I swaped a 350 tpi in my 87 camaro which was running great. But now I'm having a strange problem. The car runs ok a lower rpms but if you step on it the engine starts cuting out and the SES light starts flashing when above 3800-4000 rpm. If you let up on the gas the light stops flashing and it runs fine. Also, it will only do this while driving, it revs fine in neutral and there are no codes set. Any idea what could be causing this?

 

ehh faulty computer =/

i dunno

 

Thats what I thought, but I replaced the computer with another one I had and it made no difference.

 

Sounds like a primary or secondary ignition prob..
get a HELM sevice manual, pricey but worth it. It will help you fig out whats going on.

make sure you plug wires are n right order, on fully and are not laying on the exhaust

 

did you get a new knock sensor when you swapped in the 350

 

I had a similar problem, different but similar as in giving throttle and hesitation. My suggestion is to diconnect the EST connector and set your timing a 6*, then reconnect the EST connector. If the problem is still there, then you may want to start eliminating potential issues. Start off by replacing in this order, spark plug wires, rotor, coil, Ignition Control Module (TPI=7 pin type), then finally, the pick up coil. The pick up coil was my problem. I replaced it and VVVVVVRRRRROOOOOOMMMMMMMM. I was burning rubber in my jacked up tranny ( only had 1st and 3rd gear). To replace the pick up coil, you'll have to pull out the dizzy though. If you decide to take out the dizzy to replace the pick up coil, remember that there is a small c- type of pin that holds the pick up coil in the base of the dizzy. NOTE!!!!!!!! My explaination of the pick up coil only apply to the Large Cap Dizzy!!!! If you got the small cap with a remote coil, then disregard my instructions of replacing the pick up coil.. Also here is some websites that will help you fine tune your ride......
http://74.125.155.132/search?q=cache...&ct=clnk&gl=us

and

http://mpikas.blogspot.com/2008/08/t...june-2000.html

 

This may help you to if you made a 305 to 350 conversion
http://tpiparts.net/305_tpi_to_350_tpi_conversion

Man, I'm the man. I've got you covered with a junk load of good info.
Good luck bro. Let us know what happens.
One more thing, check your trouble codes and use this website as a reference for identifying the causes for the trouble code.....
http://www.gnttype.org/maint/malf.html

Man, there I go again dropping good info. I feel like I'm on a roll. Gotta go peeps . Peace.

 

I actually had mine on the exaust. All that I ran into was a miss fire. I notice there was a white looking color kind of like chalk dust. With the engine running, I grabbed the plug wire to get it away from the header and TICK, TICK, TICK.
Last time I felt a shock like that was when my little brother pushed me while I was connecting a lamp into the wall. Shock the (BEEP) out of me. I looked around to see if someone saw me and I saw my neighbor covering her mouth trying to hold in her laugh. She knew I had just gotten shocked because when I jumped, I hit my head on the underside of the hood while yelling curse words.

 

what code is it setting? Are you still using the prom from the 305, or did you swap in a 350 prom?

Could be the ignition coil needs to be replaced.

 

If you need to swap a PROM Chip, I would like to make a suggestion, http://www.summitracing.com/parts/HYP-127062. It, for a 350. Read the specs. I know it costs $200 dollars, but Summit does price matching. Just give em the web address ( http://www.ourdealsrock.net/46-127062.aspx $174.39) and they will match it. I got this chip in my 86 IROC and it is beautiful.

 

You were plugging the lamp into a wall while your head was under the hood?

 

No no no. I got shocked while under the hood (a couple days ago).
My next comment was that the last time I felt a shock like that, was when my lil bro pushed me while connecting a lamp (around 1997).

 

Now I got this issue and it's exactly as the thread states. I'm getting hesitation while in motion (around 65 mph), and the SES light flashes like crazy. I stopped and pulled the codes (ADLD port A,B jump) and I got a code 51 which is a wrong or bad PROM. Well the PROM is a Hypertech chip. So I got confused. I called up a good board member ( Chevy8588) and he told me the same as mentioned above; if I changed the knock sensor. So thats my next objective. CHange the 305 knock sensor to a 350 knock sensor. I'm also gonna try the old PROM (305) first to see if there is a issue with the Hypertech PROM.

 

the SES light flashing as it did under these conditions is most certainly the wrong or bad PROM. A 305 prom just can't run a 350. Also, just a friendly reminder to be EXTREMELY cautious when working with the ECM and the PROM, as even the slightest little spark of static electricty will fry either.

The simplest solution to this will be to check the PROM and make sure it's inserted tightly and correctly, none of the pins got bent, etc. If that's ok, then you probably need the correct PROM for the application.

 

I know about ESD (Electro Static Discharge). You dont even need a spark to "fry" a circuit board. The slightest amout of charge can destroy the memory inside a chip. A spark, believe it or not when you touch someone, is around 50,000 volts. It doesn't kill you because there is not enough amps in the discharge. So even 1/2 a volt which doesn't display a spark can ruin chipsets which in this case, the ECM contain "non-volatile memory." This means that the memory cannot be erased unless it is being completely reprogrammed by a computer. RAM is volatile because it needs electricity to hold memory. Once the electricity has been shut off, the memory erases thus calling it "volatile memory." The best way to protect a circuit board or ECM is to touch the case of the ECM. Once youve touched the case, the charge is now equal between you and the ECM. The danger is if your walking around with the ECM in your hands because as you walk around, you begin to slowly build charge, so not only is the charge building on your body, it's occuring to the ECM as well. So to better dissipate charge, sit down with the ECM in hand and touch any bare metal part of your computer so that the "charge can ground onto the case of the computer and ultimately flow to the ground via ground wire/ nuetral wire of the wall outlet.
I had the 350 PROM in the IROC for about 2 months now and barely yesterday, the issue came about. The ECM itself is interchangable between the 86 and 87 IROC's and probably others. TBI is different than TPI. Also before the IROC took a dump, back in 2003, without realizing, I was driving my Camaro with a 305 PROM, 19 lbs injectors, and it had a 350. So obviously the PO made a 305 to 350 conversion without swapping 305 components to 350 components. And I never had a problem. Never had a SES light. Then I threw rod #5.

 

Also, didn't I not mention in post #10 that I got a Hypertech PROM chip for a 350, along with 2 links to view the specs. HHMMMMMMMM Yup yes I did. So yeah,,,,, I got the correct PROM in my ECM.