98 s70 GLT Misfire

samtron6 · Post by **samtron6** » 25 Feb 2016, 09:39

i will check the wires again maybe thier not making good contact... um the code on side of cam cover says B5254T

Post by **misha** » 25 Feb 2016, 09:57

It's lpt.
I think that spark plugs are wrong for that car or not properly gapped.Gap is crytical for turbo engines.

Post by **abscate** » 25 Feb 2016, 10:02

At some point, and you are past this point, you stop thinking about what you have recently done and start troubleshooting.

You start with a compression test to make sure your engine internals are in good shape.Then you go to spark. Then you go to fuel. Finally you go to timing.

The whole time, you stop looking for the 'one thing' that is causing your problem and allow that you may have multiple things wrong.

samtron6 · Post by **samtron6** » 25 Feb 2016, 10:12

yeah thats true... i think i read somewhere for this motor to gap the plugs at .026 so thats what i did i hope thats right

Post by **erikv11** » 25 Feb 2016, 10:45

erikv11 wrote:Yeah OK that 3923 Autolite plug should be fine on a 98 LPT, gapped 0.028 to 0.030. Check into Robert's intake idea too.

That plug is fine, my 98 GLT had Autolite 3923 plugs when I got the car, I eventually changed them out but they gave no problems. Open up the gap a little, check it carefully.

The first step of troubleshooting is visual inspection, especially when something new shows up immediately after working on the car. Some things to check:

- crank sensor wires and connector
- cam sensor wires and connector
- ALL vacuum lines including brake booster; check really carefully even better use starting fluid, these are a pain. I just replace them all when I get a car.
- engine grounds, there are a couple on top of the engine, did they get broken? Clean their attachments, anyway.
- test the MAF it is a free and easy test and yes it could be the cause
i- nspect the distributor cap and rotor, is the cap clean inside, is there any sign of arcing? Cap and rotor must be Bosch, no way around it.

Failed electronics in the rotor will give exactly these symptoms, have seen it several times. Unfortunately that one the only way to check is to swap in a good one.

There are a lot of possibilities you will be better off if you are systematic and actually check each thing, not say "oh I think that one is probably OK."

samtron6 · Post by **samtron6** » 25 Feb 2016, 12:57

well i regapped the plugs now only missing on cylinders 2 and 4 no more 5.. maybe i have them gapped to little everything else is fine no air leaks good compression on all 5 rotor and cap looks great

samtron6 · Post by **samtron6** » 28 Feb 2016, 08:40

well fixed misfire but now it bucks kinda like surging going down the road... and rpm coming to a stop gets to almost 300 rpms so now what lol

Post by **erikv11** » 28 Feb 2016, 08:53

Low RPMs coming to a stop is usually a vacuum leak.

Bucking and surging could be the MAF. Testing the MAF it is a free and easy. Unplug the MAF, then start the car and drive it around. If that makes the problem go away then the MAF is bad.

samtron6 · Post by **samtron6** » 28 Feb 2016, 08:54

sweet thank you sir i was about to try that will let you know ....

Post by **misha** » 28 Feb 2016, 09:04

Now you have a Maf symptoms erikv11 was mentioned in some previous post.

Disconnect it,start the car and see if it runs better.

How did you solved misfiring problem?What was the problem,gap?