mikebondi

Need some help. My car died on the highway today. It is hot out and the temp guage got up to 220. This is the highest I've ever seen it I was doing 75 on the highway and shifted to 6th gear and it started bogging down like a carburated car does when it vapor locks. I pulled off the highway and it fired right back up but wouldn't run. I am running stock 91 guages and im a bit worried they may not be reading right.

can a fuel injected ls motor vapor lock. I'm a bit out of my area with the ls motor and slowly learning.

Its a lq9 motor bored to 408 ls6 heads and intake and 85 mm throttle body.

Any help is greatly appriciated

Thanks

dprest68

iTrader: (1)

Ut oh. Man, that sucks Mike! I hope you get it figured out. I'd offer advice if I had any, but I'm just learning about the LS platform as well. Did you try posting this on LS1tech?

TTOP350

iTrader: (8)

What is your fuel psi? Lots of things to check to see whats failing..

mikebondi

I will post on ls1tech when I get it home tow truck is on its way. It ran ok for about 10 miles then shut down again. Guage only got to around 210 this time.

don't have a fuel pressure guage or any means right now to check that. Thanks though when I get it home I'll figure that out.

I think aftermarket guages are an upgrade very soon the stock guages seem to be a best guess.
thanks guys

Jim85IROC

iTrader: (2)

Buy a fuel pressure gauge and get it on there. It sounds like your fuel pumo is dieing. I think the temps are unrelated.

POP6482

iTrader: (2)

^^^^I agree, start with checking the fuel pressure. What pump are you currently running?

mikebondi

Its a 255lph walboro pump. Its pushing 60 pound injector but the injectors are turned down to 45 percent duty cycle. These are on there for the dry shot that is in the car but has not been sprayed.

I'll get the guage first thing in the morning im leaning the fuel way as well. Its pretty odd to say the least it runs fine after it sits for about 30 minutes. But only goes about ten miles then it dies.

on a side note while im doing the fuel pressure guage should I do some other ones. I was thinking an oil pressure guage. Maybe a nitrouse pressure one as well that's not under the hood. Won't need it right now but shortly. Any other that I should have

And thanks for the advise

INTIMIDATOR Z

iTrader: (4)

who tuned it and did they mess with any of the safety settings. these motors rely alot on the coolant temp sender. if the motor gets too hot it retards the timing alot and run it rich as hell so you wont overheat the car. sometimes it will even cut power off completely.

Jim85IROC

iTrader: (2)

Electric motors weaken when they heat soak. My guess is that the motor is on its way out, so it's drawing extra current which is making it heat up. When it heats up, it goes from bad to worse. This might explain your low HP numbers on the dyno too.

Not only would I get a new pump in there, but I'd rewire the fuel pump power feed, maybe using a relay just outside the tank to switch a larger gauge power feed in.

dprest68

iTrader: (1)

Yeah, I had that problem on my GTA. The car just quit running when my girlfriend was driving it. She got all freaked thinking she broke my car. We went back to it a little later and it started right up and we were able to get it back to my house. I ended up installing a new Walbro pump and Racetronix hotwire kit on it.

mikebondi

jim iroc.

i was thinking the same on both accounts. with more research both dynos were SAE corrected dyno numbers so it lost about 30 hp since it was last dyno tested. shouldnt make any difference on altitude since it was SAE corrected from what i read.

whats the best pump to buy. i read the walbro 255 is only rated to 500 crank hp which even my weak dyno i was above that. is this what the hotwire kit is for.

after i settled down last night from it already being towed home i remembered i have a fuel pressure guage under the hood. i will run it and see what the pressure is at tonight when i get home. i want to move that to the pilar here in the near future.

im still not ruling out that it overheated and the motor shut down to protect itself. my coolant overflow set up is a disaster. im buying the how to swap an ls series engine into anything book tonight. im hoping i can find a good diagram to tell me how it should be set up. i looked at 57kid's 6 speed car and it is much more simple and what i am used to seeing.

i greatly appriciate everyones feedback. the knowledge here is amazing

TPI TERR

iTrader: (9)

What intimidator z said .

Get a hold of a scan tool
I had a buddy with a bad ect sensor . (driver side)
If the sensor is bad or broken It can be an Issue . Make sure you get the right one 2pin vs 3 pin.
This pulls fuel and spark adjustments and protects it from overheating.
At start up it was fine and once it warmed as he drove it , it struggled (limp mode) /safe mode

INTIMIDATOR Z

iTrader: (4)

kinda funny thing happen to my iroc today. ive been tryin to finish things up and fired it up and it ran fine, then shut it off and tried to fire it up again and now im not getting any signal from my fuel enable pin. so wiring it to a switch and then to ignition for now until i can figure it out.

mikebondi

Just started it and checked fuel pressure its right at 55 to 56 psi at idle. Now this was when the car was cold not while having an issue. I'll drive it here soon and if it has an issue I'll Remember to jump out and check the guage. Even at idle if I read right im a few psi low right.

five7kid

iTrader: (14)

Unless it's a high quality gauge, the permanently mounted gauges should be double-checked with a diagnostic gauge.

If it is using the Vette filter/regulator, it should be at 58 psi.

I don't know if you've talked to Rick at the track with the silver 2001 Camaro. Last year he was having problems with it shutting down on him. Turned out to be a crank position sensor wire - small gauge, it fractured within the insulation and was making intermittent contact. Ran new copper, no problems since (except for redlighting against me in the final... ).

vwdave

Ive seen this problem alot lately. Basically the fuel pump gets hot and starts to lock up. It gets to a point, locks up and the car stops. After it cools itself down, it frees up and the car will run again.

What something is reading while its running correctly is mostly not that important. Its what its reading when its not running correctly that makes all the difference.

You can also take a mallet or piece of wood, or whatnot and bang on the bottom on the tank while cranking after it stalls and see if the car restarts for a few seconds. Dont hit it hard enough to damage the tank of course....

DiabolicalRS

holly schiesse! your the one who bought that car? that car was for sale where i lived and lived down the street from me. no offense to the guy who sold the car but everytime i pass his house i think to myself who what a dumb idea to sell that car. he had sooo muuch money in that car! but good buy for 8k or 9k! hope everything works out for ya

Prokilllsx

How close is your fuel line to the driver's side header collector?

mikebondi

yeah i bought it 8200 plus shipping. its run pretty well needs some things here and there to get it exactly right. i coudnt have built the motor for what i paid. all and all i couldnt be happier with the purchase. it is a bit ruff on the paint and some of the swap stuff needs cleaned up. but he did very nice work on the install and the motor build is pretty top notch needs heads and intake upgraded. 422 rwhp and a 13.8 on worn street tires 2.2 60ft at 5300 feet second time out isnt to bad.

it found a permanent home. my little girl will race/drive it when i cant anymore.

mikebondi

as an update

had the cooling fans looked at today somehow they were set to come on at 190 and go off at 188 it is staying within a safe range on temps now. drove it about 35 miles in the heat today.

almost back to my office it died just like it did when i started this. temps were only about 185 190 this time and i immediatly jumped out to check my fuel pressure. bingo the guage was reading 20 psi started the car again it idles way ruff for a few seconds at 20psi and shut off again. let it sit about 20 minutes turned the key to on and it was back to 55 psi started up and ran fine to my office which is like a mile down the road from where it died.

im seeing a new fuel pump and a hotwire kit in my future. anyone have any insights on this install. i have to drop my rear end in a week or so to put tje s60 in so im thinking that is when ill do the whole thing.

mike

vwdave

Good to hear you found your problem. I would also do the pump at the same time as the rear end, save yourself the work.

dprest68

iTrader: (1)

I'm glad you got it figured out Mike. Better get it taken care of real soon. If it already acting-up, you never know when it's just going to die for good. You should definitely do both the rearend & pump at the same time.
Here's a link to my fuel pump swap with pics: https://www.thirdgen.org/forums/tpi/...p-install.html

Good luck with it.

mikebondi

man i was pretty sure the fuel pump was the fix. then i found a very long thread about what appears to be the same issue goin on with tpi cars. alot of them have changed the pump and ran into the same issue shortly after or are on multiple pumps. the bad part is noone found a fix yet.

i think i am going to do the pump and the hotwire kit anyway while the rear is out just to be safe.

i also do think i lost some hp on the dyno from this fuel pump issue. it broke up way bad a 5900 and the cam specs are good to 7200. i have the valve springs to match the cam in there and good roller rockers. i thought it was the heads chocking it out. maybe it is the pump. maybe do the pump and have it re dynoed on the same dyno. to bad it wont be the same as before with drag wheels instead of the heavy 18 inch wheels and the s60 and new driveshaft.

good times with this stuff