Engine bogging, on full throttle?????

[gstfire]

hey fellas, just picked up '97 Eclipse GST Spyder. with 60K. Has intake, exhaust, BOV, and APex Fuel Comp. Now the car idles fine and when accerlating slowly runs great. But they second i smash on the gas it jumps and boggs down. So i replaced the fuel filter, spark plugs thinking that could be it, but not so lucky. I tried to reset the Apex to the cars factory setting. When i pulled the old plugs they were BLACK. never seen them that bad. I've looked for a broken hose and things like that. My next option was gonna take it to a local shop and have them actually tune the car correctly with this Apex. Think that will solve my problem or any one have any other ideas? thanks fellas.

 

[kenamond]

If the previous owner put in larger injectors, you'll run pig rich with factory defaults.

Do a boost leak test. It's described 2305872103984 times on this forum, so a bit of searching will give you more than you'll ever want to read.

What plugs did you use? What gap? Should run NGK BPR6ES gapped to 0.028".

But I'd say a boost leak test should be top priority.

 

[gstfire]

yeah thats what i've been readin for the boost leak test. that somthin i could do myself? haven't found that part out yet. I'm running iriduim plugs. not sure it thats how you spell it.

 

[tonygk85]

when the last time you did a tune up with new plugs and wires

 

[gstfire]

just bought the car, so haven't done anything yet. but it was still acting up before and after the new plugs and filter. There is a Apex SAFC 2 hooked up. i talked to the guy and he said he messed with it a little i tried to follow the directions to resest it back to factory. I'm thinking its running way to much fuel or not enough while on full throttle. I dont' really know thou. I'm open for any ideas.

the guy i bought it from knows his cars as he has a supercharged 350z and a '93 RX-7. i'm gonna try a few more things and then its goin back to him t o fix!

 

[forcefed 95]

well if your plugs are black your def. running rich and not lean. casue at wot if you were to lean out you would be able to hear it and plus your plugs would be whiter than snow. Im def gonna have to say a boost leak possibly a little 1 but none the less enuff for you to not be getting the metered air that it thinks its getting.

 

[blazebolt]

I'd say boost leak test, change your sparkplug cables, and get it tuned. If your cables have never been changed, it could cause your bogging problem. I've had the same symptoms you have now and the cables were the culprit.

 

[gstfire]

there are aftermarket wires on there already. Checking the hoses yesterday i found i guess the "PCV" hose, where it goes into the valve cover on the back right side. I was checking the clamps and i seen some had tried to JB weld it. like they tightened the bolt to much and cracked the valve cover. so i went and got a new one from a junk yard and replaced it but its still bogging, doesn't seem as bad thou. and there is a oil seperator (like a littlre air filter) on the side of the valve cover. should i replace that and just run a hose from the intake there? I've been searching all over for these pieces to make a boost leak tester, haven't had any luck yet thou. An there is the APEX fuel comp in there. now if the computer was pushing to much or to less fuel would that be causing it to. i'm tryin to get into a shop to where they can professional tune it right.

 

[gsxeclipse97]

you may also want to consider the o2 sensor. My car was doing something like that and i replaced it and car runs great. well at least while it was running it ran great but its down again. but I'd start with the boost leak test and if all is good there try the o2 sensor, and a good tune

 

[kenamond]

If you're open to anything and expect to tune and wrench on this car, I'd recommend a logger. www.pocketlogger.com is a common option, and you'd have to buy a PDA (I like my PalmIIIc). That will give you the ability to tune the SAFC. If you can find out FOR SURE what injectors are on the car, you should be able to dial in the SAFC to some standard initial guesses. With that and a logger, you can tune the car yourself.

Ask the guy about the O2 sensor. They're about $50 new from www.oxygensensor.com, but I'd guess that you're running rich due to the SAFC settings.

Boost leak test requires a tester (easy to make yourself and costs $10 or so) and a compressed air source (either an air compressor with a regulator or a portable compressed air tank). Helps to have an aftermarket boost gauge so that you can see how much you're pressurizing the intake. Look at the 2g turbo stage 0 mods page on this site for more info on boost leak testing. Basic construction is a rubber coupler hose that fits your turbo compressor inlet, a PVC endcap that fits inside that hose, two hose clamps that fit around the hose, and a tire valve. Drill a hole in the middle of the PVC endcap big enough for the valve, bolt the valve inside the PVC endcap with nuts, metal washers, and rubber washers (to seal any holes between the valve and endcap). Clamp the hose to the PVC endcap with some RTV. Let dry.

To boost leak test: Disconnect the intake pipe from the turbo inlet and clamp the boost leak tester to the turbo in its place. Pressurize to 5psi above what boost you're running (requires an aftermarket boost gauge) and see how well the intake holds that pressure. If it leaks down faster than 1psi every few seconds, you have leaks. You can hear big leaks. A spray bottle full of soapy water sprayed on various couplers, gaskets, etc. will bubble/foam up at leaks for smaller leaks. Common leaks are couplers, holes in the intercooler, BOV flange or diaphragm, throttle body gaskets, vaccuum lines, throttle body shaft seals, BISS o-ring, injector insulators (between the injectors and head), PCV valve, and intake valve stem seals. Make sure you block off the BCS bleeder line that connects to the bottom of the intake pipe (if you still have the stock boost controller). If you have an MBC, plug the inlet to the MBC during the test. If the PCV valve is leaking (unscrew from the valve cover and see if air is leaking out the valve), get a new OEM one; the Autozone/Carquest ones WILL NOT WORK.

Try putting NGK BPR6ES plugs in there gapped to 0.028". Those are the "blessed" DSM plugs for stock boost levels. They're cheap, and they work great. If you expect to run more boost, you might opt for BPR7ES plugs instead (0.028" gap) which are colder plugs. They're about $2.50 each at NAPA.

Do the boost leak test, fix leaks, change plus, and let us know how it's going.
Do the boost leak test and plugs first.

 

[gstfire]

found nothing. had car on dyno today. still ran like shit! would actually right good after 5500rpms. Could this possibly be a injector problem. THis is really a pain. either it gets fixed shortly or its goin back to this guy an probably to court, seeings how he doesn't wanna help much.

 

[kenamond]

found nothing. had car on dyno today. still ran like shit! would actually right good after 5500rpms. Could this possibly be a injector problem. THis is really a pain. either it gets fixed shortly or its goin back to this guy an probably to court, seeings how he doesn't wanna help much.

Did you do a boost leak test? Did you just do a pull on the dyno, or did they attempt to tune the SAFC?

 

[gstfire]

no. not yet, gonna try and find the stuff to make it today. somwhere. did a couple pulls, and tuned the SAFC. he thought it would be best to start from square one, so i went home and pulled that damn thing out. after setting it back to stock of course. thought maybe the wiring was wrong but it was all good. he said to take it to mits. dealer and have them run their test but i'm guessin that gonna cost couple bucks.

 

[force it in]

I tried to reset the Apex to the cars factory setting.

Make sure that the SAFC is set up correctly. Airflow meter type should be set to karman. Also check that your throttle sensor type is correctly set. Here's a link for the SAFC2 manual. http://www.apexi-usa.com/pdfInstallation/15.pdf

Good luck

 

[kenamond]

This is getting rediculous. If you have larger injectors than stock, you NEED SAFC. The factory defaults WILL NOT WORK. But do you even know what injectors are on the car?

And what was this: "did a couple pulls, and tuned the SAFC"? Does this mean someone just blindly tinkered with the trims and gave up, or did someone who knows how to tune take a shot at it and have problems?

And what do you mean by "after setting it back to stock of course"?

Find out from the previous owner what injectors are on the car. If they're larger, let us know what size.

Do a boost leak test.

Keep us posted.

 

[Gstclipse69]

http://www.dsmtuners.com/forums/showthread.php?t=169435

 

[gstfire]

well i go this morning to get a smog test to reg my car. and yep it fails big time. the guy said my car wasn't reading any signals from anything. told me to take the MAF apart an clean it. now thats what i'm doin but there is like almost looks like glue holding the top plastic cover on. Is that normal, and on the bottom there is looks to be an inlet of some sort and that hole is covered/filled with glue as well. is it suppose to be like that?

 

[itzadawdge]

kinda sounds like the car is being starved for air

 

[gstfire]

well i broke down and took it to the dealer. come to find out, they said that my pcm is shot. he said its been "flashed" a couple of times. And when this other guy put this S-AFC in, that could have caused it. so now i'm in the market for a new PCM. any leads?

 

[kenamond]

well i broke down and took it to the dealer. come to find out, they said that my pcm is shot. he said its been "flashed" a couple of times. And when this other guy put this S-AFC in, that could have caused it. so now i'm in the market for a new PCM. any leads?

Go to the classified section. They're under $200. Lots of folks sell theirs to get money for an EPROM ECU.