fan vents air flow problem

[dmiller1]

Any help with the following would be greatly appriciated. I picked up my first r5 turbo on sat. It made it home 200 miles but got a few problems.( i knew this when i bought it)main problems are a noisey as hell fuel pump and not running great on boost( strong smell of fuel) I think the two are related. Other problem is heater vents. The fan turns on top of matrix and i get heat into matrix coil but no air flow through any vents. When the car is moving you then get heat through the vents. Any help with this would be greatly appriciated. Not a great start to my first 5 turbo, but i guess thats the joys of owning a classic.

[francob80]

Pretty common to get a smell of fuel with these and depending on which type of fuel pump they can also be noisy. Mine is newish and very noisy (albeit a more powerful one). So I wouldnt assume that your fuel pump is to blame for poor running or issues on boost. It is more than likeley carb related but to get any idea of what is going on I would advise buying and fitting an AFR gauge so you can tell how the car is fuelling, without one you are guessing. You might also want to consider an overhaul of ignition related parts also - dizzy, rotor, leads & plugs, these can also cause poor running and potential issues on boost.

Ideally I'd get the car to a member nearby who knows 5s, your average garage these days won't have a clue.

Oh, a decent boost gauge might also be a wise purchase if you haven't already got one. Understanding fuelling and boost is probably your first port of call.

[Ian S]

Does the ventilation fan increase speed to the faster setting(s) when you turn the knob? I've forgotten how they work. Whether it's different coils in the fan motor, or switching in different value resistors.

[markg]

The speeds are controlled via the rheostat. I'm not up on electronics however it looks like the rheostat just contains resistors presumably to adjust the amount of electricity going to the fan on each setting.

[markg]

Not the best picture of a rheostat but here you go. This lives in the heater box but in this instance I am pretty sure its not what is causing the problem. Might be worth checking the cables from the two knobs which control temp and also which vents air comes out of are connected at both ends. That's where I would start.

[Matt Cole]

As mark has said if you are getting heat through some vents and the fan speeds are ok on all selections then it will be the vent position sector cables. There's a horrible clip behind the facial of the selector knobs that falls off or the retaining plastic lug breaks. This clip holds the outer cable in place. If it's not there, the vent positions won't adjust.

Fuel smell will be the carb, over feuling, perished gaskets, loose carb too all common items to check and renew. I would grab a carb rebuild kit from the shop, use the article to help you rebuild, adjust and set up.

[dmiller1]

Thanks for all the suggestions, i have managed to track down someone up here who lives and breaths 5 turbos. Calling him tommorow. So hopefully he will help me with carb set up and other things. Really appriciate all the advice i have been given. Glad i joined RTOC.

[Matt Cole]

No problem boss. That's what the club's for! is it another RTOC member helping you?

[Alex]

Its worth mentioning that you don't get warn air through the centre vents - only cold air comes from them

[dmiller1]

Thanks again, the problem with all the air vents including windscreen and feet is that the matrix fan turns and speeds up and down but when the car is sitting still, no air flow. When I am driving the car I get airflow and heat(if its selected) through the vents. Cheers

[Ian S]

i have managed to track down someone up here who lives and breaths 5 turbos. Calling him tommorow.

Is his name also Miller?
https://www.rtoc.org/boards/member.php?4-Miller

[dmiller1]

Hi Ian, yeh I think he might have the same surname as me. I got his number from a friend who works with his bro in law. Cheers

[dmiller1]

Just a quick update on my first full week of finally owning R5 gt turbo. I knew it wasnt going to be easy but Wow......
1.. Sluggish running was due to knackered fuel pump and a phase one filter being fitted( about a 1/3 rd of the size of proper one.) loads of fun trying to make both fit with the after market bracket that has been installed. still a bit sluggish but reckon carb needs set up.
2.Came home to a completely soaking passenger foot well. Found manufactured hole next to bonnet pull on inner body work leaking. Sealed with gorilla tape until grommets can be sourced.
3.After rewiring anti perc fan, discovered previous owner had *******ized two old fans to make one new. Internal fan blade is smashed as it hits inner cone when running.
4.Found out why no air flow from face vents. Someone has glued a blanking plate over airflow outlet. ( i can only assume they either used to have gauges in place of vents or trying to increase air flow to other areas.
5. After changing fuel pump and filling car up with vmax, fuel gauge is stuck on 1/4 of a tank, will need to remove sender unit and have a look.
All i can say is thank feck i was working away most of the week. If i wasnt ,god knows what else i would have found. Thanks to everyone who has gave me advice this week its really appreciated. ( still wouldnt change the car for anything though. You actually make people's day when they see a 5 turbo

[Alex]

Thanks for the update. It all sounds about right for a 25+ year old GTT!

If you suspect the carb needs setting up it might be worth a rebuild using a kit from the shop and see how it is then?

Is it not worth you removing the perc fan altogether? Most people seem to have done this with no real ill effects (just takes a little longer cranking when warm)

Try cleaning up the connections to the sender first and see if that makes a difference? failing that removed the sender and investigate.

[dmiller1]

Hi Alex ,thanks for getting back to me. The carb rebuild might be a possibility, just for peace of mind. Yeh removing the perc fan could be an option. I Wanted to keep the car as original as possible, but I am coming round to the idea that a few modern upgrades might be better.Cheers

[markg]

If you do keep the perc fan make sure it has had the recall to fit an inline fuse in the loom close to the motor.

[dmiller1]

Yeh the fan fitted has the inline fuse. Cheers

[Ian S]

You may not need the fan, being in Scotland with lower ambient temperatures. It tends to be noticeable when the engine is hot and you're stuck in traffic.

It was an upgrade to fit the bigger (quieter) fan from the Renault Safarne (however that's spelt) as it moved more air.

[dmiller1]

You may not need the fan, being in Scotland with lower ambient temperatures. It tends to be noticeable when the engine is hot and you're stuck in traffic.

It was an upgrade to fit the bigger (quieter) fan from the Renault Safarne (however that's spelt) as it moved more air.

What do you mean Ian???? Its a balmy 11degc up here today. I have my shorts on.

[Ian S]

The human body acclimatises. The 5GTT simply goes faster.

Perhaps you yet to feel that. On cooler evenings and when the autumn arrives, the inter cooler works better and the car pulls harder.

In the winter, with too much intercooling, carb freeze can happen. A layer of ice forms on the throttle spindle and, I presume, the jets, and the car won't start well and runs badly until warm.

[dmiller1]

[dmiller1]

Finally found the problem of no air flow out the vents. The fecking heater matrix fan is turning the wrong way As its dc is it just a matter of swapping cables on heater matrix or is it going to be further back along the line. Any help would be greatly appriciated. Feel as im never off here asking for advice. Thanks again. Dougie

[markg]

I can check my heaterbox tomorrow but would have thought the fan only fits into the contacts one way. If thats correct then as you say soundd like something is amiss further back down the line.

[dmiller1]

I can check my heaterbox tomorrow but would have thought the fan only fits into the contacts one way. If thats correct then as you say soundd like something is amiss further back down the line.

Yeh mate thanks, motor only fits on connections one way, Im sure on dc power units if the polarity is wrong way round it could reverse the motor. Hopefully someone more clued up than me with the electrics can confirm this with me. Thanks for getting back to me. ( car is like pandoras box}

[Ian S]

Do you have a multi meter? To check the polarity at the fan terminals.

I haven't looked at the wiring there for probably 15 years and don't remember it.

It might be a case if using the Haynes manual to trace through the wires then try and see them in the car and test they are the correct way around.

[dmiller1]

Do you have a multi meter? To check the polarity at the fan terminals.

I haven't looked at the wiring there for probably 15 years and don't remember it.

It might be a case if using the Haynes manual to trace through the wires then try and see them in the car and test they are the correct way around.

cheers ian thats my next port of call