idle problems (could be fixed, I hope)

gjp

gjp

another post whore
Re: idle problems

Re: idle problems

i am using a datamaster.
I had the same setup before I trore the engine apart.
tps stays the same at .58volts
iac counts go up when it stumbles fron 20 to mid 30's
fuel pressure goes up from 35-38lbs
vac is at 19.83 and drops to 19.1
volts stay 12.8 and drop to 12.2 when it tries to die.
the chip and setup workedf fine before.
when i plugged the vac line on the tb going to the pcv valve the truck died. I opened the screw on the tb and now then i plug the vac the idle drops but does not die out. with the vac on the tb opened it idles high and stumbles but does not die? that does not sound right to me.?

when the engine is cold it takes longer for it to stumble. if I restart it again it will stumble quicker. The engine temp has yet to get past 150*
With it being a new setup could air in the watter lines cause this?? I dont think its got hot enough yet to open the t-stat?
 
gjp

gjp

another post whore
Re: idle problems

Re: idle problems

a few quick videos. you can hear the engine surging. the wbo2 started at 12.9 at startup and went up to what you see in about 2 min. look at the fuel guage in the video. it moves too. its steady untill it starts to surge. also when I give it gas the wbo2 drops down to 11.8 and jumps back up. If I keep it at 200rpm it runs fine and steady

 
W

wantingasy

Active member
Re: idle problems (now with video)

Re: idle problems (now with video)

I'm just going to throw out my guess, even though it's probably wrong. But I'm going to have to say its in your tuning/chip. Either that or a vacuum line somewhere?!? Hopefully someone else will guess or know what it is, but that seems weird to me. :roll:
 
gjp

gjp

another post whore
Re: idle problems (now with video)

Re: idle problems (now with video)

tried my other ecu....same thing. the chip worked fine before the build. in fact it was rich before. I needed to turn the fp down lastr time. I dont get it. I have done lots of reading and still cant figure it out. I have another phil chip I will try to rule that out. Most the parts are new or worked fine before. The gremlins I have in this truck have always been wierd but the truck would run. Now it wont. Somethings causing it to start out normal and go lean.

Any ideas guys?? I would love to hear them. I will pull out the plugs and check them. Again the big things I did were new ported l35 heads and the trans. Ran with no electric fan and same thing happened.??

could itr be a vac leak. My truck runs at 20.2 vac. used to run 19.8 before the build. I replaced all the vac lines. Anything I can record that would help let me know. I might just call a mechanic to have a look but I dont want to spend the money. I cant think of anything. Totaly lost on this one.
 
gjp

gjp

another post whore
Re: idle problems (now with video)

Re: idle problems (now with video)

Thinking.... I siphoned out the gas. Could i have done something to the pump in there? fp look fine but maybe I have low volume? put in new fuel lines but i see no leaks?
 
W

wantingasy

Active member
Re: idle problems (now with video)

Re: idle problems (now with video)

I find it hard to believe it's fuel related unless you're totally out of gas. You said your voltage was low? I would try to figure that one out first. My TY used to surge bad!!! and it had high 12's voltage and would get as low as high 10's, low 11's when starting. I replaced it with a new alternator and got like 14.0 and the surging pretty much stopped. Voltage has a lot to do with the way an engine runs too, surprisingly. At least to me it was :) I know you have a new alternator, I would check all those connections and grounds if you do have low voltage.
 
gjp

gjp

another post whore
Re: idle problems (now with video)

Re: idle problems (now with video)

for the hell of it i will try my old alt. could be low voltage messing with pump.
 
gjp

gjp

another post whore
Re: idle problems (now with video)

Re: idle problems (now with video)

Jonathon and Rob were right on the money.
Its a voltage problem.
Rob you are a f-ing genius. Hooked back up the stock alt. Voltage was 10.4 :eek:
Rob said to get a large wire and connect to - of battery to alt bracket. Soon as I did that I saw sparks and voltage jumped up to 14.1 volts. :tup: Idle went up and it idled good for 3 min. Now I have to replace the bad ground wire but I hope its fixed. Thanks guys.
 
Syclone'D916

Syclone'D916

Syclone Owner #2414
Re: idle problems (problem fixed, you guys kick a$$)

Re: idle problems (problem fixed, you guys kick a$$)

Alt. i think mine is doing the same thing now it idles god but ever once in a while it has a little stumble in the idle like a hic-up,my batt level is just under the half way mark.it's been buggin me for a while,what all did you do,to clear it up.
 
WyoSyclone

WyoSyclone

Active member
Re: idle problems (problem fixed, you guys kick a$$)

Re: idle problems (problem fixed, you guys kick a$$)

Never been called that before Gary..... :oops:
Glad you got it nailed down!
 
gjp

gjp

another post whore
Re: idle problems (problem fixed, you guys kick a$$)

Re: idle problems (problem fixed, you guys kick a$$)

WyoSyclone said:
Never been called that before Gary..... :oops:
Glad you got it nailed down!
Click to expand...
I have done so many electrical systems in cars before. I worked for a car stereo install place in HS. just did not put the lean condition to a voltage problem. pump still showed 38psi.

I hade some #8awg wire in my van. I put one end on the alt bracket bolt and when I touched it to the neg. on the battery it sparked a lot. the truck idled up and the voltage went from 11.5 to 13.9. I have it on the datamaster too but dont know how to snap shot the screen. have to find a fix but It should be easy now I know the problem. Makes me wounder if that was my idle issue before. I never found my missing problem. I added a #10 ground to the engine and I thought that helped but my trans died the next day and I never got to test it.
 
gjp

gjp

another post whore
Re: idle problems (problem fixed, you guys kick a$$)

Re: idle problems (problem fixed, you guys kick a$$)

ok figured it out. You can see the voltage in red. I touched the wire a few times and you can see the volts shoot up. the break in the graph is where it died. You can see how low the volts were before.
dm.jpg
 
G

Grimgrak

New member
Re: idle problems (problem fixed, you guys kick a$$)

Re: idle problems (problem fixed, you guys kick a$$)

Do you think u could take a quick glimpse at my log? My voltage never dips below 12.9.... according to the DM when yours dipped to 10 was that seen on the DM?
 
Syclone'D916

Syclone'D916

Syclone Owner #2414
Re: idle problems (problem fixed, you guys kick a$$)

Re: idle problems (problem fixed, you guys kick a$$)

Ya I'll do that and see what happens to my idle. I have a ground from the front intake bolt to the frame,it's 2 gauge wire,and would the Batt in the bed be a problem?
 
WyoSyclone

WyoSyclone

Active member
Re: idle problems (problem fixed, you guys kick a$$)

Re: idle problems (problem fixed, you guys kick a$$)

D916... make sure the ground from your battery to the frame is good. It's usually best to get the engine-to-frame ground as close to the alternator as possible, because every bracket and bolt will cause some resistance.
If you think the battery to alternator ground circuit may be bad, just take a length of heavy gauge wire and touch the case of the alternator on one end, and the battery negative on the other (don't let the wire get caught up in the fan blades!!). If your voltage goes up when you do this, this ground circuit is bad (remember, when the vehicle is running the alternator supplies ALL the current the vehicle needs to run).
 
gjp

gjp

another post whore
Re: idle problems (problem fixed, you guys kick a$$)

Re: idle problems (problem fixed, you guys kick a$$)

I would like to take this time to thank Chris and his great powdercoat for my voltage problem. Duh.... I should have known the powdercoating is non conductive. Question is does the Ac compressor need a case ground? guess I will run a smal ground just in case.
 
Syclone'D916

Syclone'D916

Syclone Owner #2414
Re: idle problems (problem fixed, you guys kick a$$)

Re: idle problems (problem fixed, you guys kick a$$)

WyoSyclone said:
D916... make sure the ground from your battery to the frame is good. It's usually best to get the engine-to-frame ground as close to the alternator as possible, because every bracket and bolt will cause some resistance.
If you think the battery to alternator ground circuit may be bad, just take a length of heavy gauge wire and touch the case of the alternator on one end, and the battery negative on the other (don't let the wire get caught up in the fan blades!!). If your voltage goes up when you do this, this ground circuit is bad (remember, when the vehicle is running the alternator supplies ALL the current the vehicle needs to run).
Click to expand...
Ok,I do that.I'll re-check all the grounds too.
 
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