Ignition problem, out of ideas.

[Gone2]

My '95gt has started hitting a brick wall at about 3500+ rpms. Searching on here led me to replace the original coil with the MSD Blaster OEM replacement. Still does it [not as bad].

Symptoms:

- under acceleration @ 3500+ rpms it feels like someone cuts the power in half.

- the tach seems to jump in 400-500rpm incriments after 3500rmp, almost like its sticking.

- in park, the tach moves smoothly up to 5000rpm with no problems.

- the problem also started the same time I began to get engine noise through the radio. The noise went away when I changed the coil tonight.

- The plugs, wires, & coil are new. The cap/rotor are about 1yr old.

What next?
(Does that capacitor next to the coil go bad? I remember my dad always had a few in his tool box.)

 

[Gone2]

After more testing, I found it will stutter at around 2000rpms while going up a steep hill under a load.

The tach actually looks like the second hand on a clock ticking.

 

[HISSIN50]

Any codes? A PIP or IDM code might pop up and shed some light.

Good luck.

 

[Gone2]

I dont have a way to get the codes myself.

 

[Gone2]

After much more reading, I think I'm going to start with the TFI Ignition module in the morning.

My head hurts.

 

[greenlantern]

After much more reading, I think I'm going to start with the TFI Ignition module in the morning.

My head hurts.

I would replace the stator sensor (PIP) while your at it.

 

[HISSIN50]

You can pull the trouble codes with a paperclip, your G/F's hair-pin, etc.

You can have the TFI tested at the parts store, but since it has not completely gone south, it might not test bad.

Good luck.

 

[Gibbo97]

here's something you may want to look at as well- it could be your clutch is beginning to slip. I had a guy who was having problems about power being down after a certain rpm and it turned out that his clutch was starting to let go. Just a thought.

 

[Blackened302]

go to autozone/advance... they'll pull the codes for free and tell you what's wrong w/ it.

 

[fawcett]

i just had this problem. turned out something in my distributer went bad. i ended up replacing everything until that part, piece by piece. now if you dont want to spend that kind of money you can try using someone elses parts to elimonate buying everything. i honestly didnt mind replacing the whole ignition system and now that its all on and complete i couldnt be happier. I have a mallory digital hi fire box and coordinating system. all of my cars signs pointed to a bad coil, but it wasnt. now i am tackling my coolant system new fluidyne 2 core, possibly an electric water pump, new hoses, and new overflow tank.
best of luck with everything, i remember what it felt like to hit that wall while driving down the highway. it was pretty scarry.
-fawcett

1995 gts, frpp 340bhp 302, e-cam, gt40x's, track heat w/ spacer, full mallory ignition system, frpp 24lbs, prom 80, aeromotive fpr, d&d viper spec t56, afm super king cobra clutch, afm alum flywheel, d&d alum ds, 3.73's, full exhaust, saleen heat extractor hood, projectors(wost money spent), cobra r's, brembos all around

 

[Gone2]

Thanks, I'm picking up the new distributor this afternoon. I've replaced the (in order) coil, ignition module & cap. They've all been improvements but the tach is still freaking out.

Replacing all of these (which probably could have used replacing) is going to cost less than $200. I'm not too upset.

 

[Gone2]

No dice!

New distributor, still lays down before shifting @ full throttle. Tach goes crazy, now not even under a load. I can be in park, rev and hold at 3000rpms (or anything above 2000) and it bounces up and down about 700rpm increments. The engine is NOT changing speed when its doing this.

My tach reading and ignition problem used to be sychronized but not anymore.

 

[Gone2]

and I cant find the delete post

 

[chefster]

ok dude,check your new wires and make sure none are against the exhaust,thatll toast them quick. At night go out and start the sucker up and look at the engine closely in the dark checking for sparks. mist it with lightly with some water...get under it and look up at it to.....also check all your air intake for any holes past the air intake sensor.

 

[Gone2]

AAAAAAAAAAAHHHHHHHHHHHHHHHHH!!!!!!!!!

I forgot to plug back the hose on the intake tube that goes to the oil filler neck. I took all of that off back this morning when I replaced the ignition module.

Stand by, I'm going to go slam my head in the hood a couple of times then go for a test run. This may have just cost me $90.

 

[HISSIN50]

a tach gets its signal from the negative side of the coil, which comes from the TFI module (the pulses to fire). But stock tachs have a dedicated pin in the puter harness.
I still say getting codes will help.

Good luck.

 

[Gone2]

It was the freakin' hose from this morning, I'm an idiot.

I was pulling the codes this morning using the paper clip method. I ended up turning off the key to do it again because I messed up, and it seemed to erase them. I've got to take the distributor core back to autozone in the morning, I'll see if they can check the codes. I wonder if they will take back a slightly used distributor?

My wife just told me since my oversite cost and unneeded $90, no more toys for 90 days.

 

[Gone2]

Paper clip codes: I'm getting 3 flashes about 2 seconds apart, 3x I think.

 

[HISSIN50]

That crankcase ventillation hose should NOT have been the cure to this issue. Give it some time and see how it does.

Good luck.

 

[Gone2]

Well, the problem is 75% gone. Every now and then I get power let-off. Usually at higher rpms, but sometimes I get just a single bump like miss while cruising. My tach is still freaked out.

I sprayed my wires with water tonight. My entire new coil is fuzzy with blue electricity. A couple of the wires have a little bit of electric fuzz where they touch, but no major arcing anywhere. The wires are about 1 year old.