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Hot fuel vapourisation w Bosch pump?


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Quick question re: fueling on hot days/traffic (NZ's in the middle of an awesome summer, though I realise that's not going to generate much sympathy currently...)

 

CR series PI w a Bosch fuel pump. Runs like a pig when in caught in stop/start traffic and hot (has an Revington fan so "hot"= fan on and just over normal). Main symptom is hesitation on initial acceleration that improves considerably after a short run at normal speeds. Feels like its missing on a cylinder temporarily then improves.

 

Can the Bosch pumps also get some vapourisation or is this something different? Do TR6s just not like modern traffic conditions?

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Nah. Original nylons.

 

Heard Europe's nippy. On the other hand, any visitors most welcome

 

beach-side-P%C5%8Dhutukawa.jpg

Edited by matttnz
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If it's any consolation we get our share of wet in your summer...and there's a good reason why NZ's so green

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Matt

 

Same car, same hemisphere, same fuel pump, no electric fan

 

Car never overheats even in traffic ( temps up to mid to high 30's)

 

Previous owner told me to beware

 

Never let it get below 1/4 full

 

Never had a problem

 

How much fuel are you running

 

Graze

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I've had something like this with a failing alternator, the bus voltage drops with all the loads on at idle.

 

Can you measure the voltage at the pump when hot idling?

 

Ideally with a proper DMM, I don't think the dash voltmeter responds quickly enough or is that accurate.

 

Good luck,

 

Mike.

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Be aware that a Bosch pump might be able to pump more fuel around than the tank outlet can supply. Further they are not designed to work with pre-filters. If you have fitted one it has to be high debit and non restrictive.

As mentioned by Andy they draw more current so a heavy supply with relay is the advised.

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Having overcome cavitation around the pump, Lucas in my case, by upgrading the power feed I've only experienced cavitation in the engine bay.

Fitted a Kenlowe fan, which I use only in traffic jams, I've not had a problem since. Despite the hottest summer some time back in the distant past.

Recently changed the rad and cleaned out a water way in the block and now the car runs cold, cant win.

Also changed fuel lines to stainless and no difference.

I'm running without a rad cowl so that more cool air can circulate.

Have changed the thermostat to a winter one as need the heater to work.....wish I was running a summer one !!!!!!

Dave

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Thanks guys:

 

The engine itself isn't overheating as such (AK temps never up to Brisbane's insanity-dunno how you cope Graze, I'd spontaneously combust!). Seems to be more that when I'm stuck in traffic it runs ugly after awhile.

 

Fuel tank filling doesn't seem to be related

Fuel pressure measures ok

New alternator (70A now) after the original failed after 40y of faithful service (to the previous owners...) The rough running is nowhere as bad as that was. Though it might be that there's not enough wiring getting through the old loom to the new pump power feed. The dash voltmeter measured low prior to the old alternator giving up the ghost. It's a reliable 13V now, 12V when idling. Things don't improve when I shut off the radio which is fairly power hungry...(no comments about the 6 soundtrack please-I like both options)

I wired in a relay-didn't seem to make a huge difference but it does draw a pretty impressive current. It might be that I didn't run a heavy enough gauge wire but it is about double what the old wires were. I should check the ground again.

 

Food for thought. I'll have a look at the return flow and remove any filters. Might be an issue w my pump supply & that it's not as good as I thought it was. Or maybe an HT lead is stoofed in a way that is unmasked over a certain temp...

 

Cheers

MT

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