running extremely rich

[steelbuckeye]

i own an 85 dodge 600, 2.2 with a turbo. it is getting about 9 miles a gallon. i replaced a stuck pcv valve, found a bad map sensor (voltage spread only about 1.5volts), when i put a good map sensor in it would almost stall as soon as i give it throttle. with bad map, it is driveable just runs extremely rich all the time. i checked cam timing (good) and dist timing (good). then i checked vacuum, it's about 12"hg, which is low. i then put a vacuum pump on egr valve with car idling, drew about 20"hg and nothing. my question is, since im new to these motors, am i heading in the right direction? i know i need to check the valve further but, do these tubes clog up, and are these common issues? any other suggestions of things to check or common problems will be greatly appreciatted! thanks

[Screamin4banger]

Vacuum being low could be a slipped belt throwing the cam timing off. That's common. I would check that. Engine Timing Instructions - 2.2 and 2.5 SOHC

How did you test the map sensor? testing with vac only wont give you the full range of the MAP. The replacement was new? used? but it was from a turbo car right?

The EGR tube being clogged wouldn't cause your car to die... just fail emissions for NOx. When you applied vacuum, did you go right to the EGR or the transducer on top of it - makes a difference.

you said your cam timing was good, but @ 12hg vac, your idle will be really high if its a vac leak. Did you remember to disconnect the CTS during ign timing?

And of course, Did you check your trouble codes?

[phantomrt]

The fuel pressure regulator is probably ruptured. Remove the vacuum line from it and start it up to see if gas comes gushing out.

[steelbuckeye]

yea i checked the cam timing after discovering low vacuum too and it's still ok. i checked the voltage by backprobing the wires at map it started at 2.5v@5"hg and with 20"hg it was at 1.2v. the new map (new from parts store, for a turbo car)checked correct using this method(going from like 4.5v to .6v). but like i said, it almost dies as soon as you give it throttle. i checked the egr valve at the transducer on top. i figured pulling a vacuum on it would cause the diaphragm to open and should do something noticeable to the idle. but it didnt even burp. i dont have a check engine light, the bulb is burnt out, but i took it to a friend and put it on the snapon scanner and the only code was for system running rich(other then the start and end codes). i also forgot to mention that the sensor was the first thing i replaced. i did disconnect the cts during ign timing. the car doesnt have a tach so i dont know what the exact idle is, but it sounds to be around 750-800rpm, that is where i checked the ign timing and it's about 14.thanks.

[steelbuckeye]

i removed the vacuum line from the pump and ran it. no fuel came out of it, and the idle is exactly the same. thanks.

[Screamin4banger]

Quote:

Originally Posted by steelbuckeye the new map (new from parts store, for a turbo car)checked correct using this method(going from like 4.5v to .6v).

Ummm...Nope. 4.5v @ 5"hg sounds like an N/A Map. Check this out:
Voltage Tables

Quote:

Originally Posted by steelbuckeye i checked the egr valve at the transducer on top. i figured pulling a vacuum on it would cause the diaphragm to open and should do something noticeable to the idle. but it didnt even burp.

Right, its a backpressure transducer... it means it controls the EGR depending on backpressure. Go right to the EGR for that test if you want to test it.

Quote:

Originally Posted by steelbuckeye the car doesnt have a tach so i dont know what the exact idle is, but it sounds to be around 750-800rpm, that is where i checked the ign timing and it's about 14.thanks.

You should have been able to check the engine speed with that scanner. If you could get the idle up to where it should be and the timing correct, you just might find your missing vacuum... or at least not stall.

Keep us updated

[steelbuckeye]

it's been like a month since i had time to screw with this car, so i was giving numbers from memory. i just remember reading a chilton's and the old sensor checked bad, new sensor checked good. i just went out and measured both map sensors: old sensor2.88v key on, 2.49v=5"hg, 1.36v=20"hg......new sensor:4.53v key on, 3.69v=5"hg, 1.17v=20"hg. the chiltons was basically saying it needed something like 2.5v spread from 5"hg to 20"hg to be within spec. and when doing the egr test there was no response when vacuum was applied. it didnt stall hiccup or anything. thanks for your help, and sweet avatar, im a huge floyd fan.

[Screamin4banger]

I'm still a little hung up on those MAP voltages you got... Did you check out the link to NAJ's post about the voltages? Nevermind the 5v reference seems low ( I would backprobe with the car running) but if you are like 3.7v @ 5"hg - thats less than a volt off of your reference voltage. Now Chilton can tell you to have 2.5v spread 'tween 5" and 20" all day long - I don't care. How do they expect the computer to read from 5" all the way to 14.7 PSI on less than a volt. Think about it.

[steelbuckeye]

new sensor is 2.7v at idle and old sensor is at 1.9v at idle. i can tee into a couple different spots, even right at the map sensor, i get right around 12-13"hg. according to that voltage table neither sensor is getting very much vacuum.

[Screamin4banger]

Quote:

Originally Posted by steelbuckeye new sensor is 2.7v at idle

Is telling the computer that you are in boost at idle. Maybe look at it the other way 'round than you are now.

I guess what I am suggesting is that you Ignore chilton for a minute and instead of looking for a 2.5v sweep from 5" to 20", you should be looking for 4.5v sweep from 14.31# to 24.01" [14.31PSIG/4.90V -> 24.01HG/.43V].

Another way to say it is: If your reference voltage is 4.53v, then 2.27v should be about 1Bar in you car - thats 0"Hg, 0PSI, that's the pressure touching your skin right now.

This car is stock, right? your MAP is in the LM in the kick-panel?

[steelbuckeye]

im not even thinking about the chiltons anymore. im just trying to keep this engine from runnin rich and washin out the cylinder walss. the car is stock, map is in lm in kick panel. ive had the car for about 2mo.s and have really been to busy to mess with it. the previous owner told me that this isnt the original engine, it's actually out of another 85 dodge 600 with about 85000 miles on it. i deal with diesels all day long, but i havent tried my hand at mid 80's gasoline technology.

[steelbuckeye]

i do see what youre saying that the comp is thinking its at boost even though im just idling and there really is vacuum. would it automatically be a bad lm, or is there another direction i can start looking? thanks again

[89turbodude]

you may want to check on the actual year of the motor in that car

[Screamin4banger]

Quote:

Originally Posted by steelbuckeye i do see what youre saying that the comp is thinking its at boost even though im just idling and there really is vacuum. would it automatically be a bad lm, or is there another direction i can start looking? thanks again

I'm still a little suspicious of that sensor, but if you want to move on there is alot you can check. I would start by making sure your vacuum line to the Map sensor is routed correctly and is in good condition (along with the other vacuum lines of course). specifically, the source line from the manifold goes to the BARO READ solenoid (pass fender/strut tower) and then goes through the firewall to the MAP sensor on the LM. I noticed there are more than a few well-meaning people who see open vac ports and put caps on them. make sure there are NO vacuum caps on those solenoids. the BARO sol should be the one on the right (looking at the 4) and the manifold vacuum should be going to the bottom port, with the line to the MAP sticking out the top/side port, and the top, top (sticking straight up) port should be open - NO caps - NO lines -Nothing. There was a little foam filter there once upon a time but they are usually gone after 20+ years.

just to re-cap:
- brand new O2 sensor
- pulled vac off FPR and there was no fuel in line or change in idle. That's something worth checking if you have a guage. static fuel press should be around 53~55psi with vac unplugged and go down with vacuum and up with press.
- swapped original MAP for a new one and car runs worse with new one.
- new PCV Valve
- tried testing egr and got nowhere
Did I miss anything?
I figured this was an automatic for some reason.
Does the car still have a catalytic converter? if the exhaust is that rich it could have melted itslf half-shut by now

i guess i would minimize the BS under the hood. when I picked up a POS 86 charger I went down to the auto parts store and picked up a vacuum cap assortment, a couple vacuum T's, and some new rubber vacuum line.
I yanked that stupid vacuum harness out and put a big cap on the big port of that black thing and ran a new line to the little port going to a multi-port "T". I only ran lines to 1- FPR 2- BARO sol 3- Wastegate sol 4- Boost gauge. I made sure the line to the MAP was good and same with the wastegate line making sure I included the small orifice inline to the wastegate can. I left the brake booster line alone but removed all the emissions lines to the engine and plugged their respective ports on the throttle body, etc. I even eliminated the PCV. I mention all this because the 86 is the same as your 85....

[Screamin4banger]

I just re-read all your posts and thought of a couple things.
- when you and your buddy had the snap-on scanner hooked up, did you do any actuator tests? One of the tests is for the IAS motor to cycle it and make sure its working.
- It could be a bad Hall-Effect Pick-up under the distributer, or related wiring. I know you said you only had a code for the O2 but stranger things have happened. I mention this because a bad HEP in 85 would trigger a "limp-in" mode. 86 and newer will simply not start or run.