Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[JamesV6CDX]

I've had this problem with my V6 manual for some time, well before the LPG conversion. Now, I know it's not good to push an engine when it's not warmed up, but I'm still sure this problem isn't the norm.

Symptoms are as follows:

When starting the engine from stone cold and driving off, there is a big loss of power at about 4k rpm. if you hit 4,000rpm in 2nd gear with a cold engine, it hangs there, and it really struggles to rev higher. From this point, the power delivery seems to come in "stages"

Once the engine has been run for a few mins, this problem completely goes away and she's free reving right up to the red line.

There are no codes stored, plugs etc are in good condition and the engine is well serviced. I can't find anything amiss.

Any ideas? CTS crossed my mind, but I don't see how it could effect it when cold (unless it was fooling the ECU into thinking the engine is warm) - and anyhow I'd expect a code.

I'd appreciate any opinions

[Kevin Wood]

f you hit 4,000rpm in 2nd gear with a cold engine

 

[TheBoy]

CTS does sound a candidate. Won't throw error if in range.  Live data would show...

[JamesV6CDX]

f you hit 4,000rpm in 2nd gear with a cold engine

 

Hehehe.... when pulling out of the road where I live, poeple drive like a racetrack, it's an A road, and you need to either give it some beans or die!!  

[JamesV6CDX]

CTS does sound a candidate. Won't throw error if in range.  Live data would show...

To be honest, it's the ONLY thing I can think of.

I think a good live data run (from cold) would be really beneficial on my car....

[Kevin Wood]

Does it still do this since the low voltage issue was sorted?

Just thinking that's likely to be at its' worst just after startup. Could be there's not enough power for a decent spark with a rich mixture :-/

Kevin

[JamesV6CDX]

Does it still do this since the low voltage issue was sorted?

Just thinking that's likely to be at its' worst just after startup. Could be there's not enough power for a decent spark with a rich mixture :-/

Kevin

Voltages are now fine - it's done this from Day one

[cem_devecioglu]

Does the performance of engine change with air temperature even slightly ?

And is there any hesitation when moving..

[JamesV6CDX]

Does the performance of engine change with air temperature even slightly ?

And is there any hesitation when moving..

Air temp seems to make no difference...there is no misfire, it just struggles to rev high when cold

[cem_devecioglu]

Here is my experience

After CTS change idle become worse..

After Lambda change engine become better

Crank sensor hesitation lost..

Cam sensor better smoother engine but hard to explain

MAF > power delivery everytime linear in every RPM not important engine cold or hot..

May be I'm wrong..But cant you try a newer Omegas MAF..


Also valve conditions and valve gaskets may effect too much when cold..


Ps: Fuel pressure regulator is the next item on the plan

Also the injector gaskets..

[Martin_1962]

Can you idle it for a minute first and see what happens?

I don't know what mine does, always has about a minute before geting revved.

[MikeDundee]

After reading this post I had to try this, engine was cold and managed to get it up to 4500 in second before I had to brake (traffic on Old Kent road ). Struggle during the day to get a decent stretch without traffic in London  

[TheBoy]

I wouldn't let my engine run that high until engine temp up a fair way...

[Jay w]

mine has been doing this since i damaged one of my cats, when cold in 1st its fine, in second it is really sluggish and feels very retarded.

we have concluded the cat is breaking down badly and causing the issue, i will hopefully have a replacement cat on there this weekend so will be able to report if this has sorted it

[JamesV6CDX]

I wouldn't let my engine run that high until engine temp up a fair way...

No choice when pulling out onto A40 with Artics coming at you