General Tech Good at troubleshooting? Have a non specific issue? Discuss general tech topics here.

engine surge/idle rough

Thread Tools
 
Search this Thread
 
  #1  
Old 04-14-2010, 12:12 PM
STSevilleSTS's Avatar
Member
Thread Starter
Join Date: Feb 2009
Posts: 42
Default engine surge/idle rough

95 Seville STS northstar
Codes P070H S044H

I have been noticing lately while driving around 35 mph that the car is surging Also I can feel a slight miss while at idle. Yesterday I took off the EGR valve and cleaned it and the throttle body. When I had the throttle body off, there's a metal flexible hose attached to like a 1" spacer behind throttle body (see picture). It was completely plugged up with carbon. What is that btw? I put new spark plugs, new plug wires, new fuel filter on it, runs much better except the surge and little miss is still there. The P070 is the throttle position sensor, would that make the car surge and idle a little rough? Is there an adjustment for it or will I have to buy a new 1?

Also while having the throttle body off I looked inside the hole in the plastic intake and noticed a little bit of oil in there. The car uses about a quart of oil a month. Would that be the intake gasket needs to be replaced?
 
Attached Thumbnails engine surge/idle rough-101_0122.jpg  
  #2  
Old 04-15-2010, 03:54 AM
tombomb661's Avatar
Junior Member
Join Date: Mar 2010
Posts: 12
Default

throttle positioning sensors can be adjusted. although im not quite sure how its done. i think a multimeter is involved.

and i dont think your intake gaskets would cause oil in the intake. the intake deals with the air and fuel. maybe valve guide seals?? im not too sure really
 
  #3  
Old 04-15-2010, 10:41 AM
2001_Seville_SLS's Avatar
Senior Member
Join Date: Apr 2009
Location: Seattle Area
Posts: 108
Default

The picture is a lot different from my '01 Seville, but it is probably the EGR pipe. If it is, the other end of the pipe will be connected to the intermediate exhaust pipe. Hopefully you cleaned and inspected the passages in the 1" spacer as well. The 1" spacer that you have described is probably part of the water crossover. That is what it is on an '01. You should remove the water crossover and clean the EGR passages when the EGR valve and EGR pipe get dirty.

Too much EGR flow could cause a rough idle, stalled engine after cold start, misfire, surge during cruise. Too little EGR flow could cause poor mileage, hot engine, knocking, failed emissions.

Because the car uses oil and had a plugged EGR pipe, I would do a compression test to verify the status of the engine.
 
  #4  
Old 04-15-2010, 11:32 AM
STSevilleSTS's Avatar
Member
Thread Starter
Join Date: Feb 2009
Posts: 42
Default

Thanks for replies, the 1" spacer thing has no coolant going through it just one 1/2" hole where the metal hose attaches, the other end bolts to the block. Must be exhaust I don't know. The end of hose where it bolts to spacer was completely plugged up.

The car runs very strong, plenty of power, barks the tires when shifting, its just the slight miss at idle and i mean slight. Not like the engine is shaking or anything, I can just feel and hear it. And the surging around 35 mph.

I just looked at the local parts store and the TPS is only $25 so I'm going to pick one up and see if it helps. I was thinking it would be a lot more than that.

The oil inside the intake is what's worrying me now.
 
  #5  
Old 04-16-2010, 11:46 PM
STSevilleSTS's Avatar
Member
Thread Starter
Join Date: Feb 2009
Posts: 42
Default

OK,now I'm lost,,,I disconnected the negative battery cable while I replaced the new TPS (throttle position sensor) and now have the following codes and message battery not charging/battery voltage too high,

P016 voltage out of range
P052 PCM memory reset
P109 lost battery power
P110 generator L terminal problem
I042 battery voltage too high

I cleared all codes but as soon as I start car they appear again!
 
  #6  
Old 04-17-2010, 09:55 AM
slowroll's Avatar
Tech Certified Members
Join Date: Oct 2007
Location: in the mitten
Posts: 3,160
Default

What is the condition of battery cables?
 
  #7  
Old 04-17-2010, 09:58 AM
STSevilleSTS's Avatar
Member
Thread Starter
Join Date: Feb 2009
Posts: 42
Default

They are clean, I came outside this morning to start car and the battery is dead. The battery and alternator was bought new less than a year ago. All this started after I disconnected the negative battery post to replace throttle position sensor,,,,

I have the battery on charge now, any help appreciated
 
  #8  
Old 04-17-2010, 07:11 PM
STSevilleSTS's Avatar
Member
Thread Starter
Join Date: Feb 2009
Posts: 42
Default

I charged the battery today, put it back in the car and still on the dash says BATTERY NO CHARGE, BATTERY VOLTS HIGH,,,,,,,Service Engine Soon is on also.

codes p016H p052H p109H p110H I042H I052H

The alternator and battery were both bought new July last year (9 months ago) The negative battery cable is new also and the connections are clean.

I cant believe this all happened from disconnecting the negative battery cable to install the new throttle position sensor.

The alternator is not a dealer part, but has worked fine all along. I hate the thought of taking it back off to have it tested. When the alternator went bad the first time I had no messages at all on the dash.

Anybody have any ideas before I take the alternator off?
 
  #9  
Old 04-18-2010, 09:34 AM
slowroll's Avatar
Tech Certified Members
Join Date: Oct 2007
Location: in the mitten
Posts: 3,160
Default

Should be related unless key was on when battery was disconnected. Check ground connections at engine. Any repairs prior to "TPS" concern? It seems like this a cable issue, check voltage to fuse block under drivers side underhood panel that covers relays.
 
  #10  
Old 04-19-2010, 05:28 PM
STSevilleSTS's Avatar
Member
Thread Starter
Join Date: Feb 2009
Posts: 42
Default

UPDATE: Took alternator off and took it down to advanced auto to have it tested. Sure enough it was bad, only been 9 months on the car. At least I could exchange it at no cost. They said it was "stuck on". I guess that's why the BATTERY HIGH VOLTS was displayed. Weird it died at the moment I disconnected the negative battery cable to install a new TPS. Put new one on today and all is good except I still feel a miss and a surge while driving around 35 mph.

Is there any learn procedure/adjustment to do for the new throttle position sensor or does the computer automatically do it on a 95 seville sts?
 


Quick Reply: engine surge/idle rough



All times are GMT -5. The time now is 05:44 AM.