Where to buy IAC valve for Volvo 740

I am looking for a good source to buy a new or used IAC valve
for a 1990 Volvo 740GL. [P/N 1389557] The only place I could find it
was at fcpgroton.com and they want $202 for it. I was hoping to spend
a little less than that seeing as how I only paid $200 for the car.

What is the best way to test an IAC valve to see if it is faulty.
I took mine off and noticed that the plastic electrical connector
area will rotate. When it does, there is a crunching noise inside
the part. I assume that this connector should not be able to rotate
unless all of the electical connections are also rotating with it
inside the body. Is there a way to put power to the valve to see if
it will actuate? If I hook a multimeter to the two terminals, what
resistance should it read?

Any info will be appreciated.

Ryan B.

 

There isn't any easy way to test an idle valve except by substitution.
And a valve that works fine on one car may work poorly on another, and
vice versa. It sure does sound like yours won't work properly on any
car, it shouldn't rotate like that. However, that may make it easy to
take apart and clean.

 

There were at least three styles of idle motors found on the 700s (the motor for
the Bosch LH-2.2 FI, the Bosch 2.4/3.1FI, and the Rex-Regina system).

The Bentley manual lists tests for two styles of Bosch motors (I have no idea how
reliable the tests actually are).. what do you have on your car?

However, it may be as simple as running some carb cleaner through the motor.

What sort of problems are you experiencing?

- alex

'85 244 Turbo

 

As far as the type, I think it is a regina, based on the part number
for the IAC. I only make this assumption because on one of the part
sites I was at, there is a different part number than what is on my
IAC, and the site said it was for Bosch systems.

It's kind of a long story. I tried to keep it as brief as I can, but
I thought some points may be relevant to the overall problem.

When I got the car, it had been sitting derelict for 16 months.
It had 176000 miles on it.

The only problem that I was told it had was that the catylitic
converter was missing. It had about 1/3 of a tank of old
gasoline in it, so I put in a couple of bottles of fuel injector
cleaner. I removed the spark plugs and sprayed some anti-
seize cleaner down in the spark plug cavities. I then jump
started the car. I got it to start by spraying carb cleaner and
starting fluid directly into the throttle body. At this time, It was
idling at about 1500 rpm, but it was running pretty rough, and
loud because of the missing cat. I pulled it into my garage,
and went to work on temporarily fixing the exaust. I bougt a
cheap exhaust repair pipe and clamped it in place where the
cat was. The cat had been cut off just above the flange. Actualy,
The flange was still there, but it was cut about half way through.
I had to cut it the rest of the way, but I saved it just in case it is
needed in fhe future.

With the exhaust patched, I was able to get it started again, but
it would only start by spraying the starting fluid and carb cleaner
directly into the throttle body. It was still idling at about 1500
rpm, and when I put it into gear, (automatic trans) it would lurch
pretty good. I took it for a spin around the neighborhood. It seemed
to run OK. It had good acceleration, and the engine seemed to run
well. I drove it about 6 miles and stopped at a carwash. I had to
start it again by spraying starting fluid and carb cleaner into the
throttle body again. I then got it onto the higway and it made it
up to about 90 MPH. Everything seemed fine. The only problem
I saw was that the overdrive switch on the trans seemed not to be
working and it seemed to hang out in 2nd gear a little to long. I
drove it about 9 miles on the highway and then exited to take it back
home. This is where it all started to go downhill.

At the exit, I stopped at a gas station. Since it still had about 1/4
of a tank of bad gas, i figured that I would fill it up with premium
to try to flush it out. I filled the tank with 92 octane and then
tried to start the car. I again had to spray carb cleaner and
starting fluid in the throttle body to get it started. This time,
however, the idle had jumped to about 3000 RPM. I couldn't even
get under the hood to try to adjust it, because of the wind coming
from the fan. I stopped and started it several times the same way,
and each time it idled at 3000. I was about 7 miles from home. It
was about 10 PM and the road I was on led straight to my house. It is
a country road and was pretty deserted at this time. I dropped the
car into gear and began the journey home. About halfway there, I
noticed that I forgot the latch the hood. I pulled over to close it,
and when I put the car in park, the idle was surging up and down
between 1500 and 3000 RPM. I closed the hood, got back in and limped
the rest of the way home. I could not take my foot off of the
throttle. It seemed like it wanted to stall if I did that. I got it
back home and into the garage. Where it stayed for a few weeks,
untouched.

I then discovered the brickboard and read many of the postings there.
It was there that I realized that spraying carb cleaner into a fuel
injected engine may not have been wise. I also learned that my
problem nay have been a dirty throttle body. I went to eeuroparts on
the web and bought a new TB gasket and new plugs and wires. I removed
the throttle body and TPS and cleaned the throttle body. I adjusted
the throttle position screw and the TPS lilke the instructions on the
brickboard FAQ said. I then replaced the throttle body and started
the car. It started ok, but it idled at about 2500 RPM. I loosened
the TPS and clicked it back and forth to make sure it was in the right
position. In the idle position, it would go up to 2500. When I
clicked it into the open throttle position, the idle would surge
between 1500 and 3000 rpm in about 1 second intervals. I readjusted
the TPS, and it was still idling at 2500 conistently.

At this point, the boneheaded mistakes were many. I went to do more
research. I turned off the engine, but left the key in the on
positon. When I got back to the car, several days later, the battery
was dead. It was an old battery and didn't hold a charge well. I
tried to jump it, but couldn't get enough juice. I then took the
battery out of my Ford Ranger. I was anxious to get the car running
again. In my haste, I hooked the battery up backwards. There was a
horrible hissing noise as white smoke came from the ground cable on
the alternator to the engine block. I quickly disconnected the
battery. The only visible damage was that the insulation had melted
off of the ground cable. At this point, I thought that the car was
fried. I removed the ground wire, and inspected it. The only problem
was the insulation. I wrapped it heavily with electrical tape,
replaced it, and put the battery in the right way. I was able to
start the car one more time. It still idled at 2500 RPM. It ran for
about 5 minutes. When I put it into gear. the idle would drop down to
about 1100 rpm. In neutral or park, it was at 2500. I shut the car
off, removed the truck battery and left.

I then learned about the IAC valve from Mike F. This sounded like it
might be a winner. I bought a new battery and installed it.
Unfortunately, I could not get the car started to thest the valve by
restricting the hose. I pulled the vavle off the car, and inspected
it. I sprayed WD40 into it to clean it. Not much dirt came out. It
is the type of valve that cannot be dissassembled. When I was wiping
it off, I was holding it by the plastic connector end and twisting a
towel around it with my hand to dry off the rest of thw WD 40. This
is when I noticed that the connector was twisting in the valve body.
When this happened, there was a grinding noise in the valve. I
figured that it was the electrical connections tearing loose. Since
there is no way to dissassemble the valve, I have no idea what's
happening inside. I reinstalled the valve, but the car still won't
start. At this point, I have no idea what the problem is. If I spray
starting fluid into the manifold, It will turn over and run until the
fluid is burned off. It seems now that there is no fuel going to the
engine. I don't know if this is a clogged fuel line, a bad fuel pump
relay, or a bad ECU. All of the fuses are fine. It's a bugger
getting to the relays. I haven't checked them yet. How do you test
them?

Could I have done more damage than I thought by putting the battery in
backwards? I was able to get the car running one more time after
doing that. The only other thing that I noticed since then is that
the radio speakers don't work. The radio powers up and receives
stations, but no sound comes from the speakers, even at max volume.
What is the radio noise suppression relay, and could it be affecting
this? If the connectors are bad in the IAC, could this keep the fuel
pump from turning on?

If you read this entire post, thank you for your patience. I hope I
didn't piss anyone off. I am not ready to give up on this car yet.

I can email pictures of the engine, If this will help.

Regards,

Ryan B.
St. Clair, MI

 

That was a good post.. the more information the better. That way, someone
can ask more useful questions of you. Expect a more complete followup
later on this evening.

- alex

'85 244 Turbo

 

I had a lot of luck today. I played around with the IAC some more. I
looked in my Haynes manual and it had a cross-section view of the
valve. It looks like maybye the whole inner assembly may rotate
inside a solenoid. I sprayed some lubricant inside the valve to make
it easier to rotate. This made the "grinding" stop when it rotated.
I did notice a click about every 180 degrees of rotation. The manual
said that the resistance betweent the two terminals of the valve
should be 4 ohms. I rotated the connector until it clicked. I
checked the resistance and got no reading. I rotated it agan until it
clicked. When I checked the resistance, I got around 4.1 ohms. This
was close enough for me. I reinstalled the valve.

I still could not get the car started. I did some more reading in the
Haynes manual. I thought that the trouble might be the fuel pump. I
took out the fuel pump relay and jumpered the connectors that start
the fuel pump. I could hear it running. I replaced the relay and
tried to start the car. To my amazement, it started, but stalled
right away. I started it again and kept it running by giving it some
throttle. I was able to keep it running, but now, the idle is at
about 500-600. I like this better than 2500, but it seems to be on
the verge of stalling. I'm not sure whether or not I fixed the IAC.
I don't know if it is funcitioning, or if it went from being stuck
open to stuck in a more closed position. When I remove the hose from
the IAC at the manifold, the idle jumps back up to 2500 RPM.

One thing I did notice: When I remove the vaccuum hose from the
pressure regulator on the top of the manifold (I think it is the
pressure regulator) I get a better idle. It goes up to about 700 RPM
and the engine runs smoother. Is it possible that the pressure
regulator is faulty, or does it need cleaning? How is it
disassembled?

Thanks again,

Ryan B

 

Not suggesting this is your problem, but don't always be fooled by hearing
the pump running, the fuel pump failed in my 240 Turbo a few months ago and
the pump sounded just fine, just that internally the impeller had broken off
the nubs on the motor shaft that engage it so the motor was buzzing away but
no fuel was being pumped.

 

The pressure regulator is one of those things that is cheaper and
quicker to replace than it is to test. Based on your report, if this
was my car, I'd put in a new regulator, then (assuming it's clean) set
the throttle plate and throttle switch, which I'm not 100% sure how to
do on a Regina equipped car, although I think it's the same as on the
LH2.4 models as explained at:

http://brickboard.com/FAQ/700-900/E...rottleBodyandThrottlePositionSwitchAdjustment

 

The first step is to make entirely sure what type of fuel injection you've
got. If it's a Bosch setup, you'll have a cylindrical coil, and an air
mass meter (a large cylinder in the air intake path with a big flat
electrical connector). If it's a Regina setup, you'll have a weird
(square I think) looking coil and a MAP. I believe that the MAP will
either be in the passenger compartment with a vacuum hose going from the
air intake path, or the sensor will be in the intake ducting itself and
will have a smaller electrical connector.

Yes. It sounds like you're not getting fuel at all. If it's the Regina,
I really have no idea about the specifics.

With the relays (on the Bosch FI 240s at least) you can just jump the
appropriate fuses to bypass the fuel pump relay (or get a test relay for
the earlier 240s). Not sure with the Regina setup. Also, once you get
the fuel pumps running, you can check for fuel flow. On the 240s it's
simply a matter of jumping the two fuses.. or you could just convince the
relay to do its thing with a toothpick or something.

If there's a radio suppression relay, perhaps that has gone bad?

The brickboard's 700/900 FAQ's fuel injection section has a few other good
ideas (including a clogged fuel rail or fuel pressure regulator) worth
checking.

- alex

'85 244 Turbo

 

It's definitely a Regina system. This really stinks because all of
the regina parts are more twice as expensive, if not more, than the
Bosch parts. For example, the fuel pressure regulator on FCPGroton is
$37.03 for Bosch and $105.00 for Regina. Maybe its because they only
have genuine Volvo parts for the Regina.

I think the problem is with the IAC. I disassembled it last night,
even though it was made not to be disassembled. I ground off the
rolled over end that held the connector in place. This allowed the
connector to slide out. Both connections were twisted and broken. I
soldered them back together and covered the exposed wire connectors
and solder with a urethane epoxy. This will keep them insulated so
they don't touch the sides of the valve body. I reassembled the unit
and cemented it together. I took a 12V power supply and touched the
tow terminals. The solenoid actuated the valve, which it never did
when I tried this before. I am currently waiting for all the
adhesives to cure. I will then put it in the car and test it. If if
works, I saved $200 for the new valve.

Actually, I don't think it is the fuel pressure regulator. From what
I've read elsewhere, if the diaphram goes bad, I should be seeing fuel
coming through it. This is not the case. I think the idle is poor
because the IAC is completely shut and the engine is starved for air.
It runs fine when I give it some throttle.

I will keep you posted. I think I am getting close!

Regards,

Ryan B.
Michigan

 

Yeah, I would be curious to see what's so special about the Regina FPR. If it's
merely a different fitting or a different pressure, you would be able to use some
sort of generic FPR quite easily.

Supposedly the FPR can fail in a way that would either completely inhibit gas from
getting to the engine, or completely inhibit gas from returning to the fuel tank.
Neither result would yeild reasonable running.

Indeed. How did your idle motor fix go?

- alex

'85 244 Turbo

 

Isn't the Regina system used on some Buicks? Perhaps it's like the blower
motor in the 700's that you could buy a generic one at any autoparts store.