p1550, limping

I'm about 300 miles from home working, on my way CEL light came on when I was accelerating to pass.... lost power. Pulled over, cleared code and let car cool and was able to go another 45 min with no probs.

While I had the hood up, noticed my #4 injection line is leaking - related?

My memory is kind of fuzzy, but seems like I went through this back in 2003. That was when I cleaned the intake and ran silicone vac lines.

I figure I'll start by looking at the intake and vac lines. Just wondering if I should order a n75 since mine is original, or is that something that rarely fails? That is once I find injection lines online, no luck so far - may have to check the classifieds.

dude, im not 100% familiar with p1550 code. sounds like your vac lines need to be checked. it sounds like the last time you did vac line svc was ooh 15years ago?? best bet, change out all vac lines, make sure all are in right order, dont forget the one inside the ecm!, try that and gl
i also by now find it rather smart to service the alternate vac lines, the ones for the vent unit. once it gets into/past the firewall, it can be unserviceable w/o pulling (part of)dash apart. ie getting to the vent box.

when you replaced the vac lines did you replace the small one inside the ECU metal housing? that goes to the map sensor and it does develop small cracks over time. I don't think #4 injector line would cause that. that code is related to boost control from my quick search. When the car is running do you hear the N75 clicking rapidly? If its not clicking it might indicate something wrong but it does click fairly loudly when its working. Also check the vac line running from the intake hose to the ecu. If you are near any auto parts stores and are able to grab some 4mm ID vac line and have some basic hand tools I would check the small line inside the ecu casing.

My 97 would go into limp mode seemingly random but more when giving her the beans, I replaced the ecu vac hose and haven't had limp mode or a CEL for 3 years now.

Fuel line can be found at idparts. I also had leaking fuel lines between 2 to 3 and 3 to 4 recently before upgrading my nozzles and had no CEL or effect other than smelling raw diesel as I drove.

Look for a boost leak.

Depending on where the injector is leaking (supply or return line) I'd have to say that it's unlikely to be contributing to your issue.

Check to make sure your line from N75 to the turbo is intact. I know you've switched your hoses to silicone so you shouldn't have a problem with it but that would be the first spot I would check. The connection at the turbo is vulnerable, I lost mine a while back and switched to Gates fuel return line (1/8") at that location because of oil contamination.

As OH said you might also look for boost leak, a slit hose maybe.

Steve

Made it back home. No limp mode or engine light, but felt down on power. I'm going to be replacing the hard lines to solve that leaking #4 line tomorrow - it's pretty bad leaking right at one of the clamps. Also a new fuel filter.

So, I changed the fuel filter, and the hardlines due to the leaking line. Inspected all boost hoses and vac lines. Have put 40 miles on - did a lot of wot with no issues.

I didn't pull the intake, just not into taking on that job. but thinking back - I cleaned the intake years ago, but not the ports in the head. Seems like someone had destroyed their engine cleaning the ports at the time, so I was scared.

You guys think it's worth it to pull it off and clean the ports?

a few years ago i had my intake cleaned, took them 24hrs to soak and clean. i forget did he charge me $50?? its been a while..
at the same time i blocked off my egr. had a different head, so the head was off, not an on-the-car port cleaning.
as you know you can drop a load of soot from a port your cleaning into a cylinder. you can clean ports/a head thats on the car. the trick. the port your cleaning, close the intake valve. i take a vacuum and an attachment to clean as much as you clean out of the post. take the 'side' attachment, the rectangular one, i take a hose 1/2" or so, tape it on attachment, and clean out port good. gorilla tape works good. small stuff will pass easily. cyls will blow it out exhaust. as long as its small it should make it past the turbo exh side. (after starting give a couple of seconds and raise the revs to blow stuff out, about 2k rpms).(<as long as it runs ok at first)
looks like this week im going to take that head i ve had on off. it ll be the first time i ve had a look in the intakes since i did that work.
since doing the egr block-off and intake cleaning i ve had a noticeable power increase. 2 years later or so and same, same power increase. i like it.

the other day i was looking at different parts. i think it was IDparts, has egr block-off plates. not necessarily inexpensive. they have a neat one, one with a hole so you can put in an EGT sensor. but i thought these were too thick, you just put on a gasket and the plate over. i dont think its smart to leave the egr cooler unhooked. you cannt reasonable remove it, these cars still have to pass emissions, mostly a visual will do. egr cooler should be there.
i had a friend at a shop get me a scrap, sheet of iron(i think it is, its heavy). i took a cut of the sheet in a strip, so i can make multiple 'blanks'. i took the rest of the scrap back to my guy, he was happy, and gave him a couple of bucks, and a thanks, i was happier, i can make blank plates.
so i have a egr pipe i broke. its the one that connects to the manifold. cut enough of my strip for bigger than a needed 'plate'. used the connection i have as a template, made block-off about the size needed. as installed you have to look real hard to really see it. thats the idea. clamped connection template and made up plate so i can drill holes, so they will fit. some light grinding, wire wheeling, to clean up, and de-burr. take it between two gaskets and 'slap-it-on'. to fasten i used stainless 8mm nuts and washers. the copper nuts that come with car, are to tamper-resist emissions systems, and just tend to round. the nuts stand out though.
egr is just there, mostly disconnected, i disconnected the water hoses when i put in new ones, ran a hose from one to the other to close this off. just in case i dont need cooler fouled from leaving open.

My friend had a lot of problems with his mk3, turned out to be the waste gate was stuck solid. Being the mk3 it didn't give as much info from a scan so took a bit off faffing around to find it.