PT Cruiser Forum

PT Cruiser Forum (
-   General Turbo Discussions (
-   -   Weird Fuel Problem (

KalebSikora 06 Dec 2017 12:37 am

Weird Fuel Problem
I made a post about this in the past, but the issue has only gotten stranger. One of the main suggestions to me is that perhaps I have a cracked exhaust manifold, but I don't think that can be it anymore.

To sum up my issue, my car was getting about 15 MPG with the CEL on with a lean engine (checked at AutoZone). My mechanic noticed that my valve cover gaskets were leaking oil and also leaked oil into the spark plug wells. He swapped the gaskets and resealed, while also cleaning out the spark plug wells.

The CEL turned off and for a few months my MPG returned to normal. The CEL came back on a few months later with the same MPG only to turn off again after a month returning my MPG to normal once again.

After several months the CEL never returned by my MPG started to plummet from 20 all the way down to 11. I just dealt with it for a while avoiding driving my car until my mechanic suggested using a engine cleaner. I ran some Techron through my car and it boosted the 11 MPG up to 21 MPG. It started to fall back down until I put a second Techron cleaner through.

It's been a few weeks since I put any in there and it's stayed around 16 MPG. Could it be the fuel filter? Or could it simply be something that is still lodged in there? This is getting very strange..

rob302 06 Dec 2017 11:14 am

Re: Weird Fuel Problem
1 Attachment(s)
there is no "real" fuel filter on these cars. they just have a sock on the fuel pump inlet. anything that gets through the sock ends up in the injectors. for what it's worth, my PT at 240,000 miles had the cleanest tank inside i'd ever seen. looking inside, you couldn't tell it apart from a brand new tank. i think with a plastic tank there just really is no need for an inline filter. the one on my mustang i can change the filter every oil change and have black crud pour out when i drain it backwards. meaning if i pour gas through it it comes out clean, if i tip it so the gas comes out the inlet, it comes out like murky pond water. i believe it is rust/metal, and the plastic tank in the PT prevents this from ever being an issue.

Attachment 26475

i believe any sediment or gunk that get through this usually sprays right through the injectors and out the tailpipe. it is possible that as the tiny debris passes through the injector it gets smashed as the injector opens and closes and accumulates over time, causing it to either spray funky, or to continue to add fuel when it should be closed/sealed since gunk is holding it open.

if injector cleaner fixes it every time, you might try to use a different gas station. everyone has their local gas station they use constantly. might be best to change where you gas up for a while to see if it prevents the problem. ...or just add the cleaner periodically

anyone else have thoughts on this?

rob302 06 Dec 2017 11:20 am

Re: Weird Fuel Problem
next time try the Berryman B-12 that Busted_PT raves about. they sell it all over. it works, and is CHEAP

rambojoe 06 Dec 2017 04:26 pm

Re: Weird Fuel Problem
I religiously use 87 oct but winter gas sucks! (they mix it with that ethanol crap and other "stuff") our mpg nose dives unless we use 89... come summer ill go back to 87.

also when our spark plug wells filled with oil it took at least 4 times of cleaning to get all the oil out of the boot- I think you are on track. when there was any (read- ANY!) liquid up in the boot it would arc to the block. also make the engine idle like crap. p.s. chem tool b12 berrymans is all ive ever used because its the only cleaner that is nice to orings and viton. love it!

KalebSikora 06 Dec 2017 10:02 pm

Re: Weird Fuel Problem
I appreciate all the feedback. In terms of the gas I use it is generally Chevron with Techron inside of it. The cleaner I actually used happened to be Techron. I'll fill it with Shell and use that Berryman B-12 stuff. I hope it all works out because I would hate for it to be something more.. Involved.

rambojoe 08 Dec 2017 04:02 pm

Re: Weird Fuel Problem
don't drink the chevron Kool-Aid... its all the same. :)

KalebSikora 15 Dec 2017 02:36 pm

Re: Weird Fuel Problem
After running some cleaner the MPG didn't increase and is now going down. What is the next step then?

chuzz 15 Dec 2017 02:42 pm

Re: Weird Fuel Problem
Have you done a tune-up? Spark plugs, wires, air filter and PCV valve? Give the throttle body a good cleaning?

NitroPT 15 Dec 2017 03:11 pm

Re: Weird Fuel Problem

In heads where the spark plug have tubes...when cleaning them as long as there are no lose metal parts simply spraying a carb or brake cleaner directly into the tube with the spark plug removed is an easier way of cleaning them. While I know some of you "THINK" OMFG Nitro said that have not really rebuilt many engines to know that most crap mentioned will burn and blow out the exhaust system in a couple of seconds after the engine is fired up and running. The small about crimmy dirty substances that goes into the combustion chambers will not harm any valve train parts, pistons,rings or cylinder walls.

oldthom 15 Dec 2017 03:45 pm

Re: Weird Fuel Problem
No one has mentioned the #2 or rear oxygen sensor messing with the fuel trim. It will do what ever it has to in order to protect the cat. Including make the computer tell the car to run rich. I don't know of any way to check this condition out except to put it on a shop scope. The front sensor could be faulty making the rear go rich or the cat could be faulty. To much to guess at so I would have it put on the scope. This is something to think about after you run through all the easy and cheaper stuff.

All times are GMT -5. The time now is 02:32 pm.

Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO 3.6.0 PL2 © 2011, Crawlability, Inc.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60