sr20det missing in high rpm range

[240sxproblems]

I have an sr20det that is missing in the high rpm range. It usually starts about 4500 and randomly all the way to redline. The problem seems to be worse in second gear, and started today when I changed from the stock ka fuel pump to a walbro 255. My wideband is showing way to rich when the missing takes place. I checked all of my plugs and coil packs and they are fine.

[S13FASTBACKSR]

it happened right after you changed the fuel pump? you mustve not hooked it up correctly..go back and double check everything..anything that you werent sure about?

[SlowS13Silvia]

if its running rich its not getting enough air. so itsounds like a boost leak check all your couplers for tears while your at it.

[IanS]

do you have an aftermarket FPR if you are using stock this may be the problem

[IanS]

funny thing, my redtop started doing this tonight, grrrr, I checked my plugs, maf, timing, and got some octane booster. everything is as it should be, tomorow at work Im gonna recheck fuel pressure, and build a boost leak tester, anyone have any other ideas.

[S13FASTBACKSR]

check your tps and coilpack voltage too..also your injectors may be crappin out at higher rpm range just a thought..any symptoms at idle such as bad idle or richness?

[IanS]

check your tps and coilpack voltage too..also your injectors may be crappin out at higher rpm range just a thought..any symptoms at idle such as bad idle or richness?

she idles perfect, runs and drives perfect, but when I go WOT and it gets to full boost it starts to miss, if I hit if from 3000 in second or third (havnt tried fourth or fifth) it will miss 2 maby three times befor I have to shift.

oh, and it does it at stock PSI and at 11

[S13FASTBACKSR]

you said you checked your maf but did you clean it? its possible that its dirty..use a can of electronic cleaner it comes in a can like wd-40 you spray it on to clean it dont wipe..also check all those other things

[IanS]

you said you checked your maf but did you clean it? its possible that its dirty..use a can of electronic cleaner it comes in a can like wd-40 you spray it on to clean it dont wipe..also check all those other things

no I didnt clean it this time, I just checked to make sure it didnt have fuzzys clinging to it like last time.

[Blown240sx]

SOunds like you need a FPR and SAFC. I had the same problems with my Redtop when it was stock. Hooked up a SAFC II and thinned out the fuel and wala fixed.

[IanS]

Ive had this motor for over 2 years, more than 40,000 miles, and its only started doing this recently

[240sxConvert]

Check your plugs and regap them and see if it still does it...You can't forget the simple things...

[S13FASTBACKSR]

he said he already checked his plugs though..but yes a fpr will cause this problem as well but this is how i look at it...when you maf, fpr, o2 sensor and tps (in most cases) and in some cases your ecu go bad you will run abnormally rich..so if i am not running rich then i can pretty much rule out that those things are not the culprit..however i will never completely 100% overlook them...just a thought

[IanS]

Im not even 100% positive too rich is the prob, I did check the gap on the plugs (NGK irridium) and it was fine, and they were not black, Im beggining to think I may have an IC coupler thats starting to fail, has anyone had experiance with the couplers that come with the Greddy VSPL, the one where the turbo connects to the hotpipe went last fall and Im thinking they might all be starting to go bad

[S13FASTBACKSR]

well the cutting out/ missing could be leanness too which could be injectors or ecu or other things as well..i dont think the couplers will go bad that soon or for a very long time for that matter..just depends on if its tight enough or not..you should definately build a boost leak tester

[IanS]

yah, I had one for a while when I first did the swap but I borrowed it to somone and he lost it, Im pretty sure its not too lean, it feels more like a rich condition, and I started checking my couplers, and the one between the hotpipe and the IC has a bunch of little cracks in it

[S13FASTBACKSR]

hmmm... are some of the cracks in between the clamps? or past them to where they dont matter?

[240sxproblems]

I am runnning an s14 dohc maf. I know it is not supose to work, but it worked fine when I was running a stock fuel pump. I also have a wideband so I know that it is running rich and not lean. I believe that it is the maf, but I am not really worried about it because I just got a power fc dejetro. thanks for the help. Feel free to thead jack, I really don't care that much. It might help someone else out.

[IanS]

hmmm... are some of the cracks in between the clamps? or past them to where they dont matter?

there are cracks both between and outside the clamps, just little ones, and I ohmed out the injectors today and they are fine, I also had a friend follow me while I went through second and third gear he said he could see little puffs of black smoke when it would miss so its deffinetly rich.

[S13FASTBACKSR]

i think the easiest thing for you to do right now would be to check your ecu for codes

[IanS]

wouldnt I have a check engine light if the ECU was throwing codes? although now that I think about it, Ive havnt seen my check engine light since I did the swap, other than when I start the car

[S13FASTBACKSR]

your check engine light does the same blink sequences as the ecu's l.e.d. does..you can look at one or the other..but the check engine light isnt going to blink until you go through the proper steps to check for codes

[FSUDrifter]

if your ignition coils aren't grounded well then that could be the problem. mine were bad. i'm about to go throw them on and see if that definitively fixes the problem... my symptoms were the same as yours

[IanS]

weird, I always figured that it would turn one when a code was thrown like any other OBD 1 system

[S13FASTBACKSR]

no what i mean is when checking the ecu for codes the check engine light will flash in the same exact sequence as the ecu's l.e.d. would...meaning you can look at either the l.e.d. or the check engine light once you have put the ecu in the code reader mode..your check engine light could come on when you have an ecu code stored but even if it doesnt come on i would check anyways because mine didnt when i had a code stored

[IanS]

no what i mean is when checking the ecu for codes the check engine light will flash in the same exact sequence as the ecu's l.e.d. would...meaning you can look at either the l.e.d. or the check engine light once you have put the ecu in the code reader mode..your check engine light could come on when you have an ecu code stored but even if it doesnt come on i would check anyways because mine didnt when i had a code stored

yah I understood what you meant, Im gonna go check for codes right now, once Im done eating.