Computer chip?

Will a 93 jet chip work for my 91 xj??

depends what engine you have and the chip was designed for... IMO those chips are a waste of money.

i think i read somewhere on here that jet got sued because apparently those chips do absolutely nothing performance wise.

i heard the jet chip will give you about 40-50 hp.

i heard NOS stickers do too... anyone else on this?

don't bother getting one if you aren't going to get a header, exhuast, and intake

oemjeep91 said:

Will a 93 jet chip work for my 91 xj??

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I have first hand experience of the JET chip on my '92 XJ and my advice would be not to waste your money on it.

On such an early vehicle with primitive computer control......with no restrictions basically (rev's, HP, etc)

I doubt a chip would do much anyway, regardless of what type it was.....

Now maybe with OBD-II and above you could get some gains, I've heard that as well for other vehicles.

I got a Jet chip for free from my local shop (wouldn't work on his cherokee anymore since he added a turbo and custom ECU) and figured what the hell...

I've got a 97 4.0 stock engine for now...and I really like the difference it makes, not a ton more power but a much better torque curve and easier passing on the highway, really makes it nicer to drive

And people have noticed that it seems more powerfull when riding along with me...so I'm not just crazy

Would I spend $250 on one...probably not unless I had other things done first (header, exhaust, intake)



Oh yea :wave: I've been lurking for a bit...

Maytag (driver of the 4XFridge)

Right, but that is a 1997 with OBD-II

I don't see it making a difference with OBD-I.

I was thinking about getting a chip are there any other brands out there that give better performance.I have a 94 sport 4.0

I had a Jet chip and it died after just over about of year of use. When it took a dump it left me with an engine that wouldn't run until I figured to remove it. IMHO not worth the money and :bs: .

im guessing then jet is the only brand?

SKIM said:

im guessing then jet is the only brand?

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hypertech makes them also though none better. There is no free lunch you only get more power in a chip bolt on by decreasing other stuff. Its not magic, its a compromise and a bad one. You can get TONS of check engine codes from these crap-ola generic chips.

read this thread

http://forum.anothersite.co.uk/showthread.php?t=133862


specifically these parts apply to you, the poster is a fuel system programer as is my dad (20 something years for big 3 and suppliers)

EXCERPT from link
“Tricking” your ECU for more power.
One of the oldest tricks for more power in a fuel-injected engine used to be tricking the ECU. People would (and still do) use resistors in-line with the water temperature sensor. The idea is to fool the engine is cold and needs to add fuel enrichment to run properly – this is a bad, and mostly a stupid idea.
When do you want maximum power? I hope you said: “When I’m at WOT, Scot” (yes, I am a poet). Any other time and you’re wasting fuel. Modern fuel injection goes into open-loop fuel enrichment at WOT, usually around 12:1 air / fuel ratio. Tricking your ECU into fuel enrichment at any other time is just plain silly and wastes fuel.
When you’re cruising down the road at part-throttle, there is no need to run any richer than stoichiometric (14.6:1 air / fuel), running richer is just wasting fuel. Now for a little sermon on air / fuel ratios:

The 14.6:1 air /fuel ratio is where you should try to operate at all times other than at WOT. This “Stoichiometric” mixture is the best ratio for complete combustion and maximum economy legally & safely (lean-burn is better for economy, though NOx emissions skyrocket…. maybe a topic for another discussion). Now, combustion in an engine is never complete, so there is a little bit of oxygen left over during stoichiometric operation. When you need power, go WOT and into fuel enrichment, this surplus O2 is used up and a bit more power is the result. Don’t be fooled though – the benefit of running 14.6:1 and saving a bit of fuel far outweighs the benefit of added power at 12:1 air / fuel ratio (at part-throttle operation).

In summary, if you’re running anything richer than 14.6:1 while you’re driving around town, you’re wasting fuel.

“Chipping” your ECU for more power.
Chipping, or changing the fuel and spark curves in your ECU to get more power is popular in today’s electronically controlled engines. This kind of modification works most of the time, but be careful – you may not like how your engine runs “chipped”. The manufacturer has many things to think about when they calibrate your engine in your vehicle: driveabilty, startability, emissions, durability. Your engine comes calibrated from the manufacturer to reliably start, drive and respond well, meet federal emissions standards in such a way as to not risk any internal engine components.
Aftermarket chips can only do so much with a stock engine and it usually is not the best thing to do. They will crank the spark curves up to the maximum levels to get the best torque and at the same time will increase fuelling to help keep detonation lower. What ends up happening is that the customer is forced to run premium fuel to keep the engine from knocking and the increased fuelling almost always results in poorer fuel economy.
To make things worse, many people that buy these products claim to not feel a difference in power, but the vehicle definitely drives worse. IMHO, reprogramming your ECU is better left for engines that have been internally modified (different camshaft, strokers) and need different spark and fuel curve to run properly