2000 S70 Hesitates and Surges
 

Hi All, I am new to Volvo forums with three Volvos. My 2000 S70 has a couple issues but one is it was surging and hesitating mostly during acceleration. I was told the throttle body was the culpurate or that the MAP sensor may be bad. I pulled a MAP from same yr and model which takes about one minute and the problem was solved. I also have a large mass air flow leak which I put a new seal in the gas cap and Im waiting for the system to test the sensors after 50 or so miles and filling the tank over half.

wow you confusing me. S70 do not have primitive MAP sensors. Its similar, but another ball game with them.

The ETM (throttle unit) failure is very common. Only way of fixing it is replacement, and/or reprogramming.

The Mass Air o-ring is leaking?? That will cause a lot of issues. But you replaced the fuel filler cap to fix that?? hua?

All you need to do is 3 drive cycles (start drive ~5 miles turn off = one cycle)

Lifesgoodhere, thanks for your response. I believe that you are incorrect regarding the MAP sensor, unless we are calling it the wrong name. It is an atmospheric pressure sensor on the tube coming from the Throttle Body, and is about the size of your thumb. Since I replaced it my mileage per gallon has increase from 19mpg to 20.4mpg a little over 5%.
Where is the Mass Air O-ring that you say may be leaking?
Thanks again.

Same issue with my 2000 C 70
 

My C 70 surges between 1500 and 2000 RPM especially at slow speeds between 30 and 50 MPH

Surging is almost always excessive air. MAF, or a leaking hose. You should likely have a code. You may look to drive with a code reader in. sometimes the code requires a little time to set.

Maf
 

That is what I am hearing. I found a MAF on AMAZON for $29. It looks easy to install. I will let you know if it works. I love driving this car but it is death by 1000 cuts. Even my Dodge Durango with twice the miles on it is more reliable.

I've read threads where people take the actual MAF sensor out and clean it. There is a MAF cleaner spray you can get from the parts stores. I think the only problem is the screws are usually secure torx (the little pin in the center) and if you don't have the torx set for that you can't get it out. if you go that route, be careful of the filament. its very fragile.

Cleaning MAF
 

Interesting you said that. I took the whole unit including the tube housing off and cleaned it with carb cleaner. It runs much better but the light is still on. I figured I would do that while I was waiting for the new part. The new one looks like it comes with a new tube section so it will be easy to install. My ABS is shot as well so I am not sure if my check engine will go off but for $28 I figured it is worth a try.

Next it will be the oil leak (turbo return seal I hope), then the ABS. When I get a job I will tackle the driver side window regulator. I glued the back window in with a special kind of gorilla glue, not the kind you buy at home depo It has to be special ordered. It is holding so far. This car reminds me of the boat I used to have.

Spraying the MAF with carb cleaner may have been a bad idea. I'd get some MAF cleaner and re-clean it. You may find it runs better after that. The carb cleaner is bad for the sensor filament and will cause it to read incorrectly.


Also, I never advocate spraying carb cleaner into newer cars. Back in the carb days, it didn't matter because the emissions were either non-existent or minimal. Now, with O2 sensors and catalytic converters you can get very unexpected results. For the few minutes it takes and the cost of a gasket it's better to remove it and clean it

Your check engine light will not go out on it's own, it will have to be reset.

Thanks for all the help. I guess I should waited before I sprayed the carb cleaner. I hope I didn't do any permanent damage. Last night I drove it and the light went off but my dash lights go on and off because of the bad ABS module. It has run much better. I just wanted a temporary fix intil I receive the part.

How about the fuel filter ? That can cause it to fall off idle and overshoot on recovery.. stall ..surge ..