Fuel pump reseal, now engine runs, but runs away

I resealed my fuel injection pump with the two seals for the cover and adjuster as well as the oring on the head, and it started up without too much cranking. It stubled at idle a bit, but cleared up after cracking the injector lines to bleed air out of them. At that point the engine revs started increasing, so I killed the engine. The engine will start easily, idle around 1200 RPM, but will begin to slowly increase the revs on its own after 5-10 seconds. I've always killed the engine by the time it gets to around 2500 RPM, which is usually in about 30 seconds.

I hooked up the VCDS and went to check the IQ, but the mg/str value never registered above 0.2. Here is the printout for the FAULT CODES. I had to kill the engine before it completed, but I got a few relevant codes before I killed it AFIAK.

I didn't see any loose wire connections or hoses, and I had repositioned the IQ adjuster as close to the scribe marks as I could get it. Any pointers on where to start 1st?

You make sure the peg on the bottom of the QA located correctly on the adjusted collar? I think that is the big thing in play with throttle. Quickest guess I could think of.

Hammer mod the QA to the driver side. Google search it, if you don't know about it.

-Todd

ToddA1 said:

Hammer mod the QA to the driver side. Google search it, if you don't know about it.

-Todd

Click to expand...

I am prepared to do the hammer mod, no problem, but getting the VCDS working properly was my priority. I don't have any experience with this to do it by feel. It seems that the VCDS should have been giving me some values for IQ and that I have perhaps some other problem.

Celco said:

You make sure the peg on the bottom of the QA located correctly on the adjusted collar? I think that is the big thing in play with throttle. Quickest guess I could think of.

Click to expand...

I lined everything up almost precisely where it was before. I made sure that that dowel pin was lined up with the hole that must point up in the component in the body when I put it back together. There was no resistance when I was reassembling.

It doesn't take much to be off with IQ. Less than a millimeter of movement between the body of the pump and the QA can have a big impact on IQ. Research the hammer mod and bump it a little to raise the IQ number, lowering the quantity injected, and start the car to see where it is. You can kill the engine with the ASV if it gets out of hand. Do this until you get in a healthy range (2.5 - 7) and fine tune it from there.

Sent from my mobile look-at device

ToddA1 said:

Hammer mod the QA to the driver side. Google search it, if you don't know about it.

-Todd

Click to expand...

to the passenger side... if he hammers it toward the drivers side it will get worse and rev higher

Brain fart... thanks for the correction. It's been a while since I needed to do it.

-Todd

\/\/0J0 said:

You can kill the engine with the ASV if it gets out of hand. Do this until you get in a healthy range (2.5 - 7) and fine tune it from there.

Click to expand...

Mk3/B4 didn't get the ASV? That didn't get introduced until mk4 with the ALH?

Stromaluski said:

Mk3/B4 didn't get the ASV? That didn't get introduced until mk4 with the ALH?

Click to expand...

Ah! My bad. Then an improvised asv can be used.. Chunk of 2x4 or plywood to cap off intake in case of runaway

Sent from my mobile look-at device

Thanks for the replies, everyone. I'll perform the hammer mod ASAP.

VVojo, Regarding killing a runaway, would you mind elaborating on capping off the intake? Also, is this the kind of runaway that killing the ignition won't stop, similar to when the turbo fails and the engine burns oil? I wouldn't think so, but just making sure.

If you remove the charge air hose that goes into the egr valve (flying saucer deal) it'll give you a good surface to press a hard flat object against to seal off air from entering the engine and continuing a runaway situation. I'm not sure if the electronic VE pumps are capable of continuing to runaway with the key off but I know the mechanical ones are. In both irritations, you're essentially doing the same thing--sliding the collar towards or away from spill port to change baseline fueling.

Sent from my mobile look-at device

the E-VE pumps can run away with the key off ... i started an engine with no electronics, aside from 12v on the FSS, by tapping the QA toward the trans and controlling the "throttle" via the ASV ... if i had let it go it would have over-revved ... it was a smoky exciting experiment

I performed the hammer mod and the IQ is back in range, and it purrs as it did before. I don't see any torque specs for those torx bolts holding the IQ adjuster. I know it must be low torque since they are aluminum female threads.

Is there a spec? Or do you just snug them down with some threadlocker on the threads?

Glad to hear it's back up and running! Just tighten those bolts up with a 1/4 in drive ratchet and you're good to go, no thread locker necessary.

Sent from my mobile look-at device