Hello, Im hoping someone can help i Have a 98 type r and it hesitates-misfires from cold between 1000 and 3000 rpm. Ive disconnected the 02 sensor and it still does it. Ive changed the 02 sensor twice (bosch) , the maf once, fitted plugs a few times ( NGK 7Bs) and again tonight still the same. Also i get a miss on idle every now and then which you can here popping through the exhaust mainly when warm. Ive just bought an apexi pfc and i want to get it mapped but i would like to sort this fault out beforehand just incase it may cause a problem. The car is standard over than a decat exhaust system and a green panel filter.
Cheers

James

 

coil packs in good condition?

 

Have you had timing belt replaced or pulleys changed, get your timing checked , Disconnecting your 02 will cause more problems and remap is required after decat so get that sorted then go from there.

 

Ive got the single coil pack,No signs of arcing, Is there a way to test it?
Cheers

James

 

Have you always fitted the same plugs? Are they too hard? What gap? Have you tried closing it up a bit?

 

Cheers for the reply Stewby/nixxon. the belt was changed before i got the car over 3 years ago and ive checked the timing and all was ok. I only disconnected the 02 sensor as a test to try and rule it out.

Ive tried various plugs NGK6Bs, NGK7BS and NGK7G now back to 7Bs gapped to .65 mm

Cheers
James

 

Does anybody know what the manifold vaccum and the fuel pressure should be please.
cheers
james

 

With the vacuum hose off of the FPR, then it should be at 3bar/44psi. Drops to about 2.6bar when connected.

 

Cheers for that joz8968, ive just got to get a pressure gauge to test it with. I did a manifold vacuum test today and vacuum was good between 17 and 21 in hg which i think is normal but the gauge started to flicker. i did a search on readings and says that the plug gap is too small i set them to 0.65mm and previously 0.7mm, what does everyone else set them to.

Cheers
James

 

If you have new coilpacks, or know them to be working perfectly, then 0.7mm

If you're unsure, then your 0.65mm should be fine. Could go to 0.6mm to be sure though.