New Owner issues, questions

[gusexcel]

So after putting a few miles on the car, a few things

1]In fixing the fan relay it got me watching the temp gauge. When the fan turns on the temp gauge rises[instantly electrically, not temp related]. Volt gauge reads low and seems to get lower when headlights are on, but it does not appear that the actual voltage is low. Feels ground ish but could also be supply voltage

2]There is no purge pump at all, I think it wants one

3]Very iffy under 2k rpm. huge dead spot, more than just weak acceleration. sputters etc. Carbs were rebuilt not long ago, replaced one vacuum line myself

4] Very high RPM with AC on, sometimes, about 2500 rpm


5] Accelerator pedal is really high, quite a bit higher than brake pedal, makes me hit it by accident when trying to stab the brakes, not good. Yet it appears to need the travel

comments suggestions?

[pompey ice]

Hi there ,Can you give a bit more info , like year of car smiths or vdo gauges then i'm sure you will
get a few tips
cheers Ian

[DavidOliver]

Hi Gus, first thoughts.
1/. Duff battery? What voltage on alternator output? The Excel has many earthing problems, fibreglass body you see, spend an hour touching around with a multimeter. Engine earth strap? Relays also develop bad contacts.
2/. Early models (like mine) have no purge pump. Even here in Malaga I have no problem restarting, the old technique of fully open throttle on startup is my purge pump.
3/. To what degree were the carbs rebuilt? If it got as far as throttle plate removal ( sometimes done to fully clean carb bodies to look nice) you need to know you have had a full carb retune or get one done, including plugs and ignition previous check.
On this Forum some members have found the book - How to Build and Power Tune Weber and Dellorto by Des Hammill - very informative and very easy reading.
4/. Probably sorted when checking out 3/.
5/. Again could be related to 3/. Check the brake pedal height against the clutch pedal height. Sometimes the Pedal Box cracks and gets distorted, mainly on brake or clutch pedals area, not easy to check. Visual checking is called the Lotus position.

Happy Halloween. Next week you can wish us a Happy Guy Fawks night.

Dave the cog.

[robertverhey]

So after putting a few miles on the car, a few things

1]In fixing the fan relay it got me watching the temp gauge. When the fan turns on the temp gauge rises[instantly electrically, not temp related]. Volt gauge reads low and seems to get lower when headlights are on, but it does not appear that the actual voltage is low. Feels ground ish but could also be supply voltage

I’m gonna take a punt that it’s a later VDO model, and my gauges are also all over the shop, I don’t trust any of ‘em, except the oil pressure. Wish I could shed some light, I’ve just learned to live with it

2]There is no purge pump at all, I think it wants one

The purge pump was never robust enough for the job. I replaced the burnt out little motor in mine, tbh it didn’t really seem to be doing a great deal, so I disconnected it.

3]Very iffy under 2k rpm. huge dead spot, more than just weak acceleration. sputters etc. Carbs were rebuilt not long ago, replaced one vacuum line myself

Later models had a known flattish spit around 2000 rpm which I think was addressed with three stage jetting but never fully eradicated. Sounds like something is amiss and I’d be checking that those vacuum hoses are connected as per the service notes. If all that checks out strip the carbies down and check that everything is in its place. In particular, with the float chamber full, check that there’s a good steady squirt of fuel into the Venturi when the accelerator is depressed


4] Very high RPM with AC on, sometimes, about 2500 rpm

mine does this from cold start, the combination of the cold advance system and the AC idle step up solenoid really gets the revs up, to around 2500. But in a warm engine turning on the AC only raises the idle a little. The solenoid idle step up is adjustable via screw and locknut

5] Accelerator pedal is really high, quite a bit higher than brake pedal, makes me hit it by accident when trying to stab the brakes, not good. Yet it appears to need the travel

Sorry can’t shed any light onto this

comments suggestions?

[gusexcel]

Thanks for the replies

Sorry, it is an 87 SE, VDO gauges

I have checked the voltage at the battery and it is correct, so it is just the gauge wandering

trying to decide if I think the temp gauge going up when the fan runs is bad power connection or ground connection

[Phantasm]

2) I repaired my purge pump as well, it since quit again (cheap eBay remote control module I rigged up) It's really not worth repairing, like the others said, stomp the gas it'll start with a few cranks when the engine is hot and been sitting a bit.

3) Yeah, my 91 is touchy there as well around 2k rpm. Clean the grounds. Especially the ones connected to the AB 14 on the driver side wheel arch. Cleaning those up helped mine a lot!

4) Throttle Jack is located on the front top center of engine. It's a solenoid activated by the tach/rpm sensor or a/c switch; it pushes out when energized and pushes the throttle up a tad. The screw can be adjusted up and down and actuates a lever to the carbs, screw going out increases revs, go to far and you'll actually affect the basic/normal idle too. minor adjustments make significant changes IME. Also, Mine doesn't throttle up the RPMs as high from idle as it does when it's coming down from a higher rpm -the solenoid isn't strong enough to act that much pressure on the lever.. When the a/c is off and the throttle jack is acting, you can hold the brake and let the clutch out a bit for a moment to pull the revs down at a traffic light to get back to normal idle quicker.

5) the pedal box is tight in general. Narrow "driving" shoes are key. In my combat boots (US Army) I have a hard time pushing the clutch and brake at the same time. I'm super careful when driving in uniform.

[gusexcel]

Its not so much touchy at 2k, as dead below it

I have also realized I'm getting about 16mpg[US gallons]

It will start hot, but it would be nice for it to be a little better

I wonder if it is more heat soak in the whole carb, was watching the fuel bubble around the clear lines one hot day

[gusexcel]

5) the pedal box is tight in general. Narrow "driving" shoes are key. In my combat boots (US Army) I have a hard time pushing the clutch and brake at the same time. I'm super careful when driving in uniform.

Oh, it is not so much shoe size, the pedal is just stupid high, it will get fixed so it is level with the others, but I was just wondering if it was 'wrong'

I drive my Exige with my hikers, and also my slightly modded S2 Seven, Excel is a piece of cake.

[Alan_M]

Flat below 2000 rpm could be for a number of reasons. You will need to check through carbs, timing and ignition system.
Mine was like that when I got it. Turned out to be a combination of several things.

Last person who changed cambelt got timing one tooth out.
Carbs out of balance and poorly tuned.
Duff plug
Vacuum system for distributor fault - thermal valve internal leak meaning no vac advance
Jetting on carbs

[gusexcel]

So, at least one answer

Changed the oil, someone put the filter on with a giant wrench,grr

As a result had to remove air filter housing to gain access. One carb air horn was loose, grr again.

Got the oil filter changed put it back together and went for a drive.

Low RPM response was much better.

Uhhhh, I changed the oil, wait that loose horn would not do that


Then I remembered, I had noticed a few seeds on the K&N filter so I blew it out and thought little about it

Clogged air filter, looked fine, don't know if there was too much oil on it or what. I am going to swap it out for a stock one, but in the mean time washed it out

[Phantasm]

Have you tried disconnecting the Rev Limiter? The second I did this, my engine came to a whole new level of alive-ness. I have since installed a new adjustable limiter, which I put in the glove box, By turning it down to zero it's a sneaky little anti-theft that no one would ever figure out on top of the already confusing immobilizer by Sigma. My fear is they'd just tow the whole damn car away.
This is the unit I replaced it with:
https://www.jegs.com/i/Speedmaster/746/ ... 1/10002/-1
Speedmaster Single Stage Safety Rev Limiter Soft Touch Ignition
Part Number: 746-PCE386.1001