Tumeke's 2.5 PI Trumpet

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Pulled some stuffs off on the weekend to have a wee look at timing and other such things.


Something wasn't quite right when checking the timing of the fuel metering unit (to manual specifications) so pulled the dizzy out and found things to be off from where should be


Fudged stuff about for a long period of time and made the dizzy dog line up to 12 o'clock and the metering unit injector # 6 position to be within the satisfactory limit, and the dizzy rotor to be at number 1 lead for timing at TDC compression stroke.

Then flushed through injectors again, all worked (some a bit temperamental but ok with a good smack)

Then managed to started car. It did kinda start with a bit of ether up it, but not running properly. Rotated the dizzy and got it to stay running. Feels like the timing marks on the pulley are wrong..?  Didn't have a timing light to check any further into that. Got it running on 4-5 of a possible 6. Still, progress I think.

Tonight I'll try to put a timing light on it, replace a couple of injectors with more reliable spares and see what happens then.

You, too can tell me how the TC is much more reliable, like everyone at the European British car show, by clicking here.



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Went back last night. Something is not right....

New theory - anyone had this kinda thing below happen? 


(Interweb pic - not mine) or has the key just fallen out / shattered?




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Lil more progress however she's running oh-so-rich - to the point that I keep fowling plugs / black smokes.

Been through a few plugs now trying to diagnose. I reset the max fuel screw to factory spec on the metering unit and fluffed about with trying to balance the throttle bodies. These could do with a bit more work, but I don't think they are out enough to cause this kind of enrichment. Also, overfuel/choke lever is resetting per guidelines. Blew the over-fuel return clear with the compressor, and then checked for vacuum pressure to metering unit  - which seemed a bit low - however I might have also fowled a plug in this process. Did a compression check and all around the 160 mark which I would consider healthy. 

Did a dort sans bonnet up the road

So, next steps (and yes - please comment/suggest) are : Double check ignition side -  try another coil in case it's weak, replace/clean plugs again, test lead resistance,.

Vacuum to Metering Unit: more vacuum diagnosis across all three sets to see if any difference with side of metering unit to check travel. 

Metering Unit: Double check fuel pressure with another gauge, then if that all turns pull metering unit again, replace all seals / rebuild and/or start playing with calibration adjustments under top cone of metering unit. (I don't want to do this.... see below) Also - all o-rings at both injector end and metering unit end could also play into problems.



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Small update - trying other stuffs:

As previously mentioned, engine is running rich enough to kill a set of plugs in a few minutes.

The metering unit requires vacuum to control fuel supply. Not enough vacuum  = rich.  There are three throttle bodies, each used for vacuum supply. 1/2 = dizzy advance, 3/4 = metering unit, 5/6 = vacuum reservoir then to brake master via one way valve. For those playing along at home, the screw on the end is the idle control. In/out  etc. You can check if your butterfly's are closing correctly by jamming your finger over it. Stall = good.


So, checked throttle bodies for leaks, including balancing pipes, other pipes etc. All seemed ok. Possibly small shaft leakage but I'll leave that for now.


Threw a vacuum gauge off a T inline and got a bouncing reading under 6hg. Not good. Factory says 10-12hg. Checked other throttle bodies - same deal.

I'd previously checked the tappets with @Threeonthetree and we reset to factory 10 thou just the other day. Then it struck me - has someone put a more aggressive cam in this? A bit of research suggested it might have something like a Piper fast road cam. Opened up the top and changed clearances to 16 thou. Reconnected vacuum gauge and what do you know. 12hg. God knows what cam i've got - this is gonna make setting things up more interesting :|

Anyway, now with the correct vacuum the metering unit has the prescribed travel on the control link  (see previous post for pic) but, alas, it was still running too rich. Had a think about adjusting the xmas tree of fuel delivery on the metering unit but knew this might be a tad out of my skill set so tried something a little more creative.


Knowing there was likely some wear on the follower and control links of the metering unit, I decided to sacrifice some feeler gauges. Warmed the car up, and slowly started increasing size between the follower and roller on the control link until maximum idle was achieved without stalling the car - the theory that this was backing off the fuel cam. Got to 18 thou and found what I assumed was a sweet spot so cut the gauge in half, stuck it in the metering unit and road tested.

Findings so far :  car not as rich at idle now = win! Car now has no top end pull = lose. 

Next steps: Back of the gap a bit more between the control roller and follower and try and find a compromise between idle and full noise, check ignition advance, play with fuel load fuel setting screw.  PI Lyfe. 


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Risked the lawand cruised to an Oldschool meat one night last month.

Realised how useless the gauges were for reading at night. First step was to remove the dimmer switch -  and this helped marginally. Second step was $4.85 on Aliexpess for some LEDs. Whilst I'm not sold on the green (I'll try white next time) at least I can see how slow I'm going / how much water I've lost etc now. I'll also look at updating with a suitable dimmer in the future but keep the factory dimmer knob if possible.


Before - with photoshop enhanced brightness so you can see something.


Aliexpress Goodness.

I then did some maintenance stuff like oil


(complete with rounded bung that's since been replaced with a more traditional hexagonal one) 

Gearbox - sounded a bit chattery so thought I'd top it up (with almost 4 litres of oil.....)


Next step - let's try for a WOF.

I cut the worst of the noticeable rust out and welded a new panel patch in temporarily, rather than fail on rust. Long term I'd like to replace the whole front guard (you guys hook me up pls)


BL quality assured badge still intact.

Next: WOF check:


PTO for more? Nah - one page mate.

A lot of fail and a lot of good fail - i.e. Driveshaft bolts loose etc. I've learnt I can't trust anything on this car to have been done right in the past. Such Barry'd.

Done most - recheck tomorrow hopefully.


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Will it fit? Tune in next time for more.


Spoiler: It fits. Need to install it's partner now too. Pics to come.

Engine has been making a lot of tapping noises (like tappets need adjusting). Tracked it down to the metering unit. Spoke to Chris Whitor and he suggested winding down the fuel pressure since I had the bosch unit installed. Backed it off to 100 psi. Success.


Went cruising with the Trumpet club on the Sunday. Many dorts. Developed a pretty substantial vibration in the drive-line. Suspecting gearbox mount and/or engine mounts. Will raid of project car (if they are the same) in next few days and see if that sorts the issues.


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