so i just picked up a 94 formula... i got on it the other night on the highway and at about 90mph it starts to chug while accelerating and the check engine light flickers on and off really fast. the car does not have any cats and i know for a fact it needs a new heater core... any ideas?

 

The SES light flashing indicates a missfire. Scan the car to get the exact code(s). AZ lends code scanners out for free. First I would check your plugs and wires. I could be something as simple as a damaged/broken wire. How many miles are on the car, probrably time for a tune-up.
Also put your car information in your signiture; year, mods, trans, etc. Helps people diagnose your problems.

 

You really need to get it scanned, otherwise it is guesswork on what the actual problem may be.

 

car has 124k miles on it. no mods other than the cats removed.

 

Could be an injector

Mine would miss and stumble and run like crap when one was bad

Best bet is to get it scanned

 

I'm curious how you know you heater core is in need of replacement? They get clogged and need to be cleaned but unless its leaking inside the car it might be ok. The next step is to get the codes read.

 

My money is on a P0300, any takers?

 

P0300 is a OBD-II code, his car is a 94 making it OBD-I. Once he gets it scanned we can offer him a better idea of what to look at.

 

ill try and get it scanned sometime this week... but we just got over a foot of snow in the last 24 hours so that car is gonna stay in the garage. and about the heatercore. i took it to a shop tried gettin it back flushed and got a few small chunks outta it. so im just replacing it since i have no idea what all the previous owner did with the car

 

I believe that is only the case with OBDII, but yes the codes need to be retrieved if there are any.

 

I've noticed several posts where you respond on the assumption that the vehicle is OBD-II. FYI... 93-95 LT1's are OBD-I, do not have misfire detection, do not have a (intentionally) flashing SES light, can not be scanned with an OBD-II scanner, do not have Pxxxx DTC's, and typically can not be scanned by the auto parts stores that only have OBD-II scanners.

 

My bad.

 

Here is my tip. Find some LT1 guys locally and have them help you track it down. A location on your profile would help people help you. It's hard enough diagnosing some problems under the car, it's harder behind a computer monitor.

-Dustin-

 

correction... it is the check guages light that flashes while the car is chugging. it was flashing so fast i couldnt even tell

 

To my knowledge the check gages light comes on when one of the gauges is outside operating range. Did you notice any of them reading very low or high? Twitching even?

My first thought would have been a charging issue, in which case headlamps and interior lights probably would significantly dim or brighten.