[BlazerPride]

I recently bought a '98 Blazer LT. Shortly thereafter, the "Service Engine Soon" light came on, so I went down to O'Reilly's and picked up an OBD II Reader. The only codes I get say misfire. I changed plug wires, and the light still comes on, if I get on the throttle. I checked the cap and rotor, and found something that looked odd, to me. The marks looked like they were way out of alignment. The repair manuals say you can't adjust the distributor. But, I can't belive there isn't some way to get the rotor to align better with the cap. Anyone have any experience with this? Or, any ideas?

Love the other ideas I've read from some of you. i.e. MAF screen removal.

Thanks, for the help.

 

[98esten]

I had the same problem with my 98. I had 2 fuel injectors that were leaking and the timing was off just a little. I turned the distributor a little bit and it did helpp a little. If you can take off the plastic intake and put the fuel lines back in and presurize the fuel system and see if you have any leaks. I am not sure what else to tell you . Also How is your cat converter it will cause misfires if it is begging to get clogged.

 

[BlazerPride]

Thanks...

for the suggestions. I just recently bought a set crow's feet wrenches, so I could loosen the distributor hold down bolt. Haven't tried turning it, yet. But, I will soon.

I'm, definitely, going to check your ideas, also.

Thanks, again.:bowdown:

 

[Wicked X]

98esten. How did you check the timming? Where did you get the specs from?

 

[98esten]

a friend of mine has a OBD2 reader from snap-on tools and it tells you what timing is set up it was at negative 2 running kinda crappy so i moved it a little and it cleared up. That snap on reader is like what the dealer has. I think it wa around 5000.00 dollars so not just anyone has one I guess.

 

[kropelin]

BlazerPride, after you changed the plug wires did you clear the error codes out of the computer?

 

[BlazerPride]

Yup.

The OBDII reader I bought from O'Reilly's, will clear the codes. I've done it a number of times, because the damn SES light kept coming on (multiple misfires).

What a freaking pain:bs:

Is this sufficient to clear the codes and reset the comp? Or, do I have to disco the battery, for a day and a half? Like I see you guys discussing, from time to time?

In fact, the other day, I checked the coil with an ohm meter. Coil checked fine. But, when I reconnected the battery cable, It was very hard starting. It acted like the battery was drained. It did start, and seemed to run the same as before. But, now every so often, it starts hard. In fact, ever since I bought this Blazer, it takes quite a while for the engine fire, when I turn the key. Is this normal for these engines? Or, a good indication that I have some kind of problem? Like, whatever is causing the misfire codes.:dunno:

Sorry for the length.

 

[98esten]

It could be the M.A.P. sensor (Manifold Air Pressure) It senses what the vacum pressure is in the plastic part of the manifold. If you have a vacum leak it might be causing misfires . I still say it is the injectors leaking. The injectors have O rings on them and a little plastic washer I had to replace the O rings and the plastic washers on mine and the misfires went away. If you have a propane torch you can check for vacum leaks around the TB and plastic intake by dont lite the torch just start the truck and let it run, open the valve and move the torch around if you have a leak the truck will run different. I would bet money it is the injectors.

 

[Wicked X]

check your fuel pump. seems like they go bad. alot of guys
complain about them.

 

[BlazerPride]

Fuel pump?

Could that be the whinning sound, I hear coming from underneath the truck?

I've never heard anything like that before.:wtf:

 

[Wicked X]

yes thats the winning sound. If the engine runs to lean you can get a misfire code. Check your fuel pressure at the shrader valve on the intake manifold. Should be no lower than 46 psi.

 

[Kenny Brown]

yea....you have CPI injection on that truck and the regulators tend to leak a lot...umm...it will cause an extened crank condition..and all...soo..i would definatly check that...but i don't think that is your misfire code...can you power brake and feel a miss?? And does it tell you what cylinders are missing?? did you try plugs...b/c GM has been having problems with the newer delco platinum plugs...soo..check those...You also have what is called a ditributor mdule...which controls spark.....take your rotor button off and look underneath it and see if there is a hole burnt in the middle...i have seen that a thousand times...soo..just check those thing....start simple...then work your way up to the hard stuff......i would check...like many said fuel pressure...definatly check the rotor button....to see if it is burnt underneat and all.....hope this helps
Kenny

 

[BlazerPride]

Wow!

You are just a font of knowledge.:angel:

Thanks, for all the suggestions, Kenny. :thumbup:

I'll give them a look see.:bowdown:

 

[wolfmangk]

a friend of mine has a OBD2 reader from snap-on tools and it tells you what timing is set up it was at negative 2 running kinda crappy so i moved it a little and it cleared up. That snap on reader is like what the dealer has. I think it wa around 5000.00 dollars so not just anyone has one I guess.

Yeah I got a few of those. I used one to prop up a coffee table, and to charge the batteries on my cell phone, and the other one I turned into a low amperage AC only arc welder. The third one I took the wires and stuff out and used it for a clothes hamper. The wires I made rope out of to hang my wind chime. The circuits and parts I buried next to my house to keep the lightning from hitting my TV antenna.