1G 1g Wont Rev past 3500rpm???

[1ggsx604]

Ive searched and searched and cant figure this out. No one has found a solution it seems like.

My wife gave me a 1991 Laser that has been sitting in a field for 7 years that they had.

Well i got it and the car is in good shape. Some stole the turbo and half the exhaust.

I buy a 14b for the car put it on and go to start it after cleaning everything. And Nothing

Well Find out the fuel pump is bad.

I Bought a Walbro 190, New Fuel Filter, New PCV valve, Boost Leak Test, Timing dead on, TPS dead on, CAS dead on, EGR valve and vacuum line deleted, New Plugs and Wires, ECU tested (good).

And i still cant figure it out.

The car will start and idle fine. Has a slight miss but dosnt die. But when you rev it, it will rev to about 3000-4000 and start cutting out like a rev limiter and blows black smoke (runnin rich but has the 390 injectors???)

I cant figure this out, Did a compression test and it came out as 142-151-140-140.

I dont have a aftermarket boost gauge (gettin one soon) but the stock gauge goes up to 7 lbs when it does this.

Can someone help, im running out on what to do and ive been to 3 forums.

Thank you and sorry for the long post.

 

[1ggsx604]

Sorry

Ecu was checkef and good. Tryed two different ones and same thing.

Maf was changed also and again same thing.

Car is an auto.

New gaskets on manifold, turbo, o2 housing.

The car starts perfect and no problem. Has alittle miss every couple seconds?

Like i said, i know its inaccurate but this is ### it shows.

Ill start the car and the gauge reads lean. Even after a min or two of warm up. If i hold my foot on the gas for like 30 secs the gauge will start movin up slowly to optimal, when its in the middle i can rev it freely and no problem. So idk. But if i just start it and let it warm up the car cuts out at 3500.

New ngk plugs gapped right, walbro 190, 14b turbo, 390 takin from runnin car, new pcv valve, egr delete, vacuum delete, new wires, checked multiple times and right order. Cas flipped multiple times and same thing. No cel but does work. Car ideals around -20 and when reved it goes to 5 psi.

 

[AlaskanDsm]

I am not sure about this, as I would like to ask for other people's opinion on this as well but what if the cat in the exhaust is clogged... could that be causing some of these issues? I know that there should never be a buildup of boost when not in gear.

to the OP, is the PCV valve one from autozone or checker,shucks, oreily or did you get a Mistu OEM one? If it is anything other than an OEM Mitsu one, they tend to not work correctly on our cars if at all.

 

[viprez586]

I am not sure about this, as I would like to ask for other people's opinion on this as well but what if the cat in the exhaust is clogged... could that be causing some of these issues? I know that there should never be a buildup of boost when not in gear.

to the OP, is the PCV valve one from autozone or checker,shucks, oreily or did you get a Mistu OEM one? If it is anything other than an OEM Mitsu one, they tend to not work correctly on our cars if at all.

That is another thing I'd look into. If you don't want to buy a whole exhaust system or highflow cat, soak all the bolts in PB blaster for a day or so, coating it every few hours. Remove the catalytic converter, get a long pipe or pry bar and start smacking out all the honeycomb material.
You can build a very small amount of boost free revving but 5psi is like stutterbox.


Thank you, First lets forget about the narrowband, do you have a logger? Friend with a logger?

Food for thought here: At work when I see CATs dying - on a particular LX470 when revved - on deaccel the rpms "Flutter" or "hop". CEL is on for catalyst efficiency.

My brother has a dying cat on his focus, big lack of power, however CEL is on.

Since your 1G you wont get P0420 codes/catalyst efficiency. So even if it isn't your CAT your gaining a little bit of power removing it. Hope you don't have to emissions test though.

See if the problem persists with MAF disconnected.

 

[1ggsx604]

Car is running off stock downpipe only. Someone stole the cat and turbo. So thats why i bought a 14b. I ran a 3" downpipe by itself on my gsx and never one problem. Imma buy a logger but would rather spend on parts. The pcv came from oriellys, but a guy i know who has a 600+ hp talon and his room mate with a 10.5 sec talon both use orielly parts and never one problem.

But no emissions here but im not drivin the car right now, just tryin to figure it out.

 

[viprez586]

The logger will help pin point what is going on. Post back once you get a logger.

Something fishy is definitely going on here.

Pull off your timing cover and verify your timing marks are set correctly. I could only imagine the condition that belt is in after sitting for 7 years of 4 season changes.

 

[1ggsx604]

Where do i get a logger,

The belt is new and everything timed and checked multiple times.

 

[400hp93talon]

Check the closed throttle switch and see if it is sticking to the closed position. Its on the top left side of the throttle body when your standing at the passenger side fender. I had a problem like this a while back and I think it was part of the problem.

 

[Shadow21]

Hey man i have a cable that hooks up to the ecu and has a db9 connector at the end. I used it once for my 90 GS but ive since gotten rid of the car. If your laptop doesnt have a db9 connector you can buy a keyspan. This is the cable that doesnt need to be unplugged from the car once youre done with it. I paid 30 shipped for it. 20 shipped sound good to you? If youre interested send me a PM.

 

[viprez586]

digital tuning, inc.

Or ebay has some decent packages.

PDA: I'd recommend a color screen, easier to view logs.
Rechargeable is nice but seems like battery life blows.
Removal-able batteries seem to last a little longer, but if you don't switch them fast enough you loose all the memory.

 

[1ggsx604]

I picked up the software and cable for $20 to hook to my laptop. So we'll see how everything goes once i start logging.

 

[TenSecondSTi]

That odd. Hey I have a ECU to go with the 390's you have just has one leaking cap but it's really clean. And I have like new 390's I can send you pictures if your interested. all for a 90. Came off my colt gt I got a 90 2.0 ecu to install my 450's and some other stuff... Still need a 14b or 16g turbo before i turn the boost up and tune using my safc2

Also I have the Palm logger and it works great it is very had to see though on that small screen. I'm going to load the software into my lap top soon and sell the logger if anyone want one. I paid 90 for it I'd take 60 without cable and software disc i can copy for you.

 

[viprez586]

Pretty sure he should figure out why his car isn't running right before he continues to modify/throw parts at it.

 

[TenSecondSTi]

Pretty sure he should figure out why his car isn't running right before he continues to modify/throw parts at it.

Well It could be a bad ECU. In witch case I can help him out. But one should Diagnose and find the issue first I agree. But on these car's it's not easy. Remove the ECU and cover and inspect for a burnt board. But the eye can only see so much most will need to check the electronics to get a full diagnostic.

 

[1ggsx604]

Im running out of parts to add. Lol.

And if u read again. Ecu was checked good. Even tryed out of friends running car along with maf.

No check engine light.

And i just bought a new set of 390s also. Neithet helped car.

I got a logger comin so we'll see what the car is doin.

 

[TSi Kid]

this is exactely how my car is running now and we're trying to find out the problem
i'll keep you updated
how is your idle?

 

[1ggsx604]

Mine starts and idles fine. But just the reving problem. If u find your problem let me know. And ill post my log once i get it.

 

[EGLTAWLN]

90's have a different computer than the 91 and up.
two wires are different, one is an airflow wire.
you can make the 91+ work on a 90, you just have to swap those two pins.
nobody mentioned it yet. maybe it's that? can you tell if your computer is stock or tamperd with? maybe someone had a problem with the 90 comp and threw in a 91+ and it never worked right so it sat in a field. or maybe you have n/a cams... just putting ideas out there.

 

[1ggsx604]

Cars 91. Sorry its a 91 rst. I got rid of my gsx.

Doubt would be n/t cams.

How can i tell if the comps right. Nothin was tampered with.

 

[TSi Kid]

i'm guna try my timing and spark plugs tommorow
i'll let you know bro

 

[1ggsx604]

Me and a buddy just retimed mine to make sure and i changed plugs. But didnt help. So im lost. Lol

 

[habitatguy187]

How can i tell if the comps right. Nothin was tampered with.

ECU Part Numbers for DSMs

 

[PROJECT_90_GSX]

I have this same problem, has anyone figured this out yet?????Also mine has a clicking from the bottom of the TB, and the stock boost/vac gauge will jump to "0" atherwise it wont start!?? had to diss-re-connect the batt a couple of times.........

 

[1ggsx604]

I looked today and its the right ecu.

Im waitin on my logger so we'll see ### it shows

Mines he same. Sounds like the isc wont stop clicking. But my aftermarket boost gauge stays at -18 to -20 at all times till i give it gas. Once it starts cuttin out the boost gauge is around 5 psi and you can hear the turbo spooolin and then the blow off valve blow off.

Idk what is wrong. It has me confused.

Even if i put it in gear and try to take off it wont move. Just starts kickin like crazy.

 

[PROJECT_90_GSX]

Oh ya and the after market boost gauge does the same,its the stock that shows boost at iddle, aftermarket that shows vac.....???

 

[JEFFREYCASTGSX]

Oh ya and the after market boost gauge does the same,its the stock that shows boost at iddle, aftermarket that shows vac.....???

Hmmm that's weird, the stock boost gauge reads airflow and if it show boost then a lot of air should be going through the maf, which there isnt. Though you already swapped maf's, I would try disconnecting the maf and see IF it changes, someone also mentioned swapping pins. Seeing how old and what the car did during its life I wouldnt be surprised to find open in wires (like maf).