94 850T odd startup/acceleration?

volvo850freek · Post by **volvo850freek** » 09 Jun 2016, 22:25

Hello all,

lately my car has been behaving weird. At start up in the morning, it starts up rough and then the gas pedal will have poor response or won't respond at all and then it will randomly accelerate a little on it's own. This happens for about a minute or two and then car starts to act like normal.

after i shut off the car I can hear the radiator or some fan running under the hood for a few minutes. When i get back no matter if it's a few minutes or a few hours, when i start this time it sputters and then when it catches, the rpms keep rising till about 4000 and then goes back to idle and the car seems to be back to normal again.

So from reading a lot of forum posts I think my throttle body is dirty, throttle cable is sticky, or a bad etc sensor?

in the past few years the thermostat has been changed, new cap, rotor, sparkplugs, fuelpump,fuel pump relay, turbo hoses, fuel filter, air filter, pcv system, alternator, battery, water-pump, timing belt.

thanks,

Sommerfeldt · Post by **Sommerfeldt** » 10 Jun 2016, 01:41

Your throttle body might be dirty (well, almost certainly is), but your trouble could also be a stuck IAC, or a bad MAF. The best thing would be to see if you've got any codes - throwing parts at it gets costly in a hurry.

- S

volvo850freek · Post by **volvo850freek** » 10 Jun 2016, 14:41

so i don't have an OBDII reader but here's the OBD codes from under the hood

A2
315-EVAP system
232-Long term fuel trim, idling
241-EGR system flow malfunction
113-fuel trim limit?
A5-there wasn't even a port, just a hole, i could see right through it
A6-nothing...not sure why but pressing and waiting multiple times gave no lights
A7
113-fuel gauge open circuit
122-Temp. sensor interval too long
231-??? not sure

Sommerfeldt · Post by **Sommerfeldt** » 10 Jun 2016, 16:31

At first glance, I'd say you have both a vacuum leak and a bad MAF. Check ALL your hoses for leaks. That's the cheapest way to go. Check the MAF connector, and/or see if you can find a MAF from a junker to swap in, and see if that helps. A new Bosch MAF is about 140 - 150 usd on Amazon.

Check / replace hoses, clear your codes and see what comes back. Temp sensor can also cause a lot of weirdness, so don't rule it out yet.

- S

beigg · Post by **beigg** » 10 Jun 2016, 19:15

Iac hose might be breached. Check it for degradation.

volvo850freek · Post by **volvo850freek** » 11 Jun 2016, 00:21

hmm ok I'll check the hoses and clear codes, but I recently got the Silicone Intercooler Hose Kit and have already replaced those hoses, except the one L shaped hose that's under the car, beneath the radiator, but it seemed okay at the time.

Sommerfeldt · Post by **Sommerfeldt** » 11 Jun 2016, 00:44

Also go over all your vacuum hoses. If the haven't been changed on a 20+ year old car, it's high time.
That bottom IC hose takes a bit of a beating, so get to that one as well. I've always found it easier to reach from underneath - get the air guide off, and it's easy-please.

- S

volvo850freek · Post by **volvo850freek** » 22 Jun 2016, 16:19

OK so the Intercooler hoses are all good. I looked under the airfilter box and there was 3 color coded lines, the yellow and red were very brittle and definitely will have to change if i can find a tutorial but i think right now it's still fully connected. The blue line was completely missing like half of it broke off, i can't find where the end piece was connected to. but these are just turbo hoses? i can live with no boost.

I should mention another time while i was driving the temp gauge kept dieing and then going back up just to the middle and then dieing again. and then intermittently the gas pedal wouldn't respond while this was happening especially if i'm making turns and accelerating like getting on and off a highway exit. One time it just shut the car off completely. it started back up instantly but the temp guage kept doing this 3 O'clock-die-3 O'clock dance.

My plan right now is to replace the ECT sensor and then spray some MAF cleaner through the airfilter opening.
any other hoses should i try to check? or any other suggestions?

Sommerfeldt · Post by **Sommerfeldt** » 23 Jun 2016, 00:26

Hmm... Okay, the gauge thing is probably your 122 code. That can also lead to a variety of strange behavior. So, change your temperature sensor.

1: No, you can't live without boost. Or rather, you can't live without the possibility of it. So your system needs to be air tight, as it were. ANY air coming in other routes than through the MAF, or indeed escaping out other paths than your exhaust, will make a lot of trouble. Replace those brittle vacuum hoses, and check the elbow on the right hand side of the intake manifold. Also check your vacuum tree, that there are no open ports.

2: DON'T spray maf cleaner through the air filter opening. Take the MAF out, and spray from the "rear" of it. Check the connector as well - they're a known PoF.

What you CAN do, is get some starter spray, and spray around your hoses with the engine idling. Surging = leak. Be careful with this - starter spray is (duh) highly flammable.

- S

volvo850freek · Post by **volvo850freek** » 24 Jun 2016, 19:04

Thanks Sommerfeldt, I replaced the temp sensor. The old one's connector was all corroded together with the other connection and it didn't look good for both pieces when i disconnected them/pulled apart. I also took out the maf sensor and sprayed it down good. Temp gauge was slow to work the first time i turned it on but a few drives and it looks good. I wasn't sure about doing the starter spray thing and accidently starting a fire ha so i held off on that. Seems to start well enough for now.

Vacuum tree looked good, and I'm gonna order those ipd silicone tcv hoses, try to get a mechanic to replace those, I am not so mechanically inclined.