Although this isn't a question directly related to chips, I'd appreciate your help. Using the test mode on my odometer I checked the operating temp idling and under load at both part and wot. It read fairly cosistantly at 89 C (192.2 F)with peaks of 90 C(194 F). Ambient temp was 80 F. In one of your posts you stated even in SC engines a cooler T-stat isn't recomended. My Kenne Bell kit came with a 180 F T-stat. Once the engine reaches operating temps it develops slight hesitation and a stumble with light throttle conditions around 2,000 rpm. Once past this everthing is great. Occasionaly on grades, mild detonation can be detected in 3rd and 4th .WOT is great. No stumble or hesitation when engine is cold. Thermostat problem?

Also how accurate and where can I find out what the other test readings off the odometer are? There are qiute a few.

I should note I am using the supplied chip, terminals are thoroughly cleaned, computer has been reset twice and have tried numerous 91 octane fuels. Possibly thinking about using my old superchip and getting a custom burn. Any recommendations, I live in San Diego,CA. Other than SC truck is stock. If you need any other details let me Know(the post was getting long).

2001 4.6L F150

 

Hi JSC,

Well, this just *might* be a chip problem after all, we'll get to that in a minute................

On a supercharged engine and/or any highly modified engine we have no problem with dropping the T-stat to a 180 degree unit (the Lightning uses that from the factory and works just fine), as sometimes that is what it takes to keep the coolant temps under control when driving hard in summer.

We generally don't like to see T-stats under the stock 192 degrees unless that is what it takes to keep the coolant temps under control for a particular vehicle given it's state of modifications & the conditions it has to operate under, and there certainly is some variance in all of that. If the vehicle is supercharged, or highly modified and/or is going to be drag-raced, then sure, drop a 180 t-stat in there, as long as it stays closed-loop during normal driving. Some tuners will automatically drop a cooler thermostat in *any* forced induction motor.

The bottom line is, your coolant temps sound "ok," though they are a bit cool for best power, you were in only 80 degrees ambient & they will go up when you nail the throttle and put that supercharged engine to work, so you're probably just fine where you are at. 200-210 degrees coolant temperature generally gets you the highest raw power output, and is also when you see best mpg too, generally speaking. I don't think that your t-stat is the source of your problem, not unless you're actually going back into open loop, and you can attach a scan tool to check for that to verify. It would be a good idea to attach a scan tool and to also monitor what happens when you drive it to recreate that symptom, to see what the various sensors are reporting at that time.

Just hip-shooting here, because this does not happen until the system goes closed-loop, this indicates that it's most likely not a vacuum leak, but instead is either a fuel filter that needs to be changed, a potential problem with an O2 sensor perhaps being marginal, or a tuning issue.

If you have not changed your fuel filter in the last 5K (5000) miles, go ahead and change it & see if that helps, as a clogged fuel filter can sometimes cause that symptom. It may not, but it could, and it's an easy thing to do as part of your troubleshooting process. With any supercharged engine it's very important to keep the fuel filter fresh anyway, don't go over 10K miles on a fuel filter. Many of us Lightning owners change them at even 5K intervals, as there is a lot of water in gasoline most places these days. Supercharged engines have a higher BSFC (brake specific fuel consumption), so they use more fuel to make the same amount of power, basically, compared to a normally aspirated engine, making more frequent fuel filter changes a must.

If the fuel filter doesn't take care of it, then it's time to take a look at the tuning. We'd be happy to take care of that for you, but if Kenne-Bell supplied you with a custom chip for their supercharger kit, then they are responsible for any tuning issues of course, so I would immediately contact Kenne-Bell and talk to them about this if they supplied your chip (after you change the fuel filter, if it has more than 5K miles on it!), as they should take care of this if it's a tuning issue, if it's their chip.

This is really not something we can properly diagnose or discuss here, but if you'd like to give us a call I can go over this with you in some more detail to get this nailed down & point you in the right direction.

To answer your question about the accuracy of the readout you are getting on the digital odo when you convert it to the various "test gauges" that it can display, that is the coolent temp being reported by the ECT (engine coolant temperature) sensor to the PCM, but it's actual "refresh rate" is a bit slow, and that may be why, along with not being at WOT except just briefly, you only saw about 90 C, as you will *always* pick up more than 1 degree C under full-throttle operation. 90C would be a bit cool for my personal tastes for WOT operation in general, there we like to see about 200 degrees. Scan the PCM to make sure it's staying in closed loop, and once that is verified, you can dismiss that (a too-cold t-stat) as the culprit.

I can't tell you what every single one of the test guages are off the top of my head (nor would I have time to type all that out, in reality), as we rarely use them, we use scan tools for any data we need.

Last, since you are in California, I would stick to Chevron gasoline, as they are generally delivering about the best quality, octane & energy content among the fuels out there.

Good luck!

 

Thanks for the reply mike. I pulled the Kenne Bell chip and the problem went away. Dropped it off at KB and had it back the next day! Fuel tables were made richer and did something w/torque managenent. Feels like the problem was fixed(I'll give it a couple of test days).

I've got a Superchip I would like to have burned for a 2001 Harley edition F150(5.4L NA). Nothing special just the standard program. Code is PTJ3. Hopefully you or superchips has it on file. Only mod is K & N intake.

 

Hi JSC,

OK, glad to hear they took care of your problem, so it turned out to be a chip problem after all, as I suspected.

On the new program for your '01 truck, sure, we have a nice program available for your PTJ3 code, so we can take care of that for you anytime. Just give us a quick call & we'll be happy to make those arrangements.

Congrats on getting your tuning issue solved!