Ken

It seems like my car(83 944na) is having trouble with it's fuel injectors. My guess is that they're old and/or dirty. What's the best thing to do? Buy new stock ones? Just have them cleaned? Or can i upgrade to a higher flowing injector?

keith

have them cleaned - try RC Engineering
about 24.00 apiece, 2 day service.

Greg Hammond

Have you tried using a couple bottles of Chevron Techroline injector cleaner? It's the only injector cleaner recommended by Porsche, and does an excellent job IMHO. If you have a "stuck" injector, it probably requires replacement.

What makes you think your injectors are "bad"? How many miles do you have on your car? Typically injectors are good for 175,000+ miles, even without routine cleaning.

Greg

Ken

I've got 119,000 on my car. I think they're bad cause currently i'm having problems starting my car, and expieriencing power loss when driving(accel is not a exciting as it used to be). It cranks, but it acts like there's either no gas or no spark. If i add some gas, it usually helps to start it. Also, i added some injector clearner(not the stuff you mentioned), and it made starting alittle easier.
My current goals are to replace the coil, maybe the fuel pump, and try and see if i can get the injectors clean. I think that should help. My only other thought is if there's something wrong with the idle system, although this i have no idea how to fix. My other goal is to bring her in for a complete checkup from a Porsche mechanic to see if he can find anything wrong overall.

JasonN

Please please please let me know the results after you change each thing (coil, fuel regulator, injectors, Idle controll, etc.). I have the exact same problem. I had the entire top end of the engine (including injectors) cleaned with a "terra clean" engine cleaning machine. It did not help and actually, it may have gotten a bit worse. Anyway, I'll keep you posted if I change anything and please do the same. Thanks

keith

Contrary to popular belief, Porsche injectors will NOT last that long. They will function at those mileages, but will not perform correctly.

I spent 6 months chasing down a stuttering idle and a flat spot ~ 3400 rpm on my old NA, and having the injectors cleaned cured those problems and VASTLY improved the overall running condition of the car.

Anything over 100k would have the injectors sent off for cleaning, if it were in my garage. This is also a good time to replace the injector seals and test the FPR and damper.

It is well worth the $100.

Ken

Where can i get just the injector seals? And what are FPR and damper, and how do i check them? Thanks for the help. Also, would it be worth it to completely replace the injectors? (65 each from Paragon) Or do properly cleaned injectors work as well as new?

keith

If you can afford to replace, fine. You will get more lifespan out of new than rebuilt. However,my cleaned injectors have been in my 951 for a year now, no problems. The cleaned ones in my old 944 started to leak (from the housing) about 2 years after cleaning, and were recently replaced with new.
Seals can be obtained almost anywhere. If you do just the seals, be sure to get instructions from the list or other sources before you put them on, as the re are parts of the seal kit which are not used, and correspondingly, parts of the original injectors that MUST be re-used. Cleaning includes the new seals installed, as do new injectors, of course.

The Haynes manual has testing procedures for the FPR and damper. It will require a fuel pressure gauge. You will likely have to buy a fuel rail end cap (about $5.00) to modify as an adapter to use a fuel pressure gauge on your car. Some of us (myself included) just went a head and bought a samll fue pressure gauge (19.99) and permanently mounted it to the end of the fuel pressure rail. This allows you to keep a running check on your fuel pressure...

Did that address all of your questions?

JasonN

Forgive me for sounding like an idiot, but is there a visual way to conclude that ones injectors are leaking? Or do you just know by the way your car is behaving?

keith

no.
(well, you can tell if it is leking through the housing visually)
what happens is - the injector gets dirty (clogged) and doesn't spray right, or fully close, and drips. You cannot see that.

try this - smell your dipstick (easy now!) for gasoline. If your oil smells like gasoline, you DEFINITELY have a leak.

Mouse.

Ken, I also have an 83 944 and last year I replaced all of the injectors. (Pretty simple thing to do) I was amazed at how well the car ran after doing so. Idle was smoother, had more power and just felt better. I bought my injectors at Pep Boys for 40 apiece and they came with the o-rings.

keith

are you F------ kidiing me? Pep Boys has the injetors for $40.00?!

Hallelujah (excuse me while I dance around the office!)!

That's amazing.

Ken

I second that!

Keith - Yeah, that answers everything. I think the best thing to do would be replace them. Hopefully that'll solve the problem, or at least help it.

Mouse - Thanks for the tip. I'll check with the Pep Boys by me and see if they got 'em.

I'll drop another post after i put the new ones in. Thanks for the help!

Skip

Not trying to be a spoiler here, but, I've checked most of the major parts stores... and just called a couple PepBoys. They only carry the early injectors (83-85.1) for $44/ea... but these are reman (rebuilt). New ones are still up there in price (~60-80 depending on application)...

However, as someone already pointed out... you can have yours rebuilt for ~$25/ea by RC Engineering or Marren Motorsports. The difference being that these guys will flow match the set (so they work together well - little to no deviation). Uses new O-rings and filters. They will also provide a data sheet of the before and after results (just to back up your diagnosis).

Just a very satisfied customer

Good Luck!

Ken

I am considering the cleaning of the injectors, but my major problems with it are:

1. The down time of a week(maybe more) for my car, which i drive to work.

2. The quote from Keith, "The cleaned ones in my old 944 started to leak (from the housing) about 2 years after cleaning, and were recently replaced with new."
Why should i pay to get these cleaned, and then have to replace them in a few years? This may have been an isolated incident, but should i take the chance?

I do like that they flow match the injectors, but i would hope that a new set of injectors would be pretty close in flow. (For the price of them, they shouldn't done some damn testing! )

Finally, i agree that maybe the Pep Boys ones aren't the best choice. (Thanks for checkin it out Skip) I'm still not sure what to do....