JeffsR50

Had this same issue with my 97. - vacuum leaks!! - first was the fuel tank vacuum cut-off valve. Do you get a whistle sound under the truck? This valve is supposed to close off the intake vacuum before it reaches the gas tank. Mine was shot. After replacing that valve, I also did a cheap cigar smoke test on my intake and found that I had a leak at the bottom hose of the EGR control valve. When the truck was cold, it gave enough gas to offset too much air in the intake, when she was warm the air leaks messed up the whole show. Fixed the vacuum leaks - she starts first time every time now. Just another note - my pathy really seems to love seafoam. I add a full bottle to the tank every other month or so.

It wasn't until I did a cheap cigar smoke test on my intake that I found the leak at the rubber hose at the bottom of the EGR control valve. Ive also seen that a leak in the evap system can give fits (especially after warm up) as well. Just a little additional unexpected air into the intake mix can cause misfire for sure. ..Some MAF cleaner might not hurt.. I also had a recent stalling/ misfire issue that was solved by a cleaning of the negative battery cable connector.. good luck- seems like you are on the right track

Holy smokes!! yep Id say you found a bad part looks like you are on the right track

Hey FreidEGs, yup that's it...as I remember, the cut valve is supposed to stop intake vacuum from reaching the fuel tank, when I applied pressure to mine it made a sick sort of whistle instead of preventing flow. There are a few tests to do, blow through one side and it should flow, blow through the other and it should have some resistance, then its also supposed to prevent any flow when suction is applied from the intake side. I found the specific test procedure in the service manual that has been posted in these forums. good luck! Since figuring out the different little vacuum leaks (cut valve to the tank, then leak at bottom little hose of the egr control valve) She's performed perfect!! -Im sure replacing the entire ignition system didn't hurt, but in the end my issue was the vacuum leaks IMHO.

..took the family up Pikes peak road n did a little fishing at the lake sure was beautiful up there

hey thanks very much you guys - Man these forums can be a lifesaver! update- OK a few real good days of driving the misfire is 99% better. She did give a cel and the po302 p0325 codes early Saturday but no flashing and no noticeable shimmy. yesterday it was fairly hot and I did a lot of running- she started on all cylinders every time and no sign of a cel. sweet! The only other thread Ive found with this same model and same codes was a vacuum leak/vapor lock thing - I think the EGR tube fixed it but its just taken her several days to relearn. I'll update again after some more road time but yep big difference. thanks again friends

according to the sticker under the hood my timing belt was repl at 90k - Im at 140k so yeah maybe I need to look at tension - hmm, just wondering though, if I had jumped a tooth, wouldn't my misfire be more consistent? she runs and idles great once were goin down the road. any way of checking for a jumped tooth without taking her all apart? Yep Pat you were right, misfire is back but according to my freeze frame at the p0302 cyl 2 msfire, my fuel trim is back normal (perhaps my new egr tube straightened that out) again, hard starts are completely gone - she starts every time now -just the pesky misfire for a minute when starting hot. she does run smooth but might get a cheap harbor freight timing light just for giggles. Ill also have a look this weekend at the fuel hoses to the rail - thanks guys much appreciated

thanks pat - yep I like the fuel rail clog idea - sounds like a possibility. however- I did the cheap cigar leak test on the intake manifold - and did find that the little tube at the bottom of the egr control valve was leaking! it was on there, but it fit loose - so I did replace that little chunk of hose havent really had the misfire since, but its been alot cooler here too- this does certainly seem to be much worse when its hot out - really really hoping that the little egr tube does it. (please please please) this is certainly my 'bitch about my truck' thread - but the truck has really been running great for the most part. Next weekend is my new cv joint install - got to get her ready for some bouncin up the mountain. thanks again man Ill update after it gets warmer n I find out for sure.

thanks kingman - hmm not that line in particular, but I have tested the fuel pressure which seems to hold steady both during and after running. - Also unplugged the fpr tube - fuel pressure increased like the service manual said it should. also really sprayed some carb cleaner around my intake connections and gasket trying to find a leak today - no avail! - thinking about the cheap cigar smoke test next. - also considering the downstream o2 sensors maybe? looked at freeze frame STFT again today and it was +25 on bank 2 - jeez only misfires on warm start after sitting for a few. - if I come back and start it within a few minutes its fine - 20 min in the sun and I have a misfire for sure. restart a few times and it clears

Theres still this very interesting sidenote- whenever the misfire happens, the priming of the fuel pump has a distinct 'gurgle' in the fuel tank. almost as if the pump itself is releasing air bubbles as it primes.? - like today, I just ran an errand, came back out, turn the key notice regular pump noise no gurgle - no misfire runs perfect. wait 15 minutes.... turn the key to prime the pump - gurgle gurgle in the tank - misfire #2

Switched plugs for o2 sensors, misfire stayed on #2. hmmm. Thanks deltaR50, I can do that (I did replace it less than a year ago, but of course that doesnt mean it isnt wonky) but it does seem to communicate ok with the fast idle cam I did back offf the fast idle cam screws after installing the new cts, to get the idle arm back to the factory screw on the throttle body, not sure maybe I went too far n that might have messed up my warm idle? -although when we are up to temp and running down the road - she idles great - 750-800 rpm no problem, no stalling etc thinking about doing the cheap cigar smoke test on my intake - did the seafoam trick over the weekend, if the exhaust manifold is leaking I sure didnt see it

fuel pressure test today - 40lbs at ignition, 34 while running, leak down test holds pressure very well - doesn't seem to be leaking back gas to the tank or from any of the injectors. still rumbles on startup after sitting while hot. turn it of and restart a few times or wait while idling and the misfire clears. always cylinder 2 po302. thinking about the o2 sensor thing Pat - ill switch the plugs left and right upstream o2s tomorrow and see if the misfire moves.

thanks! Im in the Springs

bumper before ..and after! sanded, cleaned, primer for plastic on the plastic pieces, regular primer on the bumper, then rustoleum bed liner. Happy with the results, Ive done the front end, luggage racks and spare tire rack sleeves so far.. hey we'll see how it lasts but so far so good

whats up nightfire785 - CO native here too, denver born - now in the Springs (also used to drive a 4runner -'86) yep pics look good.

interesting...yep I havent really tried to look for exhaust leaks -maybe Ill do a seafoam treatment this weekend just for that purpose.

yeah I knew going in that it might require a few cranks of the wrench - and yep the regulator line was a bit loose on the fitting when I removed the intake - but I raced to the shop and got a good 3 feet of nice new vacuum line + replaced most of the lines - ( definitely the ones in back). yep the iacv is working good - bump the wheel or turning on ac bumps up the idle right away. I did just run some injector cleaner - chevron - I was thinking maybe I got some winter mix fuel and that was doing crappy things when the weather turned hot - I put 85 in and havent had the misfire since, but its been a bit cooler out too. - but yep Ill do another check and make sure the new lines back there havent somehow wiggled off. + I am going to put the other disty cap on and see how she does over the next several days. thanks again man fun n games

thx for the info Pat much appreciated - yep Ill see if I can get a little more diagnostics - my cheapo code reader only does so much. I did put my stethoscope on injector #2 during the misfire - seems to be clicking away just fine so Im leaning away from the injector wire but yep the fuel trim thing is interesting + I do have a different distributor cap now that you mention it - might just swap that thing for giggles n see what happens. Yep she does have a few bugs still but still she grows on me - I must just dig spooky chicks.

also has brand new upstream o2 sensors....

Update - she has not had a hard start since replacing the cut valve between the fuel tank and the intake, HOWEVER - Still starts and runs great in the AM. When I warm it up, park it for a little bit, (especially in hot sun) - I get a shaky idle and a po302 po325 blinking CEL. -turn her off, restart, usually after one or two tries the misfire clears. I read in another forum that someone had this same issue and discovered a corroded evap line from the canister to the purge valve, but man my line seems to look just fine - no rust no corrosion + no evap codes at all. figured it might be #2 injector either leaking or clogged, so, yep I removed the pain in the arse manifold replaced it + all the litlle vacuum lines associated with the intake with new lines - No avail! Still misfiring after getting to temp and parking her. shes had new disty, plug wires, plugs, fuel filter, fuel pump all within past year Runs fine once the misfire clears- only seems to be an issue after I park her for a few. freeze frame on my reader shows short term fuel trim #1 as -7.8 and short term fuel trim #2 as +14.1 (not sure if this is issue or?) - just about ready to take her to the stealership and drop my drawers.

1997 SE no lift stock wheels Hankook dynapro atm 31/10.5/15 a little tight but no issues so far

This is by far my favorite color/ texture for refinishing orig aluminum wheels that I have seen thus far. Yep I think Ill do this on my 97 - probably wait until I put my new tires on (then mask) to avoid dings at the tire shop nice job!

She looks badass. ...great build + great pics!

OK!! - PROBLEM SOLVED!! Yep havent used starting fluid at all since the installation of the new cut valve. Intake manifold vacuum was getting to the fuel tank which was causing the hard warm starts. been over a month with varying temps- given her many opportunities to mess up but she starts every time. Yipee!! Now she gets a new set of 31's here in a few weeks.

Yup sure dig those rims and tires. Looks like fun!