joejoe

I used witchhunter for a set on one of my '86.5's. Less than 1 week turn around and definetly made a difference for motor.

FIA-F1

What exactly are the symptoms? I was running about 50 today and the car "stumbled" twice...it was as though the ignition was cut off momentarily. Otherwise you could not tell there was anything wrong with it.

Jamesr6967

You could have a worn ignition switch. Most people hang a full set of keys off the ignition, which wears out the contacts. Us truck drivers put 140 k + mikes a year on our trucks, and I have seen plenty of drivers do this to their trucks ignitions.

FIA-F1

Alright, I could see where that could happen...I do have a lot of keys on my keychain. In my case, I had just filled up with gas on a tank that was on fumes when it happened but I had driven a couple of miles before it did so not sure if that could be linked. I drove several more miles with no symptoms after that.

dr bob

It's hard to blame injectors alone for that intermittent stumble. For most of us, 'normal' driving is part-load at nest, so we seldom use the full flow requirememnts. That same low duty cycle use means a partially-restricted set of injectors will get compensation from the oxy sensor, and from the learning ability of the later LH controllers as they slowly clog. In my case, the car ran fine for my casual driving demands, and only showed obvious symptoms at the smog sniffer checks when high HOx pointed to some slightly lean cylinders. Nice clean injectors smoothed out the idle very noticeably, solving a symptom I didn't recognise until it was gone. NOx went from "just barely passing with help", to way below average numbers at the next test. This was at just shy of 100k miles. I'll speculate that the injectors could benefit from cleaning at miles well short of my number, perhaps in concert with the oxy sensor replacement schedule at every 50k milesn and no less often than the ritual MAF rebuild at the same 100k interval. All of these things are slow deterioration items, so slow that we don't notice them until we decide to fix them as PM, and things suddenly get better.

I think Roger has a deal on replacement injectors sets. Worth a look if you want to do the whole set in and out in an afternoon, rather than waiting for turnaround from a service.

FIA-F1

Since I do not know the history of my S2 prior to 96K miles, I am interested in options with the injectors. I do not know the reference to Roger so if you can provide a link or contact info, that would be great. Thanks.

Wisconsin Joe

Roger Tyson. "Parts Supplier Extrordiare"


928's 'R' Us
http://s287999742.e-shop.info/

alabbasi

I'm toying with the idea of going in with a friend and buying a stand alone injection cleaner system. One of my other buddies is getting ready to close his shop down and has one for sale. This is not the type that cleans the injectors while they're on the rail. The injectors need to be removed from the car and mounted on the machine where they are ultrasonically cleaned, flushed with a solvent and flow tested.

Buying one will cost a pretty, but as I have a couple of V12 jags with spare injectors, and my 928 has sat for a while, I think I may have about 40 injectors which need cleaning, which will cost me around $1000 to send out. For this reason, it may pay to own something like this, especially if I can offer a low cost service to local members.

What do you guys think? good idea or bad idea?

chrisjbell

A couple of things to keep in mind...

Regarding using various chemical cleaners, don't forget that there are filters inside each injector. Over time you will get stuff in them, and the only way to get it out is to remove the injector from the engine and clean it. A decent shop will replace the filters and pintle cap when they clean them.

As far as new injectors, I have been told (and believe) that even off the shelf you may not get perfectly matched spray patterns. I'm sure it varies with the injector type and it is probably negligible for new injectors but something to consider...

The key is to get someone that will take the time to clean them and then flow test them. Most places that clean them will do that much.

I'd be jealous and would do it if I could afford it. (Just what I need... another specialized and expensive hobby tool.) I just got the injectors cleaned for my V12 Jag... 300 bucks, and I did the teardown and hoses. Add that together with the set for the 928 and I dropped $500 to clean injectors for two cars this year. :-P

I don't think it is rocket science to clean injectors... just a question of having the right tools and being detail oriented. Kind of like, say, working on an older Porsche or Jaguar.

alabbasi

Chris

Me and you should talk offline some time. The buddy that i'm going in with has become quite the Jaguar guru. My 75 XJ12C was converted to run on propane. All the wiring, D-Jet stuff, fuel rail etc , fuel tanks etc have been removed. I've bought two parts cars so that I can put it right and he's going to build a new wiring harness for it. This will be his third wiring harness as he fixed two burn cars.

With a new wiring harness, rebuilt injectors, new hoses on the rail and plugs and wires it's amazing how silky smooth these cars are.

The work started on Thursday. I expect for it to take a couple of months. Back on topic, on the injector machine. I should be up and running by the end of the month