No power when pulling away.

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Tempus

Tempus

Member
Posts
15
Location
Minehead (SW UK)
I have a P38a 4.0 Thor auto

I have not driven it for some time since acquiring it, as was off rode for general sorting out. Cant run two cars at once.😔
What is happening , is that when I am pulling off from a stand still, I have no "UMPF" or lack of guts to the thing.
When finally moving, it will drive fine and accelerate rather well.

Notable points:
1: Dual fuel. drives about the same on both.
2: Do not remember it being this way when I parked it up. (was off road-ed for general fixer uppery and stuff..... but was started up periodically ).
3: Revs are low on tick over... or seem strained?!
4: Put your foot down when pulling away, there is no over revving , noise or anything that I can see that is the fault. just a slow pull away as if I was deliberately pulling away slowly.
5: As with the size and sound of the engine, I am not able to discern if there is extra vibrations from the drive or not.

My guessing is that it might be a torque converter issue. but not sure. The signs don't point clear enough to it. Just my guess.

Any help and insight would be greatly welcomed.
 
RangeRoller dt said:
Could be something simple like brakes have bound on bit. Did you leave handbrake on when it stood?
Does it rev okay when not in gear?
Click to expand...
Break was on. But it was move back and forth occasionally. As well as when I let the break off but is still in park, it "bounces"/Rock's back and forth in park. So I don't think it is likely to be the break.... but who knows. That's why I am here.
It does rev fine. I have checked and cleaned the maf sensor as well as the air bypass valve. they seem to be ok.
 
Datatek said:
I agree, binding brakes are a distinct possibility, include the handbrake drum in that.
Plug leads and coils may also be the problem.
Click to expand...
Previous owner had new plugs leads and pack's fitted.
I do have two injectors that are playing up. cold start is a little hampered, but is ok when warmed up.
Secondly..... It is a dual fuel. So runs on LPG when warmed up (and tank has GAS).
 
Sure there's a "stall test" in Rave?

But low idle should be looked at, what do you consider low/strained?

J
 
Tempus said:
Previous owner had new plugs leads and pack's fitted.
I do have two injectors that are playing up. cold start is a little hampered, but is ok when warmed up.
Secondly..... It is a dual fuel. So runs on LPG when warmed up (and tank has GAS).
Click to expand...
For all testing I would only do it on petrol TBH.

J
 
marjon said:
Sure there's a "stall test" in Rave?

But low idle should be looked at, what do you consider low/strained?

J
Click to expand...
Not sure on the petrol, but I would expect the torque convertor to stall between 2k & 3K rpm with the bakes on. Only do a stall test briefly or the ATF will overheat.
I assume the oil level in the auto box is OK?
 
OK.... just did a little round the block and stuff.

I have an iCarsoft tester that has a P38 setting.
Right, now I know that I possibly have two dodge injectors... but that might not be the case now. ?!?
Before I confuse myself and everyone else, this is what I found on my latest test. To be fair, was not the case back when I was doing all my initial testing and fixing way back when.

First fault set that pops up in one section is a run of warning that say that there is misfiring on 4 , 6 and 2 ( before it was just 4 and 6 ).
But when I clear the fault set, the engine runs buttery smooth for 5 to 10 (or more ) seconds. Then back again.

Second fault set comes up with EGR-GAS recirculation ........... bla bla (cant remember sorry.) . That too when clearing will run fine for a bit then back again.

Car free wheals fine in neutral and does move by itself in D and R. Just no guts when wanting to shift it at speed from a stand still or instant accel from low speed. When going and revs are higher, it shifts well.

I live on sopey terrain with slight incline. It will move up the slope, but slowly. Not revving or anything, just slow as if ( in normal cases ) somebody was wanting to crawl up deliberately slowly while in gear. Hope that makes sense.
 
Do you run it mostly LPG?
They need to run petrol to keep them running ok, I had to drive a p38 that had a misfire on petrol cos it had been driven mostly on LPG all the time. (Left foot cleared that issue)

EGR??? Something isn’t right.

J
 
marjon said:
Do you run it mostly LPG?
They need to run petrol to keep them running ok, I had to drive a p38 that had a misfire on petrol cos it had been driven mostly on LPG all the time. (Left foot cleared that issue)

EGR??? Something isn’t right.

J
Click to expand...
Currently mainly LPG. But was intending to run a few tanks of just Petrol at some point. Trip to see family or something like that. But was not going to go long distance while it is playing up like this.

My brain is starting to think in different directions now as to what it might be.....
1: Torque converter ..... ( not yet checked the levels or condition)
2: Bade coil pack? (possibly a duff one from where ever the previous person got them).
3: An ECU issue !!!!! ( hope not).
4: Something yet to think about
 
Tempus said:
Currently mainly LPG. But was intending to run a few tanks of just Petrol at some point. Trip to see family or something like that. But was not going to go long distance while it is playing up like this.

My brain is starting to think in different directions now as to what it might be.....
1: Torque converter ..... ( not yet checked the levels or condition)
2: Bade coil pack? (possibly a duff one from where ever the previous person got them).
3: An ECU issue !!!!! ( hope not).
4: Something yet to think about
Click to expand...
I would say it's not limp mode and I very much doubt it's the torque convertor. It's certainly worth checking the ATF level.
 
Im unsure if the coil packs are interchangeable? substitution would be a cheap method to diagnose if you can diy.
If you swap the packs and the problem follows then that’s your culprit. Again, im unsure if they are interchangeable but someone here will know.
 
Tempus said:
Currently mainly LPG. But was intending to run a few tanks of just Petrol at some point. Trip to see family or something like that. But was not going to go long distance while it is playing up like this.

My brain is starting to think in different directions now as to what it might be.....
1: Torque converter ..... ( not yet checked the levels or condition)
2: Bade coil pack? (possibly a duff one from where ever the previous person got them).
3: An ECU issue !!!!! ( hope not).
4: Something yet to think about
Click to expand...
Have you tried unplugging MAF sensor and see if there is any change to it running
 
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