SR Problem (Searched)

[soulessphoto]

Yo, I don't post here that much because I basically just come in and properly use the search button. Unfortunately I searched a lot and could not find a similar problem to this.
Here are the details:
90 Coupe.
Redtop SR.
Stock Boost, Stock Turbo, Stock ECU.
Motor has good compression.

Problems starts when it hits boost. The engine will rev to w/e RPM as long as it's at vacuum, once it hits boost (around 5psi), it just hits a wall. It falls flat on its ***. At first glance we thought it was a boost leak, the vehicle originally had an EBAY bov, I changed that to a Greddy TypeR. Originally it had some sloppy *** turbo inlet pipe which sat the MAF too close to the turbo, changed that. I had the harness redone completely thinking it was some screwed wiring by the previous owner.

Injectors work, Coils work, Timing should be good. But if timing was the culprit of this problem, the car would basically break up at a certain RPM and then rev up till redline, basically when it hits this "wall", it just stops. Only option is to let off.

Only other option is the ECU or maybe the CAS. I'm wondering if anyone has experienced a problem like this before. Motor turns on fine, idles perfect, doesn't overheat....nothing. Just this one problem.

I checked the codes.
First it threw at 12. Which is the MAF, that was before I re-did the harness though, haven't checked again. The second code it threw though was a 55. Which is "No Malfunction". Now, this is in theory, if the MAF wiring was fawked (which it was) then maybe the ECU would first throw at 12 then a 55...
Now, again I haven't checked the codes since re-doing the harness and I am getting another MAF tomorrow...

[Monooxide]

Check plugs, my car did the same exact thing just at 7-8 PSI.

One of the plugs basically had double the gap.

Good luck.

[soulessphoto]

^So basically your car idled fine, turned on fine, revved up perfect to any RPM as long as it's in vacuum. But at 7-8 psi it would just die?? The spark plugs caused that???

Thanks for your input btw.

[Monooxide]

Yep drove perfectly fine everywhere except when it built up to that boost.

Felt like a brick wall when it happened too.

[soulessphoto]

^Ooooffff same shit that's happening to mine. That's number 1 on my list for tomorrow. Thank you sir!

Basically what I have on the car are the Iridium BKR7ES plugs, which I did not gap at all because they already come "pre-gapped". I should have double checked either way, which I will do tomorrow.

[ford_o]

my car seems to be doing the same as yours im all stock as well! im goona check my plugs tomorrow!

[mikez97]

that plug is 2 steps colder that might be your problem.

[finesses240]

that plug is 2 steps colder that might be your problem.

I run all my sr's with the same plugs no problem yet.

[DirtyS14]

My car was doing the same type of thing. The plugs i had were 5 heat range.. basically too hot for the SR.

Replaced them with 7- range plugs... BPR7ES I believe and it solved the problem.

Can you rev all the way up if you stay out of boost?

[fliprayzin240sx]

Yah, just make sure you gap it to .030. Also, Id still double check the timing.

[soulessphoto]

My car was doing the same type of thing. The plugs i had were 5 heat range.. basically too hot for the SR.

Replaced them with 7- range plugs... BPR7ES I believe and it solved the problem.

Can you rev all the way up if you stay out of boost?
Yeah I rev all the way up as long as it's not boosting. I'm gonna check my plugs now and the ecu codes too, if any.

[soulessphoto]

Checked plugs. Fixed gap to .030, re-checked ECU codes "55" No malfunction.
Same Problem :(:(:(

I'm gonna get another MAF in a while, and see if maybe that's the problem. Other than that....I'm trumped. And I'm really trying NOT to take it to a shop....but if it's not that MAF, I'm not gonna have a choice. Damn.

[Monooxide]

Check for Boost leaks.

[soulessphoto]

^ I checked for boost leaks, and I don't have any.

There's one more thing that I just overlooked because I figured that wasn't going to be the problem, but the fuel pump that came with this car is extremely loud, supposedly it's a Walboro, but I've talked to people who have the same pump and they tell me it's not loud at all.

I have nothing to loose, I guess I'll just buy another walboro and see if maybe that's the problem.

[Monooxide]

Check for a leak on the intake to the MAFS, that caused my car to do something far worse than my spark plug issue.

My Walbro isn't loud at all.

[deukalionS14]

Somebody correct me if i'm wrong but i thought that if the MAFS was fucked then it would even be abe to drive properly right?

So, if it's a problem with building boost then it would mainly be a leak or ignition issue correct?

Also, I have a walbro pump too and i can hear it but it's not like my homie's Skyline fuel pump back in the day that was annoyingly loud in his stripped 180.

[handinpants]

Would a bad maf cause the car to run super rich?

[KiLLeR2001]

Sounds like a spark issue. Have you checked all your coils? Is the coilpack harness grounded properly? Are all your grounds tight and secure on bare metal with good connections?