bad cold start with H cam

dex

i’m experiencing some bad cold starts after ive fitted a h-cam. does anyone have some suggestions on how to improve the starting. runs fine when warm

Forg

Sorry, I’m totally clueless … but what year-model are we talking?

I suspect it makes a difference to those in the know as to whether it’s LH2.2 or LH2.4 (or as a completely outside chance, Motronic).

dex

Forg 88 740 lh 2.2

Forg

Again, I have no clue and am guessing ... but do all LH2.2 cars have a cold-start injector? I'm pretty sure the fuel-rail I've used is from an LH2.2 car and it's got the port for a cold-start injector.

So ... I wonder if you can do something to make that cold start injector do a bit more injecting during a cold start?
And this is where The Knowleddgeable come in.
In fact, maybe it'd normally be able to cope with the H cam, and the injector just needs a clean?

Roinik

Forg later LH2.2 did not have a cold start injector. I'm running a K cam on LH2.2 without a heap of issues. Starting is fine, but idle is lumpy. Mine is manual too.

jamesinc

If you're saying you had no problems, then you put an H cam in, and now it struggles to cold start, it's possible you are just experiencing a worn motor. You should do a cold compression test and see what you get.

What cam were you running before the H cam?

VolvoHordz

Did you check the valve clearances when you changed the cam?

Anthony

242GT H cam into EFI engine - most likely cold start issue.
Seem to be chasing not enough initial fuel squirt from injectors.
On cold start the engine is meant to idle faster for a bit (more air for more fuel). Did the engine do this before cam change?
If not perhaps
Coolant temperature Sensor CTS in block
Fuel pressure regulator

Thats presuming everything else is spot on, and when warm a H cam from 4,500 rpm should pull like a train and really rev nice to 6,000 rpm.

ramrod

You cannot speculate this stuff

Everything (and I mean everything) needs to be tested when dealing with poor running issues.

I agree, valve clearance is something that’s too important to not get right. For all we know, the valves might not even be closing so there goes all hope of generating any compression