebix on 05-21-2020 01:37 AM
cebix
Member
Posts: 1020
From: Poland
Registered: May 2011


Feedback score: N/A
Leave feedback

Rate this member

Report this Post05-20-2020 03:38 PM Click Here to See the Profile for cebixSend a Private Message to cebixEdit/Delete MessageReply w/QuoteDirect Link to This Post
'85 duke auto with A/C (not working at the moment). No check engine light, no codes stored. Timing set at 8 deg. BTDC with trans in D and ALDL shorted to ground.
195F thermostat and 235 fan switch (fan works and goes on at that temp - verified with ECU data when engine shut down and heat soak did its thing after a few minutes).

I've been fighting three problems since (and some time before) the engine rebuild a year ago. Car was started first time in 10/2019 and I've done roughly 2200 miles since then.

1. Overheating with no throttle applied. Or so I thought since the ECU coolant temperature sensor reads within spec. So I would ignore that for now but I wasn't able to replicate an almost pegging temp. gauge at the first heat up cycle. Will post a log if I can replicate that again, might have to drive a little longer for that.

2. Hard cold start (fires up and dies immediately, most time won't start until "clear flood" is applied). Runs rough for a few seconds and stumbles for a while at part throttle. Gets worse when it's raining I noticed. All this time it smokes pretty bad and smokes more with more throttle but after a minute or two there is almost no smoke at idle or wide open throttle. Then I can drive all day and everything looks ok until I shut off the engine and then...

3. Hard hot start. It starts almost immediately but within seconds idle goes down and will die very often. Will die almost always when I shift into D with no throttle. A little throttle helps a lot. During this time and a minute or two after this hot start the car is a smoke machine and likes to stumble some. This minute/two passes by and all is back to normal.

Can somebody help me understand and look at the logs if you are seeing something suspicious? I've been doing some reading and here are my thoughts on these logs and if anybody would chime in I would be grateful.

A. Does the coolant temperature look ok? It fluctucates quite a bit but maybe that's the way it should be?
B. My TPS reads 1.5% at no throttle and 86% at wide open throttle. WinALDL setttings are 0.54V for 0% and 4.60V for 100%. Is that within spec?
C. It seems the o2 sensor voltage varies very early in the heat cycle. Is this normal or could be a bad sensor? It should be no issue though I guess with a cold start since it's ignored?
D. My INT values are somewhat below 128 on a lot of occasions. Don't know if that's ok. My BPW seems to be a lot of times over 140 and from what I read it should be lower? Means it's almost going lean?

Any tips would be great. Here's a link where I have a both hot and cold start log in .txt form. Note I start the log before the engine is started and you can see a few crank attemps when cold and some throttle movement on a hot start to keep idle going. Many thanks in advance.

EDIT: Changed the links to a more friendly service (again)

https://drive.google.com/op...JQHYwuDFzz2SA-l3PutZ
https://drive.google.com/op...dSrDNQ2kLlO6ByMxPhWK

Cold start smoke video:
https://youtu.be/OgX4rXXx0rs

[This message has been edited by cebix (edited 05-20-2020).]

IP: Logged
PFF
System Bot
Patrick
Member
Posts: 29666
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 439
Rate this member

Report this Post05-20-2020 04:13 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by cebix:

EDIT: Changed the links to a more friendly service

https://file.io/38KggAMv
https://file.io/NqJe6UIa



Not friendly enough apparently.




You've mentioned "smoke" several times, but unless you mention the color of the smoke, you're not telling us much. Is it black or blue or white? And what does it smell like? Overly rich, burning oil, coolant?

[This message has been edited by Patrick (edited 05-20-2020).]

IP: Logged
cebix
Member
Posts: 1020
From: Poland
Registered: May 2011


Feedback score: N/A
Leave feedback

Rate this member

Report this Post05-20-2020 04:39 PM Click Here to See the Profile for cebixSend a Private Message to cebixEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

Not friendly enough apparently.




You've mentioned "smoke" several times, but unless you mention the color of the smoke, you're not telling us much. Is it black or blue or white? And what does it smell like? Overly rich, burning oil, coolant?



So sorry, just did a reupload. Seems that service deletes files after only one download. Here are google drive links, hope it'll work:

https://drive.google.com/op...JQHYwuDFzz2SA-l3PutZ
https://drive.google.com/op...dSrDNQ2kLlO6ByMxPhWK

It's hard to tell really. Mostly white/blue I guess. Maybe a little grey. Looks blue but can't really smell that burnt oil. Also can't smell "sweet" coolant.

Here's a video I remembered I shot for a cold start smoke. This is just seconds after startup. Notice the smoke doesn't appear immediately but takes a while. Goes more blue when driving at this time and giving it some throttle but then again it just might be my mirror... Still haven't done one for a hot start, that may involve a rear view mirror but I'll try.

https://youtu.be/OgX4rXXx0rs

EDIT: Man, does it sound smooth idling cold when looking at that video... When hot it hunts a little but not terrifying.

[This message has been edited by cebix (edited 05-20-2020).]

IP: Logged
Patrick
Member
Posts: 29666
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 439
Rate this member

Report this Post05-20-2020 05:28 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by cebix:

Here's a video I remembered I shot for a cold start smoke.


From what I can tell, it looks like condensation in the exhaust system burning off.

 
quote
Originally posted by cebix:

Here's a link where I have a both hot and cold start log in .txt form. Note I start the log before the engine is started and you can see a few crank attemps when cold and some throttle movement on a hot start to keep idle going.

Does the coolant temperature look ok? It fluctucates quite a bit but maybe that's the way it should be?



It's been years since I've played around with any WinALDL files. I've posted your cold and hot start Coolant Temperatures... and then posted one of mine. I suspect the weirdness at the start of your graphs are the multiple "crank attempts".

Cebix cold start...




Cebix hot start...




For comparison, one of my Fiero's cold start...

[This message has been edited by Patrick (edited 05-20-2020).]

IP: Logged
cebix
Member
Posts: 1020
From: Poland
Registered: May 2011


Feedback score: N/A
Leave feedback

Rate this member

Report this Post05-21-2020 01:37 AM Click Here to See the Profile for cebixSend a Private Message to cebixEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thank you, so I guess the temperature is normal.

For the other issues can you see anything suspicious in those logs that could cause problematic hot and cold starts and running poorly for a minute or two after these starts?

The cold start is not that bad compared to the hot one. I really need to take a video of that...

[This message has been edited by cebix (edited 05-21-2020).]

IP: Logged

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock