Weird Running R32 Gts4

[tsterls]

Hi I am new here and recently bought a r32 gts 4. It is just doing a couple of wired things and I wanted to try and diagnose it before going to get it dyno’d. The first issue is cold starts. It doesn’t like to start when cold. It seems if I let the fuel pump fully prime it will turnover off the starter motor and then the revs will just fall from there to stall, if I give the throttle a pump it will pick up to 1000 rpm and then idle fine. The second issue is top end power it seems to run out. It continues to rev but doesn’t pull like it does when it comes on boost. It feel like it stops pulling after like 5000rpm. IT also doesn’t seem to have much go bottom end. Like it wont pull up hills in second if under 2500rmp.It is a completely stock rb20det with a very quiet 3” turbo back exhaust. I have compression tested it and got between 145 and 150 across the board. Boost is running at 12psi, tested the afr’s just tonight and was getting 15’s at idle and would push down to mid 13’s on boost. Reset the ecu and then it pushed down to 13flat. Haven’t quite tried everything yet but am almost sure that it is spark related. Just wondering if any of you guys have any ideas. Any input would be greatly appreciated. I am also getting exremely bad fuel economy. in the order of 200km to 250km from 45L. Not sure if that makes any difference.

Thanks

Tom

Edited September 12, 2006 by tsterls

[blind_elk]

It's only a little 2 litre engine, trying to haul 1.5 Tonnes of car around.

Skylines in general are renowned for pathetic fuel economy - learn to live with it.

As for your start problems, get the injectors sonic cleaned. That may also help your top end performance as well. It could also be related to a dying fuel pump.

Clean the AAC valve. Check the cold start valve, located under the throttle body. Check / change spark plugs. Check base ignition timing.

That should keep you occupied for a while.

[Kozeyekan]

I've got a 32 GTS-4 also, and have some of the same things.

On a steep hill, you drop back to 1st or second. The RB-20 is just like that. Not much you can do here.

Cold starts fine when revved? Maybe tighten the idle screw?

The gts-4 just isn't meant for speed, it's more about grip. It's heavier than the GTS-t and not as powerful as the GTR. I chose to upgrade the handling as my higher priority, so I'm looking at coil overs, brakes, rotors, michi pilot tyres and assorted braces. The car isn't much of a high speed demon (though a few go fast bits do help) but it'll stick to corners that would see a GTS-t (and also the Falcadores) run into a wall.

And with the fuel economy, well not much you can do. Some of it is driving stye. I get about 350k's, but a lot of it is freeway driving, and gentle acceleration/braking.

[tsterls]

thanks guys,

yeah the only reason i posted was a mate has a gts4 aswell and he gets 350's. The 200 to 250 is keeping it off boost. which is odd. My mates car also accelerates up to 7k where as mine doesn't. im going to check the base timing tomorrow and also clean the afm, aac valve etc. thought i should just check what everyone thought before i spent to money on a dyno run, lol im to cheap. im expecting about mid to high 80's at the rears. What is standard i have read about 116kw. is this true?

thanks

[tsterls]

time for an update. on thursday i cleaned my afm and acc. i also changed my fuel filter. while doing all this i found that one of the hoses on the second fuel reg was not pluged in (the one on the end of the fuel rail, it runs into the return. is this standard??) pluged that in, also tried to check the base timing and got about 8 degrees advanced, we thought this must be wrong as it should be about 15. turned motor off and since then havn't been able to get the revs back down to 650rpm. all that aside after cleaning and replacing the fuel filter took it for a spin. was great, pulled up to 7grand, afr's were more normal (dropped down to low 12's high 11's underboost. still thought they would be lower) car made a few werid noises but nothing savage. Then when starting it on friday it was back to normal. it didn't feel like it was accelerating after 4500rpm. i checked the compression which was 145 plus or minus 5 across the board (is this low??). i ran the ecu codes off the back of the ecu, they gave me 55. it also told me my 02 sensor was fried, but i believe this isn't a performance part. any one got anyideas, today i plan to borrow my mates afm and see how that goes.

ill keep ya posted.

[Cubes]

I am also getting exremely bad fuel economy. in the order of 200km to 250km from 45L. Not sure if that makes any difference.

A car that is maintained should never achieve fuel economy so poor.

Drive it lightly for a complete tank and you should see at LEAST 400km's to a tank of juice ~50litres.

A few places to start looking regarding fuel economy.

O2 sensor, airflow meter, injectors.

When my fuel economy went to sh*t and started getting 350km's to a tank I replaced the o2 sensor with no affect, I then replaced injectors and it was all fine and dandy again.

and for the cold start hessitation.. The only way I fixed mine was with a PFC.

[J_R32]

cold start: live with it, all rb20det's i have being in owned needed a little prod of accelerator to start when starting them cold.

also in terms of ur performance, remember ur car is all wheel drive, there is much more driveline loss cos ur little engine has to send power to all four wheels pretty much. THere will be much more friction loss etc, hence poorer performance. IN fact HPI found out that a r32 gts4 is about almost a second slower then r32 gtst! And having driven an auto gts4 then straight into a auto gtst, the difference is noticable.

[OGR88 R32]

yeah mine has problems with cold starts but with the fuel econmy mine gets 450kms per tank pretty easily!

[Kozeyekan]

with the car running out of legs after 500 rpm, do you have a pod with no heatshield? I'd probably look at getting it dyno tuned, just to test some things out.

[OGR88 R32]

i got a pod with no heat shield and mine runs ok?

[123456]

If i was you i would take it to a mechanic and get him to test the fuel pressure and flow.

Mine was maxing out so bad at about 4.5krpm that i could almost feel myself getting pushed forward in my seat instead of back once it hit those revs, then it climbed damn slowly, was alot more noticeable in 2nd than first as well (The boost gauge didn't indicate my problem either).

I tried a number of things and it ended up being the Fuel pump, i fixed that and it pulled alot harder, didnt feel any real drop off till about 6krpm.

[gts4-t]

HEy

I have recently purchased a 94 gts4-t auto.... Firstly, 350 to 400 kms is an average mileage that i get with a 95 prem.... Secondly, i had a similar with the lack of pulling (reving passed 4 to 5 grand) and considering it was my first skyline i had no idea.... soo i sent it to a mechanic! My car would suck the gas and not even go....!

Thing that were changed! (similar to what cubes sugested)

1. changed spark plugs - NKG

2. air flow meter - off a 300zx will work

3. ECU - wreckers? possible

The cold start seems to occur with alot of turbo cars especially gts4-t skylines....

The mechanic change over all over the above however the spark plugs permantly fitted the problem... appparently i was running some "performance spark plug" with incorrect gapping.... Try that the spark plugs could expalin why u are using alot of fuel and hitting that 4 to 7 grand flat spot! once my were changed over...... it snaps the 4 to 7 grand mark! and it shouldn't cost u an arm and a leg to place them! fu*K u need to change them eventually anyways!

The ECU was replaced because the car went spaztic... and i mean spaztic.... won't accelerate at all.... like my 1.5 litre paseo had a quicker take off! and then it would kick in and pull forward then drop off.!

Hope that helps!