I recently modified my map sensor, to fool the engine I was running 20lbs of boost all the time, It started just fine. I've also broken the line off my map sensor which told the engine, 0 boost, ran like crap but started fine. /ubbthreads/images/graemlins/shrug.gif


I think you might have another issue to look into. Not sure what could cause that though. good luck I'm sure someone can help.

 

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but I think the MAP Sensor is not operating properly. Truck acts like it is flooding itself and doesn't start.
Any suggestions would help.

Thanks in advance.

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please explain the "flooding" comment further.

Are you getting lots of white smoke out the exhaust? Thats an indication of a glow plug circuit failure.

MAP sensor should have no effect on the engine until its up and running.

 

I am in Texas today it was 73 degrees out.. I wouldn't expect the glow plugs to play much of a roll in getting it started.

When I say Flooding I mean when starting.. It puffs Black smoke for a second or two then turns gray and eventually whiter and doesn't start.... and thats at any outside temperature. Ice on the windows or 75 degrees.

When its plugged in it will start, even then it acts like it doesn't want to.... when it does start, it lets out a constant whitish gray haze that reeks of fuel. the haze gets pretty bad under light throttle.. say when putting around a parking lot, but under acceleration it clears up and runs great with good power... but comes back when I stop at a light or stop sign.. I have notice though, when down shifting towards a light or stop sign(i have the 6 speed), and let out the cluth to let the engine help slow me down, there is no haze, but it returns when I mash in the clutch and the engine returns to idle at the light.

I am sure its just a fuel/air mixture ploblem at idle. Could too high or too low of fuel pressure cause these symptoms ?

I have changed the

CPS
IPR Vale and sensor in the oil rail that controls it
Oil Temp Sensor
MAP Sensor
EBP Sensor -- replaced with SP Diesel Dongle from SP Diesel
All 10 glow plugs replaced in the last year
All injector O rings replaced within last 6 months
#5 injector 14 months ago

There is no codes in the PCM. I have done the 10k mod, IN-tank mods, the 10k mod and the pre-pump filter. pre-pump filter shows no air bubbles.

Currently trying to find someone with the AutoTap, Ease or some other diagnostic software so I can see what the truck is seeing while its idleing. Cuz I am completely stumped.

 

Might be a bad injector cup, it happens /ubbthreads/images/graemlins/shrug.gif

Any fuel in water?

Fuel have water in it?

hows the blow-by is it extreme if you pull the oil cap off?
A cylinder with low compression could cause the eye burning fuel reeking.

I dont think its a fuel air mixture at idle, if it is then change your air filter but the air is not metered in like a gasser is.

No I dont think high fuel PSI could or would cause this

Oh I only have 8 glow plugs in mine /ubbthreads/images/graemlins/laugh.gif

Just my opinion /ubbthreads/images/graemlins/frown.gif

 

The MAP sensor is a capacitance device. You can't measure the resistance to see if it's working. I've hooked up some test wires while it's plugged into the harness to measure voltage across it, and the voltge tracks external pressure that I applied to it. Like others have said, I don't think your MAP sensor is causing your problem.

From the description of your problem, you may have a base engine problem, possibly low compression in one or more cylinders. That would cause the smoke you're seeing when the fuel injected into a low compression cylinder fails to ignite.

It's also possible that you have an injector problem.

A scanner that will do a cylinder contribution test will probably give you more to go on.

Also a compression check sounds in order.

Hope you get it worked out, and it isn't too serious.

 

I would start by pulling the 10k mod out and have someone watch the data stream and see what the MFDES fuel is running at and also do you have a chip or tuner not listed in your sig ??

 

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Any fuel in water?

Fuel have water in it?

Oh I only have 8 glow plugs in mine /ubbthreads/images/graemlins/laugh.gif



[/ QUOTE ]


Its 4 in the Morning....Just got home from the road.. 2 days running from Houston to Tulsa,OK and back here into Austin.

All the water, fuel, and oil are in their respective sytems as they should be.

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Oh I only have 8 glow plugs in mine /ubbthreads/images/graemlins/laugh.gif

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My first thought.... "I wonder what he uses to plug the other two holes?" /ubbthreads/images/graemlins/blush.gif OK ... mine only has 8 as well and No chip or tuner. My truck is still pretty stock.

I guess this weekend it goes to the shop to get the contribution test and the compression check.

Thanks for all your input guys... weak cylinder seems to be a common thought.

 

[ QUOTE ]
I recently modified my map sensor, to fool the engine I was running 20lbs of boost all the time, It started just fine. I've also broken the line off my map sensor which told the engine, 0 boost, ran like crap but started fine. /ubbthreads/images/graemlins/shrug.gif


I think you might have another issue to look into. Not sure what could cause that though. good luck I'm sure someone can help.

[/ QUOTE ]Sorry for the thread hijack, but I'm curious as to how to do this and it's benefits. Thanks.

EDIT: Never mind, I did a search and found your thread about it. I'm off to read...