ok, my car has been in the garage all winter and I just tried to get it running for the good weather. When I put it away for the winter everything was great. I start it last week and it running like s**t. Feels like a bad miss, power loss, stalls, poor ideal,bog.. So here what I have done so far. Changed the cap,rotor,plugs,wires and coil-put in a new fuel filter in last year. I have also checked my timing and fuel pressure. After all that it still runs like hell. I have no codes coming up at all. Today I was thinking it could possibly be a bad mass air sensor even though i haven't gotten a code for it. I disconnected the plug from the mass and it ran even worse so I don't think its that. So any ideas!??? lets hear them!!! thanks guys in advance

 

Maybe put an injector cleaner in the gasoline. Also ohm the injectors and see that they are above 12 ohms. Could be the gasoline has gummed up the injectors by sitting all these months.

 

check for vaccume leak my car has done that a cople of times when i stored it.

 

 

mine has just been put back on the road and now idles poorly. bout a month ago i took it out and it ran fine...now just started surging on me yesterday..but runs fine at all other rpms. just started idling bad on the way home from inspection and they didnt touch the car cuz i got a hook up and watched what they did the whole time

i wonder if its old bad gas in the injectors

 

I rule out the gasoline, If you there wasnt any type of fuel stabilizer moisture will form in the tank and water it down. Plus fuels octane level goes down after it sits.

 

i say its the gas, u have to put a fuel stabilizer in gas tanks when cars sit, it gets gummy and varnishes etc i would say that and its prob gummed ur injectors up too now

id find a place that does a MOTORVAC system, i had it done and they flush the entire system cleaning everything, pistons, cylinder walls, heads, intake etc and get all that carbon and crap out, injectors too i believe. not that much $ too and ppl have gotten like 5hp from the cleaning.

 

Put another one down for the gummed up fuel system- I just got done with this garbage myself- run some Techron through it, ohm out and leak test your injectors, fixed some of my problems this way. If your car has the "multec" injectors (90-92 I think), theyre known to be junk after a while.

 

Bad gas!!! Sta-Bil works wonders. I never encountered a problem since I started using it.

 

ok, guys I think I figured it out. It's alittle worst then bad gas I think. So after doing to the tune up and that not working I did a compression test today. #1- 130lbs #2- 135lbs #3- 60lbs #4- 135lbs #5- 60lbs then I stopped before doing 7-8. After seeing such low compression on 3-5 and seeing those two plugs wet with raw fuel I'm thinking the head gasket went between those two cylinders. What do you guys think?? Tomorrow I plan on getting a compressor and filling # 3 with air and see if the air leaks into #5 or vise versa. Really not looking forward to ripping my SuperRam off to change my head gasket. Maybe it's time to build the 406 sitting in garage. thanks

 

prolly right on. on the head gasket

 

Don't forget to pop the valve covers- it's a long shot, but busted or weak valve springs can cause bad compression too. Kinda odd the head gasket would fail just sitting there- normally it's overheating and high cylinder pressure that kills head gaskets.

One other possibility- you said the plugs were wet with fuel, and it could be that too much fuel (from something like stuck injectors) is washing down the cylinder walls, which can lower compression. Check your oil for gasoline to check this, or run the engine for a bit with those injectors unplugged, then recheck compression. Good Luck, hope it's not a head gasket!

 

yeah, I just pulled the valve cover again for another look. Everything looks good. I only have about 40 miles on the valve springs. I just changed them last Summer. I'm gonna get a compressor and fill those two cylinders and see if ones leaking into the other before I start ordering parts to build my 406

 

oh man,thats not cool man, how old were those gaskets? and are you sure thats what the problem is???

 

well i finally pulled the heads and it was the gasket between 3-5 cylinder. I think i will be ordering a set of Brodix IK200 heads. Not sure if i should also dump a LT4 hot cam in aswell??? engine has 135000 on it but it run great. what do u guys think?? I only drive the car around 2k a year. think it could handle the cam and heads??

 

I thought I had it bad when the chipmunks packed the exhaust on my car full of acorns last winter. Yeah, If you tearing it down, to replace the head gasket, and your going to want to do both; I would go ahead and put the mods in place as well. I means why not honestly it would be the best time. After all, your draining all the fluids and taking the top of the motor off. Might as well do the cam.

 

i since you have the motor down that far take it out and have the bottom redone its way better to do it know than after you put new heads and a cam in it . Half the work is done and it would benefit you in the long run