2001 Volvo v70 sputters, wont accelerate, CEL blinking

beccasdesk · Post by **beccasdesk** » 30 Jun 2014, 01:27

This is becoming a goose chase! I just bought her a month ago and she suddenly began sputtering, wouldn't accelerate, CEL began flashing. A friend of mine is a mechanic. She took a look and said my coil#1 is bad. I ordered a new one from volvopartswharehouse.com, put it in and the problem seemed to be fixed!

She hooked it up to her code reader doohickey(sp?) and the codes were cleared/not stored upon reset. She ran good long enough to take my friend home then the same problem started up again on my way home.

We decided to try changing the spark plugs before buying another coil. All new spark plugs and new #1 coil but the problem persists. My mechanic mentioned i also have a leak in one of my vacuum hoses. Im wondering if the vacuum leak could be causing the misfire or possibly the fuel injectors or fuel pressure regulator? Im just starting out learning how to work on my own car so my terminology and "logical deductions" may be off. All thoughts appreciated!

benrk · Post by **benrk** » 30 Jun 2014, 09:29

Coils are easy enough to diagnose w/o a code reader, unplug & replug one after another, if it runs worse, the coil is good, if nothing changes, you got the bad coil. As you have already replaced the #1 coil, try swapping it with one from another position, if now it is the same coil on it's new position, the new coil is bad too, if it's still the same cylinder with another coil, you have a different problem.

If you want to do simple diagnostics & not spend a fortune, there are ELM327 bluetooth code reader modules on amazon & ebay for ~$15 & you can download free OBD apps for iOS & Android & diagnose the codes with your smartphone.

beccasdesk · Post by **beccasdesk** » 30 Jun 2014, 12:34

Thanks so much for your reply! Im not sure i understand the swapping though. If i put the new #1 coil in the #5 spot, whats going to tell me the coil is bad? Another code? Im confused.

benrk · Post by **benrk** » 30 Jun 2014, 12:51

If you put the new coil into e.g. #5 & now it doesn't make a difference wether it's plugged in or not on #5, the coil is bad, if #1 still doesn't run evnthough the good #5 coil is in, it's not the coils but rather wiring, injector or whatever else on #1.

Post by **abscate** » 30 Jun 2014, 19:04

If the coil is really bad, you will get a OBD code telling you which coil it is. Cylinders are labelled from right to left, with rightmost being number 1 and leftmost being 5. Don't forget to turn other engine around in your head if you are facing to the rear.

benrk · Post by **benrk** » 30 Jun 2014, 21:17

Funny thing, I did actually have a coil go bad myself today, took quite a bit of driving around to produce a lasting code, P0303 #3 misfire, at least I finally got around to install those new spark plugs that were overwintering in the parts shed next to the spare coils from the original engine

Post by **abscate** » 01 Jul 2014, 00:47

A vacuum leak can unbalance these fine motor cars and cause the symptoms you are seeing. The fuel system is very robust though, and on your model the vacuum does not regulate fuel pressure like the 1998 and earlier models.

A code reader like above is an essential piece of diagnostic hardware. Get a cheapie and start diagnosing!

beccasdesk · Post by **beccasdesk** » 03 Jul 2014, 12:27

Thank you all for your advice! I believe Ive found the problem(s). One of the bolts that holds the ground wire for coil #3 was loose and everytime it wiggled , the car would sputter and misfire. We tightened the bolt and the sputtering/CEL issue is fixed. As it turns out there were 2 issues we originally thought was 1. When I put her in park she sort of chokes. In all other gears she runs fine. I believe this means I need a new IAC valve?

Post by **abscate** » 04 Jul 2014, 07:02

Hopefully not on the IAC valve, because you don't have one.

Check all those ground bolts on those coils.

Stumbling or bad idle is probably that vacuum leak that your friend alluded to earlier.

beccasdesk · Post by **beccasdesk** » 06 Jul 2014, 10:33

Hahaha! Well that explains why i was having such a hard time finding it! Thank you for pointing that out! That couldve been unnecessarily costly! We replaced the vacuum hoses and its definitely better but does still choke only slightly and occasionally when in park. Otherwise, runs fine.