Car was dying and romping.. installed IAC still does it.

Myco

Myco

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The car is still dying sometimes. Tonight I had to keep my foot on the gas for a couple miles before it wouldn't die. Then when I stopped for a longer period of time at a light it started idling very low. Could this be the car getting used to the new IAC. I doubt it but I've heard people talk about this phenomenon. I suspect the fuel pump. Filter is new. I am looking around for a torque wrench to change the spark plugs and check the boots as I suspect the plugs haven't been changed in a very very long time.

97 Mark VIII btw.
 
I'm guessing CEL means engine light.

PO171
P1151
PO300
PO174

are the codes
 
i had a similar problem there was a twig in my mass air flow sensor, i had to keep pumping the gas pedal just to keep it from dying
 
topher5150 said:
i had a similar problem there was a twig in my mass air flow sensor, i had to keep pumping the gas pedal just to keep it from dying
Click to expand...


cleaned the MAF and replaced the filter about a month ago.
 
Tony, did you try resetting the computer? I don't know if it will help, but wouldn't hurt to try.
Just disconnect the battery for like 10 minutes.

You should definitely check those plugs and the coil boots.

Good luck,
Jay
 
Myco said:
The car is still dying sometimes. Tonight I had to keep my foot on the gas for a couple miles before it wouldn't die. Then when I stopped for a longer period of time at a light it started idling very low. Could this be the car getting used to the new IAC. I doubt it but I've heard people talk about this phenomenon. I suspect the fuel pump. Filter is new. I am looking around for a torque wrench to change the spark plugs and check the boots as I suspect the plugs haven't been changed in a very very long time.

97 Mark VIII btw.
Click to expand...

I had this happen to me leaving work one night about a year ago and it went away and never came back. It was awfully scary,but it finally cleared out whatever it was.
 
Myco said:
I'm guessing CEL means engine light.

PO171
P1151
PO300
PO174

are the codes
Click to expand...

PO171 and PO174 are both cylinder bank lean codes... so I would start of looking for a vacuum leak, its probably a pretty big vacuum leak... or low fuel pressure.

P1151 is an O2 sensor code indicating a lean mixture, I would look at again a vacuum leak or low fuel pressure.

PO300 is a misfire code, I woud check the spark plugs, but more than likely that is being cause by a faulty COP.... they are notorious for failing and then giving you all sorts of nasty idle problem flashing CEL (check engine light) along with random misfiring that feels like the dreaded Torqe Converter shudder :eek:
 
all info sounds correct, except p0300 is a "random" missfire code so what ever is happening, it hitting all cylinders not just one. check fuel psi, check for vac leak and let us know
 
The whole random misfire probably throws a bad COP out the window as a choice, unless they got wet in which case I have seen them turn into a major mess.

Water+COP=Fail

I would definitely like to hear a fuel pressure #.
 
kustomizingkid said:
PO171 and PO174 are both cylinder bank lean codes... so I would start of looking for a vacuum leak, its probably a pretty big vacuum leak... or low fuel pressure.

P1151 is an O2 sensor code indicating a lean mixture, I would look at again a vacuum leak or low fuel pressure.

PO300 is a misfire code, I woud check the spark plugs, but more than likely that is being cause by a faulty COP.... they are notorious for failing and then giving you all sorts of nasty idle problem flashing CEL (check engine light) along with random misfiring that feels like the dreaded Torqe Converter shudder :eek:
Click to expand...

I'm going through finals right now and haven't had time for nearly anything but I've been planning on draining the pan/replacing filter. I read somewhere where a guy replaced his IAC and his tranny problems went away. I thought It interesting esp. since the guy I bought the car from said he had the tranny fluid replaced. He also said the oil had been changed recently and it was 2k years overdue so I thought it best to just go ahead and change the fluid. I'll do the spark plug/boot issue first and see what happens.

Yesterday was the coldest day we've had here in a while. It actually snowed. :eek: Thought maybe that was a catalyst to the problem as today it hasn't died at all.

edit: Saw recent posts.

I've changed the air filter and cleaned the MAF. Where are the points a vacume leak can occur. The air intake obviously but where else? On the air intake on this car I had serious problems getting the bottom screw out and the bolt is gone but all the other bolts go right in and the air box sits in it's assembly just fine. (bolted down on top) I'll look around that area for problems. ;)

edit again: How do I check the fuel PSI?
 
To check the fuel PSI you need to proper gauge which can be rented form some auto parts stores, you use the schreader valve on the fuel rail to hook the gauge up. To get a truly accurate idea of what condition your fuel pump is in you need to see what the pressure does when the engine is under load and at WOT.

The gauge I have used has a long enough hose to attach it to the fuel rail and then tape the gauge to the windshield and take a spin and see what the pressure does as you drive.

The gen 2's have a variable voltage fuel system too, more complexity for more chances to fail...

You are in Houston huh... there are a whole bunch of Marks down in that area, XLRVIII on this site and all his crazy 8's buddies live down in that area.
 
kustomizingkid said:
To check the fuel PSI you need to proper gauge which can be rented form some auto parts stores, you use the schreader valve on the fuel rail to hook the gauge up. To get a truly accurate idea of what condition your fuel pump is in you need to see what the pressure does when the engine is under load and at WOT.

The gauge I have used has a long enough hose to attach it to the fuel rail and then tape the gauge to the windshield and take a spin and see what the pressure does as you drive.

The gen 2's have a variable voltage fuel system too, more complexity for more chances to fail...

You are in Houston huh... there are a whole bunch of Marks down in that area, XLRVIII on this site and all his crazy 8's buddies live down in that area.
Click to expand...

Didn't know XLRVIII still had a mark. He helped me do the 1-2 accum. on my first mark a couple years ago.
 
if you do check fuel pressure be sure to wear goggles. I had a bad vaccum leak when the car would die if I didn't have my foot on the pedal.
 
The common intake leak on the second gens occurs between the upper and lower intake halves.

We chased our tail on one that had a problem running Torries tune.

Replaced about 1K worth of parts on the car and it still didn't run right.

He sent the tune back to Torrie (poor torrie) then after the fact he took the car to a dealership that found an intake leak and replaced the IMRCS and the gaskets.

HAD "we" attempted to get the guy to replace those gaskets he would have thrown a fit...he ran us thru the ringer on that car...Torrie got the worst end of the stick.

Sometimes, manytimes it doesnt pay to help people... often quite the opposite.
I put probably 40 hours of work into that car and I got paid nary a "thank you".
He blamed torries tune every step of the way, refused to change parts we suggested, only to "throw" parts that he decided to put on.. he spent way too much money in the wrong places..

some people just "dont listen"...some people cant be saved from themselves.
 
XLRVIII said:
The common intake leak on the second gens occurs between the upper and lower intake halves.

We chased our tail on one that had a problem running Torries tune.

Replaced about 1K worth of parts on the car and it still didn't run right.

He sent the tune back to Torrie (poor torrie) then after the fact he took the car to a dealership that found an intake leak and replaced the IMRCS and the gaskets.

HAD "we" attempted to get the guy to replace those gaskets he would have thrown a fit...he ran us thru the ringer on that car...Torrie got the worst end of the stick.

Sometimes, manytimes it doesnt pay to help people... often quite the opposite.
I put probably 40 hours of work into that car and I got paid nary a "thank you".
He blamed torries tune every step of the way, refused to change parts we suggested, only to "throw" parts that he decided to put on.. he spent way too much money in the wrong places..

some people just "dont listen"...some people cant be saved from themselves.
Click to expand...

In searching for a "upper and lower intake halves" I came across this picture. Show me where "upper and lower intake halves" are.

http://gallery.me.com/unity/100067/IMG_0037X/web.jpg
 
That isn't a Mark intake... that is a cobra intake.

The stock Mark intake is aluminum with composite IMRC runners sandwiched between the intake and the heads.
 
No, its not a Cobra intake. Its a Mach intake.

Here is a Gen II engine.

98%20engine%203.jpg


eng%20g2.jpg


You can see your upper and some of the lower, but here is JUST the lower to give you an idea:

0d0e_1.jpg



This is about how much time it will take to swap out, inspect and replace if needed:

eabyitems028.jpg
 
Unity are you THAT FREAKING ANAL that you have to wash your beer first?

that's just a little bit "racoony" aint it?
 
Sorry, forgot to mention that its in the sink to chill. The fridge was already full of beer, this is the over flow. My bad :)
 
(bitter beer face)
I'm not a "can beer fan" for the most part.. actually "dont like beer" very much..
BUT there are a few that I can drink that dont taste like piss.. or smell like the bathroom at a concert or baseball game.

always amazed me that the tap beer they sell at ball parks.. smells just like the bathroom....HMMMMMMMm
 
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