Help!! Intermittent dead cyl problem...

Faye

where's my tiara?
Apr 30, 2013
554
2
18
San Antonio, TX
www.youtube.com
Okay so I will start by saying that I've done a lot of searching on the forums before posting this.... I'm having a hard time believing that no one else has has this problem before :-/ but I found nothing quite like mine so here goes!!!

89 turbo 5 speed with just a few mods... When I first got the car didn't run right so my response was to put it back to stock so I could diag. Stock injectors are freshly rebuilt. Plugs and wires are brand new.

I just got my Supra back on the road after my fun little off-roading adventure... Less than a week of driving her and on my way to the bridge of the gods cruise with the Toyota syndicate group she started running on only five cylinders. I had driven to Starbucks and she was running great. I sat down, drank my coffee, got back in and started her up and that's when it happened. I got out and checked for loose connections. I limped her to Shawn's house and he helped me try to diag her. My afr's fluctuated around 16.6.

Pulled the wire at the coil and has spark on all 6 but no change when pulling cyl 3. Replaced the plug wire and plug.... Nothing changed.


The next day I went to work on her.... Fired her up and drove perfect. So weird!!! Drove her 200 miles since then and haven't had a problem until 3 days later.... This morning on my way to work. I stopped at Starbucks then got into my car and again!!! Only running on 5.... And AFR's once again at 16.6 .... With the early morn fin rush traffic I tried to pull over to check and see if it was the same cyl but by the time I got over to the side of the road she was running normally again!!!

I'm thinking maybe a clogged injector or something from debris that may have been dislodged from my accident?? But I guess I won't be able to pinpoint it until it happens again.....

I am kind if afraid to drive her as I do not want to mess her up even more.... And the leanness freaks me out too... I do drive slowly and without boost to the side of the road both times this has happened....


Has anyone has this problem before??? Any input/ideas/advice on what else i can try would be much appreciated!!! Thank you!!:)


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Also, I should add here.... Already much thanks to jdmfreak for dealing with my phone calls, my panic and freaking out, and for helping me try to diag this. As always I owe you a ton and am does my Supra :)
 

BryanDyer

New Member
Jun 13, 2012
654
0
0
Georgia
I'd check your injector since you said you have spark on cyl 3. I'd imagine it's shows you're lean since that cylinder is getting no fuel so it's just air coming out raising your afr.
 

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
12,568
1
0
Fullerton,CA
Can move a coil or injector and see if the problem moves a cylinder. That will eliminate any guessing.

Also a 16 afr at light cruise or idle wont hurt anything as long as its not in boost.
 

kotu100

Active Member
Nov 23, 2006
1,899
0
36
Easton, Ma
Make sure to check the pins in the injector plug, sounds more like a loose wire than an intermittent clogged injector.
 

7M4EVR

New Member
Oct 8, 2012
695
0
0
fah, fah away
kotu100;1997594 said:
Make sure to check the pins in the injector plug, sounds more like a loose wire than an intermittent clogged injector.

I was thinking the same thing. Also, could make sure the injector wires for that cylinder aren't melting to something, but I dont know if that would do it. The loose wire thing sounds most plausible.
 

Faye

where's my tiara?
Apr 30, 2013
554
2
18
San Antonio, TX
www.youtube.com
The only code that I have is 71..... Egr.

Not this matters but I also did the igniter ground mod and have a much better ground on my coil packs also.


So I got to mess around with her a little for last two hours that work was open... Of course she wasn't doing it there's nothing I could really test for but I did measure the resistance in the coil pack just in case there was an internal short or something . Everything tested within tsrm spec .

Then I hooked up a noid light to each one of the injectors and watched to see if there is any change in the brightness of the light or the pattern. They were all exactly the same.

I also disconnected all of the injector connectors and cleaned them all. when I had disconnected the connectors while she was running she acted exactly like the situation this morning. so I'm starting to really like this theory.


I appreciate everyone's really awesome the feedback I am so grateful!!!! I will let you know what I find out if I am able to catch her in the act of doing this once again!!!

:)
 

jake8790

Life's too short for N/A
Dec 18, 2011
395
0
0
Oregon
Wait until it acts up and then listen to the suspect injector through a piece of hose. Wiring harness old and brittle or still good?
 

jdmfreak

PACNW
Oct 8, 2010
2,232
0
0
north clark co. WA.
Like she said I looked it over the first time... Didn't get to go over everything because we had to go but I am leaning towards clogged injector...

Cyl 3 was not combusting,

had spark, good spark, injector was clicking, wiggled all wires(no change)

She shut it down and left it off for 8 or 9 hours,
Ran on 5 came back next day, fired up fine
Ran fine till yesterday when it did it long enough for her to pull over and then it ran fine,

I told her next time she needs to catch it happening and pull plug wires quick to see if it's the same cyl, if there is more crud in the fuel system chances are it will be a different cylinder not firing