Loss of enginpower not gaining speed

[MrJJ]

Hello all,
I have since today a problem with my m1008
It had to go for the yearly inspection, with that the do a exaust test for particals during that test the have to push the trothel ful speed unloaded for a surtan time (its hurting your soal to hear the engine scream like that)
The engine had to much particuls in the exaust so it was not complying the test.
the advice was to drive a long way to clean the system.
During that drive the engine stopped when i hit to brake and did not come to speed it takes a long tie to gain to speed from 0 to higher.
Also it did seem that the transmission did not shifts back to lower when loosing the gas.
When the truck is parked with no load the engine makes rpm's up , but when i (ad load) shift it in D it loses all its power and the engin will not realy makes more rpm's

Is the problem in the engine ore does the th400 blocks the engine in anny way?

Hope some one knows the problem and can help me to solve this problem

Grtzzz Jos

 

[burbn10]

Sounds like the stator in the torque converter. If the stator goes, you loose all your stall speed and it can cause the engine to stall because the torque converter isn't slipping at low RPM like it should. It is trying to transfer power from the engine to transmission at all RPMs, not just above 1200rpm. If you pull the torque converter out, you can check this by simply sticking your finger down inside the torque converter and trying to spin the ring at the bottom of the shaft that goes into the transmission. If it turns freely clockwise and counter-clockwise, it is bad. It is a one way clutch, so should only spin freely one direction. Could also be seized.

 

[MrJJ]

Burbn10 tnxs for your reply, i also think it is some where in the transmision line.
But my garage thought it was the engine , he advised to do a compresion reading of the cylinders.
But it looks to me that if there is a loss of compresion the engine wouldend start easy and there should be loss of oil, what is not the case.
I have tried this morning to start the engine again, and it starts up directly.
But i have to push the trothle a bid down ,when i let loss the pedal and try to let it idel it stalls almost direct.
If you read this you still have the same feeling?

 

[burbn10]

Burbn10 tnxs for your reply, i also think it is some where in the transmision line.
But my garage thought it was the engine , he advised to do a compresion reading of the cylinders.
But it looks to me that if there is a loss of compresion the engine wouldend start easy and there should be loss of oil, what is not the case.
I have tried this morning to start the engine again, and it starts up directly.
But i have to push the trothle a bid down ,when i let loss the pedal and try to let it idel it stalls almost direct.
If you read this you still have the same feeling?

Are you trying to let it idle in or out of gear? If it is stalling only in gear, then I still think it is the torque converter stator. If it is stalling in neutral, then I would lean towards fuel system problems.

 

[mkcoen]

I have what I believe is a similar problem on my M1010. At highway speed if I take my foot off the accelerator to slow down there is no accelerator until it drops down below 35mph and then it jumps and is fine. I was told it was a sticky governor but haven't delved in to it more.

 

[MrJJ]

Are you trying to let it idle in or out of gear? If it is stalling only in gear, then I still think it is the torque converter stator. If it is stalling in neutral, then I would lean towards fuel system problems.

It stall's in p n and d. yesterday when i was driving and hitted the brake the engine stall. I have to keep a feet on the gas peddal to keep it running.
If the engine runs in p or n and i kick the gas it gains rpm's.
When it gets load the engine cant realy gain rpm's, yesterday i had to drove a small hill and the truck had to battel to come to the top.
I must say that i had the idee that the th400 didend shift down.
It shift verry late up and hars and it looks like it does not react on the down shift.

 

[burbn10]

A governor shouldn't cause a stall though. Even in 3rd gear, the torque converter doesn't have a lockup function, so it will still allow the engine to turn up to 1200rpm. Governor problems will effect shift timing more than anything. Shouldn't cause a stall. Yours may be a vacuum modulator issue also. They are prone to failure and are 2 bolts and $10 to replace. The modulator provides pressure against the governor to hold gears longer under heavy engine load. My M1008 has an issue with the vacuum going to the modulator. I'm getting full vacuum all the time from the vacuum pump, so my truck shifts at full throttle like it would at idle. Makes for a pretty slow takeoff. Mine's an issue with the vacuum valve on the injection pump though. I just haven't got around to fixing it yet.

 

[burbn10]

It stall's in p n and d. yesterday when i was driving and hitted the brake the engine stall. I have to keep a feet on the gas peddal to keep it running.
If the engine runs in p or n and i kick the gas it gains rpm's.
When it gets load the engine cant realy gain rpm's, yesterday i had to drove a small hill and the truck had to battel to come to the top.
I must say that i had the idee that the th400 didend shift down.
It shift verry late up and hars and it looks like it does not react on the down shift.

Okay. Now it's starting to sound fuel related. Try changing your fuel filter first and see if that helps. You can do a compression check too to make sure the engine isn't damaged. From there go replace the mechanical lift pump on the lower front passenger side of the engine. If none of those things help.... I hate to say it, but may be the injection pump.... Sounds like it either isn't getting fuel or has a loss of compression. The hard shifts are because you are having to push the pedal down hard to keep going and it is holding gears longer because of that.

 

[burbn10]

Injection pump timing could be way off too. I kinda doubt it, but it wouldn't hurt to check out if the filter doesn't fix things. If your compression is good, it sounds like fuel starvation. It takes less fuel to spin the engine up out of gear than it does in gear.

 

[MrJJ]

I have what I believe is a similar problem on my M1010. At highway speed if I take my foot off the accelerator to slow down there is no accelerator until it drops down below 35mph and then it jumps and is fine. I was told it was a sticky governor but haven't delved in to it more.

I was reading your planned roadtrip for suporting the VETS great idee, I'm a vet also with a miner ptsd.
Hope you solve all your gear problems before take off in june

 

[MrJJ]

Okay. Now it's starting to sound fuel related. Try changing your fuel filter first and see if that helps. You can do a compression check too to make sure the engine isn't damaged. From there go replace the mechanical lift pump on the lower front passenger side of the engine. If none of those things help.... I hate to say it, but may be the injection pump.... Sounds like it either isn't getting fuel or has a loss of compression. The hard shifts are because you are having to push the pedal down hard to keep going and it is holding gears longer because of that.

I dont know how quick a fuel filter will get disfunction , i have changed it about 3 years a go and just run a bout 3000 miles with it. the truck has standstill for about 2 years so it could be.
The truck has run the last weeks some houers and did run well.
It all went wrong after the test were they put the engine up to madness with no load to test the particel exhoust .
My problem is that i dont have the bucks to vissit garages to test all.
I have try to figure it out by my self to solve the problem, this with the great help here

 

[MrJJ]

Injection pump timing could be way off too. I kinda doubt it, but it wouldn't hurt to check out if the filter doesn't fix things. If your compression is good, it sounds like fuel starvation. It takes less fuel to spin the engine up out of gear than it does in gear.

If it is a fuel starvation problem would the engine than gain rpm's with no load or would it also stall?
Because it will exelerate when i push the gas pedal in p or n
It stalls when i try to let it idel and when i hit the brake

 

[Armada]

I would also guess fuel related. Start with the simplest/cheapest fix first, replace the fuel filter. I've had new filters go bad before with a single tank of bad fuel run through them. It was doing its job though. Also, how is the condition of your air cleaner?

 

[MrJJ]

The aircleaner looks ok , it had some rust on the place at the intake further it is verry clean.
Befor the paticel test they have trown in a bottel of cleaner to make the engine come better thru the test, could this give problems for a filter?

 

[Armada]

You wouldn't think so, but anything is possible, especially when that is when the problem started. A fresh tank of fuel along with the filter might do wonders for you, not knowing what was put in the tank as cleaner.

 

[CUCV850]

it's possible the sock screen in the fuel tank is clogged!

 

[MrJJ]

I think i have to see to get a fuel filter and try this and see what is hapening.
The first day's when i started my m1008 it has run on diesel witch had sad in the tank for 2 years but it started and drove well.
At the moment it still starts well the engine just gaining no power to keep running

 

[burbn10]

If it is a fuel starvation problem would the engine than gain rpm's with no load or would it also stall?
Because it will exelerate when i push the gas pedal in p or n
It stalls when i try to let it idel and when i hit the brake

Yes, the engine can still rev up in park or neutral because it takes less fuel to move the unloaded engine rotating assembly. To make more power you have to add more fuel. So lack of fuel delivery would cause all your symptoms. The brake booster is fed from the power steering pump, so the braking may be causing just enough load on the engine to make it stall.

 

[southdave]

got water in your fuel sounds like to me. also you might want to check your vac lines on the IP

 

[MrJJ]

I have drained the water seperator for about 3mins drained i think a good galon but it gave not the result. (but i knop now that the low pressure fuel pump works) engine still stalls at idle. will try to get a fuel filter after the weekend hope this will help. will also check the governor of the transmission if it runs freely. And i was wondering if there is a easy way to check the working of the facuum pump and valve of the transmision?

The chevy is a nice car to drive and this are after 5 years my first real problems, beside a faulty generator and batteries.