I hate CPInjection

[bbbbssss]

I have the cpi and i hate it...... Every year i have to replace it and it drives me crazy... I love the truck but i hate the fuel injector.. Is there any thing i can replace it with besides
a carb?? Another question: where can i get a replacement
4.3 motor for cheap cheap cheap???

[Matt 4.3 TBI]

You could swap to TBI. You would probably need to change your fuel pump to a lower pressure TBI pump. I'm not sure how much pressure the TBI regulator can adjust for. I don't think the return line is large enough to send back all the excess fuel. You would need to change the ECM, possibly the wiring harness. The only sensor difference I can think of is there is no IAT sensor on a TBI.

[Maximus]

If your replacing the CPI spider every year you have something wrong causing the failure.I don't like CPI but they still shouldn't be going bad any were close to that much.

[Sparky2263]

Agreed. Avg. cpi unit life is about 5-6 years. Lindertech uses the Cadillac regulator in their reman. units. Much better unit.

[Maximus]

I would love to take on changing a CPI intake in to a TPI clone.Would be one very bad ass unit.But that's off topic.

[stumpy]

Nothing wrong with my cpi, its going on 10 years im sure. You definitely have something wrong.

[importmaster1300]

What do cpi and tbi stand for?
I thought cpi was Carb, something injection (or something along those lines) and TBI was throttle body injection.

[yellow02zq8]

What do cpi and tbi stand for?
I thought cpi was Carb, something injection (or something along those lines) and TBI was throttle body injection.
CPI-Central Port Injection
TBI-Throttle Body Injection

[Sparky2263]

CPI- One of GM's engineering miracles. As with most others, short lived. Dumbasses.

[blazen]

i have the cpi. its awsome when it runs and has tons of power. i beat tons of people with the tbi unless they have major mods to it. but it is a real pain in the ass when it done run.

[Matt 4.3 TBI]

CPI's biggest gains over TBI are in the heads and cam. The long intake runners are great for helping with low-end torque, but if you just slap a CPI intake on a TBI block it won't make the same power. The CPI's lift is .434 intake and .442 exhaust vs the TBI's .390 intake and .410 exhaust. The heads also flow about 30-35 cfm more than the TBI's.

Now, a TBI intake on a CPI engine, I'm curious how close that would be.

My heads are a few CFM more than L35's now (about 200cfm), and my cam is a bit more aggressive (.479+.488 lift) and JJ's engine analyzer pegged it at about 209 hp and 255 ft/lbs. The TBI intake runners are just a lot shorter than the CPI's, so I still have a little less torque. I've definitely given a lot of thought to the CPI system, I wonder where that would put it, and how it would affect the power curve.

[1993blazerlt]

i will be able to tell you about a TBI on a CPI engine soon. Me and a friend are almost done putting a new engine in his blazer. I picked a CPI engine up cheap on eBay Until he can save up more money he is just running the TBI until we swap in the CPI unit. The TBI manifold needs to be modifyed to clear the Balance shaft though

[Maximus]

Im rebuilding a CPI block but it's gonna have vortec heads and a GMP cam and basicly nothing left from the CPI lol.So mine won't be a good refrence at all.But yeah CPI has some advantage over TBI but the CPI intake is in no way the total reason why they have more power than the TBI.Matt your Edelbrock intake probablly brought you as close to the torque numbers of the CPI as a TBI style intake can get.

[bbbbssss]

Any suggestions to what might be causing it crash sooner???

It runs fine. starts, idles, and sounds good. I was told the the injector just gets over worked and can't take the heat. My blazer is my only transportation, I run it 15miles to work and back again. The only major problem I ever have is the CPI.

[bbbbssss]

Any suggestions to what might be causing it crash sooner???

[1993blazerlt]

when you unit is failing what is going wrong with it, is the diarpham leaking or is the injector selinoid failing?

[bbbbssss]

the injector is failing.... when i pull the upper manifold off its dry on both sides...

[bbbbssss]

What chance is there for swapping the CPI for a CSFI ?????

[1993blazerlt]

could you measure the voltage that is being sent to the injectors and the restance of the injectors. If you post these numbers up it would tell us alot and then i could look up the specs. To do this test unplug the conector that runs to the Unit out side of the manifold. Use a volt meter with the enigne being cranked to check the voltage going to the injectors and use a ohm meter to check the restance of the injector

[bbbbssss]

could you measure the voltage that is being sent to the injectors and the restance of the injectors. If you post these numbers up it would tell us alot and then i could look up the specs. To do this test unplug the conector that runs to the Unit out side of the manifold. Use a volt meter with the enigne being cranked to check the voltage going to the injectors and use a ohm meter to check the restance of the injector

Will get back to you with the numbers... Could I have a bad computer module??????

[bbbbssss]

Will the ECM from a GMC Jimmy work in my Blazer?? Both are same year model and motor.. Might be able to get one from a buddy??

[blazen]

What chance is there for swapping the CPI for a CSFI ?????
if you could get a hold of obi (the jedi master)he would tell you all about it. he told me i could do it and it wouldn't be that hard but he didnt get into any detail on how to do it. he told me i could do it for a supercharger because the cpi can only handle 4 psi and if i changed it to csfi i could start off with the 6 psi base and than go up from there. good luck getting ahold of him though he's not an easy man to get in touch with (still easier to get a hold of than arthur though)

[bbbbssss]

if you could get a hold of obi (the jedi master)he would tell you all about it. he told me i could do it and it wouldn't be that hard but he didnt get into any detail on how to do it. he told me i could do it for a supercharger because the cpi can only handle 4 psi and if i changed it to csfi i could start off with the 6 psi base and than go up from there. good luck getting ahold of him though he's not an easy man to get in touch with (still easier to get a hold of than arthur though)

The cpi to csfi is just a option I'm exploring. I'm think my ECM is corrupt and it might be causing the cpi to fire more often? A very long time ago I took my blazer to a mechanic to replace the cpi and I remember them saying something about the ECM spitting gibberish out..?. I thought they fixed it, but maybe not....?.

Never again will i take any vehicle to a mechanic.... transmission shop YES motor shop NOO. I'll do what ever it takes to keep this engine running... =)

[Sparky2263]

You've just been taking it to the wrong mechanic. Plenty of guys that have the ability and knowledge, you just gotta find 'em.

And no, it ain't the cheapest shop in town ;).