Surging '99 Solara

THarms · #1 (**permalink**) 08-24-2006, 09:46 PM

Mustang (or anyone else that has some advice...)

My wifes '99 Solara SLE (3.0L V6) has this weird problem... The car idles fine, accelerates fine and runs great on the hwy... but when you are driving in town between 20-40mph, with the engine turning between roughly 1500-2100rpm, the rpm's tend to surge then relax to the point where it feels like you are pumping the accelerator about 1/2" then letting off (I don't know how else to describe it). Its not a real fast jerk, just a pulsing surge but its bad enough that its really annoying when driving around town.

I've recently did a basic tuneup (cleaned the MAF sensor, cleaned the throttle body, changed spark plugs, new air filter, new fuel filter, etc.) which made it idle perfectly. But it still has that engine surging/pulsing in that same rpm range.

My hunch is that the MAF sensor and/or oxygen sensor(s) are in the process of failing... but I don't have any error codes (atleast yet). Before I start throwing any more money at it, I thought I'd see if anyone else has seen this problem.

mustang67408 · #2 (**permalink**) 08-24-2006, 11:54 PM

Quote:

Originally Posted by THarms

Mustang (or anyone else that has some advice...)

My wifes '99 Solara SLE (3.0L V6) has this weird problem... The car idles fine, accelerates fine and runs great on the hwy... but when you are driving in town between 20-40mph, with the engine turning between roughly 1500-2100rpm, the rpm's tend to surge then relax to the point where it feels like you are pumping the accelerator about 1/2" then letting off (I don't know how else to describe it). Its not a real fast jerk, just a pulsing surge but its bad enough that its really annoying when driving around town.

I've recently did a basic tuneup (cleaned the MAF sensor, cleaned the throttle body, changed spark plugs, new air filter, new fuel filter, etc.) which made it idle perfectly. But it still has that engine surging/pulsing in that same rpm range.

My hunch is that the MAF sensor and/or oxygen sensor(s) are in the process of failing... but I don't have any error codes (atleast yet). Before I start throwing any more money at it, I thought I'd see if anyone else has seen this problem.

Is the fuel tank 3/4-full?
I have a few ideas depending on your answer.

THarms · #3 (**permalink**) 08-25-2006, 07:36 PM

The level of fuel in the tank does not seem to have a noticable impact... although the other day the tank was very low (<1/4 of a tank) when I was driving it and the surging was very noticable.

mustang67408 · #4 (**permalink**) 08-25-2006, 08:29 PM

Darn, thats shoots that idea.

I'll keep thinking about it.

Have you tried disconnecting the egr valve and see if that helps?

THarms · #5 (**permalink**) 08-25-2006, 10:20 PM

Disconnected the wire sensor plug to the EGR valve and took it for a test drive. The check engine light came on about 2 blocks from my house... Took about a 5-mile loop around town and it seems the surging has gone away. Stopped off at home and reconnected the sensor plug and the surging returned (check engine light stayed on, but loaned my OBD scanner to my dad a few weeks ago so can't check the code or reset the computer).

From this, I assume that I have a bad EGR valve that needs to be replaced. Is it ok to drive the car with the EGR unplugged for a few days until I can pick up a new one from the dealer?

Thxs for you help!

mustang67408 · #6 (**permalink**) 08-26-2006, 01:46 AM

I dont think it is the EGR valve.

I THINK it is the EGR POSITON SENSOR. See attachment.
They are known for failing and giving false readings.
Unplug it, remove 3 nuts and lift. Its that easy to change.

You probably have a code p0401 and maybe another. Its ok, you set it when you disconnected the EGR Position sensor. It wont hurt anything with the engine light on, just leave everything plugged in, until you can replace it.

PM sent

THarms · #7 (**permalink**) 08-29-2006, 12:07 PM

Quote:

Originally Posted by mustang67408

I dont think it is the EGR valve.

I THINK it is the EGR POSITON SENSOR. See attachment.
They are known for failing and giving false readings.
Unplug it, remove 3 nuts and lift. Its that easy to change.

Tested the EGR position sensor with my digital test meter. Ohm reading was ~5.2 so it was out of the 1.5-4.2 range suggested in the attachment.

Picked up a new sensor at the dealership (~$35) and it took me about 10 minutes to install. Car runs again like new... it evens idles better now.

Thxs again!

mustang67408 · #8 (**permalink**) 08-29-2006, 01:42 PM

Glad you were able to fix it yourself

.
You know how those dealership people are

CharlieWilson · #9 (**permalink**) 09-16-2006, 05:40 PM

Thanks for your help. I have a 98 camry that had the same symptoms. I took it to the dealer and they said my spark plug wires were arcing ($46). I got those replaced (Pep Boys $200), but the symptoms did not improve. I disconnected the EGR vacuum hose (As you suggested) and saw the symptoms disappear. I tested the Vacuum Control Valve (VCV or "that purple round thing") and it was faulty. After replacing it ($60), the problem persisted. I then replaced the EGR position sensor (As you suggested) even though the ohm meter reading was 4.26k which was still barely within spec. (The new sensor cost $50 from the dealer and measured about 3.0k). The problem is gone!

mustang67408 · #10 (**permalink**) 09-18-2006, 07:00 PM

Quote:

Originally Posted by CharlieWilson

Thanks for your help. I have a 98 camry that had the same symptoms. I took it to the dealer and they said my spark plug wires were arcing ($46). I got those replaced (Pep Boys $200), but the symptoms did not improve. I disconnected the EGR vacuum hose (As you suggested) and saw the symptoms disappear. I tested the Vacuum Control Valve (VCV or "that purple round thing") and it was faulty. After replacing it ($60), the problem persisted. I then replaced the EGR position sensor (As you suggested) even though the ohm meter reading was 4.26k which was still barely within spec. (The new sensor cost $50 from the dealer and measured about 3.0k). The problem is gone!

Another satisifed customer

Fishtech · #11 (**permalink**) 03-19-2007, 10:17 PM

Quote:

Originally Posted by mustang67408

I dont think it is the EGR valve.

I THINK it is the EGR POSITON SENSOR. See attachment.
They are known for failing and giving false readings.
Unplug it, remove 3 nuts and lift. Its that easy to change.

You probably have a code p0401 and maybe another. Its ok, you set it when you disconnected the EGR Position sensor. It wont hurt anything with the engine light on, just leave everything plugged in, until you can replace it.

PM sent

Can you provide me with the attachment? I am having P0402 and P1411 errors on my 99 Camry. Do you think it could be the same thing?

mustang67408 · #12 (**permalink**) 03-20-2007, 10:22 AM

Quote:

Originally Posted by Fishtech

Can you provide me with the attachment? I am having P0402 and P1411 errors on my 99 Camry. Do you think it could be the same thing?

Yes, i think it is probably the same problem as long as your camry is a V-6

PXLpainter · #13 (**permalink**) 03-20-2007, 12:32 PM

Mustang - thanks for your technical expertise here! Greatly appreciated!

Larryr · #14 (**permalink**) 03-25-2007, 03:45 PM

Hey this was my problem exactly. Did what was said and it cleared it up. Will buy new postion sensor tomorrow. Thanks- The internet is a wonderful thing and thanks for this great web site.

Larry R