9 replies to this topic

[308mate]

I've a problem with my VT 5 litre. It in a HQ Panelvan (sorry not the Torry). I've been trying to work it out for ages.

 

Basically wont rev much past 4,000rpm, or if it does theres no power at all. Seems to go quite OK below that. No hesitations. Idles and seems to start OK.

 

Ive changed plugs, cap, leads, had the module rebuilt, tried another factory vt distributor. Harness is a CAE. The computer throws no faults.

 

 

At one stage I had the cam out (roller cam). I was going to put a bigger cam in  but decided against it. I reinstalled the original cam. I assume its factory standard roller cam. Car is factory th700 r4 electronic auto.

 

I'm at a loss. I'm investigating the possibility that I reinstalled the cam wrong. (Definite possibility!) This is where I need the help at this point.

 

 I made a spark Plug piston stop and found true TDC. Dial gauge on Intake valve rocker arm. I'm getting the intake valve beginning to open at 10-11 degrees BTDC. At 18 degrees ATDC I have 50" lift. The intake valve appears fully open 112-114 degrees. Intake valve closes at between 132-139 degrees (I suppose the variation is hydraulic lifters & my errors).

 

Does any on know how to interpret these figures for my application? Is my cam out?

 

Cheers, Scott

[Lima31]

Before taking the cam out, just check it's not something silly on the fuel side like low fuel pressure or injector flow (assuming the ECU isn't monitoring those)?

 

The stock 195i cam should open intake* past 0.050 around 14 degrees after TDC and close 40 degrees after BDC, exhaust 30 deg before BDC and 4 deg before TDC. I found this video helpful

 

 

 

*Edit that is at the cam not the valve, remember to account for the rocker ratio

Edited by Lima31, 19 July 2015 - 01:15 PM.

[TerrA LX]

How good are the valve springs?

[yel327]

You could pull the timing cover off and check the links in between the dots on the gears, but they aren't fun to get back on with the sump on.

[308mate]

Thanks LEE> I have an in-line fuel pressure gauge & it seems to read fine, Injectors have been redone... I found the video helpful. I didn't take into account the rocker ratio at 0.050'...

 

Terra I dont know how the valve springs are...

 

Yel, I'm trying to avoid that. Lazy I guess!

[Sven]

This may sound silly, (and I felt silly when I discovered it on a car I used to own) have you checked the air filter?

[Rockoz]

Have found a few people saying that they have had injector problems after having been supposedly serviced.

Is the throttle body opening fully?

[308mate]

Thanks Rob and Steve. Yeah New air filter and I have checked the spray pattern on the injectors & they seem fine.

 

But after a long and arduous journey I booked my Pannie into my favourite mechanic...but then I thought i'd check one more thing. Exhaust is new, cats are hi flow & new but I pulled out the O2 sensors and drove the car to see if there was a restriction & voila! it revs through the range!

 

Theres a blockage in my sidepipes or the cats  . That episode did my head in!

 

Cheers for your help. May I one day return the favour...

 

Scott

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[Rockoz]

Get in touch with Sureflo Exhaust at Ingleburn.

He has some good products including hi flow cats

[TerrA LX]

Scott

pan1.jpg

WoW your diff looks so far forward.