91wayota

I have a 1991 ext cab 4x4 with a 3.0 it seems like when the motor warms up it is hard to start and smells like old gas. The old dude I just got the truck from said the the EFI relay was bad and he has one on order for me but I fear it may be something else. The truck has 155k on it and the timing belt was just done at toyota. Is there anything else I can check or look for in the mean time? thanks

StewsRunner

iTrader: (1)

Hey my twin! Mine does the same thing and it started at round 155xxx. What I came to the conclusion of mine is that somehow it is flooding? my mechanic said it was nothing fuel related however. I changed the ECT sensor and the CSI time switch and the problem got worse so I then flushed the coolant and it seemed to have fixed it for about 3 weeks. Now i'm back to the same old thing. I had the new sensors in there for about 2 weeks before I changed the coolant so I thought my sensors had build up on them as did the old ones. I pulled the ECT to check it and it was a little dirty. SOmething came up so I was unable to finish the job but something cheap you could do is pull the two sensors, scrub them and flush your coolant. see what happens then.

How does it sound when it acts up? does it crank fine? when it finally catches does it sputter at a low RPM? Another thing you could check is when you think its going to act up, pull of the cold start injector, put it in a coffee can and have someone turn the key. If fuel is coming out of the injector you may have found your problem. If not, You eliminated a good culprit.

91wayota

well I just bought it and it has 156k on the clock to be exact. I drove it 62 miles shut it off then went back out to start it and it just cranked like it was not getting any fuel. so I pulled the EFI relay under the hood and tapped on it and stuck it back in and the the truck started right up. but it smelled like stale old gas. I used it to haul bark 2 loads then it started running poor it seems to clean up about about 2000 rpms. then you let it sit a while and it starts just fine its hit and miss some days it runs fine and other days it runs poor at idle.. EFI relay on order. Then I am going to do the fuel filter. Could it be the ECM?

cambob

You should check the coolant temp sensor. That sensor was causing an identical warm start/smelt like flooding problem on my 22re truck. Its a quick check if you have a multimeter.

islanderoffroad

Coolant temp sensor is the likely culprit, was for me.

Any codes?

91wayota

no check engine light everything seems normal then it just falls flat on its face

StewsRunner

iTrader: (1)

I would pull the coolant temp sensor, drain your coolant, clean the sensor with some steel wool or something and then refill with Toyota Red (haven't used it yet but i know some guys here swear by it)

91wayota

ok changed the coolant temp sensor, fuel filter and still waiting on the EFI relay I hope this helps its such a clean 91 and it would be nice to be able to drive it

StewsRunner

iTrader: (1)

Can I ask where you picked the temp sensor up at and for how much?

islanderoffroad

I got mine at autozone... it was pretty cheap, less than $20 for sure (don't remember the cost honestly, which means it was rather cheap)

StewsRunner

iTrader: (1)

So the ECT is the smaller one on the right, right? When looking at it from the front

islanderoffroad

From what I've read here, it can vary depending on the year of your truck. On my 88, it was the one all the way on the right.

JR

Girlfriends truck had this, hard to start when it was warm, slow to start, ran rough had to give gas to get RPM up and you could smell fuel. Changed out 2 temperature sensors no change.

I believe that the cold start injector was leaking fuel when the engine did not need any extra fuel. 91 octane fuel with Seafoam seamed to clear it up. Been good for two years know

Hans

StewsRunner

iTrader: (1)

Any updates?

91wayota

well the hard start seems to be fixed but also seems like might be some bad fuel or water in the fuel acts that way I am not sure. I am going to pick up some sea foam and put it in there see if it cleans it up. The truck has been sitting a while.

91wayota

well I am out of ideas and am ready to take it to toyota or put it up for sale

StewsRunner

iTrader: (1)

Is it still starting hard?

91wayota

yes left me sitting at the store for 30 minutes then fired right up and drove 21 miles and did not miss a beat. When I shut it off would not start just cranks over. smells like stale old gas might be time to drop the tank ? I am out of ideas

StewsRunner

iTrader: (1)

How old is the coolant? Mine had been sitting for a while and I changed the ECT and it got worse. I then flushed the coolant, which looked and smelt TERRIBLE then it would start every try, sometimes took a little longer but I never ha to turn the key twice

TURBOrunnerNM

hey 91wayota. when you say you smell stale gas that got me thinking...in my '86 runner (4cyl which might not apply to your 6cyl) i had the same issue. in the morning it would start OK when i warmed it up for work but then it would be hard to start when i would go home for lunch and any time thereafter when it wasn't stone cold. it was actually the fuel pulsation damper (regulates fuel pressure in order to maintain a steady stream to the injectors). i'm not sure if toyota fixed this problem in the '91s but it has been known to be quite the offender. the pulsation damper is on the front side of the fuel rail (farthest from the firewall) and, if it's bad, it'll leak fuel and completely ruin the system pressure. next time you start your truck cold open the hood and look closely under the fuel rail. if you see any drippings of fuel (they might not reach the ground) then that could be the issue. it would make sense with the whole raw fuel smelling bit. after i replaced mine (it was a PITA) my truck starts within 2 seconds or less. let me know what you find!!!