mrpoopie

iTrader: (1)

Currently, my car isn't idling very well. In the video below you can see, idle ranges anywhere from 250-1000rpm.



So far I have:

- Checked and adjusted the thermowax (needed to be adjusted)
- Checked and adjusted the throttle cable (too tight)
- Turned engine to TDC, and restabbed CAS. (seemed slightly off)
- Fiddle with idle screw on top of throttle body
- Set TPS to 1 VDC ( have also tried the resistance method)

Before the video, I tried starting the engine, and it died twice before I it ran in the video. However, before that, the engine ran like in the video.

I also realized, that when the engine is relatively cold sometimes, i have to hold the gas pedal and wait for the engine to warm up to keep it from dying.

Has anyone had this same issues, or have any suggestions as to what might be causing this?

BushyTea

iTrader: (4)

Make sure the water thermosensor is plugged in good and making a good connection. On one of my 7's it wouldn't stay running when cold unless I held the gas for a minute. Turned out to be that the thermosensor wasn't plugged in good enough.

mrpoopie

iTrader: (1)

This is the sensor on the back of the water pump housing right? I checked it, and it was plugged in all the way. I replaced it with another one I have, and I will crank the car tomorrow to see if there is is any difference.

BushyTea

iTrader: (4)

Just check and see once you get a chance to try the new sensor. My problem was the plug would go all the way on but the little clips inside would push backwards not making a good connection with the sensor.

I eventually just pushed the wires forward in the clip while plugging it into the sensor and the it was fixed.

mrpoopie

iTrader: (1)

I tried the other sensor and made sure the plug was all the way in, and it seems to be doing the same thing.

One thing I have been noticing though, is the fumes from the exhaust seem to burn my eyes. Does this indicate that my engine is running too rich?

Here is a video I took today:

mrpoopie

iTrader: (1)

New update: I checked the voltages of everything on the ECU, and the self adjusting TPS and intake air temperature sensor at operating temperature were off. The self adjusting TPS was showing a higher voltage than specified I believe as well as the intake air temperature. Would this cause a cold start issue?

mrpoopie

iTrader: (1)

bump.... anyone?

HAILERS

Looks a bit like a vacuum leak.............somewhere, if it does this after warming up.

zeromage428

why is your oil pressure gauge sky high?

RTRx7

iTrader: (2)

Could be a vacuum leak and that's the most likely source of your problems but do you have a BAC valve?

ramz28

not to thread jack but my car is doing the same exact thing, its almost as if ur sittin in my car lol. I check all those as well and its still not working but my oil pressure isnt working. i ordered a new 1 but im sure its not that.

mrpoopie

iTrader: (1)

I've checked quite a few times for a vacuum leak but can't find any. I just found out that one of my oil metering pump lines doesn't have any oil going through it and is leaking some oil. Could this be causing such an idle issue?

Also, would a vacuum leak cause the car to run rich?

I have been wondering too, but based on what I have been searching on the forums, it looks like I have a bad sender?

Hailers seems to think it's a vacuum leak so I'll check again. I do have a BAC valve installed and it seems to be running properly.

The last time I checked for a vacuum leak, I pressurized the system, and the only areas I could feel air coming out was at the throttle lever on the throttle body. I couldn't get the gauge to show any pressure on the vacuum leak tester last time.

RTRx7

iTrader: (2)

If your coolant temp sensor is unplugged or not working the car will run rich.

ramz28

i thought it was a vac leak too but i smoked the car and i cannot find a vac leak. my runs exactly the same as yours. i thought it was the thermosensor as i dd just replace the water pump housing but its as tight as it gets and the connectors are good, i just spoke to TNRracing out here in NYC told me on 88s there is a idle mixture screw on the side of the MAF that can cause it to run rich. idk if urs is and 88 as well but im going to check that later. good luck

RTRx7

iTrader: (2)

If the videos you posted are of cold starts then your BAC valve isn't working.

mrpoopie

iTrader: (1)

This is the sensor at the radiator cap right? I've been looking for the end that this plug goes to and I can't find it. The only wire I see that is remotely close that plugs into this sensor is a brown wire that has been grounded to the chassis.

I replaced both the IAT and water thermosensor, and it's still not running correctly. What I find strange though, is the orignal IAT's voltage at the ECU was a bit higher than it was supposed to be.

That was a video of the car running after it was warmed up. Right now, when I start the car cold, it was do the warm up cycle, and the die.

Also, is the UIM supposed to be hot to the touch? The engine and it's surrounding areas get really hot. The temp gauge is in the middle when the car is warm just like in the video, and the car is currently parked in the garage.

TheAbsence

iTrader: (19)

Yeah the UIM gets hot. Have you tried spraying carb cleaner or anything flammable near common vacuum leak spots to see if the engine revs up at all? I know you already checked, but this is an easy, cheap test that can't hurt to be done again.

RTRx7

iTrader: (2)

I would be careful when spraying highly flammable materials around a hot engine.

The test gets quite expensive when your car catches on fire.

So the coolant temp sensor under the alternator isn't plugged in?

I can't understand if you are trying to find the plug or the sensor..

mrpoopie

iTrader: (1)

Oops, I was thinking coolant overflow sensor. The coolant temp sensor which is bolted to the the water pump housing and is green on the end is indeed plugged in. I also replaced it with another coolant temp sensor and it is doing the same thing. IIRC, when I was probing the coolant temp sensor on the ECU, it was reading within range.

mrpoopie

iTrader: (1)

Update:

I replaced the thermostat today, and just about all the vacuum hoses.

It still dies on a cold start, and still has a fluctuating idle when hot.

I unplugged the BAC while the car was hot and running and the engine was bucking like crazy. This means the BAC is doing its job right?

I also checked the thermowax again, and it was separated from the fast idle cam when the engine was hot. When cold, it was close to the 77 degree mark.

I still think for some reason the engine is running hotter than it should be. I had the shift boot off today, and the bottom of the shifter was too hot to touch. Is the engine really supposed to be this hot? As I mentioned before, my intake air thermosensor when the engine was hot was about 3.5 volts at the ECU, not 1-2V as mentioned in the service manual.

Any ideas??

I am going to pressurize the system sometime later this week to see if I can find any new or undiscovered vacuum leaks.

RTRx7

iTrader: (2)

The next thing in line for replacement is the AFM.

mrpoopie

iTrader: (1)

I've already replaced one of those too heh. The old AFM had a bad switch on it, preventing the car from starting up. It ohmed out fine, and the voltage for the AFM tested out fine at the ECU.

RTRx7

iTrader: (2)

Could you have a leak at one of the injectors or at the manifold gaskets?

If everything is in spec, a vacuum leak is about your only option.

mrpoopie

iTrader: (1)

I replaced the upper and middle manifold gaskets, and replaced all the lower injector grommets since they were causing a vacuum leak.

What is the vacuum hose that goes from the back of the middle intake manifold to the firewall on the passenger side? I can't figure out where the hell that hose goes to.

RTRx7

iTrader: (2)

Can you get a picture?

There are a few in that region.