Luis.

I have searched, both google and HT and I can't find definitive information or any further help in troubleshooting this car so I'm hoping the knowledgeable peers we have in tech section can help me dive a little further in depth.

Here's what the problem(s) are:

When I step on the gas anything more than about 20%, it starts bogging and sounds like a misfire and I have a loss of power as well as a loud popping sound. The RPM gauge does not jump, nor do I have a check engine light.

If I "baby-foot" it or in other words light on the throttle, I can get up to highway crusing speeds and into vtec although it sounds even worse than ever and I know NOT to take it there since it isn't running 100%.

Here's what I have:

2001 USDM GSR w/ Skunk2 gen1 IM, Vibrant 4-2-1 header, BWR test pipe, Buddyclub Spec II exhaust.

I am running any of (3) ECUs, stepdown obd2a to obd1, with either a 92-95 JDM B16 ECU, chipped P28 running a type r basemap w/ vtec @ 5600, chipped P06 (vtec added) running a modified GSR map to delete IABs.

Here's what I have done so far:

- Spark Plug wires (NGK Blues)
- Spark Plugs (NGK G-power, I can get the part #)
- ICM (from a friend's spare dizzy)
- Coil (from a friend's recently reman'd dizzy)
- New Earls inline fuel filter
- New battery (my old one was dying out)
- ran Chevron Injector cleaner (2x)
- compression tested the motor (got 240 across the board +/- less than 5%)
- I have no CELs but I'm only running 1 o2 sensor (since I use obd1 ECUs)
- checked valve lash, appeared to be within spec
- checked for proper TDC, all was fine there as well
- cleaned out IACV

Further details:

I do have a wire tuck, never had any issues wiring wise, had the car on this setup for 2yrs and drove it from NY to TN as well as daily drove it to work. I was running a velocity stack style intake (I know I should've had a filter on there on me)

The car does burn about a qt of oil every two to three weeks, but I can't find any serious leaks, so I think the valve seals are sticking or something.

Please help, I am running out of ideas/patience/time, and I'm using the car to commute to and from work by baby-footing it and letting it warm up properly every day.

Possible ideas:

-Friend mentioned possible issues with my stepdown and plugging it in and out, so I plan to swap it out with a known working on once I can.
-Dizzy itself is shot, didn't notice any issues with spinning the shaft on the dizzy, except it felt notchy throughout its turning.
-Possible exhaust leak, exhaust does sound a little irregular, however the motor isn't running as I'm used to. I'll check the exhaust at night to see if I can see anything underneath.

Former User

Have you checked the distributor cap and rotor?

Is the ignition timing set to spec with a timing gun?

Luis.

Cap looked good, no visible cracks, I passed 2000 grit on the contacts inside to ensure there was good contact, and I replaced the rotor.

The ignition isn't, so I will have to have a mechanic check that since I am not knowledgeable in that area.

Let me clarify, as far as I know it should be at spec, but I haven't confirmed via timing gun. That was never messed with but I guess it could be off spec.

SHG_Claudio

Odd ****. The loud noise makes me think its not getting fuel. Maybe the pump or injectors? Im no mechanic but that would be my guess. It sounds like when you give more throttle, more air gets in and it tries to match the fuel but it doesnt get it and leans out.

djslim23

I'm not a mechanic either, but I've had an experience with a bad MAP sensor that caused my D-series to act very similarly, but it's a strange thing to just go bad..

SHG_Claudio

Yeah it definitely sounds like theres an issue with incorrect A/F ratios.

Luis.

OK so I'll add those two things to my list to check/change:

- o2 sensor (plays a role in A/F)
- MAP sensor

SHG_Claudio

Check out www.sparkplugs.com , thats where I got my o2 for like $45 bux. Prob more for yours but it might be cheaper than elsewhere.

I have a chipped ECU and I know that it injects more fuel than it needs to and when I'm at low rpms and give full throttle it bogs/studders even if its around 2k or so.

Last week I ran out of fuel( ) and when I would I would give any more than 20% throttle I could hear a loud bang and it would studder. I managed to coast to a gas station off the exit but it does seem like the GSR is not getting proper fuel.

Luis.

Yeah that's the only problem with chipped computers. I'm wondering if a fuel pressure regulator will do anything for me, I'm using stock right now. I'm also wondering if my injectors are fine, I have to see how I can check those.

I plan to borrow a friend's 96 GSR computer (obd2a) so lets see what turns up!

SHG_Claudio

"Don't guess, troubleshoot" lol

Luis.

SHG_Claudio

Luis.

Luis.

Update:

Since I'm trying to sell the car, I'm looking to diagnose this ASAP. Weather now allows us to work on our cars here in the Northeast finally, so please assist me!

I have tried this weekend the following:

- new plugs
- another obd2 distributor (known good)
- eliminate the stepdown by utilizing a obd2a GSR ECU

I plan to, tonight:

- throw the obd2a GSR ECU back in, and read the MIL codes.

Any other ideas?

crazyjetsfan22

iTrader: (5)

crazyjetsfan22

iTrader: (5)

JRSC_EK

Does the car jump back n forth when it pops or cuts out?

bignelson001

I have a similar prob I've changed fuel filter nd fuel pump nothin same prob!

crazyjetsfan22

iTrader: (5)

Thinking it could be both of those also.

crazyjetsfan22

iTrader: (5)

Changed the throttle body, tps, map , IACv with known working ones it cleaned up the idle but still has some studdering

crazyjetsfan22

iTrader: (5)

ttt