Recently my ls vtec has started to idle all the way down to 100 rpms. It hesitates and is sometimes hard to get the revs up because it feels like it wants to die but doesn't. I held the gas so it idled around 1k to warm it up and see how it ran. Again, the rpm's dropped so I took it for a test drive.

The car surges and lacks power. It finally started to idle around 7 but then slowly went down. It throws a code when the motor starts but doesn't when you turn the key all the way forward without actually starting it.

It's OBD1 so I jumped that pin and got code 20 which is electrical load detector.

I was reading that possibly a main relay can contribute to this? I have had problems with my fuel pump priming but it is working fine right now.

There was an incident though a few days ago where it was priming but the engine would crank over and die almost instantly. I quit priming and just cranked it a few times and it cranked over.

Thanks for any help

 

I'm gonna go resolder the main relay if I find a cracked solder

 

I tried re soldering it but still the same thing. I only soldered the cracked spots and didn't have a desoldering kit so they still may not be good. I needed a new one and may just go try buying a new one since I need to figure this out instead of guessing it's my solders.

I'm gonna go try one of my other IACV's

 

I think it is my distributor. I checked the codes and now code 9 is going off which is No.1 cylinder position sensor. I took the cap off and there is bronze dust from bearings & metal contact?

 

I tried another distributor and the same thing is going on. Also tried new spark plugs since those needed to be replaced anyways. Still throwing code 9 though. Any ideas?

 

I just ran one of my other ecu's. I was using a p72 and now ran a p28.

I'm getting just code 20 with the p28. If I hold the idle once the car is warmed up, the idle bounces. Does this mean some sensor is messed up? I cleaned the IACV yesterday.

I've read it can be the fuse box under the hood or possibly a defective or disconnected sensor

 

I adjusted the throttle body so the idle is higher but that still doesn't solve the problem. I took the car for a test drive and wanted to see if it would crossover and it did, but then I tried again just a few minutes later and there was no crossover.

I'm gonna go search what all would cause the vtec not to cross, my oil light isn't on but maybe oil pressure is low?

Anyone have any ideas?

 

what is the motor tuned on?

 

It's a pretty basic setup right now.

The motor is just an ls block with p30 pistons and a B16 head with the few little things like an intake manifold, intake etc.

I've always ran it on a p72 and the air to fuel ratio was always good throughout the rpm range.

I've had the setup like this since june of this year and it just started acting up last week.

Thanks for the reply, I was getting worried since I was posting but never getting responses lol

It seems like it should be easier to eliminate since it causes vtec not to cross & the CEL only turns on when the car is running

 

what code are you throwing?

 

I get code 20 with my GSR ecu and nothing with the P28.

Today I started my car with the GSR ecu and it fired up but only went to like 200 rpm's, sounded like it died and had barely any rpm but then regained itself and idled normally.

I turned it off and tried it again and the same thing always happens.

I tried it with the p28 and it runs really nice and doesn't throw any code but the idle will surge every once in a while for a few minutes but then quit. It has never surged with the GSR P72

 

if it surges, try looking at your IACV, it's got probably two bolts, clean the sucker out with some brake clean.

Really, I think you just need to get it tuned buddy

 

I tried one of my other IACV's and it didn't fix it. I found the problem though today. My downpipe was becoming loose and not enough exhaust fumes were getting to the o2 sensor. It's fixed now.

Thanks for the help, I appreciate it. I do need a tune though, I'm saving up for hondata right now and am gonna figure out a basemap since I still want to do headwork before I pay for a tune.

 

cool, cool. crome/neptune isn't a bad alternative either. If you buy your own wideband.. AEM UEGO being the cheapest out there i think.. i could be wrong, but tuning yourself isn't really that hard. You can tune it yourself until you save extra money to get your WOT tuned, and the rest of your partial throttle

 

Thanks for the info man! That's what I was planning on doing because I'm changing my motor too much so I just want to do it all myself

 

You said your down pipe is loose so I assumed your turbo. But anyways if your car is turbocharged the low idle can be caused by a vacuum leak. Best bet would to do a boost leak test.