Hesitation, rough idle, and slow uptake on 95 850 T

Sambryan · Post by **Sambryan** » 14 May 2005, 17:57

Howdy my 850T has been running fine for months with the Check Engine light on (running rich code) and I am sure this has nothing to do with my new issue but maybe someone has an idea...

THE FACTS....
96 8580T 130,000 miles

after sitting 1 hour + when I start it car idles rough and if I hit the gas it will sit there and after 5-10 seconds TAKE OFF... It is some kind of hesitation and I don't know what is causing it.

It seems to clear up if I run it for about 10 - 15 minutes.

Once it gets going it is fine.

It has been raining a lot lately but not today at all. Possible water issue?

It doesnt die it just idles real low untill it catches and ZOOM

Just filled the tank with new fuel AFTER issue started on last tank

Anyone have any ideas???

My thoughts....

Water in the system somewhere?

Check the plugs

Check the fuel filter

Other than that I am clueless.... It is real annoying and real dangerous I would hate to pull out into an intersection and have no power and wind up getting T-boned in the side! My 3 month old baby wouldnt like that either.

Please help if you can!

Thanks,
Sam Bryan

Post by **matthew1** » 14 May 2005, 18:12

Do the easiest first: check spark plugs, air filter, vacuum hoses. Check fuel pressure at rail when car is off. Put in fuel treatment in next tank of fuel.

Sambryan · Post by **Sambryan** » 14 May 2005, 19:05

OK went out and checked a few things.

Cleared the codes... there were a bunch but they were like the MAF and othersuch ... I created these codes when I replaced the heater lines and turned the car on without the MAF attached.

Cleared that damned service light! I hate that thing....

Checked the air filter it is CLEAN

Checked the fuse panel up by the drivers side windshield. DRY

I have to wait till I get home to do the rest because I have no tools where I am at....

I did start it up again to check a thing or two and I noticed that it starts up and Idles around 700 which is fine and normal. But when I give it a shot... lets sayput it in reverse or neutral and gas it and then let off it starts idling around 300-400. Almost dies but not quite....

Keep me posted I will try a few more things in the meantime...

Post by **matthew1** » 14 May 2005, 21:01

If the above items I mentioned are all normal -- I'd look closely at this 850 stalling thread -- your throttle body may be caked with residue.

White850Turbo · Post by **White850Turbo** » 15 May 2005, 05:53

It sounds to me like your throttle body and/or idle air control valve are dirty. When you let off the gas, a certain amount of air must still be allowed to enter the manifold and this is what the idle air control valve does. When it is dirty, all of the necessary air is not allowed to enter the manifold, resulting in your rough idle/rich condition/low idle. Just take it off the car and spray some carb cleaner through it being careful of the electrical connection there. Do the same thing with the throttle body.

Sambryan · Post by **Sambryan** » 15 May 2005, 15:57

Here is the latest...

Replaced Spark Plugs... Same issue
Cleaned Throttle body .. Same Issue
Cheaned Idle Air Control Valve.. same issue
Added a can of injector cleaner.. Same issue

Additional information
Checked fuel rail valve and it squirted about a tablespoon of gas out. It didn't go real far or make a big mess... I could spit about as much as it put out

Checked the valve back before the fuel filter. It did about the same thing but a little more fuel came out this time.

I noticed the issue starts even when I start it and let it sit. It usually takes about 10 seconds and the needle starts to drop on the RPM's. Then it chugs it even made a little backfire sound once. Sometimes the car will idle up to 1000 then drop to 500 then come back up to 700 and it pretty much goes all over the place but mostly on the low side.

Anything else??? I am flat running out of ideas!!!

Post by **matthew1** » 15 May 2005, 16:57

Check your MAF.

95autoturbo · Post by **95autoturbo** » 15 May 2005, 20:02

Has anyone tried some new spark plug wires? I will see if this helps. Bosch sets go for about $90, but I just bought some on ebay for a total of $64 w/ship, I must let you folks know to hurry and take a look, cause there is a few more. I hope this helps. I wonder why the wire sets for 850's are priced so high?

Sambryan · Post by **Sambryan** » 15 May 2005, 21:58

Thanks again for the help guys and here is my latest update....

I did check the MAS and it actually had a bit of green corrosion in it. I cleaned it out the best I could. It didn't seem to help as a matter of fact now the engine runs worse.... but wait I hear a loud hissing sound and grab the little hose between the Idle Control Valve and the throttle body and it is split wide opened for about three inches....

I taped it up (temp fix) and the hissing went away. I started the car and it seemed to idle fine so I hit the gas. The car hit about 2500RPM and just cut out. It started sputtering and othersuch.

hmmm well I shit off the car and decided to do a little more work on the MAS. I made sure it was double cleaned and in case I opened the connection up so the pin contact was weak I bent the teeth down just a tad to make the connection a tighter fit. Also disconnected the two ECU's that are in that box on the pass side and put them back in.

Started it up and same thing... I decided to leave it running and go check for further leaks. I was playing around the ICV in the dark trying to find any leaks and wasn't very sucessful. I did however jiggle everything around in that area though and the Idle seemed to pick back up. Like I said now it is dark and I cannot see much but I took the car out for two test spins about 30 minutes apart and the car seems to ride pretty good. There was some sputtering to begin with but nothing like it dieing at 2500RPM's...

I still think it has a problem, two tests (one of them so so) are not very convincing to me. I will be replacing that hose that attaches to the throttlebody and the connecting one to the ICV. I hope that fixes it but I still feel there is something going on.... The hayes manual says check the vacum lines but I dont know which ones to check exactly.

Any more ideas let me know!

Thanks,
Sam Bryan

Sambryan · Post by **Sambryan** » 16 May 2005, 11:13

UPDATE

After cleaning out the blue gunk in the connector plug on the MAS and the ICV the car doesn't run nearly as rough as it once did. It does have one slight problem left....

I will start the car, back out of my driveway, put it in forward and give t gas. The car will roll forward at about 2,000 RPM's and not go much higher, then after about 5 seconds it launches and takes off like a race horse. Man it really runs great once it gets going! Better than it ever has. But the takeoff issue is not good. That is a sideswipe waiting to happen.

Anyone have any further ideas? I will be getting a replacement hose for the hose between the throttlebody and the ICV tomorrow. I cannot believe those cost 92$...

Thanks,
Sam