I cant get it to run right please help!!! (video with scanmaster)

gmmaft

Member
Joined
Sep 20, 2012
no matter what I do I just cant seem to get her running correctly.
when the car is cold it runs and idles great but as soon as she closes her loop all her little secrets come out.
what I did so far:
new o2 sensor
fixed exhaust leak
upgraded fuel system (everything pump,lines,regulator,hotwire).
new battery
bench tested alternator
new neg battery cable
complete spring cleaning gapped at .035
new egr and solenoid.

it runs 90% better then when I got it but that idle surge when im stopped at a light is killing me.
I shot 2 videos today. the first one is warm idle parked.
the 2nd video is of me driving and stopping at lights.
the car drives awesome as long as its moving but the problem is when im at a light or in park ideling.
also, my brake power booster works sometimes and sometimes it dosent. usually If i hit a bump it will kick on. would the power booster have anything to do with the idle surge im having? if not I will look into the brake booster after I solve this problem.

ps. in the video it mey sound like the engine is knocking its not one of those pulleys are making noise.
 
In the video it looks like your tps is set at .48 at idle... If it is then its too high. once you get past .46 the ecm thinks you are pressing down on the accelerator. That may explain why in open loop it runs so well and once in closed loop runs worse. I would set the tps at .42 with the key one engine off and then look at what the IAC is doing. It also looked kind of high... Remember that once you adjust the IAC the tps will also need re-adjusting as the reading will change.
 
Another thing on the TPS to look out for is the WOT voltage. This should be set to anything more than 4 volts. Also make sure that with the key on engine off you have a smooth progression from idle to WOT voltage on the scanmaster. Any "jumps" here could mean the TPS may be bad. Here is some good reading on some of the sensors for you. http://www.vortexbuicks-etc.com/basics.htm

This site was extremely helpful to me in setting IAC and TPS and lots of other things too.. good luck
 
x 100.......
that im gunna have to take it somewhere because there is a short somewhere in the wires. usually it dosent work but sometimes when I hit a bump the power brakes will kick on and work till the next day.
 
that im gunna have to take it somewhere because there is a short somewhere in the wires. usually it dosent work but sometimes when I hit a bump the power brakes will kick on and work till the next day.

The best way to fix the powermaster brakes is to replace them with a vacuum brake system and you won't ever have to worry about having brakes again. You can get the master cylinder / brake booster with a lifetime warranty from some of the auto parts stores and it will cost far less than what you will spend on fixing the powermaster unit.
 
Also fix those vacuum lines where they won't blow loose. Zip tie all of them. That Fuel pressure line just pulled right off way too easy.
 
thanks guys for all the input. so as far as the rough idle. I need to adjust the tps? anything else look bad on the scanmaster? im still learning these cars.
I also noticed that one of the vacuum lines coming from the solenoid mounted on the passenger valve cover isnt even there. only the hose going to the turbo is there. the other port dosent have any hose connected to it.
 
Been a while since I have messed with a boost solenoid but I believe that the port you are talking about had a filter on it. Not a vacuum line.
 
BlackGN is correct... the boost solenoid only has one port connected to the wastegate an turbo... the other port vents to atmosphere... you can buy the filter from kirbans or I can send you one for the cost of the stamp... I have a couple spares..
 
BlackGN is correct... the boost solenoid only has one port connected to the wastegate an turbo... the other port vents to atmosphere... you can buy the filter from kirbans or I can send you one for the cost of the stamp... I have a couple spares..
if you wanna send me one I would be happy to cover shipping. I just really wanna get this car running correctly.
.
 
Have you tried cleaning the IAC valve?

I had a problem once similar to what you describe with the engine cutting off when coming to a stop, it turned out to be the Autozone coil pack that was causing it. Replaced it with a BWD brand from O'Reilly auto parts and the problem was solved.
 
Have you tried cleaning the IAC valve?

I had a problem once similar to what you describe with the engine cutting off when coming to a stop, it turned out to be the Autozone coil pack that was causing it. Replaced it with a BWD brand from O'Reilly auto parts and the problem was solved.
is there any way I can test the coil pack with my meter to see if its good?
 
is there any way I can test the coil pack with my meter to see if its good?

Take an ohmeter to coil pack terminal for cylinder # 1 and 4, then to 2 and 5, and finally to 6 and 3. You should see 12,000 ohms of resistance for each one of those tests... I'm not sure what the range is +/- but they can't stray too far from that 12k range.
 
Take an ohmeter to coil pack terminal for cylinder # 1 and 4, then to 2 and 5, and finally to 6 and 3. You should see 12,000 ohms of resistance for each one of those tests... I'm not sure what the range is +/- but they can't stray too far from that 12k range.
thanks, i'll check now
 
Take an ohmeter to coil pack terminal for cylinder # 1 and 4, then to 2 and 5, and finally to 6 and 3. You should see 12,000 ohms of resistance for each one of those tests... I'm not sure what the range is +/- but they can't stray too far from that 12k range.
as far as the coil goes I got
12.46 on 1 and 4
13.18 on 2 and 5
12.59 on 3 and 6
does that sound ok?
I will clean out the IAC valve as soon as I read up on how to do so.
thanks again
bill
 
Hey guys new here,I haven't had my GN for about 5 years now I got T-boned :( I just thought I'd throw in a idea. What about the MAP sensor GMs are notorious for rpm jumping when they are bad.Like I said just my 2 cents..
 
Hey guys new here,I haven't had my GN for about 5 years now I got T-boned :( I just thought I'd throw in a idea. What about the MAP sensor GMs are notorious for rpm jumping when they are bad.Like I said just my 2 cents..

MAP sensors on these cars were only used for the LED boost gauge in the analog dash cars. They have no other use on these cars from what i've read.
 
Top