Redblock turbo - running problems

[Clan]

Originally Posted by mocambique-amazone

Aaah a 6 banger
I all ways forget this animals.
The only 6 banger volvo I did work on till now are k-jet (cis)

LH2.2 4 banger are without the cps

The Regina turbo are even with 2 if them

Have a nice day Dave, regards Kay

A proper 360 !

[tofufi]

Thanks everyone for the help.

Did a bit more work on it today, noticed when turning over that one of the compression strokes wasn't as strong as the other 3.

Looked at the valve shims, and one cylinder had shims miles too thick. The previous owner had checked them all under 500 miles ago, so I think he got the sums wrong when replacing them! New ones ordered, and an MOT booked for Thurs. What could possibly go wrong?

[Laird Scooby]

Good luck with getting it sorted Jim, hopefully the new shims land in time and you have enough time to measure what's in there and can find a suitable replacement to get the right clearance.

I wonder if the previous owner just threw it back together and sold it like that to hide a worse problem such as a badly burned exhaust valve or perhaps Valve Seat Recession. Shouldn't have VSR, after all they're designed for unleaded but anything is possible i suppose!

[mocambique-amazone]

When cam is out check hight of valve stems. I use a sold shaft in diameter of the cam bearings and compare the hights. They should be max in 0.5mm difference. There will be VSR or even worse a deformed valve disc.
Good luck, Kay

[tofufi]

So, new valve shims arrived today and now fitted. Engine runs a lot happier and much more quietly, but tends to idle a bit slowly while hot.

Dave, you mentioned the microswitch that should be activated when the throttle is shut. How do I test this? When I disconnect the 3 wire plug on the throttle body, at idle there is no change... is this correct?

[Laird Scooby]

Originally Posted by tofufi

So, new valve shims arrived today and now fitted. Engine runs a lot happier and much more quietly, but tends to idle a bit slowly while hot.

Dave, you mentioned the microswitch that should be activated when the throttle is shut. How do I test this? When I disconnect the 3 wire plug on the throttle body, at idle there is no change... is this correct?

When you say the engine idles slowly JIm, what speed does it run at when hot?

There's an easy acoustic test for the TPS idle switch. Engine off, open the throttle by hand gently under the bonnet. You should hear a click as the switch opens and another as it closes as you release the throttle gently.

There are 3 wires, black (common), orange and red/white on the switch. To check electrically the switch is made, get your multimeter on Ohms and check between the black and the red/white wires on the switch. With the Ohm-meter still connected and again gently open/close the throttle by hand to confirm it opens and closes the switch contacts.

If it needs adjustment, before doing it, check the base idle speed. Underneath or alongside the coolant expansion tank should be a red/white wire in a 2-way connector plug. Only one way of this plug is connected (to the red/white wire) and using a jumper wire, take the red/white wire to earth with the engine running.

If memory serves the base idle speed on the B230 is 700rpm and this is what it should idle at with the red/white wire earthed.
On the LH2.4 on yours, there isn't an idle bypass screw like there is on mine so to set the idle speed, you will need to alter the throttle butterfly position. This isn't easy as it's not meant to be touched but some interfering monkeys do.

Once adjusted to 700rpm for the base idle, re-check/adjust the TPS switch, disconnect the jumper wire from the red/white wire to earth and it should bring the idle up to about 900rpm.

I've had to generalise a little as if it was still in a 940, somewhere there should be a fuse that supplies the fuel pump relay and also pin 4 of the ECU - memory pin. If you can find this fuse, remove it for a few minutes to clear the fuel trims - they're bound to be out after the cylinder not running because of the shims. If all else fails, disconnect the battery earth for a few minutes to clear them instead.

Don't think i've missed anything there Jim, good luck and it should run considerably sweeter afterwards!

[gpl1968]

The attached pdf might help.

[Laird Scooby]

Originally Posted by gpl1968

The attached pdf might help.

Very useful! Long time since i've seen that one and if i'm honest, i'd forgotten the 0.45mm feeler gauge trick but have mostly done it by feel.

[tofufi]

Thanks once again for all the help! Very useful and I'm slowly learning a lot about LH2.4!

I took a look again this afternoon - the TPS didn't click at either full throttle or closed throttle... I removed it, and by hand it clicked only at idle but not full throttle end. At the idle end the switch worked correctly electronically (made a circuit), I should have checked at the full throttle end of rotation but didn't think to do so.

Having re-fitted and adjusted it using feeler gauges, the idle seemed stronger on cold start, but I ran out of time to run it up to temp.

What is the purpose of the full throttle signal? To tell the ECU to give it everything? I assume in that case it's worth me re-checking and (if it's naff) replacing the TPS?

Car is booked in for MOT tomorrow, wish us luck

[Laird Scooby]

Originally Posted by tofufi

Thanks once again for all the help! Very useful and I'm slowly learning a lot about LH2.4!

I took a look again this afternoon - the TPS didn't click at either full throttle or closed throttle... I removed it, and by hand it clicked only at idle but not full throttle end. At the idle end the switch worked correctly, I should have checked at the full throttle end of rotation but didn't think to do so.

Having re-fitted and adjusted it using feeler gauges, the idle seemed stronger on cold start, but I ran out of time to run it up to temp.

What is the purpose of the full throttle signal? To tell the ECU to give it everything? I assume in that case it's worth me re-checking and (if it's naff) replacing the TPS?

Car is booked in for MOT tomorrow, wish us luck

Good luck for the MoT Jim, let us know how it goes!

The full throttle switch is as you guess, when activated the system goes open loop, in between it tunes and trims the fueling for optimum driving performance under all conditions - conversely the idle switch changes the setting to an idle map for better emissions/warm up performance.

The full throttle switch might be suffering lack of use, some contact cleaner squirted inside it might revive it, if not then replacement/renewal is another option of fit a generic microswitch to the loud pedal so it's made when you're burying your hoof in the Axminster