dieseling

[tuknrm]

i just got my s10 running with a stout motor. i am running pump gas 93 octane. i have aluminum heads and 10.5:1 compression. my timing is at 15. only does it if i drive truck for a while and its good and hot or afer i idle it for a while. do you think its due to low octane should i drop a step on plugs for street driving. cause im goin to run race gas at track. which i doubt ill have issues with deiseling then.

[Scotty_S-15]

To get that beast to idle, do you need to have your throttle open and inordinate amount? Sometimes if all else fails, you might need to install a tiny idle solenoid, which would allow your throttle to close completely when ignition is shut off.

[my454s10]

do you mean pinging....deiseling is where you turn the motor off and it continues to run with the key off....that is usally caused by a really hot motor or the timing chain is lose or slipping..

[tuknrm]

ya dieseling. after run. i dont trust my autometer gauges but it says its running at 210 and i probed it with a trusted thermometer and it says its running at 180. i have a 195 stat in it. it doesnt do it all the time so far. but im thinking i need to swap in a fresh set of plugs. cause its loading up pretty bad in town. im running a 750 holley with vac secondaries and a 355. i adjusted the throttle blades last year so they were to spec then i re adjusted idle with air screws. but it hasnt ever had any sort of load on motor till last saturday. im thinking a step cooler on the plugs may help.

[tuknrm]

on a side note everything else seems to be ok. i retorqued the heads today and set up my instant center. dialed in carb with vacuum gauge also. im having one other issue though. i have v belt pulleys and i keep throwing belts every time i snap the throttle. they are all a matched set i pulled off a car. and i checked the alignment with my race damper just incase offset was different. motor is a fast reving motor. with all lightweight internals. dont no if that could do it or not. must be some flex in alt bracket.

[spacecadet]

I had the same problem flinging the alt belt. It was a cheapy belt from Advance Auto. The belt was too narrow. There computer said it was \'stock\'. I went to napa and got there stock belt and it was @ 3/16th\'s wider. It seems like a stronger belt. And it hasn\'t tossed it either.



As for the diesling, if the carb allows \'some\' air/fuel past, On a hot motor it could do that. It\'s not the spark plugs or ignigtion sytem that is makeing it do this it is \"pre-ignition\" or as you had said \'diesling\'. I would think that the engine is actully on the point of being really hot. The gauges don\'t indiacte what the temp is in different parts of the engine. The coolant passage at the t-stat housing could be 195 but the true head temp could be 230. The heads are where the heat is. If the t-stat you are using is 195 and the test gauge reads 180 than either the tstat isn\'t working properly or the test temp gauge isn\'t. I would suggsest rechecking for temp differances. It possible that the engine could be hotter than you think. Overall i would suggest checking it for a cooling system problem.

[tuknrm]

ya i got the belt for the car i got pulleys from. the belt now is bent sideways cause it flipped upside down instead of popping off. seems to do it mostly when it first fires up or if it makes it past that it does it if i rev it up. am i tightening it right? i leave about 3/8 inch play in it. i can see the belt slapping between alt and crank pulley like it needs to be tighter.

[Scotty_S-15]

We talked about belt problems here recently, and it was suggested that sometimes a \"shoe\" can be fabricated to keep the belt from whipping out too far on the long run between alt. and damper pulley or whichever is longest.

........... Are you sure the alt. or water pump, PS pump, etc. are all OK? Sometimes if one has a bearing going bad, it uses way too much power, hence overloading the belt, but usually that becomes evident with the belt wanting to slip and squeal.

[spacecadet]

If the belt has bent side ways than either it is too loose or too thin. Since it did bend, Check it for cracks, tears or unusuall marks. I would probulby suggest replaceing it anyways. The 3/8 play that you have should be at the longest part and with @ 15lbs pull. I usually overtighten them, because once they heat up the first time they are usually perfect and don\'t need readjusting.

[FordWizKid]

Heat soak in the fuel system can also cause diesling or run on. Make sure ur fuel lines are far enough away from any heat source or are insulated. You can try to see if this is the problem using some tin foil around ur lines. Double check ur total timing and deff. check ur plugs they\'ll let yah know what is really going on inside ur motor. 10.5 to 1 is on the high side for a street motor I would also try to get that bastard to run cooler. Anything over 200 is kinda warm try some water wetter and distilled water it may help. What kind of fan/waterpump are you running ?

[tuknrm]

ya i dont drive it to often anyway. but im thinking a tensioner on alt crank side is a good option i have a few feet of snowmobile track slide that prolly work. im running stock water pump a flex fan and stock 4.3 rad. i have all the fuel lines wrapped in that reflective tape from summit from the front to back. but that is a good thought cause i have never run engine before with hood down. i also have s/s braided fuel lines but they are still fairly close the headers. i used a piece of reflective tape and put it around the temp gauge sender and the gauge dropped to the thermometer reading. im planning on getting a bigger aluminum radiator and dual electric fans

[FordWizKid]

Grab a vette radiator from the parts store and a Ford Taurus fan. The fan on high speed pulls about 4000 CFM. You can get one for about $40 and it will out perform most setups.

[tuknrm]

whats the dimensions of a vette radiator. i have my stock one in the core support now and something the same size would be nice. 4000cfm holy sh!t where do i find one of them? what year?

[mzoomora]

There was also some posts about electric fans make the engine run on. The fan genrates electricity while it is spooling down, and that can be enough to make it diesel some. Also, if your carb is running on the idle transfer slot, that can make it pull in more fuel than it needs, and can cause it to run-on to burn off the excess. You can take off the carb and check them out, they should look square from under the primary throttle blades. If they are rectangular you can open the secondary side very slightly which can allow you to turn the primary side down. The colder plugs sounds like a good idea, also a colder thermostat. As for the alt pulley, try a larger diameter. deep groove pulley, they always worked for me.



Also, how old is the engine? If it has been loading up for a while, could be carbon build up. Maybe try pulling a few degrees out while you are using pump gas also.

[tuknrm]

the engine is brand new. last year when i had it running i set the transfer slot depth and opened up the the secondaries.

[Scotty_S-15]

Didn\'t you say you had a vacuum secondary carb?

[tuknrm]

yes

[tuknrm]

is the taurus fan a pusher or puller and do i what engine size do i need 3.0 or 3.8 and how do i wire it

up?

[Scotty_S-15]

On 2004-07-14 10:11, tuknrm wrote:

the engine is brand new. last year when i had it running i set the transfer slot depth and opened up the the secondaries.



I asked if you had vacuum secondaries because I think they need to be shut all the way. Sure, they need to be adjusted so the aren\'t OVER shut, and stuck. Just wondered what you meant by \"opening up the secondaries\". Like I mentioned early in this thread, the more your throttles are open, the more likely you are to have run-on.

........ And again, like I said earlier, if all else fails, you may need to install a soleniod to shut throttle completly when ignition is shut off. Some of the funky 70\'s emissions systems required that. Probably because the lack of advance at idle, the throttles needed to be open for idle, and they tended to run-on.

[wild85]

3.8 taurus sho

[MARKYMARK]

if you have 10.5 comp. your probly having to turn the carb butterflies past the idle sircut, those two little holes just under the butterflies. they allow fuel to drible in while at idle , if turned to far open starts to run off of maine , will run like shit. just remove carb and drill 1/16-1/8 hole in primary butter flies this will allow you to turn the idle screw back down to the right area. it also sounds a lot better. for your belt throughing only one way to ever stop throughing belts $$$$$$ serpentine system. v-belts 0-5500 rpm serpentine 0-8500 rpm

[JayDee]

A few years ago I bought a used ZZ4 engine and the guy I got it from said he had been throwing belts until he put deep grove aluminum pulleys on the crank and alternator.

Since my small blocks are all running serpentine belts, I still have the pulleys, if your interested.

[tuknrm]

im kinda interested unless i can find a good look serp system

[tuknrm]

well thanks guys i think i got the lil devil. put on a taurus fan set on low speed, an adjustable thermostat, step cooler plugs, a gates v belt, added water wetter, and moved the temp sender to intake (seems to read acurrate now). so now it runs at 195 and goes to 210ish then the thermostat opens and drops back to 195. the thermo in it is 195 or 185 dont remember. now the truck no longer diesels or after runs and havent thrown a v belt yet.

[tuknrm]

now the only problem is when the fan kicks on the voltage drops to 13 from 14 while driving and to 12 when idling. so looks like im going to have to invest in a high amp alt.

[FordWizKid]

I hope you have that fan run through a high current relay. That fan is capable of pulling 40 amps hence your voltage drop. Wire it up with a relay or you could easily cook sumptin !

[tuknrm]

ya its run with a relay