I have a 93 Volvo 850; N/A; GLT; Automatic; 167K Miles, recently the fuel pump gave out so i had it replaced. The idle was utter crap, kept surging, turns out it was another bad fuel pump, so it was replaced again. Right now the car runs, it will periodically hesitate from idle, but when it is under load or even with no load the car will not go above 3,000 RPMs. But if i hit sport mode, and force it to down-shift, it will shoot up to 4k and continue to wind up with no problem. As long as the tach is nowhere between 2,900 and 3,300 RPMs the car will have power and run flawlessly. The moment it hits 3k the car loses all power and starts stuttering, no matter how much i floor it. The moment it shifts up to the next gear, and drops to about 2k rpm, the car takes off again with no problem.

Work done so far

New fuel pump
New Fuel Filter
Cam Shaft sensor was replaced under warranty

Things that have been ruled out:

Clogged Catalytic converter
Clogged Exhaust
Bad Gas
Clogged intake.


The following codes are being thrown:

Port 6: 1-3-1 Engine RPM Signal <-- Cleared it, hasn't come back so far
Port 3: 2-1-3

Right now my mechanic has run out of ideas. I can take it to another mechanic that specializes in import cars, or should i just bite the bullet and take it to the dealership.
If possible I would really like to fix this myself. Any ideas would be greatly appreciated.

Thanks,
-Matt

 

Could be a bad TPS sensor.
Could be a bad Mass Flow sensor.
Could be a bad Fuel pressure regulator.

 

Could be fuel pump relay.

 

Check plugs, plug wires, cap and rotor, vacumm lines. Finish Stage 0, maybe that'll help.

 

Update:

The car won't even go above 15 mph now... still no codes.

So right now I'm starting with the TPS sensor. (Cheapest) All i need to know is the location and i can probably change it myself.

Thanks for the replies.

-Matt

 

2 torx screws and it's on the throttle body, little black thing that the wires go to, super easy swap
-Mike

 

check plugs and wires....is the car misfiring??? Idles smoothly??? cap and rotor? check compression

 

Fishbulb95,
I've been working on a very similar problem, but unfortunately, haven't got it sorted yet.
The car, 93 850 GLT, standard, n/a will burble in the 3200 to 4000 rpm range. After 4000, it takes off like a rocket.
I had the rpm sensor code as well as a camshaft position sensor code. I cleaned the connectors and cleared the codes. I've cleaned the MAS as per this forum, cap and rotor look new.
Just tonight I pulled the cover for the spark leads and sprayed a water mist while a partner revved the engine...didn't spot any leakage. Also sprayed the coil..no arcing.
If you find the problem, please, please post your results as my Scottish heritage hates the thought of replacing stuff if you're not sure.
Good luck!!!

 

I will definitely post my results, as of right now, I'm not doing anything to the car till this weekend when I will actually have some free time. Atleast you get a burble, mine just dies, and for some reason only sends enough fuel to keep it there.

I do get a code periodically for my transmission, "Lock-up not engaged" blinky arrow and all that, doesn't go into limp home mode, and if i turn the car between acc and on 6 times, the light goes away and lock-up works. And my tranny likes to clunk in reverse. Since it's always at 3k, is there some significant relation to the tranny which could be causing this problem?

-Matt

 

I just came across a test for the TPS on a volvo manual, take an ohm meter and at idle position it should be 900-1100 ohms, and WOT is should be 2300-2900 ohms

give er' a shot
-Mike

 

Update:

The Car works now, took it into a mechanic that specializes in imported cars, particularly Volvo.

I guess the fuel pump was the problem (still), Since the 1st mechanic used a 3rd party pump it was only putting out 20psi instead of the necessary 41psi. The mechanic said that they have had many problems with 3rd party fuel pumps so they only use Volvo. So now the car runs, no hesitation, no stuttering, and no loss of power.

Thanks again for all your help.

-Matt

 

Hello Matt,

Greetings from Chicagoland.

I haven't been able to reply to your post until now.

I am prejudiced on using OEM parts (parts made by the companies that supply parts to new cars) as much as I can. The reason is because you get what you pay for. I once replaced a clutch disk on an Accord, and it failed only after 10,000 miles, whereas the OEM (original) disk lasted over 100,000 miles.

Many town garages, unlike the shop you found, use cheap aftermarket parts, some of which are made in Asia (I wouldn't say which country, I am a native of Japan) or elsewhere and the quality of those parts are noticeably poor.

Volvo seems to use quite a few parts made in Germany (Bosch) or England (and France, Spain, etc...). Anyway, while many people try to save money by using cheaper parts (I know this wasn't what you tried to do), paying an additional 20~30% more money for OEM parts (or name brand top quality aftermarket parts) definitely pays off in the long run.

Glad your 850 is back in service.

Regards,


JPN