'86 GN with 28k on Odometer? Engine runs rough & spudders applying gas. Limped Home

[Grannie86]

Well Guys, learning about the GN turbo. Car ran Ok for about a week or so. Then drama has set in . First checked spark plugs (Black replaced out all 6) coil pack New. Even bought New cam sensor with LED (blinks when running). Removed orginal crank sensor, cleaned out and inspected. Reinstalled and set to reluctor ring (.020). Cleaned out injector's ( Orginal 5= 28lbs but noticed one injector has a Green ring,?) injector #6, must have been replaced out at sometime) Cleaned IAC and pleum. PCV grommet new ect. Now Big ticket item. Installed into A pillar, a ScanMaster G with a Vac/Boost guage. Fire-up GN, scanmaster G reads all points (Except for Injector Pulse-width @ 0) idles Ok do hear sight lifter knock now. (TPS at 3 at idle, spark adv around 50.2, O2 sensor new,reads up/down. BLM's up/down 100 to 150) Placed in drive went down the road. Wham same problem when applying gas, engine spudders, can not even get to a Min. Boost? Not sure what direction to Go. Ran Great at purchase, only thing I can think of is check if the cam is set correctly or even worn? Figure I post some ideas what I did at this point, need some Great advise what to do next/check?

 

[rag231]

MAF? Any check engine lights?

 

[rag231]

Definitely heading in the right direction with your troubleshooting skills!

 

[Grannie86]

Orginal MAF and No check engine codes

 

[ScottHeidinger]

TPS is what at idle?

Should be .44 not 3...


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[Grannie86]

Scanmaster G read 3 at idle, then ramps some when depressing gas pedal

 

[ScottHeidinger]

Basics

Need to set it to .42-.44 at idle and 4.6 plus at Wide open throttle. Car thinks your foot is 3/4 to the floor right now.


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[Grannie86]

Um at work now EST (almost 12 am) tomorrow I recheck TPS settings .Thanks for your input. I remember reading about the TPS sensor is critical. I did check sensor with Ohm meter, I may sure it was OK. Let you how I make out. Also told Keep it Simple

 

[ScottHeidinger]

You don’t check it with ohm meter. Set your scan master to TPS With key on engine off. Loosen the two screws that hold the TPS sensor, pull it towards the front of the throttle body and adjust it to .44 ish on scan tool. (Helps to have someone in the car while you adjust it. Tighten it up and then put foot to the floor and make sure it reads over 4.6 volts at wide open throttle. Check your IAC number as well since it’s a balance to get the IAC around 10-15 hot idle with ac off and have TPS .44 (throttle closed) to 4.6 (WOT). Car will not run right with idle TPS at 3. Kind of surprised it runs at all if your TPS is really that high.


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[Grannie86]

Copy that , will set TPS at correct voltage at idle and check at Full throttle as well. Will check back with Ya with the results. Thx Scott H.

 

[scgnx2]

BLMs should be 128+/-10, bad MAFs do not always through a trouble code.
Original MAFs are notoriously problematic. Swap it with a LS1 MAF and a translator.

 

[Chuck Leeper]

" spark adv around 50.2, " ??

 

[Grannie86]

Copy that , will set TPS at correct voltage at idle and check at Full throttle as well. Will check back with Ya with the results. Thx Scott H.

Found after setting TPS sensor with voltmeter, it had a deadspot somewhere in the middle. Ordered a New TPS sensor

 

[Grannie86]

Definitely heading in the right direction with your troubleshooting skills!

Found a deadspot in my TPS sensor. Ordered a New one

 

[GNICETRY]

Listen to Scott. I’ll add make sure the floor mats are out when you are adjusting WOT TPS (car not running of course). Some things to learn are; new does NOT equal good for factory replacement parts MAF, coil pack, etc. Do one thing at a time. Throwing $$$ at a problem with a Turbo Regal is a BIG mistake. Diagnostics are extremely important for these cars.
I would also suggest to just get 60lb injectors, a good fuel pump and hot wire kit regarding your fuel system. You probably have an old pump in there or you don’t know what is in there. I would want to be sure. Get all your #’s right on your scanmaster before you touch boost.
You HAVE to get a newer chip too preferably from TurboTweak. And lastly the stock MAF is not worth keeping. They do not always code when bad. You should look to upgrade in the future to the LS1 and MAF Translator. An easy way to tell if your MAF is bad is to tap it lightly with a screwdriver (plastic side) and if you can detect ANY idle variation, it is suspect.
And the scanmaster G being a big ticket item- I hope you mean for diagnostics and not price. Because you will wish to only spend $250 for any issue you have with the Buick. LOL

 

[Turbo6inKY]

You symptoms are the same I had when my OE MAF died. No code, but nearly undriveable as soon as it went closed loop.

If you still have the stock injectors, pull the MAF connector and start it. It'll run on the CALPAK, and probably run better. If it does, then get yourself a late model MAF and a translator on the way.

 

[BobbyBuick]

pulll the eprom and start it the car will run and the the engine light will blink .Does it run better with no eprom? if so more then likely MAF