replace fuel injectors?

nomore · 02-10-2019, 03:20 PM

74 targa. Car runs fine, cold start is a little weak but so is mine. I went through the CIS when i bought the car in 2017. I had the injectors out to test the spray pattern: Good pattern and squeal with plate lifted fully. Just off idle the flow was more of an undefined dribble, not much atomization. Like I said the car seems to run well, but are injectors a maintenance/ replacement item? THX. John.

Walt Fricke · 02-10-2019, 07:02 PM

I'd say they are a replacement item. They don't last forever, though they may get blamed for problems caused by something else. Not super expensive, and new ones give you a base line.

nomore · 02-10-2019, 08:04 PM

Thanks, Walt. No real issues with driveability. I just had them out while replacing other 40 year old plastic and rubber CIS pieces and the spray pattern just off idle seemed suspect as there really was no real "spray" or "pattern". I was just wondering if there should be an actual spray pattern off idle. Otherwise I'll get new ones.

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by nomore

Thanks, Walt. No real issues with driveability. I just had them out while replacing other 40 year old plastic and rubber CIS pieces and the spray pattern just off idle seemed suspect as there really was no real "spray" or "pattern". I was just wondering if there should be an actual spray pattern off idle. Otherwise I'll get new ones.

Nomore,

The spray patterns for the injectors should look like an inverted V conical shaped patterns, mist-like spray and uniform looking flow. If the flow looks like a jet stream, the injector is bad. The shape of the spray pattern/s should remain basically the same except for the flowrate (volume) from idle to full throttle.

Tony

shadowjack1 · shadowjack1's Garage

Get them rebuild. Do a search.

T77911S · 02-11-2019, 04:34 AM

replace.
they are a wear item then you don't have to worry about them again.

I do not think they can be rebuilt

GaryR · GaryR's Garage

Send them to Marren Injectors in CT (or somewhere local known to do work on CIS injectors). He will clean/test them for flow and pattern, replace if necessary, and give you a flow report of the set to install.

Bob Kontak · Bob Kontak's Garage

Quote:

Originally Posted by GaryR

Send them to Marren Injectors in CT (or somewhere local known to do work on CIS injectors). He will clean/test them for flow and pattern, replace if necessary, and give you a flow report of the set to install.

Flow report is pretty cool. Before and after report would be ideal for the curious.

In the 90's I just bought a set of refurbished, flow matched injectors from EBS. Pretty sure I had to send my cores to them.

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by shadowjack1

Get them rebuild. Do a search.

They are not rebuildable. I could sell you some CIS fuel injectors and have them rebuilt.

Tony

T77911S · 02-11-2019, 06:36 AM

just replace.

I had mine cleaned and tested. 2 broke the needle valve off when testing. that could have happened in the engine!!!

nomore · 02-11-2019, 06:45 AM

Thank you all for the great forum, especially the lifers. I will replace the injectors. It is good to know the pattern should be consistent across the range, mine are not. Interesting to see if there is any change at all. Bob, I might have done that if it was still the 90's and I was 25 years younger. haha. John