Jump to content
iani

Fuel Pump Woes

Recommended Posts

I have a TRGB fuel pump fitted, it's a Sytec HP019 unit, recently I've had some fuel issues with the car running fine under load but after a few miles it would struggle at low RPM, cutting out if I didn't blip the throttle, after being parked up for a few minutes it would start again and I could carry on. Today I drove about 15 miles without issue, parked up for an hour and then came home, again the car started playing up at low RPM when I was near home, managed to complete the journey ok. I went to start the car later on and the pump is making a lot of noise but doesn't appear to be pumping fuel, the car doesn't start. There is a full tank of fuel, I'd refilled near home, the tank is a couple of months old so clean, the fuel filter went in at the same time as the pump, only a few months ago so that should be ok. Is there anything I can else I should check? if I can get the car started I will connect up a fuel pressure gauge to the MU and see what it's running at, I have a diaphragm PRV, what should the pressure be set to with an aftermarket pump though?

Ian

Share this post


Link to post
Share on other sites

Ian,

Fuel pressure is the same whatever make of pump, 104 -108 psi.

However you seem to have a fault when the engine gets hot, I would check two things first. 

Does the metering unit Fuel enrichment lever fully return back after choke is closed? Don't just look, push it back towards the front bulkhead. 

Is the fuel return pipe from the metering unit clear? I would suggest air line blow gun onto the rubber pipe at the metering unit and listen for bubbling in the tank. Firstly open the fuel filler cap to vent the large volume of air blowing into the tank - don't rely on the small vent hole in the filler cap.

Alan

Share this post


Link to post
Share on other sites
50 minutes ago, barkerwilliams said:

Ian,

Fuel pressure is the same whatever make of pump, 104 -108 psi.

However you seem to have a fault when the engine gets hot, I would check two things first. 

Does the metering unit Fuel enrichment lever fully return back after choke is closed? Don't just look, push it back towards the front bulkhead. 

Is the fuel return pipe from the metering unit clear? I would suggest air line blow gun onto the rubber pipe at the metering unit and listen for bubbling in the tank. Firstly open the fuel filler cap to vent the large volume of air blowing into the tank - don't rely on the small vent hole in the filler cap.

Alan

Thanks Alan, the MU lever does work, I had checked that, I'll check the return pipe tomorrow.

Share this post


Link to post
Share on other sites

I would take the fuel filter out and check it, it only takes 10 minutes. When I fitted my new pump I was collecting loads of debris from the inside of the tank even though I had thoroughly cleaned it out.

kc

Share this post


Link to post
Share on other sites

I blew air through the return pipe this morning, no blockage there, I must have blown half a litre out of the filler cap. Then I checked for fuel delivery, No6 injector is spraying perfectly so fuel is coming through, it seems that what’s missing is a spark, I run Pertronix with a Flamethrower coil, nothing visibly wrong at the dizzy end, but the HT lead going into the coil had verdigris on the end and the coil connection was corroded, I cleaned that up with emery paper and it looks ok. What do I check from here? Unfortunately I don’t have spare coil available or I’d swap it out.

Update: I put a multimeter across the coil terminals and see no resistance, I assume the coil is shot

Ian

Edited by iani

Share this post


Link to post
Share on other sites

Hi Ian,

On standard ignition you should measure approx 3 Ohm on the non-ballisted coils or 1.5 Ohm on the later ballisted coils. You measure on the spade connections, not the central “output” to dizzy cap.  You also have to disconnect the wires when you measure, to avoid measuring “via the loom”. If you still measure zero, I think it it shorted internally. Time for a new one. Make sure you have the correct one for your car (wiring loom and pertronix unit).

since you have the pertonix system, not sure if the same values apply, others will know.

Good luck,

Waldi

Share this post


Link to post
Share on other sites
5 minutes ago, Waldi said:

Hi Ian,

On standard ignition you should measure approx 3 Ohm on the non-ballisted coils or 1.5 Ohm on the later ballisted coils. You measure on the spade connections, not the central “output” to dizzy cap.  You also have to disconnect the wires when you measure, to avoid measuring “via the loom”. If you still measure zero, I think it it shorted internally. Time for a new one. Make sure you have the correct one for your car (wiring loom and pertronix unit).

since you have the pertonix system, not sure if the same values apply, others will know.

Good luck,

Waldi

I have a Flamethrower 2 coil to match my Pertronix 2 ignition Waldi, again it's a 3ohm coil. I had disconnected the wiring to check the primary coil circuit, you can test the secondary circuit between the + terminal and the HT post if you wish. I've ordered  new coil, hopefully that will resolve it, dizzy cap & rotor arm look fine and they came from the Dizzy Doctor so should be ok.

Ian

Share this post


Link to post
Share on other sites
6 hours ago, jah said:

Ian

Check your fuel cap has a breather hole in it

John

 

The cap is fine John, it’s an original ‘69 one, they don’t have the large rubber seal at the top, simply a thin rubber seal.

Share this post


Link to post
Share on other sites

New coil arrived tonight, fitted it and...nothing, car still doesn't start, no spark.

Share this post


Link to post
Share on other sites

Hi Ian,

sorry to hear that.

since you have fuel on one injector but still no spark, I guess it’s best to focus on the ignition side first. See below point, sorry if I’m stating the obvious:

Is there 12V at the coil feed when ign is “on”?

How much volts when cranking at the coil? 

Do you have a conventional points set to replace the pertronics module?

Have you checked if there is a spark between the coil ht lead and mass (to check failure on rotor, cap and other leads, all in one go).

These are just a couple of things to check.

Regards,

Waldi

 

 

 

Share this post


Link to post
Share on other sites

The problem's are growing. I suspect that something's been disturbed when you replaced the coil or the new coil is faulty. Do you get a spark if you put the old coil back in?

Share this post


Link to post
Share on other sites
10 hours ago, aardvark said:

You say that no6 is spraying ok but what about the others?

I also tested No1 and it is fine too.

Share this post


Link to post
Share on other sites
10 hours ago, Waldi said:

Hi Ian,

sorry to hear that.

since you have fuel on one injector but still no spark, I guess it’s best to focus on the ignition side first. See below point, sorry if I’m stating the obvious:

Is there 12V at the coil feed when ign is “on”?

How much volts when cranking at the coil? 

Do you have a conventional points set to replace the pertronics module?

Have you checked if there is a spark between the coil ht lead and mass (to check failure on rotor, cap and other leads, all in one go).

These are just a couple of things to check.

Regards,

Waldi

 

 

 

I didn’t get home until 7pm last night Waldi so no time to check, Having looked at the Pertronix website I see I can test by running a lead from battery + direct to the red wire from the dizzy, that will test the HT circuit. I have also ordered a cheap powerspark unit to see if that works, would be useful to have it as a spare if it proves unnecessary.

Share this post


Link to post
Share on other sites
9 hours ago, Mike C said:

The problem's are growing. I suspect that something's been disturbed when you replaced the coil or the new coil is faulty. Do you get a spark if you put the old coil back in?

Nothing had been touched when the problem started, the old coil has been removed, cleaned & replaced with no difference.

Share this post


Link to post
Share on other sites
On 2/24/2019 at 12:00 PM, iani said:

I have a Flamethrower 2 coil to match my Pertronix 2 ignition Waldi, again it's a 3ohm coil. I had disconnected the wiring to check the primary coil circuit, you can test the secondary circuit between the + terminal and the HT post if you wish. I've ordered  new coil, hopefully that will resolve it, dizzy cap & rotor arm look fine and they came from the Dizzy Doctor so should be ok.

Ian

Hi Ian!

Over the years of ownership of my TR6, I have had at least 4 failures of repro black rotor arms. 2 years ago after having used DD red rotor arms I had a failure of a DD red rotor arm. That was a surprise to me! Upon investigation, I traced the fault to a small crack in one of the bottom corners by the spring steel. I replaced the faulty rotor arm and my car started immediately. DD replaced the faulty one with 2 others so I cannot complain about the service, no problems since.

Bruce.

Share this post


Link to post
Share on other sites

Tried new DD rotor arm tonight, no change, fitted new dizzy cap, no change, no spark.

Share this post


Link to post
Share on other sites

After you have checked all the above, you  can measure the spark plug lead resistance, just to rule it out. Comparative measurement.

Waldi

 

Share this post


Link to post
Share on other sites

Hi iani,

I had a similar problem to you and found that the Pertronix system had failed even though appeared to test ok.

In the end I re fitted the old points system and it has run fine ever since. Give it a go if you can.

If you search for one of my posts "electronic ignition" you can read the whole sorry tale.

Good Luck

John

Share this post


Link to post
Share on other sites
12 hours ago, johnw said:

Hi iani,

I had a similar problem to you and found that the Pertronix system had failed even though appeared to test ok.

In the end I re fitted the old points system and it has run fine ever since. Give it a go if you can.

If you search for one of my posts "electronic ignition" you can read the whole sorry tale.

Good Luck

John

Hi John,

I swapped the Petronix out for a Powerspark unit this morning and the car started fine, therefore its the Petronix and I've wasted money on a new coil, cap & rotor, at least I have spares now. I've had the Petronix for 11 months and it has a 30 month warranty, I guess I'll have to ship it back to the US.

Ian

Share this post


Link to post
Share on other sites

Hi Ian,

I fitted Pertronic to my 6 and had a couple of roadside breakdowns. The second time found the problem was the cable had broken internally where it joined the module. The cable conductor is not copper cored. Fitted the spare old style points that I carried in case of problems and have been working fine since. That was in 2017. Binned  the Pertronic and will stay with traditional points..

Cheers 

Rich

Share this post


Link to post
Share on other sites

Having got the car running ok, my fuel pump woes were still there, after a few mins of running the pump would start screaming and the car would cutout. I called TRGB who supplied it and spoke with Gary Bates, on his advice I checked the fuel pressure and discovered that the garage who had fitted the reconditioned/new PI kit to my car had set the PRV to 128psi, this is far more than the Bosch style pumps can supply and more than a Lucas pump would have needed anyway. I reduced the pressure to 95psi and the pump is working fine without any noise, I just have to hope that the pump hasn't been damaged.

Share this post


Link to post
Share on other sites

Hi Ian,

good that tou found the initial culprit too.

so looks like you had 2 independent issues.

the pressure should be set at 105  PSI If set lower, less fuel will be injected, so it will run leaner. 

Waldi

 

Edited by Waldi
I typed bar where it should be psi, now corrected.

Share this post


Link to post
Share on other sites
29 minutes ago, Waldi said:

Hi Ian,

good that tou found the initial culprit too.

so looks like you had 2 independent issues.

the pressure should be set at 105 bar. If set lower, less fuel will be injected, so it will run leaner. 

Waldi

 

Gary Bates (TRGB) told me to go for 95, the 104 figure is for a Lucas pump

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.