Cars runs like crap in morning when cold......

[d_snook6]

It's a 89' 2.5 TI shadow, and when i go to start it in the morning its hard starting and runs very rough, sometimes stalls, and when you are going down the road it feels like is hitting overboost. Also it doesn't always idle good, it with rev up and down between 1000 and 2000rpm. I'm getting a code 54, which is the hep, but all the wires and conections seem good going to it.

The car runs a bit better when warm but still is missing or something

[Turbodave]

Have you tried replacing the HEP? it's a common part to fail on these cars.

[d_snook6]

Quote:

Originally Posted by Turbodave Have you tried replacing the HEP? it's a common part to fail on these cars.

Haven't tried that yet, but it looks like i'll have to.....
unless somebody has a better idea

[holley]

Dumb question time:

What does HEP stand for again?

TIA

[d_snook6]

Quote:

Originally Posted by holley Dumb question time: What does HEP stand for again? TIA

hall effect pick-up

[87shelbyt2]

when u pull the HEP out check the plastic tabs that hold the shutter wheel in place. It is possible for these to crack and let loose. which gives the pick-up false readings. just my .02. -J

[holley]

Thanks Snook I can't remember all the acronyms, lol.

[mpgmike]

Snook, I'd go back to the basics. Check plugs and wires, fuel pressure, air filter, etc. Most of the time that what bites me. The coolant sensor could be bad or the wiring to/from it corroded/burnt. A weak coil is also a suspect. You know, basics first.

mpgmike
'88 Daytona Shelby
'91 Spirit R/T
'84 Rampage

[d_snook6]

I replaced my hep and traced all the wires back to the computer. All the wires check fine to the computer, But i still get code 54, and it still bucks when its cold, the fuel injectors seem to be misfiring. When it warms up it gets somewhat better but won't completely go away.