Anyone else have issue's after installing an after market fuel pump?
I had to change my Bosch because it failed on a side road and the after market was all I could get my hands on in that moment.
My car hasn't run right since, I can hear the pump always running and she idles like crap, shaking and everything. Any suggestions?
90 VDP

 

have you checked the fuel pressure yet?

 

In answer to your ask, NO, not in all the ones I have done.

I am assuming the external fuel pump on one of your Jags??.

Rare issues I have had are usually related to some crud or whatever, getting through the filter and into the injector/s, but that is RARE.

Slightly more common is that same crud blocking the fuel filter, that is why "most" pump packaging asks you to "change the fuel filter at the same time as pump install".

The fuel filter would be my first item to change. After that the "pick up" filter inside the tank would be high on my list.

Crimped or damaged hoses would be next. Especially the 2 actually AT the pump.

With a pump "failing", you may have had an engine running a tad lean, and that has probably screwed the spark plugs.

 

That's the sentence I wanted to read!

I left the engine idling and pulled each boot off its spark plug. If I had a spark/wire issue the car's idle wouldn't change when removing the boot from a plug (the way it's running now)

3,4,5 and 6 when removing the spark showed a significant change in the idle.
1 and 2 didn't. I have been running on 4 cylinders. I tried using a spark plug wire from 5 to 1, still no difference.

This leads me to reading your posting, and if all things add up it's the plugs. Although when I pulled them out they look wonderful, slightly grey with no oil/residue on them.

 

I could only wish my above post was that easy. New plugs, same issue. All wires are sparking nice. I even put the old fuel pump back in to see if the new one was the issue, nada. Same rough idle. This is new too me, so here we go.

 

Seems like I read recently a post about the same problem. One of the solutions offered was to unplug the wire to the injector to each cylinder(one at a time) to see if that makes a difference. Or even switching injectors to see if the miss follows with the injector which would indicate a plugged injector.

 

BUGGA.

So as per your very detailed diagnosis, the plugs are not the issue, nor the spark itself, so I now revert to crud in the injector/s. No real easy fix unfortunately. Removal and a professional clean is the only proper way.

Some injector cleaner MAY assist, but seriously I have never had any real success with them once the injector is actually plugged. As a maintenence item I kind of agree with it.

This does sound strange after a simple fuel pump swap, but it only takes a speck of dirt, or a drop of water to mess with the injectors.

 

Just had a further thought.

On my Pre HE V12, yeh I know not the same, BUT, injectors are injectors, and ours sometimes gets hissy and drops 2 cylinders.

By simply putting my hand on each injector with the engine running, it is so easy to "feel" which ones are not clicking, so a sharp "whack" with a suitable whacker, and away we go again. NOT scientific, and NOT good in some peoples eyes, but we have had this beast for 20 years, and at 500k kms I am NOT stripping anything just for fun. When the "whack" ceases to fix it then plan "B" will be put into action. Whatever that is.

Might be worth a try prior to removing, it just might work, and certainly will do no harm. You dont have to BELT them, just a sharp tap. I usually use a 19mm box spanner, or similar.

 

I would perform a compression check on the dead cylinders 1&2. It is common for the head gasket to go bad between cylinders.