Hi guys,

it's the time of the year I need your advice :P

I got a very good deal on Bosch Platinum +4 plugs (its not like I really wanted them but I got them brand new for cheap and it was really time for a change) and put them in yesterday. Made a test start with the engine, it ran smooth, sounded healthy. Since my transmission is making trouble again I was out for a test drive later that day to see if the trans would be alright again, and when I started the car I noticed really annoying and heavy vibrations. Not the whole car was shaking, just vibrations all over. While I was doing the test run I also noticed the car was sounding different. Unhealthy. So I turned back home and double checked the ingition wires, maybe I connected one or more wrong, but they're all correct. Went out again, did some kickdowns and had heavy hestitations and even more vibrations.
I let it sit then, and tried it again this morning. Still vibrations, still the strange sound but no more hestitation. Runs good, actually
I want to take out a plug later today to see what's it looking like and I want to check all cylinders for spark and fuel. Maybe I can save the work if one of you has had the same experiences and knows why this happens - is my Transy hating the new plugs and I should get some Delcos? Can plugs cause such symptoms?

Thanks for any hints folks..

 

bosch seems to have a bad reputation from other users on ehre, but i've enver used them. if not the plugs then you have a gap wrong or a wire, or two, crossed

 

Meanwhile I TRIPLE-checked the wires, they're correctly connected!
Does one infunctional cylinder affect the engine in sound and performance like this?

 

Is the car shaking when your in low RPM's in early gears (not first, but once u shift into second and the beginning of third) and then accelrate from those low RPM's?

 

Lets say in low RPMs and with load in low RPMs (like uphill in Overdrive) it's at the worst, so in a certain sense yes!

 

The plugs are crap. Here is the solution.

Remove plugs
Place in trash
Buy new AC delco plugs
Gap plugs .035 and Install
Drink beer now that car runs normal


Bosche +4 plugs are junk in these cars. I fouled out two sets in less than 2k miles. They work great in other cars with different ignitions but HEI systems cannot tollerate them.

 

Unfortunately cursing is not allowed here, otherwise I'd do it now.
Okay, so that's the 45TS plugs not the 43, right? Because I got two sets of plugs when I bought another F-Body and both sets are 43TS.. Can I use those too? Yeah I know use the search.
Now the final question, can I drive 500 miles with those plugs in or will the engine be harmed? I'm moving in 12 days and the way to my new home is 800 kilometres...

 

I used the platinums about 2 years ago when I still had the 305 HO in the car. Engine was rebuilt from the ground up and the CCC system worked well. The plugs that came out were AC Delcos in normal shape.

I put the platinums in, and within 2K they had kindof a carbon buildup and occasionally they would misfire. I have no idea why, but I'd never buy them again....

You can run them for awhile...I don't think it'll hurt anything. But my gas milage and performance got gradually worse...until I got rid of those "designer" plugs and put normal AC Delcos back in.

 

For me you have a spark plug wire cracked into the rubber connector, then check for this, put ACDelco rapidfire plugs & drink the beer recommended (very important).

 

Denis, as I posted before I triple checked the wires for correct connection, this includes checking them for cracks
I had two wires with cracks and replaced them with 7mm wires, so everything is okay in this part.

I also came across the thought that maybe the Bosch plugs bring out what my car really has to give - the acceleration is really heavy and I do think it runs better now, albeit the vibrations... The car in particular is having an aftermarket cam which made its idle rough from the beginning. I don't know - can plugs 'tame' a car like this?

 

Hmmm,

Ich think das "albeit" isst eine deutsche word.

 

Hahaha That was a surprise. And no, 'albeit' is no German word. I checked back with my dictionary and found the word within several postings on this board

 

Don't blow big money on fancy designer-booteek spark plugs. SBCs don't need 'em. Just go down to Wally's World and get a set of Autolites, they're cheap and work well. I think they sell platinum AP26 plugs for about a buck each. That's what I have in my LB9 and it runs fine.

I also have a set of Rapidfires ready to go when the Autolites get tired.

 

i have had no luck with the platinum 2's, it gave me a bit of a miss and vibrations because of it. I just threw in some 99c champion plugs and it ran 100 times better.

 

If it says bosch on it, chuck 'em. Theyre bad plugs all around and those screw off terminals only make things worse, the threads degrade and increase the resistance of the plug, causing weak spark, poor combustion, and misfires. I only use plugs with solid terminals that cant fall off or block the spark.

 

When I had to change plugs, I checked on this forum, asked people, and decided to stick with what I've known for years to not be considered "ultra high performance super extra terrestial material" plugs but went for the reliable ones, in my case copper Champion.

Do as people say, go for AC Delco, if not go for reliable ones, old school NKG and Champion.

 

put in my 92 305tbi and it ran HORRIBLE.. was ok when on throtle but Verry bad at idle.. my wife was not real good at shifting, and she would kill the car even when she would get on the freeway accelerating.. and i had to keeep one foot taping the gass wen at a stop light to not let the motor die, it got worse and worse till i swaped out generic platnum plugs.... i think autolite cheepes. have used bosh 4x in my 78 F250, and the work great but i have a msg ignition system, and i have a friend with a 5.7 dodge dacoda, and the 4x work great in that vehice also, but he has a complete msd also. I think the plugs are good, but onley if you have the spark voltage to make a substantal spark. Like ppl with out cars using rapidfires with a .50 gap rather than .30, more power can bridge a biger gap = more complete ignition =more hp. Long story short. they are crizap with stock ignition

 

Thanks for all the ppstings guys.
I spent half of the night surfing through the board and search for plug infos. So many people are having bad experiences with them Bosch things - but I was lucky to find some, there are only a handful part stores in Germany :P
I'll change the plugs to Delco's when I have moved - now the car has to cope with them until then.

Thanks again guys

 

Id say it would be worth it to have a set of delcos shipped out to you via the mail. The money saved on gas could far exceed the money spent on shipping. The bosch plugs really are that bad. Cant gap the +4's either. If you really truely cant get a standard type plug (any comprable plug w/ a solid terminal that can be gapped will likely work) then get the standard bosch plugs. At least they can be gapped.

 

Another vote for the Delco's.
I had this exact same thread about a year ago.
Put the Bosch's in, stalling, stuttering, the whole job.
The next morning it ran fine.
Later that night, it was bad again.

Pulled those guys out, and put in the Delco's, problems solved.

I can't tell you why, but I can tell you it's true.