SR20 cuts out.... need some advice!

[Purestock240]

I bought another 240, its a clean shell, hatchback with a red top in it. when i was picking it up the guy told me it needs a new MAF and thats why it is running poor. I unplugged the MAF and it made a difference. so im assuming the MAF is good? it will rev up but is barely driveable as it bogs under and decent load. I've been around 240s for years but never had an SR so im pretty new to them. heres a video of how it runs, sorry for the stupid tall video and shitty sound but you can kind of see and hear whats going on.

so any ideas on what to do?

SR20det red top running rough - YouTube

[Purestock240]

It has an aftermarket waste gate aswell, (although I don't see that making a difference)

[godsmack]

Clean the maf and check the IACV. Start ruling out the electronics. I don't think that you have a boost leak but go over the vacuum lines. And also make sure that your intake manifold isn't leaking by spraying carb cleaner or brake cleaner around the gaskets while it's idling. I noticed that you don't have the bov recirculated and that will cause similar symptoms but mine was never that bad so it's probably a combination of a couple small things.

[!Zar!]

Check all vaccume lines.

Also check your spark plugs.

And if the prior owner said the maf is bad, it wouldn't hurt to test a different one to see the result.

[Purestock240]

Originally Posted by godsmack

Clean the maf and check the IACV. Start ruling out the electronics. I don't think that you have a boost leak but go over the vacuum lines. And also make sure that your intake manifold isn't leaking by spraying carb cleaner or brake cleaner around the gaskets while it's idling. I noticed that you don't have the bov recirculated and that will cause similar symptoms but mine was never that bad so it's probably a combination of a couple small things.

thanks I will give those a try.

Originally Posted by !Zar!

Check all vaccume lines.

Also check your spark plugs.

And if the prior owner said the maf is bad, it wouldn't hurt to test a different one to see the result.

I pulled the plugs and they where good, I have a SOHC MAF handy and have read that it will work fine plug and play?

The last owner didnt really have a clue. it was basically a "thats what a bad MAF sounds like"

thanks guys

[Sileighty_85]

Seems like Boost/Vac leak.

I noticed your BOV is not opening (it should have with how you were reving the engine, unless the BOV is adjustable and set really tight) which means there is not a strong enough Vac to pull the BOV open IE: boost/Vac leak

[Purestock240]

I looked for a vacuum leak and couldnt find anything, the only two vacuum lines i can even see on the car is one for the FPR and one for the wastegate.

there is no BOV on the car

[Purestock240]

I pulled the MAF and the intake pipe off, the car had an s14 twin cam MAF on it and a crack in the plastic pipe between the MAF and the turbo, i'll be wiring a ka24e maf into it today. hopefully that fixes the ignition problems.

also I didn't want to start a new thread for this. But I was in contact with the previous owner and asked what else had been done to the car. He said it has aftermarket cams in it and waste gate. I couldn't find any markings on the cam other than the ones pictured. anyone know if these are stock or what they are?

EDIT: just realized my pictures are blurry, I'll try to get clear ones later

[godsmack]

Well the crack between the MAF and turbo is a problem. You're introducing more air in after the MAF reads what's going in.

[Purestock240]

got the maf issue fixed. wired in a ka maf. now it just has a sputter at low rpm if i go WOT and when its held at a continuous rpm at higher rpm. it also blows a bit of black smoke

[StryfeS13]

That's a pretty dirty cylinder head. If the cams are aftermarket I'm pretty sure they should have some kind of stamping or mark on them.

Did you wire the maf correctly? It sounds like it's running rich by your last post.

[Purestock240]

Yea I matched up wires with the single cam pig tail.
It makes power now doesn't cut out above around 2k. Took it for a rip up the driveway to make sure its fine under load and it was good. It's just getting way touch fuel now. Almost like its flooding out at WOT at low rpm

[e5s4y]

what turbo do you have? i have a redtop with an s15 t28, and when i had a single cam maf, I would be maxing it out by 2k at wot, it just couldnt keep up, so it would feel like it would bog down until about 5k rpms and then BOOM, it shot off. Max the maf, then the ecu starts dumping fuel (went straight to 10 on my wideband, but if it could have went lower im sure it would have) and car felt like shit. But above 5k it was awesome, haha

[steve shadows]

Originally Posted by Purestock240

got the maf issue fixed. wired in a ka maf. now it just has a sputter at low rpm if i go WOT and when its held at a continuous rpm at higher rpm. it also blows a bit of black smoke

What ECU? What are the shape of the injectors? Run some cleaner through them too. Sounds like shit injector come on under low fuel pressure could be a possibility too. Did you swap the plugs yet? get new ones. If you're running bigger cams with stock injectors you're going to have wacky stuff like this happening. Time for used pfc l jetro and some 550s IMO. Or you can figure out the cam size if they are only like 255 or something on duration then you could get away with just bumping up the fuel pressure a little bit.

Also what's the TPS voltage look like? Is the TPS working correctly?

What's your base timing? Did you check this with a timing light per FSM?

All critical things you also need to be checking.

All these damn cars come into the dyno or even when I help people remotely have timing that is way off and all of sudden they have 50-75 more hp and are so happy and thankful. Basic basic basics first.