kinda5150

here's the story: 83 944 been sitting awhile and would not start. traced problem back to fuel pump, therefore replaced it. car immediately started and idled fine. took it out for a spin and noticed that under acceleration it surges and bogs down at about 4k rpm. replaced plugs. ran a little better, but still not how it should. electrically everything is checking out ok, although my injectors are reading 5 ohms whereas the book says they should be 2-3 ohms iirc. ignition coil was a couple of ohms high too, so unsure if this is my meter or the parts are in need of replacement. voltage is all good. i'm thinking maybe the injectors are clogged? if so, what is the best way to check them? also, anyone have any ideas for cleaning them? i'm also thinking i may just have some build up of some sort that just needs to be burned off. i don't wanna drive it too much since the timing belt hasn't been replaced in quite some time. i appreciate any and all suggestions. btw, the fuel pump is made by carter if that makes any difference. is it possible i hooked the leads up wrong? i would imagine it wouldn't work at all if that was the case. also, the pump whines like a mf'er. i don't remember ever hearing the old one whine like that. thanks.

KuHL 951

Did you also replace the fuel filter with the new pump? A fuel pump will whine when it's pumping against a blockage. It wouldn't hurt to get the injectors serviced( www.witchhunter.com ) if the car has been sitting for awhile and fuel has gummed things up. Other things to check is TPS operation and retracking the wiper arm on the AFM. My 83 used to act strange at mid-rpms. Retracking the AFm made the best inprovement followed by a new rotor and distributor cap. These are just a few that things I've done. I'm sure you will get better suggestions.

kinda5150

thanks for the reply. no, i didn't replace the filter, will do that tomorrow. i looked at the afm and it did look a little grooved. i checked that out on clark's, so i'm gonna give that try tomorrow as well.
i noticed yesterday when driving around that it seemed to get worse the longer i drove it. i checked the vacuum lines and air inlet to make sure there were no obstructions, but everything looked really clean. i'm unsure as to why it would get worse the warmer it got. strange. never experienced these problems before. thanks again.

Mongo

I had an issue similar on my 84 944. Here's what I replaced and it seemed to have helped it:

-fuel pressure regulator
-fuel pressure damper
-intake boot (one on the car had a 3 inch slice on it underneath)
-fuel filter

testarossa_td

Heat expands and soaks...

Here is a good writeup on the AFM ( Air Flow Meter) tracks thing.

http://www.frwilk.com/944dme/afm.htm

http://www.frwilk.com/944dme/

Rip It

perform the TPS check

kinda5150

thanks for all the suggestions! got the write-ups for the AFM, TPS, FPR, and O2 sensor. i'll replace the fuel filter, which i should've done to begin with. the plug wires and dist cap only have about 8k miles on them, so i assume those are ok. i'm gonna go ahead and add 10 psi to the intake to thoroughly check for vacuum leaks. hopefully i will get it resolved this weekend. i'll keep ya posted and thanks again.

Der Rennwagen

This might be the same exact symtom that I've got - gets worse when it warms up. Here is my solution for now.
https://rennlist.com/forums/924-931-944-951-968-forum/225650-hesitation-at-mid-rpms-under-load-revisited.html

I updated my website with a photo of how I attached my temp sensor to stay "cold" until I fix the air leaks.
http://www.thompsonsmithdesign.com << look under "biography/current cars"

Thompson
1985 944.1
Club Sport targa

Luis de Prat

Remember like Der Rennwagen says, the idle control valve on these cars is located under the intake manifold and tends to "gunk" up over the years. Generally, the symptoms will go away after the car has warmed up. Congrats on that super 944, btw.

njwilser

Try the lazy man's injection cleaner. One quart atf (dexron) to a tank or so of gas. No, I'm not crazy Clark recomends as well. New filter first!
MW