IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Buick Tech => Topic started by: shmed on October 09 2016, 06:39:29 PM
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ok so we got the new motor in still a 109,
wired it up
go to start it an it fires after a bit of cranking an dies immediately ??
heres whats been hacked out of it
ac , heater box, wiper motor, cruise control, charcoal canister, power master. an the temp sensor on the top of the intake it broke off so not wired up.. think thats all i see missing..
so far we tried a new battery, coil pack an module, crank sensor. added a ground from block to frame, cleaned an tightend grounds at back of head.
all the sensor reading look ok i mean for just key on type stuff.
any ideas
thanks guys
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When something like this rears it's ugly head, I go straight to Steves site.
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yes thanks brad I've been on the site tried what he has written nothing thus far..
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Does it fire up and die every time, or did it bust off once and that was it?
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Fuel pressure?
Pump priming with the key turn?
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I get fuzzy on this~ but the two feeds to the fuel pump both come up - inc the cct that senses oil pressure?
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I'd be looking for proper fuel pressure at the fuel rail. If that checked out...then I'd go through Steve's 'no start' tree.
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Earl yes it fires an then dies every time,
texas yes can hear fuel pump when key is turned on i believe the gauge reads 20 then with another turn of the key it hits 38
I'm curious if one of the removed items maybe be causing this?
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Spark?
Injector pulse?
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Temp sensor? What happens when that's not working? I forget how important it is?
As the car fires up for a second does the fuel pressure stay at 38?
I've had the pump hold key on & also pressure jump up for a second but then die when engine fired years ago.
The 2" rubber fuel line on the pump cracked open a bit but that's probably pretty rare?
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brad yes spark an ink pulse
dave im not sure i thought that may be the problem..
i unplugged the maf an the car fired up an ran no problem. strange to me but hopefully its all it was,,,, ill post back with an update...
saturdays is race day if we can get the car off the stands....
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well so much for the excitement....
changed out the maf with my spare.. same problem starts an dies.. unplug maf fires right up???
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Are you running a translator? If so look inside the plug and see if a pen is bent.
Have you done the KOEO MAF test to see if the computer is making up numbers or if the MAF is actually reporting to the ECM?
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" an the temp sensor on the top of the intake it broke off so not wired up.."
That sensor is the overtemp to turn on the fan, if the temp goes over about 225*.
The canister.. Did you plug the hose off? If so, that's the tank vent. Pull the cap, it starts and stays running?
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earl what is the koef test? i did try key on engine off an af was at 4 then full throttle still 4 is this what you mean?
no translator stock maf
old buzzard your are correct not wired up the canister isn't there or the electrical gizmo on top i didn't plug the lines there still sitting here open ended.
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when the maf is unplugged an it does run fuel pressure is at 42 line off.
when it is running the idle is around 1800????
regardless of throttle plate stop location
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glad its our thanksgiving and I'm cooking an drinking an doing garage things lol the guests just love it lol
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earl what is the koef test? i did try key on engine off an af was at 4 then full throttle still 4 is this what you mean?
no translator stock maf
You did it right. If the MAF reading stays the same that means the ECM is communicating with the MAF. If the number goes up as you push the throttle, that means the ECM is having to guess as the airflow and there's no communication.
That test can spin you out if you're running a Translator with a bad MAF. as it means the ECM is in contact with the Translator thinking it's talking to a MAF but there isn't any actual airflow data going to the translator.
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Glad to see Chuck is here.
You did check that the TPS is a reasonable voltage and not stuck?
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I have had a similar symptom with a translator unplugged at the MAF check your wiring to the MAF
Sent from my iPhone using Tapatalk Pro
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Glad to see Chuck is here.
You did check that the TPS is a reasonable voltage and not stuck?
I'm sure he read about the circle jerk and wanted to see what it was all about. Haha
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ok am i on to something here or still spinning my wheels...
after speaking with my helper... he tells me he had the iac out an it was stuck so he unstuck it??? but said it worked fine near the end of last season??
SO i unplugged the iac an it started up like its supposed to just rpm was in the 1500 area ??
ideas thoughts??
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the IAC is a solenoid. Trying to fix it probably broke the plunger connection some how??
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Shmed, I think you can still buy the IAC from the dealer. Got a new one for my car a few years back.
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Its a bipolar stepper motor inside ,must turn a screw like part inside to move the visible part in and out a tiny bit. Dunno how one would even unstuck-it.
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Rockauto show them for $25-55 CDN. seem readily available
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Its a bipolar stepper motor inside ,must turn a screw like part inside to move the visible part in and out a tiny bit. Dunno how one would even unstuck-it.
I was thinking the late 80's F-bodys had the threaded ones you could adjust but ours was fixed.
That being said, years ago I noticed one in the junkyard on a plain ole shitbot GM beater car and grabbed it. It works fine on my GN to this day.
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Blast off the carbon if dirty with some Brake Cleaner etc & try it again. Can`t hurt.
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well replaced it with a new one no change starts then dies??
could this be a vacuum leak ???
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And still runs at 1500 if you unplug IAC?
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And still runs at 1500 if you unplug IAC?
Dave...what commands the IAC? You're the electrical wizard.
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Shmed, I found a thread on the other board that sounds a lot like your problem. Swap the ECM with a known good one. There's a driver in the ECM that has something to do with the IAC...you may have smoked it. This came from John Spina...and he's one of the best.
I had a TPS issue with my car a few years back...and I had smoked something in the ECM.
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It sounds like it is starting on the fuel pump prime circuit and the pump is not running after the key goes from start to the run position?
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Kevin, he says it will run if he unplugs the maf or the iac...so that seems to suggest it will run on the limp home mode....Brad may well be right that it is an ecm problem...only strange thing is that it will run on either...but, maybe it is going to the calpac and ignoring the ecm?
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Ooops didn't see that. :icon_eyes: I would be checking grounds carefully then. Thanks Steve
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Dave,
You know if you want it running, I'm your man. Call me. :rock: